Patent Publication Number: US-2021169262-A1

Title: Electrical device for making beverages using power tool battery

Description:
CROSS-REFERENCE 
     The present application claims priority to Japanese patent application serial number 2017-139946 filed on Jul. 19, 2017 and to Japanese patent application serial number 2017-228767 filed on Nov. 29, 2017, the contents of both of which are incorporated fully herein by reference. 
     TECHNICAL FIELD 
     The present invention generally relates to an electrical device, such as a hot beverage making device, comprising a battery-mount part configured such that a battery used in a power supply of a power tool is mountable thereon, and a heat-generating means, which can boil water by using electric power (current) supplied by the battery mounted on the battery-mount part. 
     BACKGROUND ART 
     A coffeemaker  100  described in U.S. Pat. No. 9,559,539 (JP Patent No. 5657332 B2) is shown herein in  FIG. 26 . This coffee maker  100  includes a first battery-mount part  103   a  and a second battery-mount part  103   b  located inside a battery-storage compartment  102 . Furthermore, an 18-V battery B 1 , which is designed for use as a power supply of a power tool, is mountable on the first battery-mount part  103   a,  and, likewise, a 14.4 V power tool battery B 2  is (simultaneously) mountable on the second battery-mount part  103   b.  In this coffeemaker  100 , it is possible, for example, to supply electric power to a heat-generating means (heating element) of the coffeemaker  100  using the 18-V battery B 1  or the 14.4 V battery B 2 . Moreover, such a coffeemaker  100  makes it possible to brew coffee, e.g., at a construction work site (or any other location where a commercial AC power supply is not available) using the batteries B 1 , B 2  of a power tool. 
     SUMMARY OF THE INVENTION 
     The above-described known coffeemaker  100  is configured such that a filter is housed inside a filter case  105 , hot water is discharged into the filter case  105  after a proper quantity of coffee grounds has been placed in the filter case  105 , and then coffee is dripped down into a decanter  106 . Consequently, at a work site, it is necessary to scoop coffee grounds, using a measuring spoon or the like (which must also be brought to the work site), from a bag of coffee grounds and put the scooped coffee grounds in the filter, thereby making it inconvenient to brew coffee at the work site. In addition, the above-described known coffeemaker  100  is capable of simultaneously mounting two different batteries B 1 , B 2 , which necessitates complicated electronics to prevent electrical problems. 
     It is one, non-limiting object of the present teachings to, e.g., make it easy to brew a hot beverage at a construction work site by operating an electrical device using a battery of a power tool. 
     In a first aspect of the present teachings, an electrical device (e.g., a hot beverage maker) comprises a battery-mount part, which is configured such that a battery (battery pack, battery cartridge) designed for use as a power supply of a power tool is mountable thereon, and a heat-generating means (heating element), which can boil water by using electric power supplied by the battery mounted on the battery-mount part. The electrical device further comprises: a case configured to hold a pod or other type of single-serve container, which contains a predetermined amount of, e.g., tea leaves or coffee grounds within a water-permeable bag-shaped element or a capsule, as well as a hot water supply configured such that water boiled by the heat-generating means can be supplied automatically to the case. An extraction part (e.g., a drain hole, which may optionally comprise a spring-loaded stopper) is provided on the case and permits the hot beverage produced by the hot water that had been poured onto (injected into) the pod or other single-serve container to flow out of the case, e.g., into a decanter (carafe, coffee pot). 
     According to this first aspect of the present teachings, the electrical device can be operated, e.g., at a construction work site or other location where an AC power source is not available, using a battery (battery pack, battery cartridge) designed for use with a power tool, such as a driver drill, circular saw, etc. Furthermore, because a pod or other single-serve container (e.g., a pre-packaged coffee or tea container) can be used, it becomes unnecessary to, for example, use a measuring spoon or the like to take coffee grounds out of a coffee grounds bag and place them in a filter, such that a hot beverage can be easily and conveniently made, e.g., at a construction work site. 
     According to a second aspect of the present teachings, the electrical device further comprises: a water reservoir that holds water, and a passageway configured such that the water can be supplied from the water reservoir to the location of the heat-generating means. Preferably, the heat-generating means is disposed at a location lower than the water reservoir. Thus, if the heat-generating means is disposed at a location lower than the water reservoir, a water-supplying means, such as a pump, is unnecessary for supplying water from the water reservoir to the heat-generating means. 
     According to a third aspect of the present teachings, the battery-mount part is provided at a location lower than that of the water reservoir. In such an embodiment, when water is being boiled, the battery, which is heavy, is disposed at a low location, which gives the electrical device a low center of gravity and thereby improves the stability of the electrical device. 
     According to a fourth aspect of the present teachings, a wall preferably partitions a space, in which a container (e.g., a tank) comprising the water reservoir is housed, from a space in which the heat-generating means is housed. In such an embodiment, water can be prevented from entering the space in which electrical components such as the heat-generating means are housed. 
     According to a fifth aspect of the present teachings, a wall preferably partitions a space, in which a hot water supply nozzle of the hot water supply that supplies the hot water to the case is housed, from the space in which the heat-generating means is housed. In such an embodiment as well, hot water can be prevented from entering the space in which the heat-generating means is housed. 
     A sixth aspect of the present teachings concerns the fact that, in the above-described known coffeemaker  100  shown in  FIG. 26 , it is possible to simultaneously mount an 18-V battery B 1  and a 14.4-V battery B 2  on a first battery-mount part  103   a  and a second battery-mount part  103   b  of a battery-storage part  102 . Consequently, the electrical circuit of the coffeemaker  100  requires a voltage-switching circuit. In addition, an interlock circuit or the like is necessary to ensure that the voltage of the 18-V electrical circuit is not applied to the 14.4-V electrical circuit. Consequently, the circuit configuration of the coffeemaker  100  is relatively complex. In addition, there is also a possibility that problems will occur in the interlock circuit or the like over the course of time. 
     Therefore, according to the sixth aspect of the present teachings, it is preferable to simplify the circuit configuration by making a voltage-selecting circuit, an electrical interlock, etc. unnecessary, and to improve electrical reliability. In an embodiment of the sixth aspect, the electrical device comprises: a plurality of the battery-mount parts that are preferably configured such that, when one battery is mounted on one of the battery-mount parts, it is not possible (e.g., it is impossible) to mount another battery on the other battery-mount part. In such an embodiment, even though a plurality of battery-mount parts is provided, only one battery can be mounted on the battery-mount parts at a time. That is, a plurality of batteries is never mounted on the battery-mount parts simultaneously. Consequently, a battery-switching circuit, an interlock circuit, etc. become unnecessary, the circuit configuration is simplified, and electrical reliability is improved. 
     According to a seventh aspect of the present teachings, the sizes of the battery-mount parts of the plurality of battery-mount parts differ, and a configuration is employed such that the batteries (battery packs, battery cartridges) having sizes corresponding to the battery-mount parts are mountable on the corresponding battery-mount parts. 
