JP7723444B2 - Roaster - Google Patents

Description

The present invention relates to a heater unit equipped with a sheathed heater, a reflector, and a roaster equipped with both a heater unit and a reflector.

Gas burners are typically used as the heat source for cooking food. However, in high-rise buildings, for example, cookers that use electricity as an energy source may be preferred from the perspective of disaster prevention.

A cooking appliance that uses an electric heater as a heat source is disclosed, for example, in Patent Document 1. The most common electric heater used in cooking appliances is a resistance heater, which generates heat by passing an electric current through a resistor. In particular, as disclosed in Patent Document 1, sheathed heaters, in which the heat-generating portion is covered by a metal tubular member, are preferably used for roasters that cook ingredients by grilling them. Sheathed heaters are known for their low risk of electrical leakage and electric shock.

The inventors also invented a cooking device using a cartridge-type heater, which they disclosed in Patent Document 2.

Japanese Patent Application Publication No. 9-178193 Japanese Patent Application Laid-Open No. 2021-110509

Sheathed heaters can more easily maintain a constant temperature than gas burners. Therefore, there is a demand for heater units that can heat the heating surface for cooking more evenly.

Furthermore, heaters used in roasters, which cook food by grilling it on a grill, become soiled by oil dripping from the food and therefore need to be cleaned regularly. To clean the heater efficiently, it is preferable that the heater unit containing the heater can be easily attached and detached from the main body of the roaster. Meanwhile, roasters to which heaters are attached also need to be cleaned regularly. Therefore, there is a demand for heater units and roasters with structures that make cleaning easier.

The present invention aims to provide a heater unit that can heat a cooking appliance evenly and is easy to clean. It also aims to provide a reflector that can efficiently utilize the heat from the heater unit. It also aims to provide a roaster equipped with the heater unit and reflector.

The present invention provides the following aspects.
(Item 1)
a sheathed heater having a plurality of straight line portions parallel to each other and a semicircular portion connecting two of the plurality of straight line portions;
terminal portions connected to both ends of the sheath heater;
a heater casing that surrounds both ends and terminal portions of the sheathed heater;
A heater unit comprising:

(Item 2)
2. The heater unit according to item 1, wherein the sheathed heater is formed in a flat shape.

(Item 3)
3. The heater unit according to item 1 or 2, wherein the cross-sectional shape of the sheathed heater is circular.

(Item 4)
3. The heater unit according to item 1 or 2, wherein the cross-sectional shape of the sheathed heater is different between the straight portion and the curved portion.

(Item 5)
The cross-sectional shape of the sheathed heater is
The linear portion is circular,
5. The heater unit according to item 4, wherein the curved portion has a shape that is similar to a Reuleaux triangle.

(Item 6)
The heater casing has a rectangular parallelepiped shape,
an opening for inserting both ends of the sheathed heater into one of the side walls of the heater casing;
2. The heater unit according to claim 1, wherein a fireproof plate is disposed in contact with the side wall portion in which the opening is provided.

(Item 7)
7. The heater unit according to item 6, wherein the fireproof board is formed of a pulp-mixed gypsum board.

(Item 8)
2. The heater unit according to item 1, which is grounded.

(Item 9)
It has a ground terminal,
Item 9. The heater unit according to item 8, wherein the ground terminal extends outwardly longer than the terminal portions connected to both ends of the sheathed heater.

(Item 10)
A roaster reflector disposed below the sheath heater,
A reflector for a roaster, characterized in that peaks and valleys are formed alternately.

(Item 11)
The sheath heater of the peak portion has a notch at a position opposite to the tip of the semicircular portion,
Item 11. A reflector for a roaster according to item 10, characterized in that the valley portion is formed to extend under the straight portion of the sheathed heater, there are bridge portions at both ends of the valley portion or in the vicinity of both ends, and there are holes between the both ends or in the vicinity of both ends.

(Item 12)
A heater unit according to any one of items 1 to 9,
Item 12. A roaster reflector according to item 10 or 11,
A roaster characterized by comprising:

The heater unit further includes a heater cover that covers at least a portion of the heater casing and the upper portion of the sheathed heater,
The heater cover is characterized by having a rib that abuts against a side surface of the heater casing.
Item 13. The roaster according to item 12.

The heater casing further includes a spring for pressing the heater casing.
Item 13. The roaster according to item 12, wherein the spring is grounded.

