CN114251689A - Temperature sensor assembly for induction cooking range - Google Patents

Abstract

The invention relates to an induction cooking apparatus comprising a cooktop panel, an induction coil, a controller, and a temperature sensor assembly. The temperature sensor and the guide support are positioned in sliding engagement in an opening in the center of the induction coil, with an upper end of the temperature sensor being located above a top surface of the induction coil. The controller includes a first circuit board that supplies power to the induction coil. A second circuit board, separate from the first circuit board, is electrically connected to the temperature sensor and includes a cantilevered leaf spring structure supporting the temperature sensor. The guide support is a load-bearing structure that transfers a biasing force generated by deflection of the cantilevered leaf spring structure to the temperature sensor, the biasing force operative to maintain the temperature sensor in contact with the lower surface of the cooktop panel.

Description

Temperature sensor assembly for induction cooking range

Cross Reference to Related Applications

This application claims the benefit and priority of indian provisional application No.202011041810 filed on 25/9/2020 and U.S. patent application No.17/089,878 filed on 5/11/2020. The entire disclosure of the above application is incorporated herein by reference.

Technical Field

The present disclosure relates generally to cooktops, including induction cooktops used, for example, in residential and commercial kitchens. The present disclosure also more particularly relates to a temperature sensor assembly for a range.

Background

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

Induction cooktops are kitchen appliances that utilize induction heating phenomena for the purpose of cooking food. Conventional induction cooktops include cooktop plates made of glass or glass-ceramic materials. In use, cookware, such as a deep or shallow pan, is positioned on the cooktop panel. Induction cooktops operate by generating an electromagnetic field in a cooking area above a cooktop panel. The electromagnetic field is generated by one or more induction coils made of copper wire, which are driven by a controller that supplies oscillating current to the induction coils. The electromagnetic field induces parasitic currents inside a deep or shallow pan positioned in the cooking area. In order to heat food efficiently using an electromagnetic field, a deep or shallow pan should be made of an electrically conductive ferromagnetic material. Parasitic currents circulating in a deep or shallow pan generate heat by joule effect dissipation. Thus, heat is generated only in the deep or shallow pan, and does not directly heat the cooktop panel on which the deep or shallow pan is seated.

Induction cooktops are more efficient than electric cooktops. For example, a greater proportion of the absorbed energy is provided via induction heating cookware, which is converted into heat that heats the cookware. In operation, the presence of cookware on the stove causes a magnetic flux to approach a deep or shallow pan, causing cooking energy to be transferred to the cookware. While the present disclosure is primarily directed to induction cooktops, it should be understood that the temperature sensor assemblies disclosed herein may be used in other types of cooktops and other consumer appliances. Accordingly, it should be understood that the present disclosure is not limited to induction cooktops.

Disclosure of Invention

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of all of the features of the disclosure or of all of the features of the disclosure.

According to one aspect of the present disclosure, an inductive cooking device is described, wherein the inductive cooking device comprises an induction coil, a controller, and a temperature sensor. The induction coil includes a top surface and a bottom surface, and the temperature sensor includes an upper end positioned above the top surface of the induction coil. The controller may include a first circuit board electrically connected to the induction coil and configured to supply power to the induction coil. The induction cooking apparatus further comprises a second circuit board electrically connected to the temperature sensor. The second circuit board is separate from the first circuit board and includes a cantilevered leaf spring structure supporting a temperature sensor. In other words, the first circuit board and the second circuit board are actually separated, and the second circuit board functions as an independent circuit board of the temperature sensor.

According to another aspect of the present disclosure, the induction coil may further include an opening extending through the induction coil from the top surface to the bottom surface. According to this aspect of the disclosure, the temperature sensor is positioned in the opening of the induction coil. It should also be understood that multiple induction coils and corresponding temperature sensors may be packaged together in an array for a single stove. Advantageously, the cantilevered leaf spring structure keeps the upper end of the temperature sensor flat against the lower surface of the cooktop panel to obtain an accurate temperature reading. Because the cantilevered leaf spring structure is flexible and applies a biasing force to the temperature sensor when flexed, the cantilevered leaf spring structure is configured to accommodate dimensional changes due to manufacturing tolerances and/or thermal expansion and contraction of the components of the stove.

