GB1564972A

GB1564972A - Portable electric hot plate

Info

Publication number: GB1564972A
Application number: GB5409276A
Authority: GB
Original assignee: IMANISHI FLEXIBLE TUBE Mfg CO Ltd
Current assignee: IMANISHI FLEXIBLE TUBE Mfg CO Ltd
Priority date: 1976-05-31
Filing date: 1976-12-24
Publication date: 1980-04-16
Also published as: HK73683A; JPS52147168A

Description

(54) PORTABLE ELECTRIC HOT PLATE (71) We, IMANISHI FLEXIBLE TUBE MANUPACrURE COMPANY LIMITED, of NO.

13-22, 3chome, Higashi-Nakamoto, Higa shinari-'ku, ()saka, Japan, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularay described in and by the following statement : - This invention relates to a portable elec tic hot plate adapted for table use, whereby it becomes possible to cook meat such as bed, ,pork or chicken, vegetables, and processed foods and to bake, fry, gill or roast various foods.

A variety of electric hot plates of the type as described above are now commer- wally available. These known hot plates shave heating plates made of iron, the surfaces of which are coated with polytetrafluoroethylene resin so that the surfaces will lot soorch. The resin coating is relatively courtly, which constitutes a disadvantage of the known hot plates. They suffer from other disadvantages. Thus, for example, since they employ heating plates fixed to the hot plate structure it is sometimes impossible to remove the heating plates and watarMrash them. and since the heating plates are thin they store little heat.

According to the invention a portable electric hot plate comprises a housing; a bottom plate provided at the lower end of said housing; means for supporting a heat reflector at a distance above said bottom plate; a resistance heating element positioned above said bottom plate and arranged approximately parallel to said heat reflector a terminal housing rotatably supporting therein the ends of the heating ele ment so as to enable the element to be swung upward to give access to the heat reflector and a heating plate removably placed near the top of said housing and aver the heating element.The heating element may be metal sheathed so as to permitt, upon possible breaking of wires in the element, independent replacement of the broken element with a new one. The heating plate may be made of ceramic material which exhibits excellent heat storage capacity. More particularly, the hot plate in accordance with the present invention may include a box-shaped housing, which is formed by interconnecting the free ends of two U-shaped plates, the housing being provided, along and externally of the sides of the housing, with handles each approximately the same length as that of the sides of the housing so as to increase the mechanical strength of the housing.The heat reflecting plate may have the heating element pivotally attached thereto so that the element is rotatable to an appropriate degree about the terminal housing so as to facilitate, when the heat reflecting plate has become dirty, cleaning of the reflecting plate surface. Furthermore, the bottom plate may be provided with ribs and, at portions of the periphery of the bottom plate, with members which, when in position, are received in notches of brackets mounted on the lower edge of the housing to thereby facilitate the attachment of the bottom plate to the housing and to ensure high mechanical strength of the bottom plate-housing assembly.

A hot plate in accordance with the present invention will now be described in more detail with reference to a particular embodiment shown in the accompanying drawings in which: iFig. 1 is a iplan view of the hot plate, the heating plate having been removed; Fig. la is an enlarged vertical section of the part C in Fig. 1 or Fig. 2; Fig. 2 is a longitudinal sectional view taken along line IF--IF1 of Fig. 1; Fig. 3 is a plan view of the back of the heat reflecting plate; Fig. 4 is a sectional side elevation of the right hand half of Fig 1; Fig. 5 is a side elevation of the whole hot plate; Fig. 6 is a plan view of the housing; 'Fig. 7 is a plan view of the bottom plate;; Fig. 7a is a sectional view taken along liine A-A1 of IFig. 7; Fig. 7b is a sectional view taken along line OD1 of Fig. 7; Fig. 8 is an enlarged elevation of the part B in Fig. 6, showing a seam in the housing; Fig. 9 is a plan view of the heating plate; Fig. 10 is a perspective view of the terminal housing; Fig. 111 is a sectional view taken along line E-E1 of Fig. 9; and Pig. 12 is a plan view of the interior of the terminal housing.