The sheathed heater included in the heater unit of the present invention has a shape that includes multiple straight sections that are parallel to each other and a semicircular section that connects two of the multiple straight sections, allowing a single sheathed heater to uniformly heat a wide area.

The overall length of the heater unit of the present invention can be adjusted by increasing or decreasing the number of straight and semicircular sections of the sheathed heater. Increasing the overall length of the sheathed heater reduces the number of heater units required for heating. Reducing the number of heater units reduces the work required to remove the heater units from the roaster, and the reduced number of heater unit mounting locations reduces the effort required for cleaning.

By placing the reflector of the present invention close to the sheathed heater, it is possible to reflect the heat from the sheathed heater and achieve efficient heating.

FIG. 2 is a front view of the heater unit according to the embodiment. FIG. 2 is a plan view of the heater unit according to the embodiment. FIG. 2 is a left side view of the heater unit according to the embodiment. FIG. 2 is a right side view of the heater unit according to the embodiment. 1C is a cross-sectional view taken along line AA in FIG. 1B. 1B is a cross-sectional view taken along line BB of FIG. 1C is a cross-sectional view taken along line CC in FIG. 1B. FIG. 1H(a) is a cross-sectional view of a straight portion of a sheathed heater, and FIG. 1H(b) is a cross-sectional view of a semicircular portion of the sheathed heater. FIG. 2 is a perspective view of a heater unit. FIG. 2 is a perspective view of the heater unit with the upper part of the heater casing removed. FIG. 10 is a perspective view of a heater unit according to a modified example. FIG. 10 is a perspective view of a heater unit according to a modified example. FIG. 2 is a perspective view of a reflector according to the embodiment. FIG. 10 is a perspective view of a reflector according to a modified example. FIG. 1 is a perspective view of a roaster installed on a table. FIG. FIG. FIG. 1 is a perspective view of the inside of a roaster with a heater unit attached. FIG. 10 is a perspective view of a modified heater unit with the upper part of the heater casing removed. FIG. 10 is an assembled perspective view of a connector unit to which a heater unit according to a modified example is connected. FIG. 10 is a partially enlarged view of a roaster equipped with a spring that connects the outer casing and the heater unit. FIG. 10 is a perspective view of a heater cover according to a modified example. FIG. 10 is an exploded perspective view of the inside of a roaster according to a modified example. FIG. 10 is a cross-sectional view of a roaster equipped with a heater cover according to a modified example.

The configuration of the heater unit 1, reflector 2, and roaster 100 according to this embodiment will be described below with reference to the drawings. The following embodiment is an example of the present invention and is not intended to limit the present invention.

In the following explanation, descriptions of relative positions and directions such as "up and down," "left and right," and "vertical and horizontal" correspond to the positions and directions on the drawings used in the explanation. For clarity, hatching may be omitted in cross-sectional views.

[Heater unit]

The most preferred embodiment of the heater unit 1 will be described in detail. Figure 1A is a front view of the heater unit of the embodiment. Figure 1B is a plan view of the heater unit of the embodiment. Figure 1C is a left side view of the heater unit of the embodiment. Figure 1D is a right side view of the heater unit of the embodiment. Figure 1E is a cross-sectional view taken along line A-A in Figure 1B. Figure 1F is a cross-sectional view taken along line B-B in Figure 1B. Figure 1G is a cross-sectional view taken along line C-C in Figure 1B. Figure 1H(a) is a cross-sectional view of a linear portion of a sheathed heater, and Figure 1H(b) is a cross-sectional view of a semicircular portion of a sheathed heater. Figure 1I is a perspective view of the heater unit. The right side view and left side view of the heater unit 1 have the same shape. The heater unit 1 has a symmetrical shape. The top and bottom views of the heater unit 1 are the same as those in the plan view shown in Figure 1B.

The heater unit 1 includes a sheathed heater 11, a terminal portion 12, and a heater casing 13. The heater unit 1 of the present invention is suitable for use in cooking appliances. In particular, it is suitable for use in roasters for grilling food on a grill.

As shown in Figure 1H, the sheathed heater 11 has a structure in which a linear heating element 112 and insulating material 113 are arranged inside a metal tubular member 111. The insulating material 113 can be a known heat-resistant material such as powdered MgO (magnesium oxide) or powdered BN (boron nitrite). The sheathed heater 11 of this embodiment uses a coiled nichrome wire as the heating element 112.

