WO2017083915A1

WO2017083915A1 - Oven door

Info

Publication number: WO2017083915A1
Application number: PCT/AU2016/051101
Authority: WO
Inventors: Emma Craig; Brendan John FOXLEE; Vyvyan Rose; Ashley MARSH-CROFT
Original assignee: Breville Pty Limited
Priority date: 2015-11-16
Filing date: 2016-11-16
Publication date: 2017-05-26

Abstract

An oven uses an internal impeller to evenly distribute heat within the oven cavity.

Description

Oven Door

Field of the Invention

The invention pertains to ovens and more particularly to oven cooling.

Background of the Technology

Prior art doors for ovens, particularly countertop ovens can be thought of as having two types. The first type comprises a simple glass pane with minimal additional parts. The glass pane type oven doors are easy to clean because they have a few surface details and a minimum of fasteners required to complete assembly. However, market data suggests that the simpler glass pane type doors have lower cosmetic appeal than a second type of oven door. The second type has a glass pane sandwiched between two sheet metal pressings. Doors of this type have a high quality appearance but require more parts and are often associated with higher costs. Because they have more surface details, they are susceptible to trapping debris and are more difficult to clean. In particular, doors of this type often have exposed fasteners on either the front or the rear surfaces of the doors which contributes to poor cosmetic appearance and difficulties in cleaning. Doors of this type are not serviceable nor intended for disassembly.

In an oven with top and bottom heating elements, heat tends to accumulate in the area around the heating elements. The accumulated heat will be better served is re-distributed around the interior of the oven cavity.

Objects and Summary

It is an object of the invention to provide an oven door comprising a sheet metal assembly that receives a glass view window. Neither the front nor the rear surface of the door requires a visible fastener. In preferred embodiments, the interior surface of the door is predominately glass having only a small peripheral margin of steel. Doors in accordance with the present invention are capable of maintaining a bold pillowed stainless facia that is consistent with a refined commercial aesthetic.

In preferred embodiments, the door features magnets that projects from a rear surface that aid in rack extraction and are inward further than the interior of the glass pane.

Doors fabricated in accordance with the teachings of the present invention enable disassembly for servicing or reworking during production runs.

Accordingly, a door in accordance with the present invention is made using a novel assembly process and provides both novel structures and novel benefits within the realm of oven doors.

In some embodiments an oven has an oven cavity in which is located a radial impeller within an enclosure. The enclosure preferably comprises a central intake opening and discharge openings that are located so as to direct the impeller's output toward to the oven's heating elements.

Brief Description of the Drawing Figures

In order that the invention be better understood, reference is now made to the following drawing figures in which:

Figure 1 is a perspective view of a bench top or other oven.

Figure 2 is a rear elevation of an oven door.

Figure 3 is an exploded perspective view of an oven door.

Figure 4 is a perspective view of a pane bracket.

Figure 4a is a cross sectional view through plane (a)-(a) of Figure 4. Figure 5 illustrates, in perspective view, an assembly sequence of a pane subassembly of an oven door.

Figure 6 is a perspective view illustrating a sub-assembly and a frame of an oven door.

Figure 7 is a cross sectional view of a portion of a frame bracket and pane.

Figure 8 is a cross sectional view of a portion of a frame bracket and pane.

Figure 9 is a perspective view, partially exploded to illustrate an assembly step in the fabrication of an oven door.

Figure 10 is a perspective view, partially exploded to illustrate an assembly step in the fabrication of an oven door.

Figure 11 is a perspective view, partially exploded, to illustrate the assembly of the lower bracket in on oven door.

Figure 12 is cross sectional view through a frame, lower bracket, pane bracket and pane of an oven door.

Figure 13 is cross sectional view through a frame, lower bracket, pane bracket and pane of an oven door.

Figure 14 is an inverted plan view of an oven door.

Figure 15 is a perspective view of an oven cavity.

Figure 16 is an exploded perspective view of an impeller assembly.

Figure 17 is a schematic elevation of a convention impeller, partially disassembled.

Figure 18 is a perspective view of an oven wall with convention impeller and heating elements installed.

Figure 19 is an exploded perspective view of an impeller assembly.

Figure 20 is a schematic plan view of an oven cavity and impeller. Best Mode and Other Embodiments

As shown in Figure l, an oven such as a count ertop convention oven 100 has an oven body 101. The body 101 has a user interface portion 102. The front surface of the oven is primarily defined by the front surface of the vertically orientated user interface 102 and a horizontally hinged door 103 to the left of the interface. The exterior surface of the door 103 comprises a bold pillowed frame or surround 104 and a glass viewing window or pane 105. Looking at the door from the front, the outer edge 106 of the viewing pane is concealed by the frame 104. An upper margin of the door features a horizontal handle 107. In this example, the handle 107 is supported at each end by a handle mounting bracket 108. Accordingly, the front surface of the doors free from any visible fastener of any kind.