In the drawings, the reference numeral 1 designates a housing. The housing is constructed from frame members 1s and ib each formed by bending a metal plate of predetermined length and width into an approximately U-shaped frame. For the purpose of facilitating assembly of the frame members, one of the frame members la is provided at both free ends with a plurality of tongue members 2 and the other ib is provided at both free ends with a plurality of slits 3 through which the tongue members 2 are inserted (Fig. 8).Thus, the housing is formed by inserting the tongue members 2 provided at the ends of the frame member la through the slits provided in the frame member ib and folding back the tongue members 2 to thereby interconnect the respective free ends of the frame members la andslb, as best shown in Figs. 6 and 8.

The upper end of the housing 1 is provided with a step portion 4, with which is engaged a flanged rim 6 formed by outwardly folding the upper rim of a heat reflecting plate 5 so as to mount the heat reflecting plate S in the housing 1, as best shown in Figs. 3 and 4.

The housing 1 is further provided at its lower end with brackets 7 formed by inwardly bending the lower portions of the housing 1, and two opposite brackets 7 are provided with notches 8a and 8b. Through the notches 8a and 8b are inserted, upon assembly, tongues 10a and lOb which are provided at two opposite edges of a bottom plate 9. After thus coming into engagement with the housing 1, the bottom plate 1 is secured through the brackets 7 to the hous ingi by means of screws or rivets. The bottom plate 9 is further provided with ribs 1.1 of suitable width and depth which are arranged radially with the projecting portions directed downward (see Fig. 7 and 7b).

By such provision of the ribs 11, it becomes possible to prevent the planar bottom plate 9 from being deformed or warped and thereby to ensure the mechanical rigidity of the assembly, even when the plate 9 is composed of la thin plate. The ribs 1,1 are bored at appropriate places with openings 12 through which are inserted screws or rivets ,15 into threaded holes 14 provided at the lower ends of supporting members 13, the 'upper ends of which are secured to the under surface of the bottom of the heat reflector 5.In this way the supporting member 13 is fastened with respect to the bottom plate to thereby assemble the heat reflecting plate 5, the housing 1 and the bottom plate 9, as best shown in Figs. 2, 3 and A In Figs. 1, 2, and 5, the reference numeral 16 designates handles made up of heat resisting synthetic resin material. The handles 16 are of a length approximately equal to that of one side of the housing 1, and are secured by means of screws 17 to the exterior surface of the right and left hand sides, shown in Fig. 1, of the housing 1, so that the centres of the handles 16 rest on the junction between ;the frame members la and lb constituting the housing 1.The mounting of the handles 16 is for the purpose of reinforcing the mechanical strength of the frame members la and Ib, especially the junction area thereof, and thereby preventing the deformation of the housing 1.

In Figs. 1, 2 and 4, the reference numeral 18 designates a metal sheathed resistance heating element running in a serpentine or zigzag manner, and the reference numeral 19 designates a supporting frame member for the sheathed element 18. The supporting frame member 19 serves to prevent relative movement of the element 1-8, in the event that the sheathed element 18 undergoes external force tending to make it move.

The rectangular supporting frame member 19 is provided with notches 19Q into which the sheathed element 18 is fitted, Thus, in mounting the sheathed element 18, the element 18 is fitted into the notches 19a, and both sides of the notches 19a are, as best shown in Fig. la, bent inwardly to engage the sheathed element 18 and prevent it slipping out of the notches 19a, reference num tiber 21 showing notches resulting from such bending. In this way, the sheathed element 118 supported on the frame member 19 is restrained to lie in a serpentine manner with the parallel portions being spaced apart from one another at a given distance. The reference numeral 20 designates supporting members for the supportng frame member 19 which may be S-shaped as best shown in Fig. 2. By the supporting members 20, the sheathed element 18 is kept parallel to and at a given distance above the bottom surface of the heat re flecting plate 5. The sheathed element 18 is provided at its ends with terminals 22a and 22b. The ends extend through holes pro -vided in insulators 24a and 24b which are fitted in the opposite sides of a terminal housing 23 mounted on the side wall of the heat reflector 5, as shown in Fig. 1. In the terminal housing 23, the terminals are so wired as to permit electric connection with a power source, a temperature controller and the like.