The shape of the sheathed heater 11 will now be described. As shown in Figure 1B, the sheathed heater 11 is a single, continuous heater with a zigzag pattern formed by alternating multiple parallel straight line segments and semicircular segments. In this embodiment, four parallel straight line segments 11a, 11b, 11c, and 11d and three semicircular segments 11e, 11f, and 11g are alternately formed. In other words, one end of two adjacent straight line segments 11a and 11b is connected by semicircular segment 11e to form a U-shape, one end of two adjacent straight line segments 11c and 11d is connected by semicircular segment 11g to form a U-shape, and the other end of straight line segments 11b and 11c is connected to semicircular segment 11f.

As shown in Figures 1A to 1G, the sheathed heater 11 is formed in a planar shape. The heating element 112 inside the sheathed heater 11 exists on approximately the same plane.

In this embodiment, the cross-sectional shape of most of the straight portions 11a, 11b, 11c, and 11d of the sheathed heater 11 is circular, as shown in Figures 1E, 1G, and 1H(a). The heating element 112 is arranged concentrically with the tubular member 111.

On the other hand, as shown in Figures 1F, 1G, and 1H(b), semicircular portions 11e, 11f, and 11g have a shape that approximates a Reuleaux triangle. More specifically, semicircular portions 11e, 11f, and 11g have a three-sided shape with a straight base and two arc-shaped hypotenuses. Straight line portions 11a, 11b, 11c, and 11d have boundary portions near semicircular portions 11e, 11f, and 11g where the surface shape changes smoothly. In Figure 1I, for straight line portion 11a and semicircular portion 11e, the circular cross-sectional shape is indicated by R, the cross-sectional shape that approximates a Reuleaux triangle is indicated by T, and the boundary portion is indicated by S.

Generally, sheathed heaters are formed into various shapes by bending a linear heater. In the case of a sheathed heater with a circular cross-section, the outer periphery of the tubular member expands and the inner periphery compresses at locations where large bending deformation occurs, such as the semicircular portions 11e, 11f, and 11g. As a result, the density of the insulating material between the annular member and the heating element decreases on the outer periphery, potentially reducing insulation. Furthermore, during bending, the central heating element 112 may become unevenly distributed further outward, further reducing insulation. Therefore, in the sheathed heater 11 of this embodiment, the cross-sectional shape of the semicircular portions 11e, 11f, and 11g is shaped like a Reuleaux triangle, thereby reducing the cross-sectional area of the tubular member 111 compared to a circular heater, densely packing the insulating material 113 and preventing insulation degradation.

The connection between the sheathed heater 11 and the terminal portion 12 will now be described. Of the four straight portions 11a, 11b, 11c, and 11d of the sheathed heater 11, the two outer straight portions 11a and 11d are longer than the two inner straight portions 11b and 11c. The ends of the two straight portions 11a and 11d are bent so that they are close to each other. The end of the straight portion 11a is formed with an end portion 111a that connects to the terminal portion 12. The end of the straight portion 11d is formed with an end portion 111d that connects to the terminal portion 12.

Figure 2 shows a perspective view of the heater unit 1. The terminal portion 12 has terminals 12a and 12b that connect to the end portions 111a and 111d of the sheathed heater 11. In Figure 2, the top of the heater casing 13 has been removed to show the arrangement of the end portions 111a and 111d of the sheathed heater 11 housed in the heater casing 13 and the terminals 12a and 12b.

The heater casing 13 is made of a metal, typically a magnetic material such as ferritic or martensitic stainless steel, and has a rectangular parallelepiped shape with walls constituting one bottom surface, four side surfaces, and one top surface. Hereinafter, of the four side surfaces, the surface into which the terminal ends 111a and 111d of the sheathed heater 11 are inserted will be referred to as the front wall 136, the surface facing the front wall 136 will be referred to as the rear wall 132, and the two side surfaces connected approximately perpendicularly to the front wall 136 and rear wall 132 will be referred to as the side walls. The heater casing 13 may have its bottom surface, side surfaces, and top surface formed from separate members, or each surface may be formed from a combination of two or more members. It may also be constructed by assembling members including two or more walls. In this embodiment, the heater casing 13 is formed by combining a first member constituting the bottom surface and the lower halves of the four side surfaces with a second member constituting the top surface and the upper halves of the four side surfaces, but the configuration of the heater casing 13 is not limited to this.

