Abstract:
A cotton candy preparing device is desired which does not operate with a pan portion removed. To provide a cotton candy preparing device that prevents a user from taking some time before getting aware that the device is not operating properly, there is provided a cotton candy preparing device having a pan portion that is fixed on to a main body portion by a locking piece, wherein a power supply switch is incorporated in the main body portion, wherein the power supply switch has a switch operating rod that enables on and off operations of a circuit, and a locking body that restricts a sliding movement of the switch operating rod, and wherein when the pan portion is fixed to the main body portion by the locking piece, the locking body is moved by the locking piece to thereby enable the switch operating rod to slide.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based upon and claims the benefit of priority under 35 USC 119 of Japanese Patent Application No. 2015-132439 filed on Jul. 1, 2015, the entire disclosure of which, including the description, claims, drawings and abstract, is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    Field of the Invention 
         [0003]    The present invention relates to a device for preparing cotton candies. 
         [0004]    Description of the Related Art 
         [0005]    In these days, devices have been provided by which a child, together with his or her parent, can prepare cotton candies using granulated sugar or sugar candy as a material in their house. Then, various proposals in relation to these cotton candy preparing devices (for example, Japanese Unexamined Patent Application No. 2002-187 and Japanese Unexamined Patent Application No. 2003-333994) have also been made. 
         [0006]    A conventional cotton candy preparing device includes a main body portion that makes up a base, a rotary mechanism portion and a pan portion that receives cotton-like sugar candies. Then, a heater is provided in the rotary mechanism portion to heat and melt a material such as sugar or sugar candy loaded in an interior of a rotary pot, and the rotary pot is rotated at high speeds to discharge the material so melted in the form of fine threads of sugar or candy from minute holes or gaps formed on the circumference of the rotary pot. 
         [0007]    Then, in cotton candy preparing devices, there is a cotton candy preparing device in which when a power supply switch is operated, a heater starts heating and a motor starts rotating a rotary pot, and the power supply switch is designed so as not to be switched on unintentionally and abruptly (for example, refer to Japanese Unexamined Patent Publication No. 2002-187). 
         [0008]    The power supply switch described in Japanese Unexamined Patent Publication No. 2002-187 is designed so as to be switched on by rotating an operating portion while depressing the operating portion. Owing to this, the power supply switch can be switched on only when two operations of the depressing operation and the rotating operation are performed simultaneously. Thus, the power supply switch cannot be switched on without operating it intentionally. 
         [0009]    Consequently, the power supply switch can be prevented from being switched on erroneously. Thus, the heater and the motor can be started to operate when starting the preparation of cotton candy after all the preparation work has been set. 
         [0010]    In preparing cotton candy, in order to collect sugar candy that is discharged in the form of threads from the rotary pot into something like cotton, normally, a pan portion is provided which surrounds the rotary pot. 
         [0011]    Then, the pan portion is designed so as to be removed from a main body portion when stowing or cleaning the cotton candy preparing device. Thus, in many cases, the pan portion is mounted on the main body portion when using the cotton candy preparing device. 
         [0012]    In the cotton candy preparing device in which the pan portion can be removed, when preparing cotton candy, there is a case where a parent uses the cotton candy preparing device with the pan portion left removed therefrom. However, when a child or a person who is not familiar with the device prepares cotton candy, in the event that the child or the person uses the device with the pan portion left removed, there may be a case where the cotton candy preparing device or the surroundings thereof get dirty. 
         [0013]    To deal with this, it is desired that the cotton candy preparing device cannot be activated to operate with the pan portion left removed. 
         [0014]    As has been described above, in order to prevent the cotton candy preparing device from being activated to operate with the pan portion left removed, this can be achieved by providing a sensor that detects the mounting of the pan portion. However, when using an active sensor such as a proximity sensor, electric power keeps consumed even when the cotton candy preparing device is switched off by switching off the power supply switch, resulting in the wastage of electric power. 
         [0015]    Additionally, it is considered that a mechanically operated switch is provided as a detection switch in place of the active sensor, so that the cotton candy preparing device is prevented from being activated to operate unless the detection switch that is connected in series with the power supply switch is switched on although the power supply switch is switched on. 
         [0016]    In case the function to prevent the operation of the cotton candy preparing device in the way described above even when the power supply switch is switched on is incorporated in the device, it is possible to prevent the heating by the heater and the rotation of the rotary pot even when the power supply switch is switched on. 
         [0017]    However, the person who operates the cotton candy preparing device believes that the cotton candy preparing device is activated to operate by switching on the power supply switch. It is difficult to realize that the heater is not heated from the external appearance of the cotton candy preparing device, and hence, it takes some time until the user is aware of the fact that the cotton candy preparing device is not activated. 
         [0018]    In addition, when the user is aware that something abnormal is occurring since the heater is not heated and the rotary port does not start rotating, the user may doubt if something fails within the cotton candy preparing device, and hence, it takes some time until the user gets aware that the pan portion is not mounted. 
       SUMMARY OF THE INVENTION 
       [0019]    The present invention provides by eliminating the problem described above a cotton candy preparing device that can prevent a power supply switch from being switched on unless a pan portion is mounted so that a user can be aware that the cotton candy preparing device has not yet been built up for use due to the power supply switch being unable to be operated. 
         [0020]    According to an aspect of the invention, there is provided a cotton candy preparing device having a pan portion that is fixed on to a main body portion by a locking piece. A power supply switch is incorporated in the main body portion, the power supply switch has a switch operating rod that enables on and off operations of a circuit and a locking body that restricts a sliding movement of the switch operating rod. When the pan portion is fixed to the main body portion by the locking piece, the locking body is moved by the locking piece to thereby enable the switch operating rod to slide. 
         [0021]    In the cotton candy preparing device, the locking body has an operating projection that is brought into contact with the locking piece, and when the pan portion is fixed to the main body portion, the locking piece moves the operating projection to thereby move the locking body. 
         [0022]    In the cotton candy preparing device, the locking body is superposed on the switch operating rod, the switch operating rod has an abutting projection that is provided on an upper surface of the switch operating rod so as to project therefrom for contact with an end portion of the locking body, and when the pan portion is fixed to the main body portion, the switch operating rod is allowed to slide by moving an abutment surface of the locking body that is in contact with the abutting projection to release the abutting projection from the contact with the abutting surface. 
         [0023]    In the cotton candy preparing device according to the invention, the power supply switch is made up of the switch operating rod and the locking body that restricts the sliding movement of the switch operating rod, and when the pan portion is fixed to the main body, the locking body is moved by the locking piece of the pan portion to thereby enable the switch operating rod to slide. Thus, when the pan portion is left dismounted, a switch knob of the power supply switch cannot be moved to a power supply on position. 
         [0024]    Consequently, the user can be aware that the cotton candy preparing device is in an abnormal state, that is, the pan portion is not mounted on the main body portion without any delay. 
         [0025]    In addition, the mechanism is provided to restrict the sliding operation of the switch operating rod, and therefore, the wastage of electric power is not caused. 
         [0026]    In the event that the operating projection configured to be brought into contact with the locking piece is provided on the locking body, part of the locking body is brought into direct contact with the locking piece of the pan portion, whereby the locking body is moved to enable the switch operating rod to slide. Thus, according to the power supply switch, the operation of the switch operating rod can be switched between a restricted state and a restricted operation released state by the simple construction. 
         [0027]    In the event that the switch operating rod and the locking body are superposed on each other, that the abutting projection is provided on the upper surface of the switch operating rod so as to project therefrom, that the locking body is brought into abutment with the abutting projection of the switch operating rod to thereby restrict the sliding of the switch operating rod, and that the switch operating rod is allowed to slide by moving the locking body, the whole of the power supply switch can be made smaller in size, whereby the incorporation of the power supply switch into the main body portion of the cotton candy preparing device can be facilitated. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0028]      FIG. 1  is a perspective view showing a cotton candy preparing device according to an embodiment of the invention and a power supply adaptor. 
