Abstract:
A dust case is provided for a sweeper that uses a rotary brush to sweep dust particles. The dust case has a casing having a plurality of walls, including a front wall, that together define an interior space, and having an open top and an inlet at a front wall to receive dirt particles. The dust case also includes a cover having a first cover portion for covering the open top of the casing and a second cover portion extending in a forward direction from the first cover portion. A safety bar can be provided extending downwardly from the bottom face of the second cover portion. The dust case can further include a hinge member that connects the cover to the casing in a manner where, when the cover is pivoted so that the first cover portion exposes the interior space, the second cover portion blocks the inlet, and when the cover is pivoted so that the first cover portion covers the interior space, the second cover portion exposes the inlet.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a sweeper, and in particular, to a dust case for a sweeper. 
         [0003]    2. Description of the Prior Art 
         [0004]    A conventional sweeper is disclosed, for example, in Korean Official Gazette for Registration Utility Model 20-0317923. Referring to  FIGS. 14 and 15 , the sweeper according to this disclosure includes a housing  10 , a rotary brush  20  installed in a manner rotable by a drive motor  30  installed at one side of the housing  10 , a container  40  removably installed at the rear side of the housing  10 , and a handle (not shown) removably connected to an upper side face of the housing  10 . The housing  10  has a suction port of a given size on the front lower side, and the rotary brush  20  is disposed at the suction port  11 . There is a coupling groove  12  formed at a rear side of the housing  10 , and a turnable piece  13  into which the handle (not shown) is inserted and installed at an upper side of the housing  10 . 
         [0005]    The rotary brush  20  is disposed at the side of the suction port  11  of the housing  10  and installed in such a manner that a part of it is exposed outside the housing  10  and contacts the floor surface. Also, the rotary brush  20  is configured to receive a rotational driving force from the drive motor which is provided at one side of the housing  10 , via an indirect transmission mechanism  32  (such as a belt, chain, etc.). Here, the drive motor  30  is actuated in response to an On/Off signal from an actuating switch  31  provided on an upper side face of the housing  10 . 
         [0006]    The container  40  is removably connected to the rear side of the housing  10 , and a hook  42  that is opened either upwards or downwards by a push button  41  is preferably formed on a front side of the container  42 , the hook  42  being linked into or released (pulled out) from the coupling groove  12  that is formed at the rear side face of the housing  10  to enable the installation/removal of the container  40  at/from the rear side of the housing  10 . 
         [0007]    Moreover, a predetermined guide groove  15  or guide projection  43  is selectively formed at a region where the housing  10  and the container  40  are interconnected to each other, and an appropriate number of wheels are provided at the lower faces of the housing  10  and container  40 . Tilt planes  14  and  44  of a predetermined angle are formed at the lower face of the region where the housing  10  and the container  40  are interconnected to each other to ensure that dirt particles on the floor surface being collected by the rotary brush  20  are completely gathered into the container  40 . 
         [0008]    According to this configuration of the housing  10  and the container  40  of a conventional sweeper, dirt particles when swept by the rotary brush  20  usually move along the tilt plane  14  and are collected in the container  40 , but some dirt particles flow reversely because of the centrifugal force of the rotary brush  20  and may escape again through the suction port  11 . 
         [0009]    Furthermore, when dirt particles become stuck to the rotary brush  20 , the performance of the rotary brush as a broom is degraded, and the sanitary appearance thereof is affected. 
         [0010]    Referring now to  FIGS. 16 and 17 , a conventional steam combined sweeper includes a built-in tank  10   x  where water is kept and boiled into steam to generate water vapor, a wheel  20   x  for moving a body  30   x  and a suction brush  40   x  located at the front area of the body  30   x  to sweep dirt on the floor, in which a cleaning cloth  50   x  is removably attached to the bottom face of the body  30   x , the suction brush  40   x  is coupled to the body  30   x  in a rotatable manner by a shaft support  42   x  disposed transversely, and one side of the shaft support  42   x  is connected to the wheel  20   x  and to a belt  60   x  to enable rotation. Steam being generated is spouted through steam-spouting holes  12   x  so as to dampen the cleaning cloth  50   x  attached to the body  30   x.    