Several advantages are achieved by including a second circuit board for the temperature sensor that is separate and distinct from the first circuit board that powers the induction coil. First, packaging constraints on the first circuit board electrically connected to the induction coil make it difficult to find space for a cantilevered leaf spring structure connected to the temperature sensor. In other words, space on the first circuit board that powers the induction coil is at a premium. By providing the temperature sensor with a second circuit board, sufficient space can be provided on the circuit board for the cantilevered leaf spring structure. Additionally, the thickness and material composition of the second circuit board may be selected to specifically provide the desired mechanical properties of the cantilevered leaf spring structure. Because the first circuit board supports many other electronic components, cost and other factors constrain the thickness and material composition of the first circuit board, which constraints are not present when adding a separate second circuit board for the temperature sensor. In addition, it is easier and cheaper to manufacture the cantilevered leaf spring structure on a separate second circuit board than to try to combine it on the first circuit board that powers the induction coil. Finally, by providing a separate circuit board for the temperature sensor, maintenance of the hob is easier and cheaper if the temperature sensor fails, since the second circuit board can be replaced more easily and cheaper than the first circuit board supplying power to the induction coil. In addition, assembly of the cooktop is also easier and cheaper, since the temperature sensor mounted on the dedicated circuit board can be assembled by machine, rather than by hand, and the entire temperature sensor assembly can then be assembled with the coil beam assembly.

According to yet another aspect of the present disclosure, a temperature sensor assembly is described, wherein the temperature sensor assembly includes a temperature sensor, a circuit board, and a guide support. The temperature sensor has an upper end, a lower end, a flange, and one or more wires extending from the lower end of the temperature sensor. The circuit board includes circuitry disposed on a substrate. The circuit board includes a cantilevered leaf spring structure integral with the base plate and extending to a cantilevered end. The wires of the temperature sensor are electrically connected to the circuit at the cantilevered end of the cantilevered leaf spring structure of the circuit board. The guide support has a top end, a bottom end, and a tubular structure that surrounds at least a portion of the temperature sensor in a clearance fit. The top end of the guide support is arranged to contact the flange of the temperature sensor and the bottom end of the guide support is arranged to contact the cantilever end. The base plate is made of a resilient material such that the cantilevered leaf spring structure of the circuit board provides a biasing force when deflected, which is transferred through the lead support to the flange at the upper end of the temperature sensor.

According to this particular arrangement, the guide support is free to slide, tilt and form a gimbal relative to the temperature sensor while remaining as a load-bearing structure that transfers the biasing force generated by the deflection of the cantilevered leaf spring structure to the flange of the temperature sensor. Advantageously, this relieves the load of the temperature sensor, and in particular the load at the connection between the wire at the lower end of the temperature sensor and the cantilever end. The connection between the wire at the lower end of the temperature sensor and the cantilever end may be, for example, a welded connection, which may fail under load. Manufacturing is also simplified because the temperature sensor assembly can be assembled separately from the coil beam assembly.

Drawings

Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a top plan view of an exemplary stove;

FIG. 2 is a top perspective view of an exemplary coil beam assembly constructed in accordance with the teachings of the present disclosure;

FIG. 3 is an exploded perspective view of an exemplary cooktop panel, the exemplary coil beam assembly shown in FIG. 2, and an exemplary controller;

FIG. 4 is a front cross-sectional view of the exemplary cooktop panel, coil beam assembly, and controller shown in FIG. 3;

FIG. 5 is a bottom perspective view of the exemplary cooktop panel, coil beam assembly, and controller shown in FIG. 3;

FIG. 6A is a side cross-sectional view of a portion of the example coil beam assembly shown in FIG. 3 with the cantilevered leaf spring structure of the circuit board shown in an undeflected position;

FIG. 6B is a perspective cross-sectional view of a portion of the exemplary coil beam assembly shown in FIG. 3 with the cantilevered leaf spring structure of the circuit board shown in an undeflected position;

FIG. 7A is a side cross-sectional view of a portion of the exemplary cooktop panel and coil beam assembly shown in FIG. 3, with the cantilevered leaf spring structure of the circuit board shown in a flexed position;

FIG. 7B is a perspective cross-sectional view of a portion of the exemplary coil beam assembly shown in FIG. 3 with the cantilevered leaf spring structure of the circuit board shown in a flexed position;

FIG. 8 is an exploded perspective cross-sectional view of a portion of the exemplary coil beam assembly shown in FIG. 3;

FIG. 9 is a top perspective view of an exemplary temperature sensor assembly constructed in accordance with the present disclosure, including an exemplary temperature sensor and the cantilevered leaf spring structure of the circuit board shown in FIGS. 6A and 6B; and

fig. 10 is a bottom perspective view of an exemplary guide support of a temperature sensor assembly described in the present disclosure.

Detailed Description

Referring to the drawings, wherein like reference numbers refer to corresponding parts throughout the several views, an inductive cooking device 20 and a temperature sensor assembly 22 for a stove 24 are illustrated.

Example embodiments will now be described more fully with reference to the accompanying drawings. These example embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "including," and "having" are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Unless specifically indicated as an order of execution, the method steps, processes, and operations described herein should not be construed as necessarily requiring their execution in the particular order discussed or illustrated. It should also be understood that additional or alternative steps may be employed.