           [0029]      FIG. 2  is a half sectional perspective view of the cotton candy preparing device according to the embodiment of the invention. 
           [0030]      FIG. 3  is a half sectional view of the cotton candy preparing device according to the embodiment of the invention. 
           [0031]      FIG. 4  is a bottom perspective view showing a pan portion of the cotton candy preparing device according to the embodiment of the invention. 
           [0032]      FIG. 5  is a half sectional view of the pan portion of the cotton candy preparing device according to the embodiment of the invention. 
           [0033]      FIG. 6  is a perspective view showing a state in which the pan portion is removed from the cotton candy preparing device according to the embodiment of the invention. 
           [0034]      FIG. 7  is a perspective view showing an interior of a main body portion and a rotary mechanism portion of the cotton candy preparing device according to the embodiment of the invention. 
           [0035]      FIG. 8  is an exploded perspective view showing a main body cover portion of the cotton candy preparing device according to the embodiment of the invention. 
           [0036]      FIG. 9  is a sectional view of a pot upper portion of the rotary pot of the cotton candy preparing device according to the embodiment of the invention. 
           [0037]      FIG. 10  is a perspective view of the pot upper portion of the rotary pot of the cotton candy preparing device according to the embodiment of the invention. 
           [0038]      FIG. 11  is a side view of the pot upper portion of the rotary pot of the cotton candy preparing device according to the embodiment of the invention. 
           [0039]      FIG. 12  is a bottom view of the pot upper portion of the rotary pot of the cotton candy preparing device according to the embodiment of the invention. 
           [0040]      FIG. 13  is a top view of the cotton candy preparing device according to the embodiment of the invention with the pot upper portion and the main body cover portion removed therefrom. 
           [0041]      FIG. 14  is an exploded perspective view of the rotary pot of the cotton candy preparing device according to the embodiment of the invention. 
           [0042]      FIG. 15  is a top view showing an upper surface of a pot bottom main body of the cotton candy preparing device according to the embodiment of the invention. 
           [0043]      FIG. 16  is a bottom view showing a lower surface of the pot bottom main body of the cotton candy preparing device according to the embodiment of the invention. 
           [0044]      FIG. 17  is a perspective view of the pot bottom portion and the main body bottom portion of the cotton candy preparing device according to the embodiment of the invention showing connecting circuitries thereof. 
           [0045]      FIG. 18  is an exploded perspective view showing the construction of a power supply switch of the cotton candy preparing device according to the embodiment of the invention. 
           [0046]      FIG. 19  is a circuit diagram showing an electric circuit configuration of the cotton candy preparing device according to the embodiment of the invention. 
           [0047]      FIG. 20  is a flowchart showing operating states of the cotton candy preparing device according to the embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0048]    As shown in  FIG. 1 , an embodiment of a cotton candy preparing device according to the invention is used in combination with a power supply adaptor  480  by a child and his or her parent in their house. 
         [0049]    As shown in  FIGS. 1 to 3 , this cotton candy preparing device has a tray or pan portion  201  disposed above a main body portion  110  and a rotary pot  260 , functioning as a rotary mechanism unit  250 , that is disposed inside the pan portion  201 . 
         [0050]    In addition, the main body portion  110  is formed by a main body bottom portion  141  and a main body cover portion  111  and accommodates in an interior thereof a driving motor that rotates the rotary pot  260  and a control circuit board. 
         [0051]    The rotary mechanism unit  250  is provided at a center of the main body portion  110 , and a pot upper portion  261  of the rotary pot  260  that makes up a main part of the rotary mechanism unit  250  is surrounded by the pan portion  201  so that the pot upper portion  261  is accommodated in an interior of the pan portion  201  while being allowed to project upwards of the main body portion  110  from a center of the main body cover portion  111 . 
         [0052]    As shown in  FIGS. 4 and 5 , this pan portion  201  is a combination of an upper pan  203  and a lower pan  211 . 
         [0053]    The upper pan  203  has a cover portion  205  that has an opening portion  207  that is opened largely in a center thereof, so that cotton-like candies that are prepared along the circumference of the rotary pot  206  in the interior of the pan portion  201  can get tangled up on a distal end of a stick that is inserted from the opening portion  207  into the interior of the pan portion  201 . 
         [0054]    The lower pan  211  has a cylindrical side barrel portion  213  that defines an outer circumferential wall of the pan portion  201  and supports an outer circumferential edge of the cover portion  205  at an upper end of the side barrel portion  213 . Then, the lower pan  211  has a plate-like annular bottom portion  215  having a ring-like shape at a lower end of the side barrel portion  213 . Thus, the lower pan  211  accommodates the rotary pot  260  in an interior of the side barrel portion  213 . 
         [0055]    Further, the lower pan  211  includes an inner cylindrical portion  217  having a cylindrical shape that is provided therein so as to rise upwards from an inner edge of the annular bottom portion  215  and is fixedly fitted on a holding cylindrical portion  117  of the main body portion  110 , which will be described later, at the inner tube portion  217  so as to cover circumferentially a pot bottom portion  310  of the rotary pot  260 . 
         [0056]    In addition, the lower pan  211  has a locking cylinder  221  having a cylindrical shape that is provided at a portion on a lower surface of the annular bottom portion  215  that lies near an inner circumferential edge portion of the annular bottom portion  215  so as to slightly project downwards therefrom. This locking cylinder  221  has plate-like locking pieces  223  that are provided at two diametrically facing locations thereon so as to project radially inwards from an inner wall at a lower end of the locking cylinder  221 . Thus, by adopting this configuration, when mounting the pan portion  201  on the main body portion  110 , the pan portion  201  can be fixed to the main body portion  110  at a predetermined position. 
         [0057]    The main body portion  110  on which the pan portion  201  is mounted defines a space therein by the main body bottom portion  141  and the main body cover portion  111  and accommodates therein the rotary mechanism unit  250  that includes a drive unit made up of a motor  253  and a motor gear  255  and the rotary pot  260  that is driven to rotate by the drive unit  251 . 
         [0058]    Then, as shown in  FIG. 6 , the main body portion  110  accommodates the rotary mechanism unit  250  in such a way that the pot upper portion  261  of the rotary pot  260  projects from an upper end of a holding cylinder of the main body portion  110  that is formed by the main body cover portion  111  and the main body bottom portion  141 . 
         [0059]    As shown in  FIGS. 6, 7 and 8 , the main body cover portion  111  has a flat and annular upper surface portion  115  that extends radially inwards from an upper end of a substantially short cylindrical upper outer edge portion  113  and the holding cylindrical portion  117  having a cylindrical shape that extends upwards from a central inner edge of the upper surface portion  115 . 
         [0060]    An auxiliary ring  131  and a protection ring  133  are provided at an upper end of the holding cylindrical portion  117 . The auxiliary ring  131  projects radially inwards from the upper end of the holding cylindrical portion  117 . 
         [0061]    The auxiliary ring  131  is made up of two semicircular portions. Each semicircular portion includes a circumferential edge portion  131   a  that is fixed to the upper end of the holding cylindrical portion  117  and a plate-like semi-annular projecting ring  131   b  that projects radially inwards from an upper end of the circumferential edge portion  131   a  in such a way that an inner edge is situated near a lower end of an outer circumference of a pot bottom main body  323 , which will be described later. 
         [0062]    The projection ring  133  includes a circumferential edge ring  133   a  that covers the circumferential portions  131   a  of the auxiliary ring  133  and is fixed to the holding cylindrical portion  117 . The projecting ring  133  has a protecting portion  133   b  that is directed upwards and radially inwards from an upper end of the circumferential ring  133   a . An inner circumferential edge of the protecting portion  133   b  is situated near an upper end of an outer circumference of the pot bottom main body  323 , which will be described later, so that a gap between the rotary pot  260  that projects from the holding cylindrical portion  117  of the main body cover portion  111  to rotate and the holding cylindrical portion  117  of the main body cover portion  111  is narrowed to thereby prevent the intrusion of foreign matters into an interior of the main body portion  110  in a falling fashion. 