         [0011]    Meanwhile, when the conventional sweeper described above is used for cleaning a carpet (e.g., a fur carpet), projections used for attaching the cloth  50   x  may be caught in furs of the carpet and cause damage to the carpet, meaning that the sweeper is suitable only for cleaning non-carpeted floors. 
       SUMMARY OF THE DISCLOSURE 
       [0012]    It is one objective of the present invention to provide a dust case for a sweeper with markedly improved performance as a broom, by preventing dirt particles being swept by a rotary brush from escaping to the exterior again. 
         [0013]    It is another objective of the present invention to provide a dust case for a sweeper which prevents the leak of dust that has already been collected, as well as preventing the leak of dust particles via an inlet during cleaning, so that the emptying and discharging of dust particles becomes very convenient, and the surroundings of the body are kept clean. 
         [0014]    To accomplish these objectives, the present invention provides a dust case for a sweeper that uses a rotary brush to sweep dust particles. The dust case has a casing having a plurality of walls, including a front wall, that together define an interior space, and having an open top and an inlet at a front wall to receive dirt particles. The dust case also includes a cover having a first cover portion for covering the open top of the casing and a second cover portion extending in a forward direction from the first cover portion. 
         [0015]    To prevent dirt particles being swept by a rotary brush from escaping to the exterior again, a safety bar can be provided extending downwardly from the bottom face of the second cover portion. As a further embodiment, a secondary safety bar extends downwardly from the bottom face of the second cover portion at a location that is closer to the front of the second cover portion. With the safety bar protruding downwardly from the bottom face of the second cover portion, dirt particles that would not get into the dust case by the rotation of the rotary brush are restrained from flowing in a reverse direction, thereby improving the sweeping efficiency. In addition, with the secondary safety bar positioned farther to the front than the safety bar, the secondary safety bar serves as a duster for the rotary brush coming in touch therewith to increase the sweeping efficiency and to prevent additional backflow of dirt particles as well. 
         [0016]    In accordance with another embodiment of the present invention, the dust case can further include a hinge member that connects the cover to the casing in a manner where, (i) when the cover is pivoted so that the first cover portion exposes the interior space, the second cover portion blocks the inlet, and (ii) when the cover is pivoted so that the first cover portion covers the interior space, the second cover portion exposes the inlet. This arrangement prevents the leak of dust that has already been collected, as well as preventing the leak of dust particles via an inlet during cleaning, so that the emptying and discharging of dust particles can be accomplished more effectively and conveniently. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is an exploded perspective view of a steam combined sweeper according to a preferred embodiment of the present invention. 
           [0018]      FIG. 2  shows an assembled perspective view of the steam combined sweeper of  FIG. 1  without a pad tray. 
           [0019]      FIG. 3  shows a bottom view of  FIG. 2 . 
           [0020]      FIG. 4  is cross-sectional view of the sweeper of  FIGS. 1 and 2 . 
           [0021]      FIG. 5A  shows a top perspective view of a lower casing of the sweeper of  FIGS. 1 and 2 . 
           [0022]      FIG. 5B  shows a top perspective view of the lower casing of  FIG. 5A  showing how a rotary brush and a power transmission member for rotating the rotary brush are mounted. 
           [0023]      FIG. 6A  is an exploded bottom perspective view of an upper casing of the sweeper of  FIGS. 1 and 2 . 
           [0024]      FIG. 6A  is an assembled bottom perspective view of the upper casing of  FIG. 6A . 
           [0025]      FIG. 7  is an exploded perspective view of a motor and a motor support frame of the sweeper of  FIGS. 1 and 2 . 