When an element or layer is referred to as being "on," "engaged to," "connected to" or "coupled to" another element or layer, it can be directly on, engaged, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly engaged to," "directly connected to" or "directly coupled to" another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in the same manner (e.g., "between.. and" directly between.. and, "adjacent" and "directly adjacent," etc.). As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

For purposes of description herein, the terms "upper," "lower," "top," "bottom," "vertical," "horizontal," and derivatives thereof shall relate to the device as oriented in fig. 3 and 4. However, it is to be understood that the devices and components described herein may assume various alternative orientations.

Referring to fig. 1, a stove 24 is shown as seen from above. In the illustrated embodiment, the stove 24 is an induction stove that includes an array of induction coils 26 distributed over a cooking area 28. Although there are illustrated examples and descriptions set forth herein, it should be understood that the temperature sensor assembly 22 described herein is not necessarily limited to stoves configured for induction heating, and may be used in other stoves and consumer appliance applications.

With additional reference to fig. 2 and 3, the induction coil 26 is electrically connected to a controller 30. The controller 30 is configured to supply power to the induction coil 26. In other words, the controller 30 may selectively enable (i.e., turn on and off) the induction coil 26 in response to an input to a user interface 32, the user interface 32 being electrically connected to the controller 30. Optionally, the controller 30 may activate one or more cooking zones 28 formed by the induction coil 26 in response to an input or user selection. Accordingly, the controller 30 may include a first circuit 34, the first circuit 34 being electrically connected to the induction coil 26. In operation, the first circuit 34 supplies power to the induction coil 26 and may include a switching device (e.g., a solid state switch) configured to generate a variable frequency/variable amplitude current that is fed to the induction coil 26. In such a configuration, the induction coil 26 may be driven such that an electromagnetic field is generated to heat cookware 36 (e.g., a shallow pan, a deep pan, etc.) disposed in the activated cooking region 28.

In some embodiments, the induction coils 26 may be independently activated (i.e., turned on) by the controller 30. Activation of the induction coil 26 may be in response to user-defined heating settings received via the user interface 32 in conjunction with detection of cookware 36 in the cooking zone 28. In response to user-defined settings and detection of cookware 36, controller 30 may activate induction coil 26 covered or partially covered by cookware 36. Accordingly, range 24 may provide selective energization of cooking zones 28, thereby providing a plurality of flexible cooking zones or zones, sometimes referred to as "cook anywhere" functionality.

The user interface 32 may include one or more of the following components: dials, touch pads, number readers, number displays, and touch screen displays. For example, the user interface 32 may correspond to a touch interface configured to perform heating control and selection of the induction coil 26 for cooking operations. The user interface 32 may include a plurality of sensors configured to detect the presence of a finger of an operator in proximity to the sensors. The sensors of the user interface 32 may correspond to various forms of sensors. For example, the sensors of the user interface may correspond to capacitive sensors, resistive sensors, and/or optical sensors. In some embodiments, the user interface 32 may also include a display configured to communicate at least one function of the stove 24. The display may correspond to various forms of displays, such as a Light Emitting Diode (LED) display, a Liquid Crystal Display (LCD) display, and the like. In some embodiments, the display may correspond to a segmented display configured to depict one or more alphanumeric characters to convey the cooking function of the stove 24. The display is also operable to communicate one or more error messages or status messages from the controller 30.

In some embodiments, the induction coils 26 may be grouped to form a coil beam assembly 38. The coil beam assemblies 38 may be arranged in an alternating, staggered, or complementary arrangement including a plurality of coil beam assemblies 38 that are advantageously arranged to position the induction coils 26 at evenly spaced or distributed locations in the array. This uniform spacing allows the induction coil 26 to distribute the cooking energy evenly over the cooking area 28.

As discussed herein, the stove 24 may include various novel structural and electrical components that provide improved quality and performance, ease of manufacture benefits, and cost savings. Although the stove 24, inductive cooking device 20, and temperature sensor assembly 22 described herein are discussed with reference to particular examples, various components of these assemblies may be implemented individually or in combination.

With further reference to fig. 4 and 5, a larger induction cooking apparatus 20 is illustrated, the induction cooking apparatus 20 including a coil beam assembly 38, a cooktop panel 40, a controller 30, and a temperature sensor assembly 22. Each of the induction coils 26 included on one of the coil beam assemblies 38 is mounted above and supported on a beam 42, the beam 42 extending horizontally/transversely through the burner box 44 of the stove 24 between a first beam end 46 and a second beam end 48, and the beam 42 is supported on the beam 42. The beam 42 may be made of a variety of different materials; however, the beam 42 is preferably made of a non-ferromagnetic material, such as aluminum, for example, so that the beam 42 is not affected by the induction coil 26 it supports. Optionally, a ferrite foil 50 may be positioned between each induction coil 26 and beam 42 to direct the electromagnetic field upward toward cooking area 28.