The above described terminal housing 23 is constructed as shown in Figs. 10 and 12 and is made up of suitable material which may be in the form of a die casting. The terminal housing 23 is provided, in both of the side walls, with openings to receive insulators 27. The inner walls of the openings are provided with opposed slots 25a and 25b, and the insulators 27 have holes 2i5a to insert the sheathed heating element therethrough and are provided with ridges 28. After the ridges 28 have been inserted and fitted into the slots 25a and 25b, the terminal housing 23 is attached to the heat reflector 5 in such manner that the space 29 within the housing 23 comes above a window portion 29a provided in the heat reflector 5.With such construction, both terminals 30 and 30b of the sheathed element 18 introduced into the space 29 within the terminal housing 23 can Ibe wired, internally of the housing 23, so as to permit electric connection with Q power source and a temperature -controller. As shown in Fig.

12, the terminal housing 23 is provided with a plurality of threaded holes 31 to secure the housing 23 to the heat reflector 5 by means of screws.

At appropriate positions in the interior of the housing 1 are provided, as shown in Fig.

1, a socket 33 for receiving an attachment plug to effect electric connection with a power source, and an automatic temperature controller or heat sensor 34 to keep the temperature of the heating element 13 at a predetermined level, the sensor being located between the reflector 5 and the bottom plate 9. For the purpose of facilitating the adjustment of the automatic temperature controller 34 to control the electric circuit for the sheathed element 18, the controller 34 is provided with an operating shaft extending outwardly of the housing 1 and having a kndb 36 at its free end.

In Figs. 5, 9 and 111, the reference numeral 37 designates a heating plate made up of ceramic material, the upper surface of which is provided with a recess 33 of appropriate depth. The heating plate 37 is provided with integral outwardly project- ing handles 39 at opposite sides. Further more, the undersurface of the heating plate is provided with guide walls 40 and re informing ribs 41 each of appropriate width and height. The guide walls 40 are, when in position, in engagement with the inner periphery of the edges of the heat reflector 5 mounted in the housing 1 and near the top thereof. With such construction, the heating plate 37 can be firmly set in position on the housing 1.

In Fig. 5, the reference numeral 42 designates a lid which is used to cover the heating plate and the reference numeral 43 designates a knob attached to the lid 42 to facilitate lifting thereof. Furthermore, the housing 1 is provided, in its outer periphery, with louvres 44 in order to protect the housing 1 against overheating.

As shown in Fig. 4, the sheathed element 18 is rotatable in clockwise direction to an angle 0 about the central axis of the terminals 30a andi 30b (Fig. 12), so that, in the event that the surface of the heat reflector 5 should become dirty, it can he wiped while lifting the sheathed element 18.

In the above described embodiment of the hot plate of the present invention a thermostat 34 is installed in the housing 1. The thermostat 34 permits, by way of rotation of the knob 36 provided externally of the housing 1, switching of the heating circuit in three stages, OFF, LOW and HIGH.

As a consequence, by setting the thermostat 34 in the LOW or HIGH position, it is possible to control the surface temper- ature of the heating plate within a range d from 180 to 2000C.

In this way, the heating plate (ceramic plate) can be kept at any desired temperature, it thus being possible to heat as desired different kinds of vegetables such as onions, potatoes, Ipaprikas or carrots or meat such as beef, pork or chicken.

As will be seen from the foregoing, even if juice or fat from different kinds of meat or vegetables being cooked with the hot plate of the invention should soil the inner surface of the heat reflector below the heating element 18, the soiled surface can be cleaned quite easily, by wiping with a cloth, since the heating element is, as best shown in Fig. 4, pivotally supported by the terminal housing 23 and therefore can be pivoted in clockwise direction about the central axis of its terminals 22a and 22b.

In connection with this, in cleaning the heating plate after cooking, it is possible to lift up 'only the heating pllate 37 after allowing it- to cool down to approximately normal temperature, and then to effect the cleaning quite easily, for example by wiping with a dry cloth or by washing with detergent as in conventional dish washing.