           [0026]      FIG. 8  is an exploded perspective view of a dust case for the sweeper of  FIGS. 1 and 2 . 
           [0027]      FIG. 9A  and  FIG. 9B  show cross-sectional views of the dust case in its open and closed state, respectively. 
           [0028]      FIG. 10  and  FIG. 11  are bottom and top perspective views, respectively, of a pad tray for the sweeper of  FIGS. 1 and 2 . 
           [0029]      FIG. 12  is a perspective view showing a manufacturing process of the pad tray of  FIG. 11 . 
           [0030]      FIG. 13  shows a cross-sectional view of the pad tray and an attachment/detachment member of the lower casing. 
           [0031]      FIG. 14  is an exploded perspective view of a conventional sweeper. 
           [0032]      FIG. 15  is an assembled cross-sectional view of the conventional sweeper of  FIG. 14 . 
           [0033]      FIG. 16  is a perspective view of another conventional steam combined sweeper. 
           [0034]      FIG. 17  is a bottom view of  FIG. 16 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0035]    The following detailed description is of the best presently contemplated modes of carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating general principles of embodiments of the invention. The scope of the invention is best defined by the appended claims. 
         [0036]    As illustrated in  FIGS. 1-4 , a steam combined sweeper of this embodiment includes a base assembly  100  and a mop-stick assembly installed at the base assembly. The mop-stick assembly includes a neck assembly  300  that is pivotably connected to the base assembly  100 , and a handle assembly (not shown) installed at the neck assembly  300 . 
         [0037]    The base assembly  100  includes a body  110 , with a sweeping member  140  provided adjacent the front side of the body  110  and a steam generating member  190  adjacent the rear side of the body  110 . The body  110  is formed by a lower casing  120  that forms an external figure, and an upper casing  130  that is coupled to the lower casing  120 . 
         [0038]    Also, as shown in  FIGS. 2 ,  4  and  5 A, the body  110  is divided by a partition wall  111  into a sweeping mounting section  113  on which the sweeping member  140  is mounted at the front side thereof, and a steam mounting section  116  on which the steam generating member  190  is mounted at the rear side thereof. The partition wall  111  is divided into a lower partition wall  111   a  on the lower casing  120  side, and an upper partition wall  111   b  on the upper casing  130  side. A packing  112  can be installed between the lower partition wall  111   a  and the upper partition wall  111   b.    
         [0039]    As illustrated in  FIGS. 1 and 5A , a suction port  121  where a brush  150  is disposed is formed at the front side of the sweeping mounting section  113   a  of the lower casing  120 , and a lower brush holder support  123   a  is formed at both sides of the suction port  121  for supporting a holder  152  that rotably couples the brush  150 . Referring also to  FIG. 5B , a motor seat  171  is provided at the rear side of the sweeping mounting section  113   a  of the lower casing  120  for receiving a motor  160 , and a lower passage  125   a  is formed at either the left or right side of the sweeping mounting section  113   a  of the lower casing  120  for receiving a pulley  162  of the brush  150  and a belt  166  wound around the pulley  164  of the motor  160 . 
         [0040]    Between the suction port  121  and the motor seat  171  is a dust case seat cavity  127  where a dust case  200  is seated. The dust case seat cavity  127  is defined by a stair-shaped bottom  127   a , a front face  128  extending downwardly from an edge of the bottom  127   a , two opposing lateral faces  127   b , and a rear face  127   c . The bottom  127   a  has a front side that is deeper than the lower side. The rear face  127   c  preferably has a guide groove  127   d  for guiding a locker  250  (to be described). 
         [0041]    In particular, the front face  128  of the dust case seat cavity  127  is preferably formed to have the same slope or angle as a tilt front plate  211  (to be described) of the dust case  200 . In other words, the front face  128  constitutes a primary tilt face, with the tilt front plate  211  forming one a parallel secondary tilt face that serves as the entrance of the dust case  200 . 