Although other configurations are possible, the combustor case 44 may include a bottom wall 52 and one or more side walls 54 extending upwardly from the bottom wall 52. Accordingly, the burner box 44 may be generally rectangular in form and may form an enclosure having an interior cavity configured to receive various components of the stove 24, including the coil beam assembly 38. The coil beam assembly 38 may be supported by a sidewall 54 of the combustor case 44, with the first and second beam ends 46, 48 engaging the sidewall 54 of the combustor case 44. Alternatively, the coil beam assembly 38 may be supported in the combustor case 44 by a frame or other structure supported by the bottom wall 52 and/or the side walls 54 of the combustor case 44.

The coil beam assemblies 38 extend in complementary parallel groups beneath the cooktop panel 40. The cooktop plate 40 may be made of glass or glass-ceramic material and includes an upper surface 58 and a lower surface 60. Optionally, a mica sheet 62 may be provided between the lower surface 60 of the cooktop panel 40 and the induction coil 26 to provide insulation. The upper surface 58 of the cooktop panel 40 is configured to support cookware 36 of various shapes and sizes and thus serves as a cooking surface. The induction coil 26, together with the ferrite foil 50, concentrates the electromagnetic flux field above the upper surface 58 of the cooktop panel 40 in the cooking area 28.

The controller 30 is positioned below the coil beam assembly 38. The controller 30 includes a first circuit board 64, the first circuit board 64 being electrically connected to the induction coil 26 in the coil beam assembly 38. The first circuit board 64 may be a Printed Circuit Board (PCB) including the first circuit 34, the first circuit 34 being printed as conductive traces on a first substrate 66 forming the first circuit board 64. As non-limiting examples, some materials that may be used for first substrate 66 include, but are not limited to: FR-1, FR-4, FR-5, G-10 and G-11.

The first circuit 34 of the controller 30 is configured to generate one or more high frequency switching signals. The switching signal causes the induction coil 26 to generate an electromagnetic field in the cookware 36 disposed on the upper surface 58 of the cooktop panel 40. Due to this functionality, the controller 30 may also be referred to as an inverter or an inductive power converter. The first circuit 34 includes a plurality of conductive connections and is configured to communicate control signals and/or drive currents to the induction coil 26. The electrically conductive connections of the first circuit 34 are arranged in electrical communication with the induction coil 26 via one or more electrical connectors 68, these electrical connectors 68 being electrically connected to copper windings 70 forming the induction coil 26. The electrical connectors 68 may correspond to leads (as shown) or quick connect terminals (e.g., "faston" connectors). If the latter option is used, the conductive connection of the first circuit 34 may be configured as a female terminal and the electrical connector 68 on the induction coil 26 may be configured as a male terminal, or the conductive connection of the first circuit 34 may be configured as a male terminal and the electrical connector 68 on the induction coil 26 may be configured as a female terminal to establish an electrical connection between the first circuit 34 and the induction coil 26.

The copper winding 70 of the induction coil 26 may be wound on a bobbin 72. Each bobbin 72 may be, for example, a plastic bobbin or a plastic housing. In some embodiments, the copper winding 70 of each induction coil 26 may be wound on one bobbin 72. First circuit 34 may extend along the length of beam 42 such that the conductive contacts of first circuit 34 are aligned with electrical connectors 68 on each induction coil 26. For example, in some embodiments, the induction coils 26 in each coil beam assembly 38 may share a single circuit 34.

During assembly, the coil beam assembly 38 is positioned over the first circuit board 64 with the electrical connectors 68 of the induction coil 26 aligned with the corresponding conductive contacts of the first circuit 34. The coil beam assembly 38 is then lowered such that the electrical connectors 68 of the induction coil 26 engage corresponding conductive contacts of the first circuit 34. The controller 30, including the first circuit board 64, may be mounted to the bottom wall 52 of the burner box 44 and supported by the bottom wall 52, or positioned in a plastic support tray. As previously discussed, the beam 42 is mounted in the combustor case 44 at a location above and spaced apart from the first circuit board 64.