The door structure of the present specification is illustrated in Figure 1 as having both a rounded 109 and a more square corner 110. It will be understood that the invention applies equally to both rounded a square corners in any of the four locations of the oven door.

As shown in Figure 2, the rear surface 200 of the oven door 120 is composed primarily of the rear of the pane 105. Visible in the rear view of Figure 2 are the two magnetic protrusions 201 and the rear edge of the lower bracket 202. The surface area of the rear of the oven door is predominately glass, but for a thin margin composed of the various metallic components 210, confined to a narrow peripheral margin. No fasteners are visible on the rear of the door.

To better understand its constructions, an assembly drawing of an oven door is provided in Figure 3. The major structural element of the door is a metallic surrounding frame 300. The frame forms the entirety of the front surface, the two side edges 301, 302, a portion of the bottom edge and the entirety top edge 303. The bottom edge of the door is completed, by a lower bracket 304. The lower or horizontal edge 305 of the bracket 304 has openings 306 that allow fasteners 308 to attach the lower bracket 304 to a lower edge 307 of the frame and to the pane brackets 310, 311. The major frame element comprises only a portion of the upper edge of the rear surface of the door. The vertical margins and upper corners of the rear surface are completed by the two pane brackets 310, 311.

The vertical edges of the pane 320 are held by the pane brackets 310, 311. The brackets provide mounting apertures 330 that receive a magnet 331 and magnet mounting cup 332. The bracket is also adapted to comprise pivot points or openings for the attachment of hinge components 331, 332, as maybe required to attach the door to an oven body. The brackets 310, 311 also provide a mounting surface for locating and through openings, as may be required to allow a fastener 340 to engage a threaded opening 343 located on a rear surface of a handle mounting 344. In this example, the handle mounting 344 forms one end of a pair of ends that support a horizontal rod 345, spaced away from the front of the door. The frame has openings 342 that cooperate with the fastener 340.

As shown in more detail in Figures 4(a) and (b), a pane bracket 400 has an elongated vertical slot for receiving a glass pane. The slot 401 has a vertical terminal edge 402. This edge is provided with integral punched out clips 403 that cooperate with a free edge of the frame 300. The slot-like bracket 401 can be used to form an integral tab, e. g. 404. The tab 404 has locating openings 405 as well as a through opening 406 for admitting a handle fastener 340.

The bracket 401 also features a pair of aligned through openings 407, 408. The larger of the two openings 407 is formed on a front surface 409 of the bracket 401. The large opening 407 admits the passage of a metallic or other cup 410 with a surrounding rim 410a. The cup 410 receives a permanent magnet 411. The rim of the cup 412 is larger than the small opening 408 and does not pass through it. However, the dome 413 of the cup protrudes through the opening 408 and extends away from it so that it is closer to the oven racks than the remainder of the door when closed.

The lower end 420 of the bracket 401 is bent to form a horizontal foot 421 having an opening 422 that allows the pane bracket to be fastened to a lower part of the frame and/or the lower bracket 304. In this example, a pair of frame edge locating bumpers 430 are integrally formed on the inside edge of the upper surface of the bracket 401. Frame supporting posts 450 are punched out and bent away from the bracket.

As shown in Figure 5, left and right brackets 500, 501 can be fitted directly over the vertical edges 502, 503 of the pane 504. In preferred embodiments, neither bracket 500, 501 has any impediment to the lower extent of vertical travel of the pane 504. Unless it is supported, the lower horizontal edge 505 will come to rest at the bottom of the lower extent or foot 506 of each bracket. However, from the lower position, the pane 504 can be slid or urged upward into the fully installed orientation depicted in Figure 5(b). In this orientation, the upper horizontal edge 510 of the pane 504 is prevented from further upward movement by a horizontal limit or shoulder 511 formed from a bent portion of the front surface 512 of each bracket. These shoulders 511 locate the upper edge of the pane 510 below the upper most edge 520 of the bracket. In this example, the upper edge 520 is on the rear surface of the bracket and form the rear facia upper corners.