         [0042]    A rubber partition plate  115  can be further installed at the suction port  121  at the front face  128  to prevent scratches on the floor, or to function to block the backflow of dust particles. 
         [0043]    The steam mounting section  116   a  of the lower casing  120  has a steam discharge port  129 . A steam discharge cover  129   a  (see  FIG. 3 ) can be fastened to the lower casing  120  to dispersedly discharge steam from the steam discharge port  129  in both lateral directions. A rear wheel  118  (see  FIG. 3 ) can be provided at the central portion of the rear side, and left and right front wheels  117  can be also provided slightly to the rear of the suction port  121  of the lower casing  120 . 
         [0044]    As illustrated in  FIG. 6A , the sweeping mounting section  113   b  of the upper casing  130  has an open cavity  131  that corresponds to the suction port  121  and dust case seat cavity  127  of the lower casing  120 . A tank mounting cavity  133  to which a tank assembly  192  is mounted is formed at the steam mounting section  116   b  of the upper casing  130 . In addition, a motor mounting recess  135  and a PCB mounting recess  137  are also formed between a rear face plate  132  and the upper partition wall  111   b  of the upper casing  130 . Upper brush holder supports  123   b  (for supporting the holder  152  from the top) are formed at both sides of the open cavity  131 , and an upper passage  125   b  corresponding to the lower passage  125   a  is formed at either the left or right side of the sweeping mounting section  113   b  of the upper casing  130 . 
         [0045]    The lower casing  120  and the upper casing  130  are connected to each other with a latching connection, and in particular, the lower casing  120  has a latching projection  119   a  at the far front side to engage with a latch  119   b  at the far front side of the upper casing  130  (see  FIG. 4 ), thereby enhancing the sealing force. 
         [0046]    The sweeping member  140  is composed of a brush  150  and a rotational power transmission member for transmitting rotational power to the brush  150 . The brush  150  is composed of a rotational shaft  151  and brushing filaments  153  provided on the rotational shaft  151 . Opposite ends of the rotational shaft  151  are rotably supported by the respective holder  152 . Each holder  152  is securely held for rotation at the brush holder supports  123   a  and  123   b.    
         [0047]    The rotational power transmission member is composed of a motor  160 , a pulley  162  provided at one end of the rotational shaft  151 , and a belt  166  wound around the pulley  164  that is installed at the rotation axis of the motor  160 . The belt  166  is composed of a toothed timing belt, and the pulleys  162  and  164  are preferably toothed pulleys to be engaged with teeth. 
         [0048]    The motor  160  is fastened to the lower casing  120  by the motor mount  170 . In particular, the motor mount  170  includes a motor seat  171  formed in the lower casing  120  to allow the bottom face of the motor  160  be seated thereon, and a motor support frame  173  fastened to the lower casing  120  to surround and support the top face of the motor  160 . With this configuration, the fastening work is made easier and the isolation of noise from the motor  160  can be achieved with the help of the motor seat  171  and motor support frame  173  surrounding the motor  160 . 
         [0049]    Since force is applied to one side of the motor  160  through the belt  166 , a support structure for counterbalancing this force can be provided to improve the endurance of the rotation axes of the motor  160 . This can be achieved by providing one fastening structure to the left side of the motor fastening frame  176  and two fastening structures to the right side of the motor fastening frame  176 , as illustrated in  FIG. 7 . 
         [0050]    Referring to  FIG. 7 , the motor support frame  173  includes a motor body frame  174  with heat dissipation holes  174   a , a plurality of contact ribs  175  formed at the inner face of the motor body frame  174 , and motor fastening frames  176  extending from the motor body frame  174 . The contact rib  175  has a band shape along its circumference to form a line contact with the outer peripheral face of the motor  160 , and the heat dissipation holes  174   a  are preferably formed in the motor body frame  174  between the contact ribs  175  to dissipate heat generated by the motor  160 . The motor fastening frames  176  are formed at both sides of the motor support frame  173 , which are then fastened and secured to the lower casing  120  by screws. 