         [0063]    The main body cover portion  111  has a step portion  121  formed around a lower end circumference of the holding cylindrical portion  117 , and an inner circumferential edge of the annular bottom portion  215  of the lower pan  211  can be supported on an upper surface of the step portion  121 . Substantially rectangular engaging pieces  123  are provided individually at two locations on a circumference of the step portion so as to extend radially outwards therefrom in the same height as that of the upper surface of the step portion  121 . 
         [0064]    These two engaging pieces  123  are provided in diametrically facing positions on the step portion  121  that is formed into an annular shape on the upper surface  115  of the main body cover portion  111 . A distance between outer end portions of both the engaging pieces  123  is substantially equal to a bore diameter of the locking cylinder  221  of the lower pan  211 , so that the engaging pieces  123  can be accommodated inside the locking cylinder  221 . 
         [0065]    A gap having a height substantially equal to a thickness of the locking piece  223  is formed between a lower surface of the engaging piece  123  and an upper surface of the main body cover portion  111 , so that the locking piece  223  can be accommodated under the engaging piece  123 . 
         [0066]    Further, an engaging opening portion  125  having a shape that matches substantially the shape of the engaging piece  123  is formed on the upper surface portion  115  in a position lying below the engaging piece  123 . Then, the locking pieces  223  that are provided on the locking cylinder  221  of the lower pan  211  individually have lower surfaces that are protuberant slightly downwards at centers thereof. Thus, when the locking pieces  223  of the pan portion  201  are located to lie below the corresponding engaging pieces  123  of the main body cover portion  111 , the lower surfaces of the locking pieces  223  that are slightly protuberant at the centers thereof fit in the engaging opening portions  125 , whereby the rotation resistance of the pan portion  201  is lost, thereby allowing the user or operator to determine on a proper fixing position of the pan portion  201  to the main body portion  110 . 
         [0067]    The engaging piece  123  shown in  FIG. 8  has a locking wall  123   a  at one side of the engaging piece  123  projecting from the step portion  121  which follows a circumference of the holding cylindrical portion  117 , so that the locking pieces  223  can be inserted under the engaging pieces  123  only from one direction when the pan portion  201  is placed on the main body portion  110  by placing the inner cylindrical portion  217  of the pan portion  201  on the holding cylindrical portion  117  so that the annular bottom portion  215  is brought into contact with the upper surface of the step portion  121  and the pan portion  201  is rotated in a horizontal direction relative to the main body portion  110 . 
         [0068]    An operating projection  451  of a locking body  441  of a power supply switch  410 , which will be described later, is located in one of the engaging opening portions  125 , and when the locking piece  223  is inserted under the engaging pieces  123 , the locking piece  223  moves the operating projection  451  in the direction of the center of the main body portion  110  in an interior of the engaging opening portion  125 . 
         [0069]    Further, a power supply terminal hole  137  into which an adaptor pin  481  of the power supply adaptor  480  is inserted and a switch hole through which a switch knob  423  of the power supply switch  410  is allowed to project from the main body portion  110  are provided in the upper outer edge portion  113  of the main body cover portion  111 . 
         [0070]    As shown in  FIG. 7 , the power supply terminal hole  137  is provided at a lower end of the upper outer edge portion  113  so that an upper half of a front surface of an adaptor jack  485  can bite into the upper outer edge portion  113  of the main body cover portion  111 . The switch hole  135  is also provided at the lower end of the upper outer edge portion  113  so that an upper half of the switch knob  423  of a switch operating rod  411  can bite into the upper outer edge portion  113  of the main body cover portion  111 . 
         [0071]    The main body bottom portion  141  of the main body portion  110  has a bottom plate portion  143  having a circular disc shape and a lower outer edge portion  145  having a cylindrical shape that rises from a circumferential edge of the bottom plate portion  143 . An upper end of the lower outer edge portion  145  is joined to the lower end of the upper outer edge portion  113  of the main body cover portion  111  to make up the main body portion  110  in which an interior space is defined by the main body bottom portion  141  and the main body cover portion  111 . 
         [0072]    As shown in  FIG. 3 , the main body bottom portion  141  includes feet  153  on a lower surface of the bottom plate portion  143  so as to define a space between the bottom plate portion  143  and a table surface on which the cotton candy preparing device  100  is rested. In addition, a plurality of outside air intake holes  151  are provided in the bottom plate portion  143 . 
         [0073]    Then, the main body bottom portion  141  has a pot mounting base portion  161  that is provided substantially at a center of the bottom plate portion  143 , and the rotary mechanism unit  250  made up of the drive unit  251  including the motor  253  that drives the rotary pot  260  to rotate and the rotary pot  260  is fixedly accommodated in the main body bottom portion  141 . 
         [0074]    As shown in  FIGS. 2 and 3 , a motor fixing portion  163  and a shaft holding portion  165  are provided in an interior of the pot mounting base portion  161 . The driving motor  253  is fixedly accommodated in the interior of the pot mounting base portion  161 , and a lower end of a rotation shaft  397  of the rotary pot  260  is held by the shaft holding portion  165 . 
         [0075]    Further, the rotation shaft  397  is held on an upper side thereby by a bearing plate  167  that is disposed above the pot mounting base portion  161 . Then, the rotary pot  260  which is formed by the pot bottom portion  310  that is disposed on the bearing shaft  167  and the pot upper portion  261  is supported rotatably by the rotation shaft  397 . 
         [0076]    In addition, the control circuit board  175  and the power supply switch  410  are provide on an upper surface of the bottom plate portion  143  at a portion lying on a side of the pot mounting base portion  161 . 
         [0077]    Electronic components such as a control IC  535  that controls the motor  253  and a heater  315  of the cotton candy preparing device  100 , a resistance and a capacitor are mounted on the control circuit board  175 . Additionally, a connecting plug  547  into which a connecting jack  545  of a cord that is connected to the motor  253  is inserted is also fixed on to the control circuit board  175 . 
         [0078]    The pot upper portion  261  of the rotary pot  260  that projects upwards from the holding cylindrical portion  117  of the main body cover portion  111  shown in  FIG. 6  has a protuberant portion  275  having an extended diameter at a lower end of a cylindrical outer wall portion  263  and a cylindrical skirt portion  277  that extends downwards from an outer edge of the protuberant portion  275  as shown in  FIGS. 9 and 10 . 
         [0079]    The pot upper portion  261  has a top portion  265  that projects radially inwards into an annular shape from an upper end of the outer wall portion  263  and a depression that is formed at a center of the top portion  265  as a semi-spherical loading port that is defined by a loading wall  267  and an opening and closing member  271 . 
         [0080]    This opening and closing member  271  has a shape that is substantially a half of a semi-spherical shape and has a knob portion  273  that projects radially outwards from an upper end portion thereof. When the knob portion  273  is rotated in such way as to be moved upwards, an opening portion is formed between the loading wall  267  and the opening and closing member  271 , so that granulated sugar or sugar candy that is loaded into the semi-spherical depression defined by the loading wall  267  and the opening and closing member  271  and functioning as the loading port is allowed to fall into the interior of the rotary pot  260  through the opening portion. 
         [0081]    As shown in  FIG. 6  and other figures, the opening and closing member  271  normally forms the semi-spherical depression by the opening and closing member  271  and the loading wall  267  with an upper surface of the knob portion  273  positioned so as to be level with an upper surface of the top portion  267  without producing a gap between the opening and closing member  271  and the loading wall  267 . 
         [0082]    The pot upper portion  261  has in the interior thereof an upper inner wall  281  and a lower inner wall  283  which are both an cylindrical inner wall, so that granulated sugar or sugar candy that falls from the gap produced as a result of the rotation of the opening and closing member  271  is allowed to fall on a heating plate  311  that is provided on an upper end face of the pot bottom portion  310 . 