     According to an eighth aspect of the present teachings, a pair of guide rails and a plurality of terminals are provided on each of the battery-mount parts. Furthermore, each of the plurality of battery-mount parts differs from each other in the arrangement of the guide rails and/or in the arrangement of the plurality of terminals. Therefore, the electrical device is configured such that different types of batteries, which are respectively capable of engaging with and sliding with respect to the pair of guide rails and are capable of electrically connecting to the terminals of each of the different battery-mount parts, are mountable on the respective (different) battery-mount parts. 
     According to a ninth aspect of the present teachings, a cover member is designed such that it exposes one of the battery-mount parts and covers the other battery-mount part. Furthermore, the cover member is slidable relative to the plurality of battery-mount parts. Consequently, when one of the batteries is mounted on the sole exposed battery-mount part, the other battery-mount part is covered by the cover member. That is, when one of the batteries is mounted on one of the battery-mount parts, because the positive and negative terminals (charging part) of the other battery-mount part are not exposed (i.e. the terminals are covered by the cover member), a short-circuit fault can be prevented. 
     According to a tenth aspect of the present teachings, the plurality of battery-mount parts is provided in a side-by-side arrangement, and the cover member is configured such that it is capable of sliding in the side-by-side direction of the plurality of battery-mount parts. Therefore, by sliding the cover member, one of the battery-mount parts is exposed and the other battery-mount part is covered. 
     According to an eleventh aspect of the present teachings, the electrical device is configured such that, when one battery is mounted on one of the battery-mount parts, if another battery is moved in the mounting direction with respect to the other battery-mount part, then the other battery makes contact with the battery mounted on the one battery-mount part, thereby blocking the movement of the other battery. That is, the plurality of battery-mount parts are disposed or arranged closely together, so that there is insufficient space to simultaneously mount two or more batteries on the battery-mount parts. Consequently, even in the hypothetical situation in which the cover member has been removed, it is still impossible to simultaneously mount two or more of the batteries on the plurality of the battery-mount parts. 
     According to a twelfth aspect of the present teachings, the plurality of battery-mount parts is provided on one (i.e. the same) side surface of a housing, and a lid configured to cover or close an opening of the water reservoir is provided on an upper surface of the housing. The lid is preferably located on an upper side of the one side surface of the housing on which the battery-mount parts are provided, and is configured to stand up like a wall along an end edge of the upper surface of the housing when the lid is positioned (raised) to open the opening of the water reservoir. In such an embodiment, when water is being supplied (poured) into the water reservoir within the housing, the lid, which stands up like a wall, blocks water from splashing onto the battery-mount parts. 
     According to a thirteenth aspect of the present teachings, the lid is coupled by a hinge mechanism to the housing such that the lid can pivot about the end edge of the upper surface of the housing. 
     According to a fourteenth aspect of the present teachings, the electrical device preferably comprises a cover-operation switch, which operates in conjunction with movement of the cover member. Preferably, the cover-operation switch is configured to disconnect a power-supply line between a power-supply terminal of the battery-mount part covered by the cover member and the heat-generating means, and to connect a power-supply line between a power-supply terminal of the exposed one battery-mount part and the heat-generating means. Consequently, for example, when a battery is mounted on the sole exposed battery-mount part, no voltage is applied to the positive and negative terminals (charging part) of the battery-mount part covered by the cover member. 
     According to a fifteenth aspect of the present teachings, the cover-operation switch is configured such that, if the cover member is removed from the battery-mount parts, the power-supply line between the power-supply terminals of all the battery-mount parts and the heat-generating means is disconnected. Consequently, the electrical device can no longer be used after the cover member has been removed, thereby improving device safety. 
     According to a sixteenth aspect of the present teachings, the electrical device preferably comprises: a water reservoir (e.g., a tank) that holds water; and a passageway configured to supply the water from the water reservoir to the location of the heat-generating means. Preferably, the battery-mount part(s) is (are) provided at a location higher than the water reservoir. In such an embodiment, when water is being supplied (poured) into the water reservoir, the likelihood that some of the water will splash onto the mounted battery is reduced. 
     According to an seventeenth aspect of the present teachings, the electrical device according to any one of preceding aspects, or any of the subsequently-described embodiments, further includes one or more batteries that are mountable on the battery-mount part(s) of the electrical device. 
     It is noted that not all elements are required to be utilized in all embodiments, and e.g., some aspects may be omitted to develop additional embodiments of the present teachings. For example, in aspects of the present teachings relating to the electrical circuits, arrangement of the battery-mount parts, the lid, the other components of the electrical device, etc., it is not necessary to use a pod or other single-serving container containing, e.g., coffee or tea. That is, in such embodiments, loose coffee grounds or loose tea leaves may be placed in a filter provided in the case. 
     Additional aspects, objects, embodiments and advantages of the present teachings will become apparent to a person of ordinary skill upon reading the following description of presently preferred embodiments and the appended claims in view of the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an oblique view (a battery B 1  mounting diagram), viewed from the front left, of a coffeemaker, which is an electrical device according to a first embodiment of the present teachings. 
         FIG. 2  is a front view (an auxiliary view taken in the direction of arrow II in  FIG. 1 ) of the coffeemaker. 
         FIG. 3  is an oblique view (a view in which the battery B 1  has been removed), viewed from the front right, of the coffeemaker. 
         FIG. 4  is a front view that shows a support structure of the coffee decanter (a modified example). 
         FIG. 5  is an oblique view of a drip case (for use with coffee pods) of the coffeemaker. 
         FIG. 6  is a longitudinal cross-sectional view of the drip case (for use with coffee pods). 
         FIG. 7  is an oblique view of the drip case (for use with a filter). 
         FIG. 8  is an oblique view of the drip case (for use with a filter). 
         FIG. 9  is an oblique view (a battery B 2  mounting diagram), viewed from the front right, of the coffeemaker. 
         FIG. 10  is an oblique view (a view in which the battery B 2  has been removed), viewed from the front right, of the coffeemaker. 
         FIG. 11  is a schematic drawing of a water-heating element of the coffeemaker. 
         FIG. 12  is a plan cross-sectional view (an auxiliary cross-sectional view taken along line XII-XII in  FIG. 11 ) of the water-heating element. 
         FIG. 13  is a longitudinal cross-sectional view (1) that shows the water-heating element, etc., of the coffeemaker. 
         FIG. 14  is an auxiliary cross-sectional view taken along line XIV-XIV in  FIG. 13 . 
         FIG. 15  is a longitudinal cross-sectional view (2) that shows the water-heating element, etc., of the coffeemaker. 
         FIG. 16  is an electrical-circuit diagram of the coffeemaker (when the battery B 1  is mounted). 
         FIG. 17  is an electrical-circuit diagram of the coffeemaker (when the battery B 2  is mounted). 
         FIG. 18  is an electrical-circuit diagram of the coffeemaker according to a first modified example. 
         FIG. 19  is an electrical circuit of the coffeemaker according to a second modified example. 
         FIG. 20  is a schematic side view of the coffeemaker according to a third modified example. 
         FIG. 21  is a schematic side view of the coffeemaker according to a fourth modified example. 
         FIG. 22  is an oblique view of the drip case of the coffeemaker according to a fifth modified example. 
         FIG. 23  is a longitudinal cross-sectional view of the drip case of  FIG. 6 . 
         FIG. 24  is an oblique view of the drip case. 
         FIG. 25  is a longitudinal cross-sectional view of the drip case. 
         FIG. 26  is an overall oblique view of a known coffeemaker. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     An electrical device according to representative, non-limiting embodiments of the present teachings will be explained below with reference to  FIG. 1  to  FIG. 25 . As shown in  FIG. 1 , etc., the representative electrical device according to the first embodiment of the present teachings is a coffeemaker  10  in which a battery of a power tool is used as a power supply. Here, front, rear, left, right, up, and down shown in the drawings correspond to front, rear, left, right, up, and down of the coffeemaker  10 . As will be apparent, the coffeemaker  10  is also capable of making other brewed (hot) beverages, such as tea, hot chocolate, etc. 
     Overview of Configuration of Coffeemaker  10   
     As shown in  FIG. 1 , etc., the coffeemaker  10  comprises: a coffeemaker-main-body  20  that brews the hot beverage (e.g., drips coffee); a decanter (carafe, coffeepot)  35  that collects the dripped hot beverage (e.g., coffee); a plate  30  on which the decanter  35  is placed; and a battery-mount part  40  on which two batteries B 1 , B 2  are alternately mountable. The coffeemaker-main-body  20  comprises a substantially box-shaped housing  22  that is elongated in the front-rear direction and is formed such that an upper part and a lower part of the housing  22  project forward from a center part of the housing  22 . A recessed portion  22   r  is provided, e.g., for adhering a label. Furthermore, a drip-case-holder  22   f,  which houses a drip case  21 , is provided at the location of a forward-projection part of the upper part of the housing  22 . A housing space for the decanter  35  is provided downward of the drip-case-holder  22   f.  Furthermore, the plate  30 , which is the forward-projection part of the lower part of the housing  22 , is provided on a lower side of the housing space for the decanter  35 . 
     In this embodiment, as shown in  FIG. 1 , the decanter  35  is placed on the plate  30  such that it is fitted into a bottom of a center recessed part  32  formed on an upper surface of the plate  30 . As shown in  FIG. 4 , retaining rails  33 , which extend in the front-rear direction, are provided on the left and right sides of the plate  30 , and these retaining rails  33  can confine flanges  35   f,  which are formed on (extend from) the bottom of the decanter  35 , in the left-right direction and the up-down direction. Therefore, the decanter  35  can be placed on the plate  30  by being slid from the front to the rear such that the flanges  35   f  of the decanter  35  are confined by an upper surface  30   u  of the plate  30  and the left and right retaining rails  33 . As a result, it is less likely that the decanter  35  will fall off the plate  30  while the coffeemaker  10  is being transported. 
     The drip case  21  is configured such that it can be inserted, from the front, into the drip-case-holder  22   f  of the housing  22 . The drip case  21  is also known in the art as a brewing funnel, brewing basket, pod holder, capsule holder, drip tray, etc. As shown in  FIGS. 5 and 6 , the drip case  21  comprises: a case-main-body  21   m;  a handle  21   h,  which projects forward from a front-surface upper part of the case-main-body  21   m;  and a holder  21   d,  which is substantially L-shaped in a side view and supports the case-main-body  21   m  from below. Furthermore, an extraction part  21   p,  which permits the brewed coffee, tea, etc. to flow downwardly into the decanter  35 , is provided at the center of the bottom of the case-main-body  21   m.  The extraction part  21   p  may be merely a drain hole, or may be a drain hole having a spring-loaded stopper that is configured to open the drain hole only when the decanter  35  is placed underneath the drip case  21 . As shown in  FIG. 5  and  FIG. 6 , the drip case  21  is configured such that a coffee pod CP, e.g., a bag-shaped filter prefilled with an appropriate quantity of coffee grounds, e.g., for a single serving or for multiple servings, can be set in the case-main-body  21   m.  That is, the coffee pod CP corresponds to a pod, a single-serving container or a pre-filled coffee or tea pack that is capable of preparing one, two or more servings and also is formed as a filter material that encases a predetermined amount of coffee grounds, tea leaves, etc., of the present teachings. The case-main-body  21   m  corresponds to a case (brewing funnel, brewing basket, pod holder, capsule holder, drip tray, etc.) of the present teachings. It is noted that the filter is typically formed of a nonwoven fabric, paper, or the like, but the filter can also be formed of other materials. 
     Instead of configuring the drip case  21  exclusively for use with a coffee pod CP, it is also possible to configure the drip case  21  for use with a mesh filter F, as shown in  FIG. 7  and  FIG. 8 . In this configuration of the drip case  21 , the user can place an appropriate quantity of loose coffee grounds, loose tea leaves, etc. in the mesh filter F. The drip case  21  of this embodiment may further comprise a lid  21   f  having numerous holes  21 z, through which hot water can pass, formed therein. 
     As shown in  FIGS. 1 and 13 , a water reservoir (reservoir tank)  22   w,  which holds water at a location on a rear side of the drip-case-holder  22   f,  is provided in the upper part of the housing  22  at substantially the same height position as that of the drip case  21 . The water reservoir  22   w  has an opening in the upper surface of the housing  22  and is configured such that the opening can be opened and closed by a lid  23 , which has an oblong shape. The upper surface of the housing  22  is formed into an oblong shape, and a lid-storage recessed part  22   y  (refer to  FIG. 1 ), which likewise has an oblong shape, is formed on an inner side of the edge of that upper surface. Furthermore, as shown in  FIG. 3 , when the lid  23  closes the opening of the water reservoir  22   w,  the lid  23  is housed in the lid-storage recessed part  22   y,  and thus the upper surface of the lid  23  is flush with the upper surface of the housing  22 . As shown in  FIG. 1 , a right-side part of the lid  23  is coupled to the right side (edge) of the lid-storage recessed part  22   y  of the housing  22  by one or more hinge mechanisms  24 . Therefore, by pivoting (counterclockwise pivoting in  FIG. 2 ) the lid  23  upward about the hinge mechanism(s)  24 , the upper opening of the water reservoir  22   w  is exposed (opened) so that water can be poured in. Further, as shown in  FIG. 2 , when the lid  23  has been pivoted to its counterclockwise-pivot limit position, the lid  23  is held in the state of being slightly tilted in the rightward direction and stands up like a wall. 
     As shown in  FIG. 1 , etc., the housing  22  comprises a gate-type handle  25 , which is coupled to the housing  22  such that left and right legs of the gate-type handle  25  can pivot up and down about a center part in the front-rear direction of the upper part of the housing  22 . That is, by raising the gate-type handle  25 , the coffeemaker  10  can be transported while holding the gate-type handle  25 . In addition, by lowering the gate-type handle  25  rearward down to the horizontal position, the gate-type handle  25  can be stored around the lid-storage recessed part  22   y  of the housing  22 , as shown in  FIG. 1 , etc. Furthermore, the battery-mount part  40  (described below), which is configured such that multiple types ( 2  types in the drawings) of power-tool batteries can be mounted, are provided in a vertical orientation on the right-side surface of the housing  22 . In addition, a water-heating element  50  (described below), which heats/boils water supplied from the water reservoir  22   w  and guides the hot water to the location of the drip case  21 , and an electrical circuit  60  (described below), which supplies electric power from the batteries B 1 , B 2  of the battery-mount part  40  to a heater  54 , etc., of the water-heating element  50 , are housed inside the housing  22 . 