The following describes the arrangement of the terminal ends 111a and 111d of the sheathed heater 11 relative to the heater casing 13. The terminal ends 111a and 111d of the sheathed heater 11 are inserted into the heater casing 13 through openings in the front wall 136. The fixed heater plate 131 is secured to the front wall 136 with screws, and the terminal end 111a is fixed to the fixed heater plate 131. That is, the terminal end 111a is fixed to the heater casing 13 via the fixed heater plate 131. On the other hand, the terminal end 111d is not fixed to the fixed heater plate 131, but is fixed to a free heater plate 135 located inside the heater casing 13. The terminal end 111d has some freedom of movement in the forward and backward directions within the heater casing 13, but the free heater plate 135 functions as a stopper, preventing it from coming off the heater casing 13. The configuration in which the terminal end 111d of the sheathed heater 11 is movable inside the heater casing 13 has the effect of absorbing deformation when the sheathed heater 11 heats up and expands due to heat.

An insulator is fixed to the rear wall 132 of the heater casing 13. The terminals 12a and 12b of the terminal portion 12 are fixed to the insulator, which is fixed to the rear wall 132. The ends of the terminals 12a and 12b protrude from the insulator.

If oil dripping from food ingredients or other contaminants seeps into the heater casing 13, it can cause undesirable phenomena such as fire or deterioration of the terminals. Therefore, to prevent oil and other contaminants from seeping into the heater casing 13, a fireproof board 133 is placed in contact with the front wall 136 of the heater casing 13. The fireproof board 133 is made of a gypsum board mixed with pulp.

Gaskets (sealing materials) are inserted between the components that make up the bottom, side, and top of the heater casing 13 during assembly, sealing the gaps between the walls. The gaskets are made of expanded silicone. In this embodiment, gaskets 134a and 134b are respectively placed between the first component that makes up the lower half of the side wall and the second component that makes up the upper half of the side wall. Furthermore, it is preferable that the gaps between the terminal ends 111a and 111d of the sheathed heater 11 and the front wall 136 and fire protection plate 133 are also sealed with gaskets.

Inside the heater casing 13, the end 111a of the sheathed heater 11 is connected to the terminal 12a by a lead wire 14. The end 111d of the sheathed heater 11 is also connected to the terminal 12b by a lead wire 14. When the terminal 12 is connected to a power source, power is supplied to the sheathed heater 11. The heating element 112 of the sheathed heater 11 generates heat due to the current sent from the power source.

The above is the most suitable configuration of the heater unit 1, but the heater unit 1 can be modified as needed depending on the size, heating area, and heat output of the cooking appliance to which it is applied. Below, we will explain modified examples of the sheathed heater 11.

Figure 3 shows a modified heater unit, heater unit 1A equipped with a sheathed heater 15. The cross-sectional shapes of the straight and semicircular portions of the sheathed heater 15 of heater unit 1A are all circular. The rest of the configuration is the same as that of sheathed heater 11, so a duplicated explanation will be omitted. If the insulation properties of the sheathed heater 15 are sufficiently ensured, the cross-sectional shapes of the straight and semicircular portions may be the same.

Figure 4 shows heater unit 1B, a modified heater unit, equipped with a sheathed heater 16. The cross-sectional shapes of the straight and semicircular portions of the sheathed heater 16 of heater unit 1B are all circular, and the straight portions are longer than those of the sheathed heater 11. The rest of the configuration is the same as that of the sheathed heater 11, so a repeated explanation will be omitted.

The length of the straight portion of the sheathed heater of the heater unit can be changed, as shown in heater unit 1B. It is also possible to increase the number of straight and semicircular portions to create more U-shaped shapes. In this way, by changing the shape of the sheathed heater, the heating area can be changed as needed. Even if the shape of the sheathed heater is changed, only one terminal 12 for supplying power is required, making it very easy to attach and detach from the cooking appliance.

Figure 11 shows a heater unit 1C equipped with a ground terminal as another heater unit variant. The heater unit 1C comprises a sheathed heater 16, a terminal section 12' including a ground terminal 12c, and a heater casing 18. In Figure 11, the top of the heater casing 18 has been removed to show the arrangement of the terminal section 12'. The terminal section 12' of the heater unit 1C comprises a total of three terminals: terminals 12a and 12b connected to the end portions 111a and 111d of the sheathed heater 11, and a ground terminal 12c that is grounded. When used in a cooking appliance, the ground terminal 12c is connected to a grounded wiring.

The ground terminal 12c is fixed to the heater casing 18 with a fixing bracket, and the ground terminal 12c and heater casing 18 are electrically connected. The terminal end 111a of the sheathed heater 11 is fixed to a metal fixed heater plate 131, which is fixed to the heater casing 18 with screws, so the sheathed heater 11 is electrically connected to the heater casing 18. When the ground terminal 12c is connected to grounded wiring, the heater casing 18 and the sheathed portion of the sheathed heater 11 are grounded.