         [0083]    The pot upper portion  261  has a diametrically expanded inclined portion  285  having a conically annular shape in which a lower diameter is gradually expanded so that the lower diameter becomes greater than an upper diameter and an annular projecting portion  293  having a flat annular shape that extends radially outwards in a horizontal direction from a lower end of the diametrically expanded inclined portion  285 . 
         [0084]    Further, the pot upper portion  261  has a circumferential portion  291  having a lower surface that is slightly higher than a lower surface of the annular projecting portion  293 , and an outer edge of the circumferential portion  291  is joined to a lower end of the skirt portion  277 . 
         [0085]    Then, the pot upper portion  261  has a ring member  301  on the lower surface of the annular projecting portion  293 , and this ring member  301  has a flat annular shape and is made of a metallic conductive material. 
         [0086]    As shown in  FIGS. 9 and 12 , a plurality of plate-like ribs  287  are provided in the diametrically expanded inclined portion  285  so as to project inwards from the diametrically expanded inclined portion  285 . 
         [0087]    These ribs  287  have such a height that lower ends thereof are level with a lower surface of the ring member  301  or are slightly higher than the lower surface of the ring member  301 . Then, by doing so, when the lower surface of the ring member  301  is in contact with the upper surface of the heating plate  311 , the lower ends of the ribs  287  are also in contact with the upper surface of the heating plate  311  or a slight gap can be defined between the lower ends of the ribs  287  and the upper surface of the heating plate  311 . 
         [0088]    Consequently, when sugar candy that falls into the interior of the cylindrical lower inner wall  283  remains in a solid state until they are melted on the heating plate  311 , the sugar candy can be prevented from moving from the center of the heating plate  311  to the periphery of the heating plate  311  as a result of the rotation of the rotary pot  260 . 
         [0089]    Then, six depressed portions  295  are provided at equal intervals on the lower surface of the annular projecting portion  293 , and these depressed portions  295  are situated slightly higher than the lower surface of the annular projecting portion  293  having the cylindrical shape (refer to  FIG. 14 ). 
         [0090]    The depressed portions  295  each have an identical fan shape and are opened to an outer edge of the annular projecting portion  293 . The depressed portions  295  are each formed so as to have a radial width that extends towards the center of the pot upper portion  261  from the outer edge of the annular projecting portion  293  to a radially middle portion of the lower surface of the annular projecting portion  293 . 
         [0091]    The ring member  301  is the annular metallic flat plate and has an outside diameter that substantially coincides with an outside diameter of the annular projecting portion  293  and a bore diameter that substantially coincides with a bore diameter of the annular projecting portion  293 . The bore diameter of the ring member  301  is smaller than a diameter of the heating plate  311  so that at least an inner edge portion of the ring member  301  or, preferably, a portion of the ring member  301  that extends from an inner edge to the vicinity of an outer edge of the ring member  301  can overlap the heating plate  311  so as to be brought into contact therewith. 
         [0092]    Further, the ring member  301  has six first expanded portions  303  that are provided at equal intervals therein by cutting corresponding portions of the ring member  301  into the same shape from an inner edge of the ring member  301 . Each first expanded portion  303  has a second expanded portion  305  that is formed by cutting corresponding portions of the ring member  301  further radially outwards at a center of a circumferential width of the first expanded portion  303 . 
         [0093]    Then, a diameter of a circle that connects outer edges of the six first expanded portions  303  is smaller than a diameter of a circle that connects inner edges of the depressed portions  295  that are formed on the annular projecting portion  293 . The circumferential width of each first expanded portion  303  is the same as or slightly wider than a circumferential width of each depressed portion  295 . 
         [0094]    The second expanded portions  305  that are cut further radially outwards than the first expanded portions  303  from substantially the circumferential centers of the first expanded portions  303  are formed so that a diameter of a circle that connects outer edges of the second expanded portions  305  is slightly larger than the diameter of the circle that connects the inner edges of the depressed portions  295  and that a circumferential width of each second expanded portion  305  is narrower than the circumferential width of each depressed portion  295 . 
         [0095]    Consequently, in an interior space of the pot upper portion  261  of the rotary pot  260 , a circumferential width is narrowed by the first expanded portions  303 , and the circumferential width is narrowed further by the second expanded portions  305 . Then, the interior space of the pot upper portion  261  is connected continuously with the depressed portions  295  via slight gaps at outer end portions of the second expanded portions  305 . Then, since the circumferential widths of the depressed portions  295  are wider than the circumferential widths of the second expanded portions  305 , the interior space of the pot upper portion  261  is connected continuously with an exterior portion lying outside an outer circumference of the rotary pot  260 . 
         [0096]    By adopting this configuration, when sugar or sugar candy that is loaded from the upper portion into the interior of the rotary port  260  is heated to be melted, the melt is fed into the first expanded portions  303  by means of a centrifugal force between the heating plate  311  and the annular projecting portion  293  and is fed further into the second expanded portions  305 , whereby the melt is discharged to the exterior portion of the rotary pot  260  from the gaps defined by the depressed portions  295  between the ring member  301  and the annular projecting portion  293 . Since the heating plate  311  and the ring member  301  are both heated to high temperatures, even sugar candy can be melted in an ensured fashion, whereby granulated sugar and sugar candy can be made well into cotton-like conditions. 
         [0097]    Namely, a material of a large size such as sugar candy is held long at the center where a working centrifugal force is small by the ribs  287  and reaches the inner edge position of the ring member  301  through the gaps defined between the ribs  287  when it is melted. On the other hand, a material of a small size and easy to be melted such as granulated sugar is quick to reach the inner edge position of the ring member  301  through the gaps defined between the ribs  287 . 
         [0098]    Then, the melted material that has reached the inner edge position of the ring member  301  reaches outer circumferential end portions of the second expanded portions  305  through the first expanded portions  303  whose circumferential width is gradually narrowed. 
         [0099]    Further, the melted material is lifted up from the outer circumferential end portions of the second expanded portions  305  to the gaps above the ring member  301  and is then discharged to the exterior portion therefrom. Thus, the material is heated by the heating plate  311  and the ring member  301  while being subjected to moving resistance sequentially, and therefore, the material is melted so sufficiently in an ensured fashion that the material is formed into a uniform thin thread-like shape. 
         [0100]    The ring member  301  has three legs  307  that extends perpendicularly downwards from an outer circumferential edge thereof. Lower ends of the legs  307  are extended to project radially outwards into leg end portions  309 , whereby the pot upper portion  261  is attached to the pot bottom portion  310  by these legs  307  and can be fixed to the pot bottom portion  310  by the leg end portions  309 . 
         [0101]    The pot bottom portion  310  has the circular disc-shaped heating plate  311  at the center of the upper end thereof as shown in  FIG. 13  and includes, as shown in  FIG. 14 , a first electrode plate  317 , a second electrode plate  319 , a heater holding plate  313  that holds a plurality of heaters  315 , a heater accommodation plate  321  that accommodates the two electrode plates  317 ,  319  and the heater holding plate  313 , a pot bottom main body  323  that accommodates the heater accommodation plate  321  and the heating plate  311 , and a geared plate  373  that is fixed to a lower surface of the pot bottom main body  323 . 
         [0102]    This pot bottom main body  323  has a main body circumferential wall  327  that rises into a cylindrical shape from a circumference of a circular disc-shaped main body plate  325  and a flat plate-like annular portion  329  having an annular shape that is provided at an upper end of the main body circumferential wall  327  so as to extend radially outwards. A cylindrical outer circumferential wall  331  is provided which extends perpendicularly downwards from a lower end of an outer edge of the annular portion  329 , and a lower end of the outer circumferential wall  331  is positioned at substantially the same height as a lower surface of the main body plate  325 . 
         [0103]    The heater accommodation plate  321  and the heating plate  311  are accommodated on an upper surface of the main body plate  325  and inside the main body circumferential wall  327 , and the second electrode plate  319 , the heater holding plate  313  and the first electrode plate  317  are accommodated inside the heater accommodation plate  321 . 