As shown in fig. 6A and 6B, each induction coil 26 includes a top surface 74, a bottom surface 76, and an opening 78. An opening 78 extends through the induction coil 26 from the top surface 74 to the bottom surface 76. Although other configurations are possible, each induction coil 26 has a disk-like shape and the opening 78 is located at the center of the induction coil 26. The induction cooking apparatus 20 further comprises a temperature sensor 80 for each induction coil 26, the temperature sensor 80 being positioned in the opening 78 of the induction coil 26. A guide support 82 is also positioned in the opening 78 of the induction coil 26. The temperature sensor 80 and the guide support 82 are arranged in a clearance fit with each other and with the opening 78 such that both the temperature sensor 80 and the guide support 82 are free to move, slide and tilt within the opening 78 in the induction coil 26. It should also be understood that both the beam 42 and the mica sheet 62 have apertures 84, 85, the apertures 84, 85 being aligned with the openings 78 in the induction coil 26 through which the temperature sensor 80 may extend.

The temperature sensor 80 extends axially along the temperature sensor axis 86 between an upper end 88 and a lower end 90. An upper end 88 of the temperature sensor 80 is located above the top surface 74 of the induction coil 26 and a lower end 90 of the temperature sensor 80 includes one or more wires 92. Optionally, each wire 92 may be wrapped in an insulating sleeve 94 along a portion of its length. In some embodiments, the temperature sensors 80 may correspond to Negative Temperature Coefficient (NTC) sensors configured to adjust the resistance based on the temperature proximate each temperature sensor 80. For example, each temperature sensor 80 may include a thermistor 96 and a sensor enclosure 98, the sensor enclosure 98 surrounding at least a portion of the thermistor 96. The sensor enclosure 98 protects the thermistor 96 and may optionally act as an electrical insulator. In operation, temperature sensor 80 communicates a temperature signal of induction coil 26. These temperature signals are used for temperature control and regulation purposes.

The induction cooking apparatus 20 further comprises a second circuit board 100 separate from the first circuit board 64, the second circuit board 100 being electrically connected to the temperature sensor 80. In other words, the induction cooking apparatus 20 has a separate second circuit board 100, which separate second circuit board 100 together with the temperature sensor 80 and the guide support 82 form the temperature sensor assembly 22 described herein. The second circuit board 100 is mounted above the first circuit board 64 and below the induction coil 26. More specifically, the second circuit board 100 is mounted below the beam 42 and supported by the beam 42. In some embodiments, the connection fixture 102 is used to connect the second circuit board 100 to the beam 42. For example, but not limiting of, the connection fixture 102 may extend upward from the second circuit board 100 and may be configured to engage the aperture 104 in the beam 42. In some embodiments, one or more spacers 106 may be disposed between the beam 42 and the second circuit board 100. For example, the spacer 106 may be made of an electrically insulating material, such as plastic.

The second circuit board 100 includes a second substrate 108 and a second circuit 110 disposed on the second substrate 108. For example, the second circuit board 100 may be a Printed Circuit Board (PCB), wherein the second circuit 110 is formed by conductive traces printed on the second substrate 108 of the second circuit board 100. One or more wires 92 of temperature sensor 80 are electrically connected to second circuit 110. For example, but not limiting of, the wires 92 of the temperature sensor 80 may be soldered to conductive traces forming the second circuit 110. Thus, the second circuit 110 receives the temperature signal from the temperature sensor 80. The second circuit 110 may be configured to process the temperature signal itself or may simply be configured to communicate the temperature signal to the controller 30. Accordingly, in various embodiments, the induction cooking apparatus 20 may include an electronic interface between the first circuit board 64 and the second circuit board 100 configured to communicate a signal (e.g., a temperature signal) from the second circuit board 100 to the first circuit board 64.

The second circuit board 100 includes one or more cantilevered leaf spring structures 112 that support the temperature sensor 80. Each cantilevered leaf spring structure 112 is integral with the second base plate 108 and is formed by a U-shaped slot 114 extending through the second circuit board 100. Thus, the cantilevered leaf spring structure 112 operates as a living hinge. The cantilevered leaf spring structure 112 includes a cantilever 116, the cantilever 116 extending to a cantilever end 118, the cantilever end 118 being a free end or terminal that is not connected to the second circuit board 100 except through the cantilever 116. The second substrate 108 of the second circuit board 100 is made of a resilient material such that the cantilevered leaf spring structure 112 can deflect or bend relative to a transverse plane 120 defined by the second circuit board 100. As non-limiting examples, some materials that may be used for the second substrate 108 include, but are not limited to: FR-1, FR-4, FR-5, G-10 and G-11.