As shown in FIG. 11 , the ground terminal 12c is longer than the terminals 12a and 12b, and protrudes longer from the rear wall of the heater casing 18 than the terminals 12a and 12b. Because the ground terminal 12c is longer than the terminals 12a and 12b, when the heater unit 1C is attached to the cooking appliance, the heater casing 18 is grounded before the terminals 12a and 12b are connected to the electrical wiring. Similarly, when the heater unit 1C is removed from the cooking appliance, the heater casing 18 remains grounded even after the terminals 12a and 12b are disconnected from the electrical wiring. As a result, the heater casing 18 remains grounded from the time the heater unit 1C is attached to the cooking appliance until it is removed. This structure of the ground terminal 12c eliminates the risk of electric shock in the event of incorrect operation or deterioration of the sheathed heater's insulating function due to aging.

[Reflector]

Referring to Figure 5, the most suitable embodiment of the reflector 2 will be described. The reflector 2 of this embodiment is used in conjunction with the heater unit 1 to reflect heat radiated from the sheathed heater 11 toward the food. The reflector 2 is made of a metal such as stainless steel.

The reflector 2 has a shape in which peaks 21 and valleys 22 are formed alternately. The valleys 22 are formed by two inclined surfaces that approach each other as they extend downward. Heat radiated downward from the sheathed heater 11 is mainly reflected toward the food by the inclined surfaces formed between the peaks 21 and valleys 22. The peaks 21 are located between the valleys 22, and have flat surfaces at their tops.

When in use, the reflector 2 is positioned below the heater unit 1. Therefore, the shape of the reflector 2 corresponds to the shape of the sheathed heater 11 of the heater unit 1. The spacing between the valleys 22 of the reflector 2 is approximately the same as the spacing between the straight sections 11a, 11b, 11c, and 11d of the sheathed heater 11. When in use, the valleys 22 extend below the straight sections 11a, 11b, 11c, and 11d of the sheathed heater 11. The flat surfaces of the peaks 21 contact the undersides of the tips of the semicircular sections 11e, 11f, and 11g of the sheathed heater 11, supporting the sheathed heater 11.

A hole 23 is preferably provided at the bottom of the valley portion 22. Bridge portions 24 are provided at or near both ends of the valley portion 22, and both ends of the hole 23 are closed by the bridge portions 24. The hole 23 allows oil and other debris that drips from ingredients during cooking to pass through. The end of the bridge portion 24 has a slope 25 that slopes downward, allowing dirt that falls onto the reflector plate 2 to fall as far down as possible.

The reflector 2 allows most of the heat from the sheathed heater 11 to radiate upward, enabling efficient cooking. The reflector 2 has a shape with alternating peaks 21 and valleys 22, and the sloping surfaces of the valleys 22 allow the heat from the sheathed heater 11 to radiate evenly upward. Furthermore, as mentioned above, the valleys 22 extend below the straight portions 11a, 11b, 11c, and 11d of the sheathed heater 11, so the sloping surfaces formed between the peaks 21 and valleys 22 can be brought into close proximity to the straight portions 11a, 11b, 11c, and 11d of the sheathed heater 11, allowing the reflector 2 to efficiently reflect the heat from the sheathed heater 11 toward the food.

The above is the most suitable embodiment of the reflector 2 to be used with the heater unit 1. The reflector can be modified as needed depending on the shape of the heater unit it is used with. Figure 6 below shows a modified reflector 2A, and its configuration will be explained.

Like reflector 2, reflector 2A has a shape in which peaks 21 and valleys 22 are alternately formed. The difference from reflector 2 is the shape of the peaks 21. The peaks 21 of reflector 2A have cutouts 26a, 26b, and 26c at positions opposite the tips of the semicircular portions of the sheathed heater.

When in use, the semicircular portion of the sheathed heater used with reflector 2A can fit into notches 26a, 26b, and 26c. The sheathed heater is used with reflector 2A in closer proximity than when using reflector 2. Reflector 2A can reflect the heat from the sheathed heater more efficiently.