         [0104]    The heaters  315  that are fixed to the heater accommodation plate  321  are rectangular flat plate-like PTC heaters. Lower surfaces of the heaters  315  are brought into close contact with the circular disc-shaped second electrode plate  319 , while upper surfaces of the heaters  315  are brought into close contact with the circular disc-shaped first electrode plate  317 , whereby a voltage can be applied to the heaters  315  by the first electrode plate  317  and the second electrode plate  319 . 
         [0105]    When the voltage is applied to the heaters  315 , the heaters  315  are heated to temperatures ranging substantially from 70° C. to 80° C. Since the plurality of PTC heaters are fixedly disposed underneath the heating plate  311  by means of the heater accommodation plate  321 , a wide range of the heating plate  311  can be heated uniformly and effectively. 
         [0106]    Further, although the plurality of PTC heaters are used, since the PTC heaters are flat and are energized through contact of the upper surfaces and lower surfaces with the corresponding circular disc-shaped electrode plates, wiring to the PTC heaters can be made simple, thereby making it possible to energize the PTC heaters easily and in an ensured fashion. 
         [0107]    The heating plate  311  is accommodated in the pot bottom main body  323  together with the heater accommodation plate  321  in such a way as to be closely attached to an upper side of the first electrode plate  317  so as to be heated by the heaters  315 . An upper surface of a circumferential edge portion of the heating plate  311  can be closely attached to the ring member  301  of the pot upper portion  261 . 
         [0108]    In this way, in the cotton candy preparing device  100  of the invention, the heater temperature and hence the temperatures of the heating plate  311  and the ring member  301  that is in contact with the heating plate  311  can be maintained constant by the properties of the heaters by using the PTC heaters for the heaters  315 . 
         [0109]    Consequently, the temperatures of the heaters  315  can be maintained constant by supplying a constant voltage to the heaters  315  without performing operations of detecting and controlling the temperatures of the heaters  315 , thereby making it possible to use the cotton candy preparing device  100  safely in a house. 
         [0110]    The pot bottom main body  323  has three leg receiving holes  333  that are provided at equal intervals on an inner edge of the annular portion  329 . Each leg receiving hole  333  has an inserting portion  334  that is so sized as to allow the passage of the leg end portion  309  and a leg stopping portion  335  that is provided on a side of the inserting portion  334 . This leg stopping portion  335  has a radial width that is smaller than that of the inserting portion  334  so as not to allow the passage of the leg end portion  309  while allowing the passage of the leg  307 . 
         [0111]    An engaging pin  341  and an operating pin  351  are provided below the heater accommodation plate  321  and on an upper surface of the main body plate  325  as shown in  FIG. 15 . 
         [0112]    The engaging pin  341  has a rod-like shape is positioned on a lower side of the annular portion  329  at one end thereof, and this pin end portion  343  is attached to the pot bottom body  323  in an oscillating fashion by a screw that functions as a rotation shaft  347  as shown in  FIG. 16 . 
         [0113]    Then, the engaging pin  341  has a triangular engaging projecting body  345  that projects partially into the leg receiving hole  333  from a side of the rod-shaped main body, so that an opposite end portion to the pin end portion  343  that is attached to the pot bottom main body  323  with the rotation shaft  347  can be brought into engagement with the operating pin  351 . 
         [0114]    This operating pin  351  has a rod-like shape and is attached to the upper surface of the main body plate  325  so as to slide towards the center of the pot bottom main body  323  while a center axis thereof is directed to the center of the pot bottom main body  323  and an outer end portion thereof projects slightly further radially outwards than the annular portion  329  as an operating portion  353 . 
         [0115]    Then, a lower surface of the operating pin  351  can be brought into engagement with the end portion of the engaging pin  341 , and the end portion of the engaging pin  341  is biased outwards by an elastic body  355 . The operating portion  353 , which is the end portion of the operating pin  351 , is kept projecting slightly from the annular portion  329 . 
         [0116]    When the operating portion  353 , which is the end portion of the operating pin  351 , is pushed inwards of the pot bottom main body  323 , the end portion of the engaging pin  343  that is in engagement with the operating pin  351  can be moved inwards so as to rotate the whole of the engaging pin  341  about the pin end portion  343  of the engaging pin  341  that is fixed by the rotation shaft  347 . 
         [0117]    Consequently, when the leg  307  that projects downwards from the lower end of the pot upper portion  261  is inserted into the leg receiving hole  333  of the pot bottom main body  323  and the pot upper portion  261  is rotated, the leg  307  moves from the inserting portion  334  to the leg stopping portion  335  of the leg receiving hole  333  to thereby push the engaging projecting body  345  that projects partially into the leg receiving hole  333  towards the center of the pot bottom main body  323 , whereby the engaging pin  341  is rotated inwards of the pot bottom main body  323  about the rotation shaft  347 , compressing the elastic body  355 . 
         [0118]    Then, when the pot upper portion  261  is rotated so as to move the leg  307  to a predetermined position in the leg stopping portion  335 , part of the engaging projecting body  345  is allowed to project into the leg stopping portion  335  of the leg receiving hole  333  as shown in  FIG. 15 , whereby the leg  307  can be prevented from being dislocated from the leg stopping portion  335 , and hence, the pot upper portion  261  can be prevented from being dislocated from the pot bottom portion  310 . 
         [0119]    Since the engaging pin  341  is rotated against the elastic force of the elastic body  355  when the pot upper portion  261  is rotated so as to move the leg  307  to the predetermined position in the leg stopping portion  335 , resistance is generated against the rotation of the pot upper portion  261 . Then, when the leg  307  reaches the predetermined position, the resisting force applied through the engaging pin  341  by the elastic body  355  is lost, whereby the fact that the pot upper portion  261  is attached to a predetermined position can be felt through a hand that feels a resistance-free sensation. 
         [0120]    When removing the pot upper portion  261  from the pot bottom portion  310 , the end portion of the engaging pin  343  that is in engagement with the operating pin  351  is moved towards the center of the pot bottom main body  323  by pushing the operating portion  353  inwards of the pot bottom portion  310 . This moves the engaging projecting body  345  inwards of the pot bottom main body  323 , whereby the engaging projecting body  345  can be moved inwards of the leg receiving hole  333 . 
         [0121]    Consequently, the pot upper portion  261  can be rotated so that the leg  307  is moved from the leg stopping portion  335  to the inserting portion  334  so that the leg  307  and the leg end portion  309  can be removed from the inserting portion  334 , whereby the pot upper portion  261  can be removed from the pot bottom portion  310 . 
         [0122]    As shown in  FIG. 16 , contact detecting members  361 , which are metallic plates, are provided on lower sides of the leg receiving holes  333  in positions where the leg stopping portions  335  exist, so that the leg end portions  309  and hence the ring member  301  can be energized as a result of the contact detecting members  361  bring brought into contact with the leg end portions  309 . 
         [0123]    Then, a gear wheel portion  371  that is fixed to the lower surface of the pot bottom main body  323  has a flat circular gear wheel plate  373  and a cylindrical outer circumferential wall  375  that extends perpendicularly downwards from an outer circumference of the gear wheel plate  373  and also has a toothed portion  377  on an outer circumferential surface of a lower end of the outer circumferential wall  375 . 
         [0124]    An outside diameter of the outer circumferential wall  375  is slightly smaller an outside diameter of the main body circumferential wall  327 . The toothed portion  377  of the gear wheel portion  371  is brought into meshing engagement with a motor gear  255  that is fixed to a motor shaft of the motor  253 , whereby the pot bottom portion  310  and the pot upper portion  261  are rotated by the motor  253  of the drive unit  251 . 
         [0125]    As shown in  FIG. 17 , a shaft fixing hole  379  is provided at a center of a lower surface of the gear wheel plate  373 . Additionally, two contacts of a first contact  381  and a first auxiliary contact  386  are provided in positions lying equidistant from and diagonal with respect to the center of the gear wheel plate  373 . 