As shown in Figure 6, a pane assembly assembly 600 has as its parts, the two brackets 500, 501 and the pane 504. At this point in the assembly, the pane 504 is still capable of sliding along the length of the brackets 500, 501. The assembly 600 is pressed into and thereby engaged with the frame 601. The upper horizontal edge of the pane 510 fits under the upper margin of the rear surface 603 that is integral with the frame 601. A thin edge 610 of the outer rim 611 of the frame is rolled or folded inward to both reinforce or stiffen this internal edge and allow the edge to engage with the clips 403.

As shown in Figures 7(a) and 7(b), upon insertion of the pane sub-assembly into the frame, the vertical inner edge 700 of the front surface or facia of the frame is internally supported by the bumper 430. Similarly, the bent or folded portion 610 of the outer edge engages the edge clips 403 formed in each bracket. The brackets 510, 511 also support the frame 800 from within as shown in Figure 8. As suggested by Figures 4 and 8, tabs or posts 450 can be bent away from the flat surfaces of the brackets. A tip 801 of each tab or fin 450 supports vertical portions of the frame in this example.

As shown in Figure 9, the pane 504 is in a lower assembly position. In this position, a horizontal gap 901 is formed between the upper edge 902 of the pane 504 and a lower edge 903 of the rear surface upper margin. Fasteners 904 can be inserted through the gap 901, through the openings 406 (see Figure 4) and into receiving openings 343 formed in the handle or the particular end fixtures or brackets 344 that make up the handle or handle assembly 905. In Figure 10, the handle assembly 905 is shown as fully installed on to a front surface of the frame. The gap 901 is still present.

At this point of the assembly process, the pane 504 is repositioned by sliding it toward and eventually under the inner edge 1100 as shown in Figure 11. The limit of movement is defined by the shoulders 511 (see Figure 5). When the pane 504 reaches an upper extent of its movement, the lower bracket 304 can be inserted below the lower edge 1101 of the pane. The lower edge 305 of the bracket 304 is positioned below the bracket foot 421. It is retained by fasteners 308 that pass through the frame's lower edge surface 307. When the lower bracket 304 is installed, its upper horizontal edge 1103 conceals the lower edge 1101 of the pane 504. In preferred embodiments, fasteners from this same array of fasteners 1105 are also used to attach to and secure the opening 422 in the leg 421 of each bracket. In the example of Figure 11, the lower bracket 304 has upright ends 1106, 1107 that support hinge components 1108. Either or both of the upper edges of the ends 1106 or hinge components may be used to conveniently support the lower edge 1101 once the lower bracket 304 is installed.

As shown in Figure 12, the lower edge of the pane 1101 is supported and maintained in the upper position by the upper edge of each end 1106, 1107 of the lower bracket. Figure 12 also illustrates that the array of fasteners 308 (1105) are the only fasteners required to complete the assembly of the oven door other than those used to optionally secure the handle. Further, the head of the fasteners 308 are flush with respect to a lower surface 1201 of the frame 300 owing to a recess or step 1202 formed in the sheet metal of the lower surface.

As shown in Figures 13 and 14, the horizontal portion 1301 of a bracket's foot 421 has a opening 422 (for example a threaded opening) for receiving a door assembly fastener 308. The lower bracket 304 is thus located between the horizontal part of the foot and the lower edge or step 1201, 1202 of the frame 300. The fasteners are clearly visible along the lower edge, making assembly and disassembly of the door easier. Figure 14 also illustrates the protrusion of the magnets or magnetic cups 413 above or beyond the rear surface 1401 of the oven door.

An interior or cooking cavity 1500 of a convection oven is depicted in Figure 15. In this example, upper and lower transverse heating elements 1501 extend between the left interior wall (not shown) and the right interior wall 1502 of the oven cavity 1500. In this example there are four upper elements 1503 and two lower elements 1504. In this example, the right interior side wall 502 has a centrally located inlet duct 1505. The duct has a grating 1506 and is surrounded by a tapered or funnel-like inlet manifold 1507 on its cavity facing side. In this example, the features of the side wall including the manifold 1507 and the horizontal indentations 1508 that form guide rails for the oven's racks, are pressed into a sheet of metal. The wall 1502 also includes two arc shaped discharged vents 1510, 1511 that are located in an array formed preferably about a common or near common diameter relative to the centre of the impeller. As will be explained, air is forced through the discharge vents 1510, 1511 in a way that promotes an essentially helical air flow pattern. The pattern tends to expel air away from the wall 1502 and toward and around the heating elements 501. The flow thereafter is drawn toward an axial flow core 1520. The flow core 1520 moves toward the inlet manifold 1507 and is drawn past the grating 1506.