Although not required, reflector 2A can be additionally provided with notches 26a', 26b', and 26c'. Notches 26a' and 26a can be formed so that they are the same distance from the edge of reflector 2A. Similarly, notches 26b' and 26b can be formed so that they are the same distance from the edge of reflector 2A. Notches 26c' and 26c' can be formed so that they are the same distance from the edge of reflector 2A. By providing additional notches 26a', 26b', and 26c', reflector 2A can be positioned even when rotated 180 degrees relative to the sheathed heater, allowing users to install it without having to consider the direction during installation.

The modified reflector plate 2A is particularly suitable for use when there is no need to support the semicircular portion of the sheathed heater, for example, when combined with a small sheathed heater.

[Roaster]

With reference to Figures 7 to 10, the most preferred embodiment of a roaster 100 equipped with a heater unit 1 and a reflector 2 will be described. Figure 7 is a perspective view of the roaster 100 installed on a table T. The roaster in this embodiment refers to a cooking appliance that grills and cooks various ingredients such as meat, fish, and vegetables on a grill 7.

Figure 8 is an assembled perspective view of the roaster 100. Figure 9 is an exploded perspective view of the roaster 100. Figure 10 is an enlarged partial view of the inside of the roaster 100 with the heater unit 1 and reflector 2 attached. As shown in Figures 8 to 10, the roaster of this embodiment has a rectangular heating area.

As shown in FIG. 9, the roaster 100 of this embodiment includes an outer casing 40, a filter 20, an inner casing 30, a reflector 2, a heater unit 1, a grill 7, a top cover 8, a top plate 9, and a control unit (not shown).

The outer casing 40 is housed in the space within the table T. The filter 20 and inner casing 30 are housed within the outer casing 40. The heater unit 1 is removably fixed within the inner casing 30. The reflector 2 is disposed within the inner casing 30. The top cover 8 and top plate 9 are disposed on top of the outer casing 40. The connector unit 5 and control unit, which are electrically connected to the terminal portion 12 of the heater unit 1, are fixed to the outside of the outer casing 40.

The outer casing 40 has a rectangular bottom wall 41 and four side walls 42A to 42D. An opening that penetrates the bottom wall 41 is provided in the center. A filter 20 is installed in the opening. The filter 20 collects oil contained in the smoke generated when ingredients are grilled. A duct D is connected to the bottom of the outer casing 40, and the smoke generated when ingredients are grilled is exhausted from the duct D through the filter 20 by an exhaust device (not shown).

A support wall 121 and two guide walls 122 for supporting the inner casing 30 are provided on the inner surfaces of side walls 42A and 42C of the outer casing 40. The inner casing 30 has a rectangular bottom wall 31 and four side walls 32A to 32D. The inner casing 30 is placed inside the outer casing 40. When the roaster 100 is in use, water is poured into the inner casing 30. Oil and other ingredients from the ingredients flow over the inclined portion 25 of the reflector 2, pass through the holes 23, and fall into the water inside the inner casing 30, where they are collected.

A top cover 8 is attached to the top of the side walls 42A-42D of the outer casing 40. A top plate 9 is placed on top of the top cover 8. Multiple through holes 91a are formed in the side walls 91 of the top plate 9, allowing smoke generated by food being cooked to be sucked in.

An opening penetrating the side wall 42A of the outer casing 40 is provided to connect the terminal portion 12 of the heater unit 1 to the terminal of the connector unit 5. Furthermore, as shown in FIG. 9 , an opening 32a is formed in the side wall 32A of the inner casing 30 opposite the side wall 42A of the outer casing 40. When the inner casing 30 is housed within the outer casing 40, the opening of the outer casing communicates with the opening 32a of the inner casing. The connector unit 5 for connecting the heater unit 1 is fixed facing the communicating opening between the outer casing 40 and the inner casing 30.

Referring to Figure 10, the structure for placing the heater unit 1 and reflector 2 inside the inner casing 30 will be described. A bottom wall 101 and two side walls 102 are provided on the inner surface of the side wall 32A of the inner casing 30 to support the heater unit 1. The heater unit 1 can be placed on the bottom wall 101. The side walls 102 restrict horizontal movement of the heater unit 1. In addition, a step portion 321 is provided on the inner surface of the side wall 32B of the inner casing 30 and on the inner surface of the side wall 32D opposite side wall 32B. The reflector 2 is placed on this step portion 321.

The connector unit 5 has a pair of terminals into which the terminals 12a, 12b of the heater unit 1 can be inserted. The connector unit 5 also has multiple permanent magnets inside its casing.