         [0051]    Referring to  FIG. 5A , the motor seat  171  is preferably composed of a plurality of base ribs  172  for holding up or bracing the bottom face of the motor  160 . A partial motor support  171   a  is preferably formed at one side of the motor seat  171  so as to support one end (near the rotation axis) of the motor  160 . 
         [0052]    Referring back to  FIG. 7 , a dustproof pad  178  with heat dissipation holes  178   a  is preferably interposed between the base ribs  172  and the bottom face of the motor  160 , and preferably interposed between the motor seat  171  and the base ribs  172 . A support cap  178   b  that is supported onto one end of the motor  160  is formed at one side of the dustproof pad  178  in such a way that the support cap  178   b  may be interposed between the partial motor base  171   a  and the one end of the motor  160  to absorb vibration noises. 
         [0053]    The dust case  200  that is housed in the open cavity  131  and dust case seat cavity  127  includes a casing  210  and a cover  230  for opening/closing the top of the casing  210 , as shown in  FIGS. 1 and 8 . An inlet  212  (see  FIG. 4 ) through which dust particles flow inside is formed at the front face of the casing  210 . The casing  210  is composed of a front plate (or wall)  211 , lateral plates (or walls)  213 , a back plate (or wall)  215  and a bottom plate (or wall)  217 , and serves as an outlet for cleaning dust particles piled up at the open top portion. As explained earlier, the front plate  211  is formed of a tilted (angled) front plate  211  in an inclined state, thereby serving as a dustpan, with the inlet  212  arranged at the upper side of the tilted front plate  211 . Guide projections  213   a  are formed on both lateral plates  213 , and guide grooves  131   a  (see  FIG. 6A ) are formed on both lateral plates of the open cavity  131 . The bottom plate  217  has a stepped configuration, with a rear portion  217   b  that is raised by a step from a front portion  217   a . The bottom plate  217  is adapted to be seated on the stair-shaped bottom  127   a  described above (see  FIG. 5A ). Since the front portion  217   a  of the bottom plate  217  is lower than the rear portion  217   b , it allows the casing  210  to have a deeper front end, thereby providing increased volume in the casing  210  to compensate for any dust-collection (volume) capacity that has been reduced by the height of the inlet  212  that may have taken up the front plate  211 . 
         [0054]    The cover  230  is preferably composed of a first cover portion  231  for covering the top of the casing  210  and a second cover portion  233  extending in the forward direction from the first cover portion  231 . When the dust case  200  is placed in the open cavity  131  as shown in  FIGS. 4 and 9A , the second cover portion  233  covers the top of the brush  153 . The cover  230  is preferably coupled to the casing  210  by hinge shafts  218  and  238 , with the hinge shaft  238  of the cover  230  fitted into a hinge opening  218  of the casing  210  for pivoting motion. The hinge shaft  238  is arranged between the first cover portion  231  and the second cover portion  233 , and the hinge opening  218  is preferably formed at the lateral plates  213  near the inlet  212 . 
         [0055]    Because of the locations of the hinge shaft  238  and hinge opening  218 , when the cover  230  is moved from a closed state as in  FIG. 9A  into an open state as in  FIG. 9B , the first cover portion  231  leaves the top of the casing  210  open, while the second cover portion  233  contacts the tilted front plate  211  and covers the inlet  212 . Conversely, when the first cover portion  231  is closed, the second cover portion  233  opens the inlet  212 , so that the cover  230  pivots like a seesaw. As a result, even when the casing  210  and the second cover portion  233  is turned upside down to empty dust particles, the dust particles do not sneak into the inlet  212 , thereby helping to maintain a clear appearance of the casing  210  and the cover  230 . Since dust particles are discharged and emptied through the top, the collected dust does not leak except through the inlet  212 , such that the dust case seat cavity  127  remains clean, compared a the conventional dust case which is usually opened/closed through the bottom face, where the collected dust may sneak in through any crack and then be piled up in the dust case seat cavity. 