Fig. 6A and 6B illustrate the cantilevered leaf spring structure 112 in a natural state prior to deflection, such as prior to mounting the cooktop panel 40 over the burner box 44. As shown in fig. 7A and 7B, after the cooktop panel 40 is mounted over the burner box 44, the lower surface 60 of the cooktop panel 40 is vertically spaced from the second circuit board 100 by a predetermined distance 122, the predetermined distance 122 being less than the mounting height 124 of the temperature sensor 80. Thus, when the stove 24 is in the fully assembled state, the cantilevered leaf spring structure 112 flexes downwardly and applies a biasing force 126 to the temperature sensor 80, the biasing force 126 being directed upwardly toward the cooktop panel 40. In operation, the biasing force 126 keeps the upper end 88 of the temperature sensor 80 flat against the lower surface 60 of the cooktop panel 40 to obtain an accurate temperature reading. Because the cantilevered leaf spring structure 112 is flexible, it accounts for dimensional variations due to manufacturing tolerances and components of the stove 24, including thermal expansion and contraction during use. When the cantilevered leaf spring structure 112 is flexed, it will be appreciated that the cantilevered end 118 moves in an arcuate path 128, as shown in fig. 7A.

Packaging constraints are avoided by including a second circuit board 100 for the temperature sensor 80, the second circuit board 100 being separate and distinct from the first circuit board 64 that supplies power to the induction coil 26. For example, space on the first circuit board 64 is crowded with numerous electronic components, making it difficult to find space for the U-shaped slot 114 and the cantilevered leaf spring structure 112 connected to each temperature sensor 80. By providing the temperature sensor 80 with the second circuit board 100, sufficient space is created for the cantilevered leaf spring structure 112. Additionally, the thickness and material composition of the second circuit board 100 may be selected to specifically provide the desired mechanical properties of the cantilevered leaf spring structure 112. According to some embodiments, the second circuit board 100 may be designed such that each cantilevered leaf spring structure 112 may apply a maximum biasing force 126 of 40 grams to 60 grams to each corresponding temperature sensor 80 at a maximum deflection or stroke 130 of 1.0mm to 1.4 mm. For example, the second circuit board 100 may be manufactured to have a thickness 132 in the range of 0.8mm to 1.2mm, and the second circuit board 100 is composed of a material having suitable mechanical properties, such as FR-4. Because the first circuit board 64 supports many other electronic components, cost and other factors impose constraints on the thickness and material composition of the first circuit board 64 that are not present when a separate second circuit board is added for the temperature sensor 80. For example, the industry standard thickness for printed circuit boards in this field of technology is 1.6 mm. Thus, manufacturing efficiency and cost savings are realized by providing a separate second circuit board for the temperature sensor 80.

With further reference to fig. 8-10, the upper end 88 of the temperature sensor 80 includes: a top surface 134, the top surface 134 contacting the lower surface 60 of the cooktop panel 40; and a flange 136, the flange 136 having an underside surface 138. The flange 136 of the temperature sensor 80 is part of the sensor enclosure 98 and not part of the thermistor 96. In the illustrated embodiment, the cantilever 116 has a narrower width 140 than the cantilever end 118, although other configurations are possible. In addition, each temperature sensor 80 includes two wires 92 at its lower end 90, the wires 92 being received in two holes 142 in the cantilever end 118. Some of the conductive traces forming the second circuit 110 extend down the cantilever 116 to a cantilever end 118, and the wire 92 of the temperature sensor 80 is electrically connected to the second circuit 110 at the cantilever end 118, for example by soldering.

The guide support 82 is positioned in the opening 78 of the induction coil 26 along with the temperature sensor 80. The guide support 82, which may be made of plastic, extends coaxially about the guide support axis 144 between a top end 146 and a bottom end 148, the top end 146 being disposed in contact with the upper end 88 of the temperature sensor 80, the bottom end 148 being disposed in contact with the cantilevered leaf spring structure 112 of the second circuit board 100. Thus, the guide support 82 is load bearing and configured to transfer the biasing force 126 resulting from the deflection of the cantilevered leaf spring structure 112 to the upper end 88 of the temperature sensor 80. Although other configurations are possible, in the illustrated embodiment, the guide support 82 has a tubular structure that surrounds at least a portion of the temperature sensor 80 and is positioned to slidingly engage the opening 78 in the induction coil 26. There is a clearance fit between the guide support 82 and the temperature sensor 80 and between the guide support 82 and the opening 78 in the induction coil 26 such that the guide support 82 is allowed to slide, tilt and form a gimbal relative to the temperature sensor 80. Preferably, the tubular structure of the guide support 82 includes an outer surface 150 having an annular rib 152, the annular rib 152 providing a point or line contact with the sliding point of the induction coil 26 in the opening 78.