When the connector unit 5 is attached to the outer casing 40, a pair of terminals of the connector unit are exposed inside the outer casing 40 and the inner casing 30 through the openings in the outer casing 40 and the openings 32a in the inner casing 30. The heater unit 1 is connected to the connector unit 5 by inserting the terminal portion 12 of the heater unit 1 into the terminal of the connector unit 5 and adhering the heater casing 13 to the permanent magnet of the connector unit 5. When the heater casing 13 is placed on the bottom wall 101, the heater unit 1 is in a horizontal position.

To make the connection between the heater unit 1 and the connector unit 5 stronger, in addition to the connection using a permanent magnet, it is possible to add known means such as providing a clasp or applying pressure using an elastic member.

The roaster 100 of this embodiment is equipped with a single heater unit 1 as a heating means. The heater unit 1 is detachably connected to the connector unit 5, allowing the heater unit 1 to be removed from the roaster 100 for easy cleaning.

Figure 12 shows a modified connector unit that is suitable for use when attaching a heater unit 1C equipped with a ground terminal 12c to a roaster. Figure 12 is a perspective view of a connector unit 5A equipped with a ground terminal 51c. The connector unit 5A is equipped with a ground terminal 51c between a pair of terminals 51a, 51b into which the terminals 12a, 12b of the heater unit 1 are inserted. The ground terminal 51c is connected to the ground wire on the power cord side via wiring (not shown) and is therefore grounded. By connecting the ground terminal 12c to the ground terminal 51c, the heater casing 18 is grounded.

Like the connector unit 5, the connector unit 5A has multiple permanent magnets 52 inside the casing. The permanent magnets 52 secure the heater casing 18, which is made of magnetic material, to the connector unit 5A.

Below, a modified roaster equipped with a structure for grounding a heater unit 1 without a ground terminal will be described with reference to the drawings. Figure 13 shows a partially enlarged view of a roaster 200 equipped with a spring 60 for grounding the heater unit 1. The spring 60 is fixed with a screw to the side wall of the connector casing 53 attached to the outer casing 40, and is positioned so that its tip points downward toward the inner casing 30. The spring 60 is made of a metal material such as SUS304 (stainless steel).

Before the heater unit 1 is inserted into the connector unit 5, the spring 60 comes into contact with the top surface of the heater casing 13 and presses against the top surface of the heater casing 13. When the spring 60, which is fixed to the connector casing 53, comes into contact with the heater casing 13, the connector casing 53 and the heater casing 13 are electrically connected. Because the connector casing 53 is electrically connected to the ground wire of the power cord (not shown), the heater casing 13 is also grounded.

When the heater unit 1 is installed in the roaster 200, the spring 60 comes into contact with the top surface of the heater casing 13 before the terminal portion 12 is connected to the terminal of the connector unit 5, thereby grounding the heater casing 13. Similarly, when the heater unit 1 is removed from the roaster 200, the heater casing 13 remains grounded even after the terminals 12a and 12b are separated from the connector unit 5. As a result, the heater casing 13 remains grounded at all times while it is installed in the roaster 200. By providing such a spring 60 in the roaster 200, the risk of electric shock is eliminated in the unlikely event of incorrect operation or a deterioration in the insulating function of the sheathed heater 11 due to aging.

Below, as a further modified example of a roaster, a roaster equipped with a heater cover that covers part of the heater unit will be described with reference to the drawings. The roaster 300 is a member that covers part of the heater casing 13, including the front wall 136, and part of the terminal ends 111a and 111d of the sheathed heater 11.

The heater cover 70 is positioned to prevent dirt from adhering to the heater unit 1 and to more securely connect the heater unit 1 to the connector unit 5. Figure 14 shows a perspective view of the heater cover 70. The heater cover 70 is composed of a wall portion that forms a cover top surface 71 with an L-shaped cross section, a pair of opposing cover side surfaces 72a, 72b, and a single cover front surface 73, and the side that contacts the heater unit 1 is open. The internal dimensions of the heater cover 70 roughly match the width and height of the heater casing 13.

A roughly rectangular cover-side rib 74 is arranged inside the heater cover 70, perpendicular to the cover front surface 73. The cover-side rib 74 is composed of identically shaped cover-side ribs 74a and 74b. The upper edges of the cover-side ribs 74a and 74b are each fixed to the cover upper surface 71. Notches are formed in the lower parts of the sides of the cover-side ribs 74a and 74b that are close to the cover front surface 73, and a space W (shown in Figure 16) is formed in a portion of the lower side between the cover-side ribs 74a and 74b and the cover front surface 73. Meanwhile, a taper T is formed at the lower part of the side of the cover-side ribs 74a and 74b that is located on the heater unit 1 side, so that the side is inclined inward. Due to the taper T, the width of the cover-side ribs 74a and 74b narrows as they go downward.