         [0126]    In addition, two contacts of a second contact  382  and a second auxiliary contact  387  are also provided on the lower surface of the gear wheel plate  373  in positions lying equidistant from and diagonal with respect to the center of the gear wheel plate  373 , however, the distance from the center to the second contact  382  differs from the distance from the center to the first contact  381 . Further, two contacts of a third contact  383  and a third auxiliary contact  388  are also provided on the lower surface of the gear wheel plate  373  in positions lying equidistant from and diagonal with respect to the center of the gear wheel plate  373 , however, the distance from the center to the third contact  383  differs from the distances from the center to the first contact  381  and to the second contact  382 . 
         [0127]    The first contact  381  to the third contact  383  and the first auxiliary contact  386  to the third auxiliary contact  388  are each made of a conductive metallic plate. One end of the rectangular metallic plate is fixed to the lower surface of the gear wheel plate  373 , and the other end of the rectangular metallic plate is made into a sliding contact portion that can be pressed against an object surface by means of an elastic force of the metallic plate. 
         [0128]    Then, a first electrode ring  171  that can be brought into contact with the first contact  381  and the first auxiliary contact  386  is fixed to an upper surface of the bearing plate  167  that faces the gear wheel plate  373  in parallel. A second electrode ring  172  that can be brought into contact with the second contact  382  and the second auxiliary contact  387  is fixed to the upper surface of the bearing plate  167 . A third electrode ring  173  that can be brought into contact with the third contact  383  and the third auxiliary contact  388  is also fixed to the upper surface of the bearing plate  167 . 
         [0129]    The bearing plate  167  supports rotatably the rotation shaft  397  at the center of the first electrode ring  171 , the second electrode ring  172  and the third electrode ring  173  that are disposed concentrically on the upper surface thereof and has a motor shaft hole  168  in an appropriate position radially outwards of the first electrode ring  171  to thereby support rotatably the rotation shaft of the motor  253 . 
         [0130]    A first lead portion  391  that connects the first contact  381  and the first auxiliary contact  386  together, a second lead portion  392  that connects the second contact  382  and the second auxiliary contact  387  and a third lead portion that connects the third contact  383  and the third auxiliary contact  388  together are provided on the lower surface of the gear wheel plate  373 . 
         [0131]    In the interior of the pot bottom portion  310 , the first lead portion  391  is connected to the first electrode plate  317  and one of the three contact detection members  361 , the second lead portion  392  is connected to the other two contact detection members of the three contact detection members  361 , and the third lead portion  393  is connected to the second electrode plate  319 . 
         [0132]    Consequently, electric power that is applied from the first electrode ring  171  to the rotary pot  260  by the first lead portion  391  via the first contact  381  and the first auxiliary contact  386  is supplied to the first electrode plate  317  and is returned to the third lead portion  393  from the second electrode plate  319  via the heaters  315  to thereby be returned to the third electrode ring  173 . 
         [0133]    Additionally, since the first lead portion  391  is connected to one of the three contact detection members, electric power that the first lead portion  391  receives when the contact detection members  361  are in contact with the corresponding leg end portions  309  of the ring member  301  is conducted to the other contact detection members  361  via the ring member  301 , is then returned to the second lead portion  392  and is finally returned to the second electrode ring  172 . 
         [0134]    Since the two electrodes of the first contact  381  and the first auxiliary contact  386  are brought into contact with the first electrode ring  171  in the way described above, even though the contacts move at high speeds over the upper surface of the first electrode ring  171  as a result of the rotation of the rotary pot  260  to thereby be caused to move away from the electrode ring  171  momentarily, there should no such situation that the two contact move away from the electrode ring  171  at the same time, the energization of the rotary pot  260  from the main body portion  110  can be kept executed without any momentary interruption. 
         [0135]    Similarly, since the second contact  382  and the second auxiliary contact  387  are brought into contact with the second electrode ring  172  and the third contact  383  and the third auxiliary contact  388  are brought into contact with the third electrode ring  173 , electric power can be supplied to the rotary pot  260  from the main body portion  110  such as the pot mounting base portion  161 , which is the fixing portion, and the bearing plate  167  in an ensured fashion. 
         [0136]    Since the two contacts that are brought into contact with each electrode ring are disposed in the opposite positions across the center of the gear wheel plate  373 , the two contacts can be prevented from moving away from the electrode ring at the same time, thereby making it possible to maintain the energization of the electrode ring with the lead portion in an ensured fashion. 
         [0137]    In addition, since the electrode rings are provided on the upper surface of the bearing plate  167  and the contacts that are brought into contact with the electrode rings are provided on the lower surface of the gear wheel portion  371  that faces the bearing plate  167 , compared with a case where electric power is supplied to the rotary portion by providing the electrode rings on the circumference of the rotation shaft  397 , an axial length of the rotation shaft  397  is shortened, whereby the rotary pot  260  can be disposed in a low position lying close to the main body bottom portion  141 . 
         [0138]    Then, as shown in  FIG. 18 , the power supply switch  410  of the cotton candy preparing device  100  is formed by a switch main body  461  that controls the energization of the rotary pot  260 , the switch operating rod  411  that enables the operation of an operating switch  465  of the switch main body  461  and the locking body  441  that restricts the sliding operation of the switch operating rod  411 . 
         [0139]    This switch operating rod  411  has a rod main body  413  that is a rod-shaped plate, and a first sliding hole  415  and a second sliding hole  417 , which are both elongated holes, are provided individually near ends of the rod main body  413 . 
         [0140]    Inserting shafts  475  that are distal ends of rod receiving shafts  471  that are provided on the bottom plate portion  143  of the main body bottom portion  141  so as to rise therefrom are inserted into the first sliding hole  415  and the second sliding hole  417 , and the switch operating rod  411  is supported by rod receiving portions  473  formed at upper ends of the rod receiving shafts  471 , enabling the rod main body  413  of the switch operating rod  411  to slide in an axial direction. 
         [0141]    Namely, the rod receiving shafts  471  are rod-like bodies whose upper ends are formed into the rod receiving portions  473  and having a diameter that is greater than minor diameters of the first sliding hole  415  and the second sliding hole  417 . The inserting shafts  475  whose diameters are substantially equal to the minor diameters of the first sliding hole  415  and the second sliding hole  417  are provided at the distal ends of the rod receiving shafts  471  so as to extend from the upper ends thereof so that the rod receiving shafts  471  can move in longitudinal directions of the first sliding hole  415  and the second sliding hole  417  that are elongated holes, whereby the switch operating rod  411  can move in the major diameter directions of the first sliding hole  415  and the second sliding hole  417  that are the elongated holes. 
         [0142]    In addition, the switch operating rod  411  has a projecting portion  421  that extends sideways from the vicinity of the first sliding hole  415  of the rod main body  413 , and a switch knob  432  is provided at a distal end of the projecting portion  421 . This switch knob  423  is positioned in the switch hole  135  that is formed in the upper outer edge portion  113  of the main body cover portion  111  and the lower outer edge portion  145  of the main body bottom portion  141 , whereby the switch knob  423  can move in a horizontal direction by a finger tip so as to move the switch operating rod  411  in the axial direction. 
         [0143]    The switch operating rod  411  has a locking projection  425  that is provided on the side surface where the projecting portion  421  of the rod main body  413  is provided in a position lying closer to the second sliding hole  417  than a center of the rod main body  413  so as to project upwards therefrom and an abutting projection  427  that is provided on an upper surface of the rod main body  413  in a position lying near the position where the projecting portion  421  is provided and near a central line position of the rod main body  413  so as to project upwards therefrom. 