The aforementioned and related airflow patterns are produced in accordance with the assembly suggested in Figure 16. A radial impeller 1600 is contained for rotation within an enclosure. The enclosure has an optional flat front surface 1601 in which are formed an intake opening 1602 and a vent array comprising two sub- arrays being the two exit openings 1603, 1604 that align with the discharge vents 1510, 1511 in the oven's side wall. The intake and vent openings are described as single openings, but it will be understood that a vent or opening may be subdivided into smaller openings and vents 1630, 1640. The intake opening 1602 aligns with and cooperates with the grill 1506. In this example, a rear surface 1610 of the impeller's enclosure supports internal airflow guide fins 1611, 1612 that direct air toward the exit openings 1603, 1604. The rear of the enclosure 1610 maybe formed as a dome. A central opening 1620 in the rear surface 1610 accommodates the output shaft 1621 of an electric motor 1622. The other end of the motor's shaft drives a motor cooling impeller 1623. The convection impeller assembly depicted in Figure 16 is also suggested by the schematic cross section of Figure 17. In this Figure, the interior surface of the front of the impeller's enclosure 1601 is shown as installed behind the intake grating 1506. The exit openings are in alignment with the discharge openings in the wall 1502. Air flow is established by the impeller 1600 and is directed by the stationary fms 1611, 1612 toward the oven cavity via the exit openings 1603, 1604. The back of the impeller enclosure 1801 is shown as having a circular rim 1802 and a dome-like shape 1803. It provides convenient surface for openings through when the attachment tabs 1804 of the ribs maybe affixed.

As shown in Figure 19, the exit openings 1603, 1604 maybe supplemented by additional exit openings 1901, 1902. These four exit openings align with the four discharge vents 1510, 1511, 1903, 1904. Relative to the impeller's orientation depicted in Figure 19, the impeller can be seen to be rotating anti-clockwise, providing an anti-clockwise airflow through the various openings 1603, 1604, 1901, 1902. Internal fms 1611, 1612 maybe provided in this arrangement. Accordingly, the lower most opening and vent 1604, 1510 terminates adjacent to the closest and outermost of the lower heating elements 1920. The lower elements and lower vent and exit openings 1604, 1902, 1510, 1903 are optional in some ovens. In this example the element 1920 is the lower front element. The upper most opening and vent 1603, 1511 terminates adjacent to the closest of the upper heating elements, being the upper rear-most. In this way, air discharged from the vents is directed by the helical flow pattern of the discharge toward and past the heating elements. Each of the primary or proximal opening and vent pairs 1604, 1510 and 1603, 1511, maybe provided with secondary opening and vent pairs, being 1901, 1904 and 1902, 1903. In some embodiments, the fins 1611, 1612 are not required when the secondary openings and vents are present. In these examples, the aforementioned openings and vents are accurate, approximately equal in size and are located around a common diameter with reference to the centre line of the rotating impeller. The absence of vent openings or exit openings and vents defines two (2) dead zones on each of the front surface 1601 and interior wall 1905. The dead zones are identifiable by an absence of substantial, meaningful perforation or ventilation in these areas of the cover 1910, 1911 and the interior wall 1912, 1913.

As shown in Figure 20, the relationship between the impeller, the vents and the heating elements in a convection oven is illustrated. In this example, the view is as if from the internal cooking cavity of the oven, looking toward the left side interior wall 2000. The oven door opening would be on the left hand side 2001. The oven has preferably three or four top heating elements 2002 and two (or more) lower heating elements 2003. The impeller 2004 is shown as visible although it is positioned behind both the wall 2000 and the front surface 1601 of the impeller's enclosure (the surface 1601 being optional and not shown). It will be understood that the discharge openings 2005 are in this example, generally equally sized and aligned with like openings in the front surface of the enclosure. In this example, the impeller rotates anti-clockwise 2006 from behind the impeller or clockwise when viewed from the oven's cavity.

The interior wall 2000 in the area in front of the impeller's enclosure front surface 2007 can be thought of as a circle 2008 that is subdivided into four quadrants. The quadrants are defined by a vertical line 2009 that passes through the centre of the fan's impeller and a horizontal line 2010 that also passes through the impeller's rotational centre. The quadrants can be seen as horizontal and vertical subdivisions defining a clock face with the nominal twelve o'clock position at the vertical maximum height 2011 of the circle 2008. The six o'clock position is located at the vertical minimum 2012 of the circle 2008. The three o'clock position 2013 and the nine o'clock position 2014 are located on the horizontal reference line that passes through the centre of the impeller 2010.