As best seen in fig. 7A and 7B, after assembly, the top end 146 of the guide support 82 is disposed in contact with the flange 136 of the temperature sensor 80 and the bottom end 148 of the guide support 82 is disposed in contact with the cantilevered end 118, such that the biasing force 126 provided by the cantilevered leaf spring structure 112 when flexed is transmitted through the guide support 82 to the flange 136 at the upper end 88 of the temperature sensor 80. As best seen in fig. 8, tip end 146 of guide support 82 includes an end face 154, the end face 154 being bounded by an inner peripheral edge 156 and an outer peripheral edge 158. Preferably, the end face 154 is chamfered (i.e., ramped) with a peak formed at the top edge 172 that extends radially through the end face 154 from the inner peripheral edge 156 to the outer peripheral edge 158 in the illustrated example. According to this arrangement, the top edge 172 of the end face 154 provides sliding point or line contact with the underside surface 138 of the flange 136 of the temperature sensor 80. In other words, line contact between the top edge 172 of the guide support 82 and the underside surface 138 of the flange 136 of the temperature sensor 80 may be provided when the guide support axis 144 is perpendicular to the flange 136, such as when the top edge 172 rests against the underside surface 138 of the flange 136.

As best seen in fig. 10, the bottom end 148 of the guide support 82 includes an engagement feature 160, the engagement feature 160 extending downwardly from the tubular structure of the guide support 82. The engagement feature 160 at the bottom end 148 of the guide support 82 defines a pocket 162, the pocket 162 receiving the cantilevered end 118 of the cantilevered leaf spring structure 112 in a sliding fit. Thus, the engagement features 160 and the cantilevered end portions 118 cooperate to form a free-fitting articulation between the guide support 82 and the cantilevered leaf spring structure 112 that allows the guide support 82 to slide, tilt, and form a gimbal relative to the temperature sensor 80 and the cantilevered leaf spring structure 112. Engagement feature 160 includes a shoulder 164, the shoulder 164 defining a bottom face 166 of pocket 162. Preferably, the bottom face 166 includes a straight rib portion 168, the straight rib portion 168 providing a sliding point or line contact with the cantilevered end portion 118. The engagement feature 160 may also include a bottom inner edge 170, the bottom inner edge 170 being chamfered to facilitate assembly and allow for a greater range of movement between the guide support 82 and the cantilevered end 118.

According to this arrangement, the guide support 82 is free to slide, tilt and form a gimbal relative to the temperature sensor 80 and the cantilevered leaf spring structure 112 while remaining as a load-bearing structure that transfers the biasing force 126 generated by deflection of the cantilevered leaf spring structure 112 to the flange 136 at the upper end 88 of the temperature sensor 80. Stated another way, the guide support 82 can move and tilt independently of the temperature sensor 80 and the cantilevered leaf spring structure 112. Advantageously, this relieves the load of the temperature sensor 80, and in particular the load at the connection between the wire 92 at the lower end 90 of the temperature sensor 80 and the cantilever end 118. As previously explained, the connection between the wire 92 at the lower end 90 of the temperature sensor 80 and the cantilever end 118 may be, for example, a welded connection that fails under load. In operation, the guide support 82 takes the load at the wire 92 and the connection and therefore provides greater durability.

Many modifications and variations of the devices and assemblies described in this disclosure are possible in light of the above teachings, and may be practiced otherwise than as specifically described within the scope of the appended claims. These previous descriptions should be construed to cover any combination of the novel features of the present invention which achieves its utility. Furthermore, reference signs in the claims are provided merely as a convenience and are not to be construed as limiting in any way.

Claims (15)

1. An inductive cooking device (20) comprising:

an induction coil (26), the induction coil (26) having a top surface (74);

a controller (30), the controller (30) comprising a first circuit board (64), the first circuit board (64) being electrically connected to the induction coil (26), and the first circuit board (64) being configured to supply power to the induction coil (26);

a temperature sensor (80), the temperature sensor (80) having an upper end (88), the upper end (88) being located above the top surface (74) of the induction coil (26); and

a second circuit board (100) separate from the first circuit board (64), the second circuit board (100) electrically connected to the temperature sensor (80), the second circuit board (100) including a cantilevered leaf spring structure (112) supporting the temperature sensor (80).

2. The induction cooking apparatus (20) of claim 1, wherein the second circuit board (100) comprises a base plate (108) and the cantilevered leaf spring structure (112) is integral with the base plate (108) of the second circuit board (100).

3. The induction cooking apparatus (20) of claim 2, further comprising:

a cooktop panel (40), the cooktop panel (40) positioned above the induction coil (26),

the cooktop panel (40) having an upper surface (58) and a lower surface (60); and is

The base plate (108) of the second circuit board (100) is made of a resilient material such that the cantilevered leaf spring structure (112) applies a biasing force (126) to the temperature sensor (80) when deflected to operatively maintain the upper end (88) of the temperature sensor (80) in contact with the lower surface (60) of the cooktop panel (40).