         [0144]    Further, the switch operating rod  411  has an elongated groove  431  that penetrates from the upper surface to a lower surface of the rod main body  413 . This elongated groove  431  is provided near the side of the rod main body  413  so as to extend along the side of the rod main body  412  between the projecting portion  421  and the locking projection  425 . Thus, a side surface portion of the rod main body  413  that extends along the elongated groove  431  is formed into a thin plate-like elastic portion  433  that can be deformed elastically, and a projecting portion  435  is formed on an external surface of the elastic portion  433  that projects slightly from the side surface of the rod main body  413 . 
         [0145]    The locking body  441  that is rested on the upper surface of the rod main body  413  of the switch operating rod  411  has a rod-shaped portion  445  that is a rod-shaped plate body and a head portion  443  that is a plate body that is formed at one end of the rod-shaped portion  445  by expanding the one end into a triangular shape. A width of the head portion  443  is wider than a width of the rod main body  413 . 
         [0146]    Part of this head portion  443  is made into an abutting surface  455  that is a plane that intersects a center axis of the rod-shaped portion  445  substantially at right angles. When center axes of the rod-shaped portion  445  and the rod main body  413  are made parallel to each other so that the rod-shaped portion  445  is superposed on the rod main body  413 , the abutting surface  455  and one end of the abutting projection  427  can be brought into abutment with each other as shown in  FIG. 7 . As this occurs, the inserting shafts  475  are positioned in right positions, as seen in  FIG. 18 , of the first sliding hole  415  and the second sliding hole  417  on the switch operating shaft  411 , whereby the switch operating rod  411  is fixed to a left end position in its moving range. 
         [0147]    Then, the rod-shaped portion  445  of the locking body  441  has a shaft hole  447  in a middle portion thereof. The inserting shaft  475  is inserted into this shaft hole  447 , whereby the locking body  441  is attached to the rod receiving shaft  471  so as to rotate about the inserting shaft  475  in a horizontal direction. 
         [0148]    The locking body  441  has a spring mounting portion  449  at an opposite end portion of the rod-shaped portion  445  to the end portion where the head portion  443  is formed. As shown in  FIG. 7 , a tensile force produced by a spring  459  is exerted on the spring mounting portion  449 , whereby a side surface of the rod-shaped portion  445  is brought into abutment with the locking projection  425 , and the rod-shaped portion  445  is superposed on the rod main body  413  so that the center axis of the rod-shaped portion  445  becomes parallel to the center axis of the rod main body  413 . 
         [0149]    In addition, as this occurs, part of the head portion  443  projects to the side of the rod main body  413 , and the projecting body  457  that projects downwards from the lower surface of the projecting portion  421  is positioned to the side of the rod main body  413  that is spaced slightly apart from the elastic portion  433  of the rod main body  413 . 
         [0150]    The locking body  441  has the operating projection  451  on an upper surface of the head portion  443  at a portion thereof that lies on a side opposite to the side where the projecting body  457  is provided. 
         [0151]    The operating projection  451  has an inclined portion  453  that makes up a surface that is inclined obliquely in the direction of the shaft hole  447  and is inserted into the engaging opening portion  125  of the main body cover portion  111 . 
         [0152]    Consequently, when the pan portion  201  is placed on the main body portion  110  and the pan portion  201  is rotated so that the locking pieces  223  are positioned in the engaging opening portions  125  in such a way as to be inserted under the locking pieces  223 , the locking piece  223  is brought into abutment with the inclined portion  453 , whereby the locking piece  223  can move the operating projection  451  towards the center of the main body portion  110  so that the locking body  441  rotates about the shaft hole  447 . 
         [0153]    Owing to this, as shown in  FIG. 13 , the locking body  441  rotates so that the center axis of the rod main body  413  and the center axis of the rod-shaped portion  445  of the locking body  441  are released from the parallel state, whereby the abutting surface  455  is dislocated from the abutting projection  427 , and the switch operating rod  411  can be moved in a rightward direction as seen in  FIG. 13 . 
         [0154]    As this occurs, although not shown in  FIG. 13 , the projecting body  457  is in abutment with the elastic portion  433 , and when the switch knob  423  is moved laterally, that is, when the switch operating rod  411  is moved laterally, the projecting body  457  is brought into contact with the projecting portion  435 , and a sensation of clicking can be imparted to the finger tip with which the switch knob  423  is operated as a result of resistance being generated when the projecting body  457  rives over the projecting portion  435 . 
         [0155]    Then, by moving the switch operating rod  411  laterally, the operating switch  465  of the switch main body  461  is moved laterally, whereby the supply of electric power by the power supply switch  410  is controlled to be made or broken. 
         [0156]    Then, when the power supply switch  410  is operated to activate the cotton candy preparing device  100  to operate, with the pan portion  201  left dismounted, the switch knob  423  is prevented from being moved, that is, the locking body  441  is prevented from being operated to switch on the power supply switch  410 . On the other hand, with the pan portion  201  mounted properly, the switch knob  423  can be operated. When operating the power supply switch  410  to be on or off to activate or deactivate the cotton candy preparing device  100 , the power supply switch  410  can be so operated while making the user feel that he or she has performed clearly the required operation through a sensation of clicking. 
         [0157]    As shown in  FIG. 19 , in the electrical wiring of the cotton candy preparing device  100 , one terminal of power supply input terminals  501  that are terminals of the adapter jack  485  is connected to one terminal of the connecting jack  545  that is fixed to the first electrode ring  171  and the control circuit board  175 . 
         [0158]    The second connecting ring is connected to an input terminal of a constant voltage circuit  531  via the switch main body  461  of the power supply switch  410 . The connecting ring is connected to the other terminal (a chassis earth terminal) of the power supply input terminals  501  that are the terminals of the adaptor jack  485  via a heater switch  521 . 
         [0159]    The heater switch  521  is an electromagnetic switch. A contact  525  of the heater switch  521  that makes or breaks the supply of electric power is connected so as to be inserted between the third connecting ring and the other terminal (the chassis earth terminal) of the power supply input terminals  501 . In addition, one end of an electromagnetic module  523  that controls the opening or closing of the contact  525  is connected to a constant voltage circuit  531  side of the power supply switch  410 , and the other end of the electromagnetic module  523  is connected to the other terminal (the chassis earth terminal) of the power supply input terminals  501  via a switching transistor  527 . 
         [0160]    Then, the constant voltage circuit  531  drops a voltage of 24 volts of a direct current that is inputted from the power supply input terminals  501  via the first electrode ring  171 , the second electrode ring  172 , and the power supply switch  410  to a voltage of 6 volts of a direct current to thereby output a stable control system voltage. 
         [0161]    An output terminal of the constant voltage circuit  531  is connected to an anode terminal of a light emitting diode  537  that is disposed between the power supply switch  410  that is mounted on the main body of the cotton candy preparing device  100  and the adaptor jack  485  to make up a pilot lamp, an electric power input terminal of a control IC  535  that controls the operation of the cotton candy preparing device  100  and an electric power input terminal of a photocoupler  551 . 
         [0162]    This photocoupler  551  is made up of a photodiode  553 , a phototransistor  555  and an output transistor  557 . When light outputted by the photodiode  553  is reflected by an object and the reflected light is inputted into the phototransistor  555 , the photocoupler  551  passes an electric current and outputs an H level signal from a detection signal output terminal by putting the output transistor  557  in a cutoff state. On the other hand, when the reflected light is not inputted into the phototransistor  555 , the photocoupler  551  cuts off the electric current and outputs an L level detection signal from the detection signal output terminal by putting the output transistor  557  in an energized state. 
         [0163]    Then, this photocoupler  551  is disposed on the upper surface of the bearing plate  167 , detects a code mark  561  drawn on a lower surface of the gear wheel plate  373  and detects the rotation of the gear wheel plate  373 , that is, the rotation of the rotary pot  260 . 
         [0164]    A cathode of the light emitting diode  537 , which is made into the pilot lamp, is connected to a lamp control terminal of the control IC  535  and a detection signal output terminal of the photocoupler  551  is connected to a detection signal input terminal of the control IC  535 . 
         [0165]    Then, a heater control terminal of the control IC  535  is connected to a control terminal of the switching transistor  527  so as to control the energization of the switching transistor  527  to thereby control the on and off control of the heater switch  521 . 