As suggested by Figure 20, the upper primary vent 2015 is located entirely in the first quadrant (between the twelve o'clock and three o'clock positions) when the impeller rotates in a clockwise direction when seen from the oven cavity. It is generally centred between the twelve o'clock and the three o'clock position. More particularly, it extends between the one o'clock position and about the two thirty position. In some embodiments, the primary upper vent 2015 is located below the two rear upper heating elements 2016, 2017. The upper primary vent 2015 is arch shaped and lays on a diameter that is smaller than the aforementioned circle 2008. In this example, the upper primary vent 2015 is provided with a secondary vent 2018. The secondary vent 2018 lays partially in the first quadrant and partially in the second quadrant (between the three o'clock and the six o'clock positions). The secondary vent extends from approximately the two thirty position to the four o'clock position. The arrangement of vents ensures air expelled from the aforementioned primary and secondary vents 2015, 2018 travels generally upward 2019 toward the upper heating elements. The helical movement of the air discharged from the vents carries the flow across the upper heating elements towards the front of the oven 2001 where it is thereby directed in a downward direction 2021 toward the lower heating elements. This orientation of the primary and optional secondary vents is repeated in a diametrically opposite array with respect to the primary and secondary lower vents 2020 and 2021. The primary lower vent 2020 is located entirely within and preferably centred in the third quadrant (between the six o'clock and the nine o'clock positions). The secondary vent 2021 is located partially within the third quadrant and partially within the fourth quadrant (between the nine o'clock and the twelve o'clock positions). It will be appreciated that a single elongated vent, or that three (3) or more vents can be provide in lieu of the separate primary and secondary vents 2015, 2018 or 2020, 2021.

Importantly, there are no substantial or meaningful vent openings in the area between the upper end 2030 of the upper primary vent 2015 and the upper end 2031 of the lower or left hand side secondary vent 2021. This dead zone 2032 and its diametrically opposed companion dead zone 2033 are important in maintaining optimized characteristics of the airflow being discharged through the vents and ultimately towards the various heating elements. It will be understood that relatively small openings can be provided in the dead zone 2034 without compromising the optimization of the aforementioned flows.

The aforementioned arrangement of primary and secondary vents has been found to provide a generally helical flow which is optimised for delivering air vent's discharge toward and across the heating elements wherein the air is heated before the air impinges on food being cooked in the oven cavity.

Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

As used herein, unless otherwise specified, the use of the ordinal adjectives "first", "second", "third", etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

Reference throughout this specification to "one embodiment" or "an embodiment" or "example" means that a particular feature, structure or

characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example, but may.

Furthermore, the particular features, structures or characteristics maybe combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

Similarly it should be appreciated that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Any claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention.

Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications maybe made thereto without departing from the scope of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention. While the present invention has been disclosed with reference to particular details of construction, these should be understood as having been provided by way of example and not as limitations to the scope of the invention.

Claims

What is claimed is:

1. An oven having a cavity and a sidewall behind which is located an impeller having a direction of rotation, the sidewall having formed in it a centrally located inlet duct that cooperates with the impeller, the sidewall having an array of discharge vents, the oven having upper and lower heating elements between which are located the discharge vents, wherein:

the sidewall is divided into four quadrants corresponding to horizontal and vertical divisions relative to a centre of the impeller that define a clock face having twelve three six and nine o'clock positions;

with respect of an impeller rotating anti-clockwise when seen from the cavity, a first quadrant defined as being located between the twelve and three o'clock positions, a second quadrant defined as being between the three and six o'clock position, a third quadrant defined as being between the six and nine o'clock positions and a fourth quadrant being between the nine and twelve o'clock positions;

the sidewall having formed in it only a first discharge vent located in the first quadrant and a second discharge vent located in the third quadrant;

2. The oven of claim l, wherein:

a third discharge vent is located partially in the first and partially in the second quadrant and a fourth discharge vent is located partially in the third and partially in the fourth quadrant.

3. The oven of claim 1, wherein:

more than one vent extends between a one o'clock position and a four o'clock position and more than one vent extends in diametrically opposite array and vents are not located in any other position.

4. The oven of any one of claims 1-3, wherein:

there are four upper heating elements and two lower heating elements.

5. The oven of any one of claims 1-3, wherein:

the duct is surrounded by a tapered manifold on a cavity facing side.

6. The oven of any one of claims 1-3, wherein: the impeller is located in an enclosure having a demo-like back.

7. The oven of any one of claim 6, wherein:

the enclosure has openings that are in alignment with each discharge vent.

8. The oven of any one of claims 1-3, wherein:

the impeller is a radial impeller.

An oven having a door, wherein:

the door has pillowed stainless steel facia and an interior surface that ominately glass.