         [0056]    As illustrated in  FIGS. 4 and 8 , a safety bar  240  is extends downwardly from the bottom face of the second cover portion  233 . The safety bar  40  can be formed as a rib protruding in the lateral direction so as to prevent dust particles gathered by the rotation of the brush  150  from rebouncing (the backflow phenomenon). Accordingly, the dust particles having collided with the safety bar  240  either reenter the inlet  212  or fall between the inlet  212  and the brush  150 , consequently improving the sweeping efficiency. 
         [0057]    Moreover, as illustrated in  FIGS. 4 and 8 , it is preferable (though optional) to have a secondary safety bar  242  arranged farther to the front than the safety bar  240  on the bottom face of the second cover portion  233 . This secondary safety bar  242  serves as a duster for the brush  153  to further improve the sweeping efficiency of the brush  153 . When the safety bar  240  or the secondary safety bar  242  are formed in this way, these safety bars  240  and  242  serve to block the inlet  212  as they come in contact with the tilted front plate  211 . 
         [0058]    In addition, the second cover portion  233  preferably has a see-through cover  235  for a user to be able to look at the inside of the casing  210 . The see-through cover  235  can be inserted into a part that is protruded downwardly from the first cover portion  231 , and a handle bar  236  (which can be grasped with fingers) can be formed at its lateral face. 
         [0059]    Moreover, a locker  250  for locking/unlocking the cover  230  into/from the casing  210  can be provided. The locker  250  is composed of a locking projection  251  (see  FIG. 96 ) formed at the cover  230 , and an unlocking element  253  for locking/unlocking the locking projection  251 . The unlocking element  253  is composed of an operational piece  254 , a hinge shaft  255  for allowing the operational piece  254  to be pivotable about a hinge groove (not shown) of the back plate  215 , a locking arm  257  formed above the operational piece  254  around the hinge shaft  255  so as to catch the locking projection  251  thereon, and a spring  259  arranged below the operational piece  254 . Thus, when the operational piece  254  at the side of the spring  259  is pressed, the locking arm  257  starts pivoting and the locking projection  251  is then unlocked. On the other hand, when the locking projection  251  is pressed inwardly (i.e., when the cover  230  is pressed into the casing  210 ), it pushes the top face of the locking arm  257  and engages with the pivoting, operational piece  254  into an interlocked state. Because the locker  250  protrudes from the back plate  215 , a guide groove  131   b  can be provided at the rear face plate  132  to receive and guide the locker  250  (see  FIG. 6A ). 
         [0060]    The steam generation member  190  is composed of a heater  191 , a tank  193  in which water comes in contact with the heater  191  to be converted into steam, and a connection tube  195  for delivering steam generated from the tank  193  to the steam discharge port  129  (see  FIG. 5A ). Water is fed into the tank  193  via a cap  184 . Referring to  FIG. 4 , a PCB  180  is provided in a space between the partition wall  111   b  and the rear face plate  132 . The PCB  180  functions to control operations of the steam generating member  190  and sweeping member  140 . 
         [0061]    As illustrated in  FIGS. 10-13 , the pad tray  260 , which is attachable/detachable to the attachment/detachment member, is secured to the bottom face of the lower casing  120 . The pad tray  260  is detached when the sweeper is cleaning a carpet or similar tasks, and is attached when the sweeper is used for cleaning a non-carpeted floor using steam. The pad tray  260  is composed of a tray board  261 , withdrawal openings  263  formed in the tray board  261  that are in communication with the steam discharge port  129  (see  FIG. 5A ), and pad attachment protrusions  265  molded at the front side, back side or both front and back sides around the withdrawal openings  263 . The pad attachment protrusions  265  can be made of soft plastic materials (PP or PC based materials) to help the VELCRO™ on the pad to be easily attached thereto or detached therefrom. In general, when a soft plastic material is used as a single product (i.e., it is either attached or detached as in this embodiment), its warping tendency makes it difficult to be attached to the bottom face of the lower casing  120 . This is because the conventional steam cleaner is fastened and secured to the upper casing  130 ; although the pad attachment protrusions  265  are molded with a soft plastic material onto the lower casing  120 , the upper casing  130  does not undergo any deformation or warping. 