         [0166]    The invention is not limited to the case where the electromagnetic switch is used as the heater switch  521  so as to be combined with the switching transistor  527 . Hence, the invention may adopt a case where a field-effect transistor is used as the heater switch  521  and the heater current is directly controlled to be conducted or cut off by a control signal from the control IC  535 . 
         [0167]    The chassis earth terminal, which is the other terminal of the power supply input terminals  501  of the adaptor jack  485  is connected to the heater switch  521 , the power supply input terminal of the control IC  535  and the photocoupler  551 . The chassis earth terminal is additionally connected to the outer end of the connecting plug  547  via a motor control transistor  541 . 
         [0168]    A control input terminal (a base terminal) of the motor control transistor  541  is connected to the motor control terminal of the control IC  535 . 
         [0169]    Then, as has been described above, the first lead portion  391  that connects together the first contact  381  and the first auxiliary contact  386  that are incorporated in the pot bottom portion  310  is connected to the first electrode plate  317  and one of the three contact detecting members  361 , and the second lead portion  392  that connects together the second contact  382  and the second auxiliary contact  387  is connected to the two remaining contact detecting members of the three contact detecting members  361 . When the pot upper portion  261  is mounted on the pot bottom portion  310 , the one contact detecting member  361  and the first electrode plate  317  are electrically connected to the two contact detecting member  361  via the legs  307  of the ring member  301 , whereas when the pot upper portion  261  is removed from the pot bottom portion  310 , the electrical connection therebetween is cut off. 
         [0170]    Consequently, a detecting switch  511  is formed in which the first electrode plate  317  and the one contact detecting member  361  make up a first terminal  513 , the ring member  301  makes up a connecting piece  517 , and the two contact detecting members  361  make up a second terminal  515 , and this detecting switch  511  is connected in series with the power supply switch  410 . 
         [0171]    Owing to this configuration, even though the power supply switch  410  is operated so that the power supply switch  410  is switched on, with the pot upper portion  261  left dismounted, no electric power is supplied to the constant voltage circuit  531  and hence to the control IC  535 , whereby the cotton candy preparing device  100  cannot be activated to operate. 
         [0172]    In this way, since the first electrode ring  171  to the third electrode ring  173 , which make up the three electrode rings, are provided on the upper surface of the bearing plate  167 , heating electric power is supplied to the heaters  315  by the use of the first electrode ring  171  and the third electrode ring  173 , and the fact that the pot upper portion  261  is mounted on the pot base portion  310  is detected by the use of the first electrode ring  171  and the second electrode ring  172 , whereby the operation of the cotton candy preparing device  100  can be controlled. 
         [0173]    In the power supply switch  410 , as has been described above, with the pan portion  201  left dismounted from the main body portion  110 , the abutting surface  455  of the locking body  441  is kept in contact with the abutting projection  427  of the switch operating rod  411  so as to prevent the operation of the switch operating rod  411 , whereby the power supply switch  410  can be prevented from being operated. 
         [0174]    Consequently, the power supply switch  410  can be switched on only when the pan portion  201  is mounted on the main body portion  110 , whereby with the pot upper portion  261  of the rotary pot  260  mounted on the pot bottom portion  310 , the power supply switch  410  can be operated to activate the cotton candy preparing device  100  to operate. 
         [0175]    In this way, by designing the switch knob  423 , which makes up the power supply switch  410 , so as not to be moved with the pan portion  201  left dismounted, although the power supply switch  410  can be activated to operate by operating the switch knob  423  with the pan portion  201  left dismounted, being different from the case where the rotary pot  260  is made not to rotate, the state where the cotton candy preparing device  100  is stopped from being activated to operate can be maintained without making the user misunderstand that the device cannot be activated by an erroneous operation by the user. 
         [0176]    Then, in activating the cotton candy preparing device  100  to operate, as shown in  FIG. 20 , when a power supply voltage is applied to the control IC  535  by switching on the power switch  410 , the light emitting diode  537 , which is formed into the pilot lamp, is illuminated first (S 110 ). 
         [0177]    Then, the heater switch  521  is switched on to start the heating by the heaters  315  (S 120 ). Further, the light emitting diode  537  is turned on to flash (S 125 ), and whether or not one minute has elapsed is determined (S 130 ). 
         [0178]    Then, if it is determined that one minute has elapsed, the motor control transistor  541  is energized to start the rotation of the motor  253  (S 140 ). Then, the rotation speed of the rotary pot  260  is set at an appropriate rotation speed ranging substantially from 1500 to 200 rpm to set up a state where cotton candies can be prepared. 
         [0179]    When the motor  253  is rotating, that is, the rotary pot  260  is rotating, the rotation speed of the rotary pot  260  is detected by an output signal of the photocoupler  551  (S 150 ). Then, it is determined whether or not the rotation speed of the rotary pot  260  is equal to or faster than 1000 rpm (S 155 ). Then, it is determined whether or not the power supply switch  410  should be switched off (S 160 ). The rotary pot  260  is kept rotating and the heaters  315  are kept heated while repeating the determinations on the rotation speed of the rotary pot  260  (S 155 ) and whether or not the power supply switch  410  should be switched off (S 160 ). 
         [0180]    Then, if it is determined in step S 155  that the rotation speed of the rotary pot  260  is slower than 1000 rpm, the heater switch  521  is switched off (S 200 ) to cut off the energization of the heaters  315 , and the motor control transistor  541  is also disconnected (S 210 ) to stop the motor  253 , that is, the rotary pot  260  from rotating. 
         [0181]    Further, it is determined whether or not the power supply switch  410  should be switched off (S 230 ) while executing a flashing control (S 220 ) of the light emitting diode  537  in which the light emitting diode  537  is controlled to flash in such a way that a turn-on time becomes extremely shorter than a turn-on time in normal flashing. 
         [0182]    In addition to the case where the rotation speed of the rotary pot  260  is kept constant within the range from 1500 to 2000 rpm, there may be a case where a short energization interruption time is provided and the rotation speed of the rotary pot  260  is decelerated and accelerated while keeping the rotary port  260  rotating at a rotation speed of 1000 rpm or faster. By changing the rotation speed of the rotary pot  260  in this way, when granulated sugar or sugar candy loaded in the interior of the rotary pot  260  becomes half melted, the granulated sugar or sugar candy so melted can be prevented from staying at a specific location in the interior of the rotary pot  260 . 
         [0183]    In this way, in the cotton candy preparing device  100  according to the embodiment, since the PTC heaters are used as the heaters  315 , in case the heaters  315  fail, the heating by the heaters  315  is disabled to ensure the safety in an ensured fashion. In addition, the heating temperature is controlled to be constant automatically, this obviating the necessity of controlling the application voltage. 
         [0184]    In the disassembled state where the pan portion  201  or the rotary pot  260  is removed from the pot bottom portion  310 , the heaters  315  are prevented from being heated or the rotary mechanism unit  250  is prevented from rotating. Therefore, the cotton candy preparing device  100  is safe. 
         [0185]    Further, the space can be defined between the cotton candy preparing device  100  and the table where the device is rested by the feet  153 , whereby a good circulation of air can be provided in which air taken into the main body portion  110  from the outside air intake holes  151  in the bottom plate  143  compensates for air that escapes from the main body portion  110  in the form of a rising current of air heated by the heaters  315  or air that is jetted from the side of the rotary pot  260  together with cotton candy, thereby making it possible to prepare cotton candy of good quality. 
         [0186]    The embodiment that has been described heretofore is presented as an example of the invention, and there is no intention to limit the scope of the invention by the embodiment. This novel embodiment can be carried out in other various forms, and various omissions, replacements and alterations or modifications can be made thereto without departing from the spirit and scope of the invention. The resulting embodiments and their modifications are included not only in the spirit and scope of the invention but also in the scope of inventions claimed under the following claims and equivalents thereof.