     Battery-Mount Part  40   
     The battery-mount part  40  optionally comprises a first battery-mount part  41  and a second battery-mount part  42 , which are provided side-by-side in the front-rear direction. A front-rear slide-type cover member  45  is slidable to cover either the first battery-mount part  41  or the second battery-mount part  42 . As shown in  FIG. 1 , the first battery-mount part  41  is a structure on which, e.g., an 18-V battery or a 14.4-V battery (below, called a first battery B 1 ) used by a power tool can be mounted. 
     As shown in  FIG. 3 , the first battery-mount part  41  comprises a pair of front and right guide rails  41   r,  which extend in the up-down direction. A positive terminal  41   p  and a negative terminal  41   n  are provided between the guide rails  41   r.  In addition, a pair of rail-receiving parts (not shown), which are capable of engaging with the pair of guide rails  41   r  of the first battery-mount part  41 , is provided on the first battery B 1 . A positive terminal p and a negative terminal n are provided between the rail-receiving parts of the first battery B 1 . Therefore, by mating, from above, the pair of rail-receiving parts of the first battery B 1  with the pair of guide rails  41   r  of the first battery-mount part  41  and sliding the first battery B 1  downward, the first battery B 1  can be mounted on the first battery-mount part  41 . Furthermore, as shown in  FIG. 16 , when the first battery B 1  is mounted on the first battery-mount part  41 , the positive terminal p and the negative terminal n of the first battery B 1  are respectively connected to the positive terminal  41   p  and the negative terminal  41   n  of the first battery-mount part  41 . In this mounted state, it becomes possible to supply electric power from the first battery B 1  to the heater(s)  54  of the water-heating element  50 , etc., by using (via) the electrical circuit  60 . 
     As shown in  FIG. 9 , the second battery-mount part  42  is a structure on which, e.g., a 10.8-V battery (hereinbelow, called the second battery B 2 ) used by a power tool can be mounted. As shown in  FIG. 10 , the second battery-mount part  42  comprises a pair of front and rear guide rails  42   r  extending in the up-down direction. A positive terminal  42   p  and a negative terminal  42   n  are provided between the pair of guide rails  42   r.  In addition, a pair of rail-receiving parts (not shown), which is capable of engaging with the pair of guide rails  42   r  of the second battery-mount part  42 , is provided on the second battery B 2 . A positive terminal p and a negative terminal n are provided between the pair of rail-receiving parts of the second battery B 2 . Therefore, by engaging, from above, the pair of rail-receiving parts of the second battery B 2  with the pair of guide rails  42   r  of the second battery-mount part  42  and sliding the second battery B 2  downward, the second battery B 2  can be mounted on the second battery-mount part  42 . 
     Furthermore, as shown in  FIG. 17 , when the second battery B 2  is mounted on the second battery-mount part  42 , the positive terminal p and the negative terminal n of the second battery B 2  are respectively connected to the positive terminal  42   p  and the negative terminal  42   n  of the second battery-mount part  42 . In this mounted state, it becomes possible to supply electric power from the second battery B 2  to the heater(s)  54  of the water-heating element  50 , etc., by using (via) the electrical circuit  60 . In this embodiment, the spacing between the guide rails  42   r  of the second battery-mount part  42  is set such that it is smaller than the gap between the guide rails  41   r  of the first battery-mount part  41 . Consequently, it is not possible to mount the first battery B 1  on the second battery-mount part  42 , and it is also not possible to mount the second battery B 2  on the first battery-mount part  41 . 
     Furthermore, the battery-mount parts  41 ,  42  are also preferably spaced or arranged such that it is not physically possible to simultaneously mount the first battery B 1  and the second battery B 2  on the first battery-mount part  41  and the second battery-mount part  42  owing to spatial hindrance. That is, the spacing between the rear-side guide rail  41   r  of the first battery-mount part  41  and the front-side guide rail  42   r  of the second battery-mount part  42  is set to a dimension such that the first battery B 1  and the second battery B 2  would spatially interfere with one another. Consequently, if, for example, the second battery B 2  is slid downward with respect to the second battery-mount part  42  while the first battery B 1  is already mounted on the first battery-mount part  41 , then the second battery B 2  makes contact with the first battery B 1  and thereby is prevented from being slid further downward to its mounted state. Similarly, if the first battery B 1  is slid downward with respect to the first battery-mount part  41  while the second battery B 2  is already mounted on the second battery-mount part  42 , then likewise the first battery B 1  is prevented from being slid further downward to its mounted state. 
     The cover member  45  may be a generally plate-shaped member that is configured to cover the first battery-mount part  41  or the second battery-mount part  42  and is provided on the battery-mount part  40  such that it is capable of being slid in the front-rear direction. That is, guide grooves  40   g  extending in the front-rear direction are formed above and below the battery-mount part  40 , and sliders (not shown), which are formed above and below a rear side of the cover member  45 , are coupled to the guide grooves  40   g  such that the sliders are slidable with respect to the guide grooves  40   g.  In addition, recessed handles  45   e  (refer to  FIG. 1 ), which can be hooked by the user&#39;s fingers, are formed in the front side and the rear side of the surface of the cover member  45  to facilitate the manual movement of the cover member  45 . Furthermore, as shown in  FIG. 3 , by sliding the cover member  45  to its rearmost position, the second battery-mount part  42  is covered and the first battery-mount part  41  is exposed, and thereby it becomes possible to mount the first battery B 1  on the first battery-mount part  41 . In addition, as shown in  FIG. 10 , by sliding the cover member  45  to its frontmost position, the first battery-mount part  41  is covered and the second battery-mount part  42  is exposed, and thereby it becomes possible to mount the second battery B 2  on the second battery-mount part  42 . A cover-operation switch  64  (refer to  FIGS. 16   17 ), which operates in conjunction with the front-rear sliding operation of the cover member  45 , is provided on the battery-mount part  40 . 
     Water-Heating Element  50  of the Coffeemaker-Main-Body  20   
     The water-heating element  50  is a device that heats/boils the water supplied from the water reservoir  22   w  of the housing  22  and supplies that heated/boiled water to the interior of the drip case  21 . As shown in  FIG. 11 , the water-heating element  50  comprises a hot water supply  50   y  and at least one heater  54 . The hot water supply  50   y  comprises: a pipe  52 , which is connected to the water reservoir  22   w,  a check valve (one-way valve)  53 , which prevents the water inside the pipe  52  from flowing in reverse towards the water reservoir  22   w,  and a hot water supply nozzle (“shower head”, water distribution disk, etc.)  57 , which is connected to a tip part  52   u  of the pipe  52 . Furthermore, as shown in  FIG. 11  and  FIG. 12 , a pair of the heaters  54  is mounted, such that they are arranged along a substantially U-shaped curved portion of the pipe  52  of the hot water supply  50   y.  The heaters  54  may be, e.g., resistive heating elements, such as a wire or other conductive material that heats up when a current is supplied to it. The check valve  53  forms a part of a passageway or conduit from the water reservoir  22   w  to the water-heating element  50 . 
     As shown in  FIG. 13  and  FIG. 15 , the water reservoir  22   w  of the housing  22  comprises an upward-opening-type container (reservoir tank)  220 . In addition, a valve housing  221  protrudes (extends) downward and is provided at the location of a bottom plate of the container  220 . Furthermore, the check valve  53  of the hot water supply  50   y  is housed inside the valve housing  221  of the container  220  of the water reservoir  22   w.  A base end  52   m  of the pipe  52  of the hot water supply  50   y  is connected to the valve housing  221 . 
     Inside the housing  22 , as shown in  FIG. 13 , a water reservoir space W, which houses the container  220  of the water reservoir  22   w,  and a water-heating space Y, which houses the water-heating element  50 , are partitioned by an up/down-partition wall  210 , i.e. by a horizontally extending wall  210 . Furthermore, the valve housing  221  of the container  220  of the water reservoir  22   w  passes through the up/down-partition wall  210  and protrudes into the water-heating space Y. As shown in  FIG. 15 , the pipe  52  of the hot water supply  50   y  is bent into a U-shape and is disposed in the interior of the water-heating space Y. Furthermore, as described above, because the pair of heaters  54  is arranged along the U-shaped curved portion of the pipe  52 , it becomes possible to boil the water held in the U-shaped curved portion using the heaters  54 . A tip side of the U-shaped curved portion of the pipe  52  extends upward and is led into the drip-case-holder  22   f  of the housing  22 . 
     As shown in  FIG. 13 , the hot water supply nozzle  57  of the hot water supply  50   y,  which discharges the hot water into the drip case  21  from above, is installed in the drip-case-holder  22   f  of the housing  22 . Furthermore, as shown in  FIG. 14 , the tip part  52   u  of the pipe  52  of the hot water supply  50   y  is connected to an upper end of an upright pipe  57   p  of the hot water supply nozzle  57 . In this embodiment, a nozzle-housing space N of the drip-case-holder  22   f,  in which the hot water supply nozzle  57  of the hot water supply  50   y  is housed, is partitioned from the water reservoir space W and the water-heating space Y by a longitudinal wall  212 , as shown in  FIG. 13 , etc. Therefore, no water or hot water can enter the water-heating space Y, in which the heaters  54  are housed. 
     According to the above-described configuration, when the pipe  52  is heated by the heaters  54  and the substantially U-shaped curved portion of the pipe  52  is filled with water, some of the water inside the pipe  52  vaporizes, and thereby the pressure inside the pipe  52  rises. At this time, because the check valve  53  of the hot water supply  50   y  is closed and thereby water is prevented from flowing in reverse towards the water reservoir  22   w,  high temperature hot water transits the pipe  52  of the hot water supply  50   y  and is forced out from the hot water supply nozzle  57  into the nozzle-housing space N. Therefore, hot water from the hot water supply nozzle  57  is discharged, from above, to the coffee pod CP inside the drip case  21 . Furthermore, when the pressure inside the pipe  52  drops owing to hot water being forced out from the hot water supply nozzle  57 , water from the water reservoir  22   w  is supplied into the pipe  52  via the check valve  53 . By repeatedly performing this operation, high temperature hot water is supplied into the drip case  21  automatically. That is, the heaters  54  correspond to a heat-generating means of the present teachings. 
     Electrical Circuit  60  of the Coffeemaker-Main-Body  20   
     The electrical circuit  60  supplies electric power from the first battery B 1 , which is mounted on the first battery-mount part  41 , or from the second battery B 2 , which is mounted on the second battery-mount part  42 , to the heater(s)  54  of the water-heating element  50 . 
     As shown in  FIG. 16  and  FIG. 17 , the electrical circuit  60  comprises: a first power-supply positive line  61 , which connects the positive terminal  41   p  of the first battery-mount part  41  and the heater(s)  54  (+ side) of the water-heating element  50 , and a second power-supply positive line  62 , which connects the positive terminal  42   p  of the second battery-mount part  42  and the heater(s)  54  (+ side). In addition, the electrical circuit  60  comprises a power-supply negative line  63 , which connects the negative terminals  41   n,    42   n  of the first and second battery-mount parts  41 ,  42  and the heater(s)  54  (− side). That is, the first power-supply positive line  61  and the second power-supply positive line  62  correspond to a power-supply line of the present teachings, and the positive terminal  41   p  of the first battery-mount part  41  and the positive terminal  42   p  of the second battery-mount part  42  correspond to power-supply terminals of a battery-mount part of the present teachings. 
     Furthermore, a short-circuit-preventing fuse Hs is provided in each of the first and second power-supply positive lines  61 ,  62 . As shown in  FIG. 16 , if, for example, the positive terminal  42   p  and the negative terminal  42   n  of the second battery-mount part  42  mistakenly short circuit when the first battery B 1  of the first battery-mount part  41  is mounted, then the short-circuit-preventing fuses Hs cut off the short-circuit current. 
     The cover-operation switch  64 , which operates in conjunction (accordance) with the front-rear sliding operation of the cover member  45 , is provided in series with the first power-supply positive line  61  and the second power-supply positive line  62  of the electrical circuit  60 . That is, as shown in  FIG. 16 , when the cover member  45  is covering the second battery-mount part  42 , the cover-operation switch  64  disconnects the second power-supply positive line  62  between the second battery-mount part  42  and the heater(s)  54  and connects the first power-supply positive line  61  between the first battery-mount part  41  and the heater(s)  54 . Similarly, as shown in  FIG. 17 , when the cover member  45  is covering the first battery-mount part  41 , the cover-operation switch  64  disconnects the first power-supply positive line  61  between the first battery-mount part  41  and the heater(s)  54  and connects the second power-supply positive line  62  between the second battery-mount part  42  and the heater(s)  54 . It is noted that the cover-operation switch  64  is configured such that, if the cover member  45  is removed from the battery-mount part  40 , then the first power-supply positive line  61  and the second power-supply positive line  62  are disconnected, thereby preventing further usage of the coffeemaker  10 . This disconnection function is represented by the arrow extending from the cover-operation switch  64  to the controller  70  in  FIGS. 16 and 17 . 
     As shown in  FIG. 16  and  FIG. 17 , a switching device (FET)  65  for PWM control of the electric power supplied to the heaters  54  is provided in the power-supply negative line  63  of the electrical circuit  60 . In addition, heater fuse(s) Ht, which melt(s) if the temperature of the heater(s)  54  rise(s) excessively, is (are) provided on the heater(s)  54 . Furthermore, a temperature sensor  66  (e.g., a thermistor), which detects the temperature of the pipe  52 , is provided on the pipe  52  of the water-heating element  50 . 
     The electrical circuit  60  comprises a controller  70 , which controls the heater(s)  54  of the water-heating element  50  by operating the switching device (FET)  65  according to PWM (pulse width modulation) control. A signal of a start/stop switch  72  for turning the heater(s)  54  of the water-heating element  50  ON and OFF is input to the controller  70 . Here, as shown in  FIG. 1 , etc., the start/stop switch  72  is mounted on a front surface of the plate  30 . It is noted that the “Energized” lamp is turned ON during operation of the heater(s)  54 . In addition, a signal of the temperature sensor  66  is input to the controller  70 . Furthermore, a battery-identification signal from a battery identifying circuit  74  is input to the controller  70 . The battery identifying circuit  74  identifies the type of battery based on data sent from the battery B 1 , which is mounted on the first battery-mount part  41 , or from the battery B 2 , which is mounted on the second battery-mount part  42 . In addition, the battery type may be identified by ascertaining on which battery-mount part the battery is mounted, i.e., whether a battery is physically mounted on the first battery-mount part  41  or on the second battery-mount part  42 , e.g., using a pressure switch or an electrical contact switch. 
     In addition, a constant voltage is supplied from a control-power-supply  75  to the controller  70 . That is, the control-power-supply  75  is configured such that the constant voltage can be supplied to the controller  70  by stepping up or stepping down the voltage supplied from the battery B 1  (14.4 V or 18 V) or the battery B 2  (10.8 V). 
     Operation of the Coffeemaker  10   
     When the coffeemaker  10  is to be utilized with, for example, the first power tool battery B 1  (18 V), then, as shown in  FIG. 1 , the cover member  45  is slid to its rearmost position to cover the second battery-mount part  42 , and the first battery B 1  is mounted on the first battery-mount part  41 , which is exposed. At this time, the cover-operation switch  64  operates in conjunction with the slide operation of the cover member  45  and, as shown in  FIG. 16 , the second power-supply positive line  62  is disconnected and the first power-supply positive line  61  enters a conducting state. Next, the lid  23  on the upper surface of the housing  22  is pivoted upward such that, as shown in  FIG. 2 , the opening of the water reservoir  22   w  is held open while the lid  23  is in its raised position. Furthermore, in this state, water is poured into the water reservoir  22   w.  At this time, even if some of the water splashes, the splashed water is blocked by the lid  23  and tends not to spray in the direction of the first battery B 1 . Then, when the pouring of the water has been completed, coffee grounds have been placed in the drip case  21 , and the decanter  35  has been set on the plate  30 , the start/stop switch  72  is operated, e.g., manually depressed. 
     When the start/stop switch  72  is operated, the controller  70  operates the switching device (FET)  65  in accordance with the battery type (voltage) and thereby adjusts the electric power supplied to the heater(s)  54 . For example, when the first battery B 1  (18 V) is mounted, the energized time during PWM control is shorter compared with of the energized time when the second battery B 2  (10.8 V) is mounted. In the alternative, the energized time during PWM control may be keep the same, such that the water will heat up faster when the first battery B 1  is mounted than when the second battery B 2  is mounted. Furthermore, the pipe  52  of the water-heating element  50  is heated by the heater(s)  54 , and the high temperature hot water inside the pipe  52  is supplied to the coffee pod CP of the drip case  21 . Thereafter, the brewed coffee flows downwardly through the extraction part  21   p  of the drip case  21  (the case-main-body  21   m ) and collects in the decanter  35  on the plate  30 . Thereafter, when the amount of water inside the pipe  52  of the water-heating element  50  decreases and the temperature of the pipe  52  rises, the controller  70 , which receives the signal of the temperature sensor  66 , turns the switching device (FET)  65  OFF, and stops energizing the heater(s)  54 . 
     If the second battery B 2  (10.8 V) is used, then, as shown in  FIG. 9  and  FIG. 10 , the cover member  45  is slid to its frontmost position to cover the first battery-mount part  41 , and the second battery B 2  is mounted on the second battery-mount part  42 , which is exposed. Furthermore, by sliding the cover member  45  to the front-end position, the cover-operation switch  64  disconnects the first power-supply positive line  61  and connects the second power-supply positive line  62 , as shown in  FIG. 17 . Then, similar to the above-described procedure, coffee is brewed by operating the coffeemaker  10 . 
     Features of the Coffeemaker  10  According to the Present Embodiment 
     According to the coffeemaker  10  of the present (first) embodiment, the coffeemaker  10  (the electrical device) can be operated, e.g., at a construction work site, etc., using the batteries B 1 , B 2  of a power tool. The coffeemaker  10  comprises the drip case  21  (the case) that holds, e.g., a coffee pod CP (the pod) containing a predetermined amount of coffee grounds held in a permeable bag-shaped element. Furthermore, the extraction part  21   p,  which allows the coffee produced by the hot water discharged into (onto) the coffee pod CP to downwardly flow, is provided in (on) the drip case  21 . Thus, because a coffee pod CP can be used, it becomes unnecessary to, for example, use a measuring spoon or the like to take coffee grounds out of a coffee-ground bag and place them in a filter. That is, because coffee can be brewed merely by setting the coffee pod CP in the drip case  21  and operating the coffeemaker  10 , coffee can be easily made at a construction work site. However, as was discussed above in connection with  FIGS. 7 and 8 , the coffeemaker  10  also may be advantageously utilized with loose coffee grounds, loose tea leaves, etc., in other embodiments of the present teachings, e.g., by providing a mesh filter F or paper filter in the drip case  21 . 
     In addition or in the alternative, if the water reservoir  22   w  and the drip case  21  (the case) of the coffeemaker  10  are disposed such that they are side-by-side at substantially the same height, when the hot water supply  50   y  supplies the hot water boiled by the heater(s)  54  (the heat-generating means) to the drip case  21  from above, a water-supplying means, such as a pump, is unnecessary. In addition or in the alternative, if the battery-mount parts  41 ,  42  are provided at locations lower than those of the water reservoir  22   w  and the drip case  21 , when water is being boiled, the batteries B 1 , B 2 , which are heavy, are disposed at low locations, which improves the stability of the coffeemaker  10 . In addition or in the alternative, if the water reservoir space W and the water-heating space Y, in which the heaters  54  are housed, are partitioned by the up/down-partition wall  210 , water is prevented from entering the space Y in which the heaters  54  are housed. In addition or in the alternative, if the nozzle-housing space N, in which the hot water supply nozzle  57  of the hot water supply  50   y  is housed, and the water-heating space Y, in which the heaters  54  are housed, are partitioned by the longitudinal wall(s)  212 , hot water is prevented from entering the water-heating space Y. 