Figure 15 shows an exploded perspective view of the interior of the roaster 300 into which the heater cover 70 is installed. The bottom wall 101 of the inner casing 30 is provided with inner casing side ribs 103. The thickness of the inner casing side ribs 103 approximately matches the width of the space W between the cover front surface 73 of the heater cover 70 and the cover side ribs 74a, 74b. When the heater unit 1 is accurately installed in the roaster 300, the distance between the front wall 136 of the heater unit 1 and the inner casing side ribs 103 approximately matches the width of the cover side ribs 74a, 74b.

Figure 16 shows a cross-sectional view of the roaster 300 with the heater cover 70 attached.

The function and effect of the heater cover 70 will be explained by explaining the procedure for assembling the heater unit 1 and heater cover 70 into the roaster 300. The heater unit 1 is inserted along the bottom wall 101 of the inner casing 30 and connected to the connector unit 5. Next, the heater cover 70 is inserted from above the heater unit 1 along the front wall 136 of the heater cover 13 and pushed down. The cover-side ribs 74a, 74b are inserted between the heater unit 1 and the inner casing-side ribs 103, and the tips of the cover-side ribs 74a, 74b abut against the bottom wall 101 of the inner casing 30, completing the assembly.

Tapered edges T on the side edges of the cover-side ribs 74a, 74b allow the heater cover 70 to securely connect the heater unit 1 and connector unit 50. Even if the connection between the heater unit 1 and connector unit 5 is incomplete and there is insufficient space between the heater unit 1 and the inner casing-side rib 103, the attached tapered edges T on the cover-side ribs 74a, 74b allow the side edges of the cover-side ribs 74a, 74b to smoothly push the front wall 136 of the heater unit 1 and move it to the correct position as soon as the heater cover 70 is inserted. The heater unit 1 is pushed in by the pressure of the heater cover 70, and when it moves to a position within the magnetic force of the permanent magnet of the connector unit 50, the heater unit 1 is attracted to the permanent magnet and securely connected to the connector unit 50.

[Example]

This section describes one embodiment of the roaster 100 of the present invention.

The sheathed heater 11 has four straight sections and three semicircular sections, and is 124 mm wide, 291 mm long, and has a diameter of 10 mm for the straight sections. The cross-sectional shape of the semicircular sections, which resembles a Reuleaux triangle, has a base width of approximately 10.8 mm and a height of approximately 9.1 mm. The thickness of the tubular member 111 of the sheathed heater 11 is 0.7 mm.

Currently, the most widely used sheathed heaters have a diameter of 5 mm and a 0.5 mm thick tubular member 111. In contrast, the sheathed heater 11 of this embodiment is thicker and the tubular member 111 has a certain thickness. This configuration is particularly effective in resisting corrosion caused by meat juices and the like when applied to roasters.

Specific examples of the present invention have been described in detail above based on embodiments and examples, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. This application also provides the inventions of the following aspects.

(Aspect 1) The outer casing, inner casing, and grill are not limited to being rectangular, but may be, for example, round or elliptical. The heater unit can heat not only rectangular areas, but also circular or elliptical areas.
(Mode 2) The number of straight portions of the sheathed heater 11 can be more than four, which allows a wider area to be heated.

1, 1A, 1B, 1C Heater unit 2, 2A Reflector 5, 50 Connector unit 7 Grill 11, 15, 16 Sheathed heater 12, 12' Terminal portion 13, 18 Heater casing 30 Inner casing 40 Outer casing 53 Connector casing 60 Spring 70 Heater cover 100, 200, 300 Roaster

Claims (1)

A roaster equipped with a heater unit,
the heater unit is a heater unit disposed on a reflector,
a sheathed heater having a plurality of straight line portions parallel to each other and a semicircular portion connecting two of the plurality of straight line portions;
a pair of terminal portions each connected to an end portion of the sheathed heater;
a heater casing that surrounds both ends and terminal portions of the sheathed heater;
It is equipped with
The heater unit is characterized in that the sheath of the sheathed heater and the heater casing are electrically connected and grounded,
The heater casing further includes a spring that presses the heater casing.
The spring is grounded ,
The roaster is characterized in that the spring is disposed at a position where it presses the heater casing before the heater unit is assembled into the roaster.