The reference numeral 46, appearing for example in Fig. 1, designates legs secured to the undersurface of the bottom plate 9 to support the same thereon, and the reference numeral 47 designates internal lead wires used to electrically connect the socket 33 for receiving an attachment plug, the sheathed element 13 and the automatic temperature controller 34.

The hot plate in accordance with the present invention has been described with particular reference to the structure and use of a preferred embodiment thereof. In the embodiment described above, the heating plate is one made of ceramic material, although it is to be understood that the heating plate may be made up of any other suitable material such as metal.

As will be seen from the foregoing description, the hot plate in accordance with present invention is ,possessed of many advantageous characteristics, some examples of which will be described in the following: In the hot plate, a heat reflector is supported on supporting members mounted in the lower space within a housing, a heating element is provided at an appropriate distance above the inside bottom surface of the heat reflector, and the terminals of the heating element are rotatably supported in a terminal housing mounted on the heat reflector.

With such construction, cleaning operation in the event that the heating plate is soiled can be simplified, and upon possible breaking of wires in the heating element it is possible easily to replace only the broken heating element with a new one. In addition to these advantages, the hot plate has a further advantage -that, since a heating plate can be removably placed on the housing, it, if soiled, can be separately washed with water quite easily.

The above described housing is comprised of a rectangular frame work formed by interconnecting a pair of U-shaped frame members (each made by bending a metal strip into a U-shaped frame) at both ends thereof, and a handle of approximately the same length as that of one side of the housing is secured to each of the opposed sides containing the junctions between the frame members for the purpose of reinforcing the mechanical strength of the frame work.

Thus, the above described handle serves as a reinforcing member, so that the housing, even when made up from a metal plate, can be made mechanically firm and resistant to deformation.

The above described heating element is arranged in a zigzag manner and supported on a frame to minimize the distortion or deformation or the like due to thermal ex passion which otherwise would be brought about upon connecting the heating element of the sheathed type to a source of elec tricity.

The housing is further provided at its lower edpe with inwardly 'bent members some of which are provided at appropriate places with notches used to bring the bent members into engagement with tongue memhers provided at the edges of a bottom plate. for the purpose of facilitating the attachment of the bottom plate to the hot om portion of the housing. This therefore, results in the advantage that the number uf screws used in the attachment can be decreased and that assembly can be performed efficiently.

The above described bottom plate is provided with ribs in a radial arrangement which are concave in section. At a plurality of places where the ribs are provided, the lower ends of supporting members with the upper ends secured to the undersurface of the heat reflector are fastened to the bottom plate. With such construction, there are obtained the advantages that the planar bottom plate can be strengthened and that the supporting members can be easily mounted in predetermined positions.

The heating plate which is removably placed on the housing is made up of ceramic material exhibiting excellent heat storage capacity which results in the advantage that efficient utilization of remaining or waste heat can be achieved after the element is turned off.

It is to be understood that the heating plate may be made up of not only ceramic material but also heat resisting glass and that in place of the supporting frme for the heating element there may be mounted on the heat reflector a ceramic supporting pad with depressions to receive the heating element.

WHAT WE CLAIM IS:- 1. A portable hot plate comprising a housing; a bottom plate provided at the lower end of said housing; means for supporting a heat reflector at a distance above said bottom plate; a resistance heating element positioned above said bottom plate and arranged approximately parallel to said heat reflector; a terminal housing rotatably supporting therein the ends of the heating element so as to enable the element to be swung upwards to give access to the heat reflector and a heating plate removably placed near the top of said housing and over the heating element.

2. A hot plate as claimed in claim 1, wherein said housing is formed by interconnecting the free ends of a pair of Ushaped plates, and is provided along and externally of sides of the housing with handles of approximately the same length as that of said sides of said housing, the centre of said handle means being at or near the junction bcten the U-shaped plates.

3. A hot plate as claimed in claim 1 or 2. wherein means is provided for supporting thereon said heating element which is arranged in serpentine manner, said means being a frame positioned beneath said heating element and provided with notches for fitting said heating element in position.