     According to the coffeemaker  10  of the present first embodiment, when one of the batteries B 1 , B 2  is mounted on its corresponding battery-mount part  41  or  42 , it becomes impossible to mount the other battery B 1  or B 2  on the other battery-mount part  41  or  42 . Consequently, even though two types of the battery-mount parts  41 ,  42  are provided, only one of the batteries B 1 , B 2  can be mounted on the battery-mount parts  41 ,  42 . That is, two batteries are never mounted on the battery-mount parts  41 ,  42  simultaneously (at the same time). As a result, a battery-switching circuit, an interlock circuit, etc., are not necessary, the circuit configuration is simplified, and electrical reliability is improved. 
     In addition or in the alternative, when one of the batteries B 1 , B 2  is mounted on the sole exposed battery-mount part  41  or  42 , the other battery-mount part  41  or  42  is necessarily covered by the cover member  45 . That is, when one of the batteries B 1 , B 2  is mounted on one of the battery-mount parts  41 ,  42 , the positive and negative terminals (charging part) of the other battery-mount part  41  or  42  are not exposed, and consequently a short-circuit fault can be prevented. In addition, when one of the batteries B 1 , B 2  is mounted on one of the battery-mount parts  41 ,  42 , if the other battery B 1  or B 2  is moved in the mounting direction (the downward direction) with respect to the other battery-mount part  41  or  42 , then that other battery B 1  or B 2  makes contact with the battery B 1  or B 2  mounted on the one battery-mount part  41  or  42 , thereby blocking further downward sliding movement of that other battery B 1  or B 2 . Consequently, even in a hypothetical situation in which the cover member  45  has been removed, a plurality of the batteries B 1 , B 2  can not be mounted on the plurality of the battery-mount parts  41 ,  42  at the same time. 
     In addition or in the alternative, the lid  23  of the water reservoir  22   w  is located on an upper side of the right-side surface of the housing  22  on which the battery-mount parts  41 ,  42  are provided, and is configured such that it stands up like a wall along the end edge of the upper surface of that housing, such that the opening of the water reservoir  22   w  is uncovered (opened). Consequently, when the water is being supplied (poured) into the water reservoir  22   w  of the housing  22 , any water that splashes is blocked by the lid  23 , which stands up along the right-side surface of the housing  22 , such that the splashed water does not splash onto the battery-mount parts  41 ,  42 . 
     Modified Examples (Second to Fifth Embodiments) 
     It is noted that the present teachings are not limited to the above-described embodiments, and it is understood that variations and modifications may be effected without departing from the spirit and scope of the present teachings. For example, in the coffeemaker  10  of the first embodiment, as shown in  FIG. 1  and  FIG. 13 , an example is described in which the water reservoir  22   w  and the drip case  21  (the case) are disposed such that they are side-by-side at substantially the same height, and the battery-mount parts  41 ,  42  are provided at a location lower than that height. However, as shown in  FIG. 20 , it is also possible to provide the battery-mount parts  41 ,  42  at a location higher than those of the water reservoir  22   w  and the drip case  21  (the case). In addition, as shown in  FIG. 21 , it is also possible to provide the water reservoir  22   w  at a location lower than that of the heater(s)  54  of the water-heating element  50  and to provide the battery-mount parts  41 ,  42  at a location higher than that of the water reservoir  22   w.  In this embodiment, a pump  59  or the like, which pumps the water upward, is used. Thus, by disposing the battery-mount parts  41 ,  42  at a location higher than that of the water reservoir  22   w,  when the water is being supplied (poured) to the water reservoir  22   w,  it is less likely that the water will splash onto the battery-mount parts  41 ,  42 . 
     In addition, in the coffeemaker  10  of the above-described first embodiment, an example was described in which, as shown in the electrical circuit  60  in  FIG. 16  and  FIG. 17 , the heater(s)  54  is (are) commonly used for both the situation in which the first battery B 1  (18 V) is used (mounted) and the situation in which the second battery B 2  (10.8 V) is used (mounted). However, as shown in  FIG. 18 , a configuration is also possible in which a dedicated A-heater  54   a  and a dedicated FET  65   a  are used for the situation in which the first battery B 1  (18 V) is used (mounted), and a dedicated B-heater  54   b  and a dedicated FET  65   b  are used for the situation in which the second battery B 2  (10.8 V) is used (mounted). Dedicated temperature sensors  66   a  (e.g., thermistors) are respectively provided on or near the heaters  54   a,    54   b  and respective dedicated power-supply negative lines  63   a,    63   b  are provided for the two heaters  54   a,    54   b.  In addition, as shown in  FIG. 19 , a configuration is also possible in which the A-heater  54   a,  the B-heater  54   b,  the FET  65   a,  and the FET  65   b  are used for the situation in which the first battery B 1  (18 V) is used (mounted), and the B-heater  54   b  and the FET  65   b  are used for the case in which the second battery B 2  (10.8 V) is used (mounted). 
     In addition, in the above-described first embodiment, although an example was described in which a contact-type switch is used as the cover-operation switch  64  that operates in conjunction with the front-rear sliding operation of the cover member  45 , it is also possible to use a semiconductor-type switch. In addition, in the above-described first embodiment, an example was described in which the coffeemaker  10  comprises the first battery-mount part  41  and the second battery-mount part  42 , the sizes of which differ and correspond to the first battery B 1  and the second battery B 2 . However, it is also possible, for example, to make the first battery-mount part  41  and the second battery-mount part  42  of identical sizes, corresponding to the first battery B 1  (18 V, 14.4 V). In addition, in the coffeemaker  10  according to the above-described first embodiment, although a warming function of the plate  30  on which the decanter  35  is placed was not considered, it is also possible to provide the plate  30  with a warming function. In such an embodiment, in the electrical circuits  60  shown in  FIG. 16 , etc., a warming heater for the plate  30  may be provided in parallel with the heater(s)  54  of the water-heating element  50  and the switching device  65 . In the alternative, the heater(s)  54  may be disposed between the pipe  52  and the plate  30  so that the same heater(s)  54  heat(s) both the pipe  52  and the plate  30 . 
     In addition, in the above-described first embodiment, an example was described in which, if the case-main-body  21   m  of the drip case  21  is designed for use with the coffee pod CP shown in  FIG. 5  and  FIG. 6 , then a second drip case  21  designed for use with coffee grounds, in which the mesh filter F shown in  FIG. 7  and  FIG. 8  is used, may be provided separately. However, as shown in  FIG. 22  to  FIG. 25 , it is also possible to make the case-main-body  21   m  multi-usable with the coffee pod CP and also with loose coffee grounds in which the mesh filter F is used. In addition, in the above-described first embodiment, although an example was described in which the coffeemaker  10  serves as the electrical device, it is also possible to adapt the present teachings to a tea maker and the like, in which a tea-leaf pod, loose tea leaves, etc. is used. 
     Depending on design requirements, exemplary embodiments of the controller  70  of the present disclosure may be implemented in hardware and/or in software. The controller  70  can be configured using a digital storage medium, for example one or more of a ROM, a PROM, an EPROM, an EEPROM, a flash memory, etc., on which electronically readable control signals (program code—instructions) are stored, which interact or can interact with one or more programmable hardware components to execute programmed functions. 