4. The inductive cooking apparatus (20) according to claim 3, wherein the lower surface (60) of the cooktop panel (40) is vertically spaced from the second circuit board (100) by a predetermined distance (122), the predetermined distance (122) being less than a mounting height (124) of the temperature sensor (80), such that the cantilevered leaf spring structure (112) flexes downwardly in a fully assembled state and the biasing force (126) of the cantilevered leaf spring structure (112) is directed upwardly toward the cooktop panel (40).

5. The inductive cooking apparatus (20) according to claim 3, wherein the cooktop panel (40) is made of a glass or glass-ceramic material, and the upper surface (58) of the cooktop panel (40) is configured to support cookware (36).

6. The induction cooking apparatus (20) of claim 1, wherein the second circuit board (100) is mounted above the first circuit board (64) and below the induction coil (26).

7. The induction cooking apparatus (20) of claim 6, further comprising:

a beam (42), the beam (42) extending transversely between a first beam end (46) and a second beam end (48),

wherein the induction coil (26) is mounted above the beam (42) and supported by the beam (42), an

Wherein the second circuit board (100) is mounted below the beam (42) and supported by the beam (42).

8. The induction cooking apparatus (20) of claim 7, further comprising:

a burner box (44), the burner box (44) having a bottom wall (52) and a side wall (54) extending upwardly from the bottom wall (52),

wherein the controller (30) is mounted to the bottom wall (52) of the burner box (44) and supported by the bottom wall (52), an

Wherein the beam (42) is supported within the combustor case (44) at a location above the first circuit board (64) and spaced apart from the first circuit board (64).

9. The induction cooking apparatus (20) of claim 1, wherein the induction coil (26) includes a bottom surface (76) and an opening (78), the opening (78) extending through the induction coil (26) from the top surface (74) to the bottom surface (76), and wherein the temperature sensor (80) is positioned in the opening (78) in the induction coil (26) and extends through the opening (78).

10. The induction cooking apparatus (20) according to claim 9, further comprising:

a guide support (82), the guide support (82) being positioned in the opening (78) of the induction coil (26) with the temperature sensor (80);

the guide support (82) includes a top end (146) and a bottom end (148), the top end (146) disposed in contact with the upper end (88) of the temperature sensor (80), the bottom end (148) disposed in contact with the cantilevered leaf spring structure (112) of the second circuit board (100) such that the guide support (82) carries a load and is configured to transfer a biasing force (126) resulting from deflection of the cantilevered leaf spring structure (112) to the upper end (88) of the temperature sensor (80).

11. The induction cooking apparatus (20) of claim 10, wherein the guide support (82) has a tubular structure that surrounds at least a portion of the temperature sensor (80) and is positioned in sliding engagement with the opening (78) in the induction coil (26).

12. The induction cooking apparatus (20) of claim 11, wherein there is a clearance fit between the guide support (82) and the temperature sensor (80) and between the guide support (82) and the opening (78) in the induction coil (26) such that the guide support (82) is allowed to slide, tilt, and form a gimbal relative to the temperature sensor (80).

13. The inductive cooking apparatus (20) according to claim 12, wherein the temperature sensor (80) has a lower end (90) and a flange (136), the cantilevered leaf spring structure (112) includes a cantilevered end portion (118), the top end portion (146) of the guide support (82) is disposed in contact with the flange (136) of the temperature sensor (80), and the bottom end portion (148) of the guide support (82) is disposed in contact with the cantilevered end portion (118), such that the biasing force (126) generated by the cantilevered leaf spring structure (112) is transmitted through the guide support (82) to the flange (136) of the temperature sensor (80).

14. The inductive cooking apparatus (20) according to claim 13 wherein the bottom end (148) of the guide support (82) includes an engagement feature (160), the engagement feature (160) extending downwardly from the tubular structure of the guide support (82), and the engagement feature (160) defining a pocket (162), the pocket (162) receiving the cantilevered end (118) of the cantilevered leaf spring structure (112) in a sliding fit such that the engagement feature (160) and the cantilevered end (118) cooperate to form a free-fitting hinge between the guide support (82) and the cantilevered leaf spring structure (112) that allows the guide support (82) to slide, tilt, and form a gimbal relative to the temperature sensor (80).

15. The induction cooking apparatus (20) of claim 14, wherein the pocket (162) comprises a bottom face (166) having a straight rib (168), the straight rib (168) providing a first sliding point or line contact with the cantilevered end (118), wherein the tubular structure of the guide support (82) comprises an outer surface (150) having an annular rib (152), the annular rib (152) providing a second sliding point or line contact with the opening (78) in the induction coil (26), wherein the top end (146) of the guide support (82) comprises an end face (154) bounded by an inner peripheral edge (156) and an outer peripheral edge (158), and wherein the end face (154) is chamfered such that a third sliding point or line contact is created between the end face (154) of the guide support (82) and the flange (136) of the temperature sensor (80) .

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