4. A hot plate as claimed in claim 1, 2 or 3, wherein said ends of said heating element are inserted through holes in insulators supported in opposite side walls of said terminal housing which is mounted on said heat reflector so that said heating element is pivotable about the central axis of said holes.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. heating plate may be made up of any other suitable material such as metal. As will be seen from the foregoing description, the hot plate in accordance with present invention is ,possessed of many advantageous characteristics, some examples of which will be described in the following: In the hot plate, a heat reflector is supported on supporting members mounted in the lower space within a housing, a heating element is provided at an appropriate distance above the inside bottom surface of the heat reflector, and the terminals of the heating element are rotatably supported in a terminal housing mounted on the heat reflector. With such construction, cleaning operation in the event that the heating plate is soiled can be simplified, and upon possible breaking of wires in the heating element it is possible easily to replace only the broken heating element with a new one. In addition to these advantages, the hot plate has a further advantage -that, since a heating plate can be removably placed on the housing, it, if soiled, can be separately washed with water quite easily. The above described housing is comprised of a rectangular frame work formed by interconnecting a pair of U-shaped frame members (each made by bending a metal strip into a U-shaped frame) at both ends thereof, and a handle of approximately the same length as that of one side of the housing is secured to each of the opposed sides containing the junctions between the frame members for the purpose of reinforcing the mechanical strength of the frame work. Thus, the above described handle serves as a reinforcing member, so that the housing, even when made up from a metal plate, can be made mechanically firm and resistant to deformation. The above described heating element is arranged in a zigzag manner and supported on a frame to minimize the distortion or deformation or the like due to thermal ex passion which otherwise would be brought about upon connecting the heating element of the sheathed type to a source of elec tricity. The housing is further provided at its lower edpe with inwardly 'bent members some of which are provided at appropriate places with notches used to bring the bent members into engagement with tongue memhers provided at the edges of a bottom plate. for the purpose of facilitating the attachment of the bottom plate to the hot om portion of the housing. This therefore, results in the advantage that the number uf screws used in the attachment can be decreased and that assembly can be performed efficiently. The above described bottom plate is provided with ribs in a radial arrangement which are concave in section. At a plurality of places where the ribs are provided, the lower ends of supporting members with the upper ends secured to the undersurface of the heat reflector are fastened to the bottom plate. With such construction, there are obtained the advantages that the planar bottom plate can be strengthened and that the supporting members can be easily mounted in predetermined positions. The heating plate which is removably placed on the housing is made up of ceramic material exhibiting excellent heat storage capacity which results in the advantage that efficient utilization of remaining or waste heat can be achieved after the element is turned off. It is to be understood that the heating plate may be made up of not only ceramic material but also heat resisting glass and that in place of the supporting frme for the heating element there may be mounted on the heat reflector a ceramic supporting pad with depressions to receive the heating element. WHAT WE CLAIM IS:-

1. A portable hot plate comprising a housing; a bottom plate provided at the lower end of said housing; means for supporting a heat reflector at a distance above said bottom plate; a resistance heating element positioned above said bottom plate and arranged approximately parallel to said heat reflector; a terminal housing rotatably supporting therein the ends of the heating element so as to enable the element to be swung upwards to give access to the heat reflector and a heating plate removably placed near the top of said housing and over the heating element.

5. A hot plate as claimed in any one

of the preceding claims, wherein said housing is provided along a lower edge with inwandly directed members which are provided with notches, and wherein said bottom plate is provided at opposite edges with tongues, whereby said bottom plate is mounted in said housing by inserting the tongues through said notches.

6. A hot plate as claimed in any one d the preceding claims, wherein said bottom plate is provided with Iibs of concave section extending radially from a central point, and said means for supporting said heat reflector is engaged, at its lower end, with said ribs of said bottom plate.

7. A hot plate as claimed in any one of the preceding claims, wherein said heating plate is removably located near the top of said housing so that said heating plate can be heated by said heating element, the heating plate being made of ceramic material.

8. A hot plate as claimed in any one of the preceding claims, comprising heat sensor means for controlling the temperature of the heating element, the sensor means being installed in a space between the heat reflector and the bottom plate.

9. A portable electric hot plate substantially as hereinbefore described with reference to the accompanying drawings.