     The (each) programmable hardware component can be constituted by a processor, which may comprise a computer processor (CPU=central processing unit), an application-specific integrated circuit (ASIC), an integrated circuit (IC), a computer, a system-on-a-chip (SOC), a programmable logic element, and/or a field programmable gate array (FGPA). A microprocessor is a typical component of a controller  70  or processor according to the present teachings. 
     The digital storage medium can therefore be machine- or computer readable. Some exemplary embodiments thus comprise a data carrier or non-transient computer readable medium which includes electronically readable control signals which are capable of interacting with a programmable computer system or a programmable hardware component such that one of the methods or functions described herein is performed. An exemplary embodiment is thus a data carrier (or a digital storage medium or a non-transient computer-readable medium) on which the program for performing one of the methods described herein is recorded. 
     In general, exemplary embodiments of the present disclosure, in particular the controller  70  or processor, are implemented as a program, firmware, computer program, or computer program product including a program, or as data, wherein the program code or the data is operative to perform one of the methods when the program runs on (is executed by) a processor or a programmable hardware component. The program code or the data can for example also be stored on a machine-readable carrier or data carrier, such as any of the types of digital storage media described above. The program code or the data can be, among other things, source code, machine code, bytecode or another intermediate code. 
     A program according to an exemplary embodiment can implement one of the methods or function during its performance, for example, such that the program reads storage locations and/or writes one or more data elements into these storage locations, wherein switching operations or other operations are induced in transistor structures, in amplifier structures, or in other electrical, electronic, optical, magnetic components, or components based on another functional or physical principle. Correspondingly, data, values, sensor values, or other program information can be captured, determined, or measured by reading a storage location. By reading one or more storage locations, a program can therefore capture, determine or measure sizes, values, variables, and other information, as well as cause, induce, or perform an action by writing in one or more storage locations, as well as control other apparatuses, machines, and components, and thus for example also perform any complex process that the air compressor may be designed to perform. 
     Although some aspects of the present teachings have been described in the context of a device or apparatus, it is to be understood that these aspects also represent a description of a corresponding method, so that a block or a component of a device or apparatus is also understood as a corresponding method step or as a feature of a method step. In an analogous manner, aspects which have been described in the context of or as a method step also represent a description of a corresponding block or detail or feature of a corresponding device. 
     Representative, non-limiting examples of the present invention were described above in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Furthermore, each of the additional features and teachings disclosed above may be utilized separately or in conjunction with other features and teachings to provide improved electrical devices, such as hot beverage making devices. 
     Moreover, combinations of features and steps disclosed in the above detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Furthermore, various features of the above-described representative examples, as well as the various independent and dependent claims below, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings. 
     All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter. 
     Additional embodiment of the present teachings include, but are not limited to: 
     1. An electrical device comprising: 
     a housing; 
     two battery-mount parts disposed on the housing and configured to mount two batteries designed for use as a power supply of a power tool thereon; 
     a heat-generating means for boiling water by using electric power supplied by the battery mounted on the battery-mount part, the heat-generating means being disposed within the housing; 
     a drip case mountable in the housing and having a drain hole configured to allow a hot beverage to flow downwardly out of the drip case; and 
     a hot water supply configured to automatically supply water boiled by the heat-generating means into an interior portion of the drip case; 
     wherein the two battery-mount parts are configured such that, when one battery is mounted on one of the battery-mount parts, another battery is prevented from being mounted on the other battery-mount part. 
     2. The electrical device according to the above-described embodiment 1, wherein the two battery-mount parts have different sizes and are configured to respectively mount batteries having sizes corresponding to the battery-mount parts. 
     3. The electrical device according to the above-described embodiment 2, wherein: 
     each of the two battery-mount parts comprises a pair of guide rails and a plurality of terminals; and 
     the two battery-mount parts differ in the arrangement of the guide rails and/or in the arrangement of the plurality of terminals such that the batteries, which are capable of engaging with and sliding with respect to the pair of guide rails and are capable of electrically connecting to the terminals, are mountable on the respective battery-mount parts. 
     4. The electrical device according to the above-described embodiment 1-3, further comprising: 
     a cover member movably coupled to the two battery-mount parts and configured to expose one of the battery-mount parts while covering the other battery-mount part. 
     5. The electrical device according to the above-described embodiment 4, wherein: 
     the two battery-mount parts are disposed on the housing in a side-by-side arrangement; and 
     the cover member is configured such that it is slidable in the side-by-side direction of the two battery-mount parts to expose one of the battery-mount parts while covering the other battery-mount part. 
     6. The electrical device according to the above-described embodiments 1-5, wherein the two battery-mount parts are configured such that, when one battery is mounted on one of the battery-mount parts, another battery is physically blocked by the mounted battery from moving in a mounting direction with respect to the other battery-mount part. 
     7. The electrical device according to the above-described embodiments 1-6, wherein: 
     the two battery-mount parts are provided on one side surface of the housing; 
     a lid is provided on an upper surface of the housing and is configured to close and open an opening of a water reservoir within the housing; and 
     the lid is located on an upper side of the one side surface of the housing on which the battery-mount parts are provided, and is configured such that the lid stands up like a wall along an end edge of the upper surface of the housing when the opening of the water reservoir is opened. 
     8. The electrical device according to the above-described embodiment 7, wherein the lid is coupled by a hinge to the housing such that the lid is pivotable about the end edge of the upper surface of the housing. 
     9. The electrical device according to the above-described embodiments 4-8, further comprising: 
     a cover-operation switch configured to be operated in conjunction with movement of the cover member; 
     wherein the cover-operation switch is configured to disconnect a power-supply line between a power-supply terminal of the battery-mount part currently covered by the cover member and the heat-generating means, and to connect a power-supply line between a power-supply terminal of the currently exposed battery-mount part and the heat-generating means. 
     10. The electrical device according to the above-described embodiment 9, wherein the cover-operation switch is configured such that removal of the cover member from the battery-mount parts causes the power-supply line between the power-supply terminals of all the battery-mount parts and the heat-generating means to be disconnected. 
     EXPLANATION OF THE REFERENCE NUMBERS 
     
         
           10 Coffeemaker (electrical device) 
           22  Housing 
           210  Up/down-partition wall 
           212  Longitudinal wall 
           21  Drip case (case) 
           21   p  Extraction part 
           22   w  Water reservoir 
           23  Cover 
           24  Hinge mechanism 
           40  Battery-mount part 
           41  First battery-mount part 
           41   p  Positive terminal (power-supply terminal) 
           42  Second battery-mount part 
           42   p  Positive terminal (power-supply terminal) 
           45  Cover member 
           50  Water-heating element 
           50   y  Hot water supply 
           52  Pipe 
           53  Check valve 
           54  Heater (heat-generating means) 
           57  Hot water supply nozzle 
           60  Electrical circuit 
           61  First power-supply positive line (power-supply line) 
           62  Second power-supply positive line (power-supply line) 
           63  Power-supply negative line 
           64  Cover-operation switch 
           66  Temperature sensor 
           70  Controller 
           72  Start/stop switch 
         B 1  First battery 
         B 2  Second battery 
         CP Coffee pod (pod)