         [0062]    In conventional applications, a PP plastic resin is normally used for the VELCRO™, but it can be easily deformed by heat after manufacturing by mould. Therefore, in this embodiment, a board  261   a  with soft pad attachment protrusions  265  as shown in  FIG. 12  is molded as a first tray board using a heat-resistant soft plastic material, and then the board  261   a  with pad attachment protrusions  265  is inserted into a mold to form a reinforced tray board  261   b  as a second tray board that is more sensitive to heat than the first tray board and contains hard plastic materials (e.g., PP or PC based materials with a small amount of glass fiber), thereby forming a double injection. The resin for the tray board  261   b  is a PC, which is strong enough to keep its shape under heat or other related circumstances. The second tray board  261   b  of  FIG. 12  is not necessarily manufactured separately, yet it is provided here for better understanding. As such, even though the pad tray  260  is a single product, the reinforced tray board  261   b  holds up the board  261   a  with pad attachment protrusions  265  to maintain its flat shape. 
         [0063]    The attachment/detachment member is composed of a first attachment/detachment portion  2711  formed on the pad tray  260 , and a second attachment/detachment portion  271  installed at the lower casing  120 . The first attachment/detachment portion  2711  is composed of an attachment/detachment groove  273  formed at the lateral face of a protrusion  272  that extends upwardly from the top face of the pad tray  260 . The second attachment/detachment portion is composed of an elastic locking element  277  received by a recess  276  formed in the bottom face of the lower casing  120 , and a support element  279  for supporting the elastic locking element  277 . The elastic locking element  277  is composed of a bottom sheet  277   a  placed at the bottom of the recess  276 , and an elastic locking piece  277   b  that can be elastically deformed in a cantilever shape from the bottom sheet  277   a . A slot  277   a ′ is formed at the center of the bottom sheet  277   a  for receiving a slot projection  277   a ″ formed at the recess  276 . The support element  279  is composed of a support piece  279   a  (see  FIG. 3 ) for pressing the bottom sheet  277   a  in the way of support, and a fastening piece  279   b  that is fastened and secured to the lower casing  120  for supporting the support piece  279   a . When the support piece  279   a  has a hollow shape, a disposition recess  279   a ′ where the elastic locking piece  277   b  is movably disposed is preferably formed at the support piece  279   a.    
         [0064]    As the first and second attachment/detachment portions are placed behind the pad tray  260  and lower casing  120 , it is preferable to have a third attachment/detachment portion  274  additionally in front of the pad tray  260  and lower casing  120  (see  FIGS. 4 and 11 ). The third attachment/detachment portion  274  is composed of a boss  274   a  formed at the top face of the pad tray  260 , and an insertion recess  274   b  into which the boss  274   a  is inserted. The boss  274   a  and the insertion recess  274   b  are preferably in the form of a solid trapezoid facilitating easy attachment/detachment. 
         [0065]    The pad tray  260  also has a foot press  267  at a rear side so that the user can step thereon (or use a hand to press) from a standing position. 
         [0066]    The present invention can be applied to a reservoir-type steam combined sweeper (in case a steam generating member is installed at the body), to an injection-type steam combined sweeper (in case a steam generating member is installed at the mop-stick), or to a gravity-operated steam combined sweeper (in case a steam generating member is installed at either the body or the mop-stick). 
         [0067]    While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention.