Abstract:
A vacuum cleaner includes a housing, inside of which is a suction chamber with a suction device and control electronics therein. A structural unit on the housing includes operating elements to operate the vacuum cleaner. There is an opening in the housing to the suction chamber. A support element is included that covers the opening. The support element includes contact strips providing electrical connection to the operating elements. There are plug-in connectors inside the housing connectable with the contact strip that provide a wired connection to the control electronics. The control electronics are cooled by an air stream resulting from the suction device.

Description:
Priority is claimed to German patent application DE 199 47 980.1, filed Oct. 5, 1999. 
   The subject matter of the invention relates to a vacuum cleaner, particularly a floor vacuum cleaner provided with a suction chamber in the apparatus housing for receiving a suction device as well as with operating elements on the housing for electrically controlling the output of the suction device, with the operating elements assembled as one structural unit being arranged above the apparatus housing which also receives the electronic control for the suction device. 
   BACKGROUND 
   Such vacuum cleaners (see German Patent 36 03 176 A1) consist of an upper housing section receiving the structural unit including the operating elements as well as of a lower section which is divided by separating walls into a dust collection chamber for the dust filter bag, the suction chamber and a housing chamber for a cable coil. In the assembled state, the separating walls are covered in an air-tight manner by the upper housing section with a lid hinged to the upper housing section sealing the dust collection chamber. In this context it is known to arrange the operating elements for controlling rotations and/or for energizing the apparatus as well as key for operating the cable winder as a single structural unit on an upper portion of the vacuum cleaner housing above the housing chamber for the suction device. In this arrangement, at least the keys positioned laterally of a center operating component are structured as kick pedals with large surfaces pivotally connected to the center component. The center component in essence receives rotational or slidable means for adjusting the output of the suction device which, in turn, is controlled by an electronic control disposed within the suction chamber (see German Patent 44 26 634 A1). An arrangement of the electronic control at the exterior of the suction chamber in the housing of the apparatus is also known (see German Utility Model 74 08 275). In this arrangement the electronic control is mounted on a printed circuit board or plate. 
   Furthermore, German Patent DE 93 09 493 describes a vacuum cleaner with a support plate which is attached to a cable drum which creates the electrical connection. The support plate also includes the components necessary for controlling the motor. 
   A significant drawback of the known arrangements is that the electrical connection between the circuit board of the electronic control arranged within the interior of the housing and the electrical switch and the output controls as well as visual indicators on the operating elements of the vacuum cleaner installed outside of the motor chamber have to be fabricated manually and in a time-consuming manner. The manual time-consuming wiring renders the assembly and fabrication sequence of the apparatus complex and may lead to wiring errors in case of personnel not specifically trained. This is particularly so with variants having operating elements which are country-specific or which are dependent upon given types of apparatus. Moreover, leaks may occur at wire passages between housing sections. In addition, because of tight installation conditions regarding the aspirator or the operating elements combined as operational groups, it is often a problem to arrange the electronic control with its power switches and associated cooling surfaces such that sufficient cooling is attained. In the state of the art (German Utility Model 74 08 275) in which the switch plate with its output control elements (triacs etc.) is arranged in its own chamber within the vacuum cleaner provided in its walls with cooling slots for ambient air, sufficient cooling is possible only because the cooling body of the power switch is made excessively large. However, modern compact and small vacuum cleaners lack sufficient space for such purposes. Moreover, the problem remains of time-consuming wiring of the vacuum cleaner electronics with its operating elements. 
   SUMMARY 
   It is an object of the invention in a vacuum cleaner of the kind referred to above to optimize wiring and braiding between the control electronics and the operating elements combined in a single structural unit and assembled separately from the electronic, in order on the one hand to reduce the mounting complexity and on the other hand to avoid cooling problems in connection with the power switches as well as leaks in the housing in consequence of line placements between different chambers. In this context, a uniform wiring principle for different variants of an apparatus of an assembly series is to be provided, the mounted operating elements defining the type and wiring errors being avoided. 
   The present invention provides a vacuum cleaner including: a suction device; a housing including a suction chamber receiving the suction device, and at least one opening to the suction chamber; control electronics disposed inside the suction chamber; a structural unit on the housing including at least one operating element thereon; a support element sealingly covering the at least one opening and including a contact strip providing electrical connection to the at least one operating element; and at least one plug-in connector in the housing connectable with the contact strip providing electrical connection to the control electronics. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Novel features which are considered to be characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, in respect of its structure, construction and lay-out as well as manufacturing techniques, together with other objects and advantages thereof, will be best understood from the following description of preferred embodiments when read in connection with the appended drawings, in which: 
       FIG. 1  depicts top elevation of a floor vacuum cleaner provided with operating elements at the rear of the housing of the apparatus; 
       FIG. 2  is a top elevational view on an enlarged scale of the vacuum cleaner of  FIG. 1  in partial section without operating elements; 
       FIG. 3  is a bottom view of the operating elements of the vacuum cleaner; 
       FIG. 4  is a support element for connection with the operating elements; and 
       FIG. 5  is a cross-section of the apparatus housing of the floor vacuum cleaner adjacent to the operating elements. 
   

   DETAILED DESCRIPTION 
   A floor vacuum cleaner  1  shown in top elevation in  FIG. 1  is provided with an apparatus housing  2  which is divided in a manner well known (see  FIG. 2 ) into a suction chamber  3  for the suction device  4 , a chamber  5  for a cable drum  6  for receiving the connection cable of the apparatus as well as a dust collection chamber  7  for receiving a dust filter bag. As shown in  FIG. 5 , the apparatus housing  2  consists of a lower section  8  provided with separating walls  9  for the previously mentioned chambers and of an upper section  10  of the housing tightly and releasably connected in a known manner with the lower section  8 . 
   As shown in  FIGS. 1 ,  2  and  3 , there are provided in the closing upper housing section  10  provided with a pivotal lid  11  for changing the dust filter bag and above the suction chamber  3 , operating elements  12 ; an operating element  12   a  for switching the vacuum cleaner  1  on and off, another operating element  12   b  for controlling the output via a power selection switch  20 , and another operating element  12   c  for winding or unwinding the feed cable. The three operating elements  12  have been combined in a single structural unit and together extend over the width of the apparatus housing  2 . The structural unit with the operating elements  12  consists of a separate middle piece  12   b  on which the power selection switch  20  and, optionally, control indicators and the like are mounted, as well as, on opposite sides of the middle piece  12   b , operating elements  12   a  and  12   c  are form as rocking (see arrows,  FIG. 5 ) switch keys structured as foot kick pedals. One of these kick pedals  12   a  serves to turn the apparatus on and off and is for this purposes provided at its bottom surface an appropriate switching device  13  such as, for instance, a micro switch. When actuated, the second key releases, by way of an integral actuating member  14 , the brake of the cable drum  6 . 
   As shown in  FIGS. 3 ,  4  and  5  and in accordance with the invention, there is releasably connected to the bottom surface of the middle operating piece  12   b  of the structural unit a support element  17  provided with contact strips  15 ,  16 . The support element  17  may optionally also support the electronics of the apparatus. The contact jacks  18  (see  FIGS. 2 and 5 ) of the contact strips  15 ,  16  at the upper surface remote from the apparatus are connected by plugged conductor bridges  19  to the rotation adjustment or power selection switch  20 , to separate indicator and control elements as well as to the on-off switch  13  of the structural unit of operating elements of the vacuum cleaner  1 . 
   In accordance with the invention, the upper section  10  of the housing is provided with a defined opening  21  near the suction chamber  3 . The upper margin of the opening  21  (see  FIGS. 2 and 5 ) forms a circumferential land. The opening  21  is tightly covered by the support element  17  which for this purpose is structured as a lid with a circumferential marginal lip  23  (see  FIGS. 3 ,  4  and  5 ). In the marginal lip  23 , there is formed a gasket  43  which, after the support element  17  has been mounted, engages the margin of the opening  21 . In addition, the support element  17  tightly covers a second opening  25  (see  FIGS. 2 and 5 ) leading to the chamber  5  of the cable drum  6 .  FIG. 3  is a bottom view of the operating elements  12  of the floor vacuum cleaner, removed from the vacuum cleaner  1 , with the support element  17  arranged at the middle operating element  12   b.    
   The contact strips  15 ,  16  are seated in contact holders  26 ,  27  formed integrally with the support element  17  and are either cast into the holders or injection molded into them. Opposite the contact strips  15 ,  16 , as seen in  FIG. 5 , plug-in connectors  28 ,  29  are arranged in the lower section  8  of the apparatus housing  2 ; they are releasably arranged in separate holders  30  in the suction chamber  3  and in chamber  5  for the cable drum  6 . The plug-in connectors  28 ,  29  are accessible and viewable by way of the two housing openings  21 ,  25 , the plug-in connectors  28 ,  29  corresponding to the contact strips  15 ,  16  being electrically connected to the control electronic  31  in the interior of the apparatus or the components thereof, to the suction device  4 , the connector cable on the cable drum  6  as well as, optionally, to further electrical accessories in the interior of the floor vacuum cleaner  1 . 
   In accordance with the invention, the suction device control electronic  31  and the cooling units  32  of the power switches of the rotation control, when the plugs are withdrawn, are arranged in the vicinity of the housing opening  21  of the suction chamber  3 . When the support element  17  is tightly fitted onto the housing opening  21  (see  FIG. 5 ) the electronic is fully subjected to the output air stream (see arrows,  FIG. 5 ) and sufficiently cooled. The control electronic  31  is soldered to a plate  33  or circuit board preferably releasably mounted on the suction device  4  near the housing opening  21 . At least the cooling surfaces or cooling units  32  of the power switches are arranged directly in the output air stream of the suction device  4 . 
   In the illustrated embodiment, one contact strip  15  is protruding through the opening  21  into the suction chamber  3  (super pressure chamber), and, by way of the second opening  25  in the upper section  10  of the apparatus, the other contact strip  16  protrudes to the left of the separation wall  9  of the suction chamber  3  into the chamber  5  of the cable drum  6 . The chamber  5  is conventionally exposed to ambient air. The further opening  25  is covered by the support element  17  but it is not sealed thereby. Only the contact strip  15  protruding into the suction chamber  3  is arranged within the area of the lid of the support element  17  enclosed by the seal  24  and sealed to the exterior. 
   The structural unit is exchangeably arranged at the upper section  10  of the housing, the elements of the structural units being preferably interconnected by releasable snap fit connectors. As has been mentioned, the operating elements  12  structured as kick or switching keys are rockingly connected to the common middle piece  12   b  of the structural unit, the middle piece  12   b  connected to the support element  17  being adapted to hold apparatus-specific rotation controls, indicator lamps and the like as well as, optionally, additional electronic components. 
   The invention makes it possible to optimize the wiring of floor vacuum cleaners in particular, the operating elements of which are combined in a structural unit. The support element  17  for electronic and plug-in components integrated, in accordance with the invention, in the structural unit (middle piece) makes for a simple and safe plug-in coupling of the separate motor electronics in the interior of the housing with the “capped” or operating electronic at the exterior of the housing chambers, thus preventing wiring errors during the assembly process. As a separate plug-in connector the support component  17  further provides for a simple controlled accommodation of the power switches or their cooling vanes  32  directly in the air stream of the suction device  4 . Leaks in the housing are no longer possible since separate leads through housing walls between blower and cable drum chambers are no longer necessary in consequence of the plug-in arrangement. Also, because of their direct exposure to the blower air stream, cooling problems in connection with the power switches no longer occur. 
   In accordance with a further embodiment of the invention not shown in detail, the control electronics or the rotation control of the vacuum cleaner may be provided directly on the support component  17  together with the power switches and their associated cooling vanes  32  and the like. In such a variant, the electrical components of the power control are to be mounted on a separate circuit plate on the support element  17  over the opening to the suction chamber  3 . When the support element  17  or middle piece of the structural unit is assembled, at least the electronic power switches and their cooling vanes are to protrude sufficiently into the opening  21  to the suction chamber to be optimally exposed to blower air. To ensure a tight seal of the support plate it may be necessary to injection mold the electronic components into the support element  17  and to solder the plate or circuit board to the injected components. As an alternative to an injected power switch (triac) with cooling vanes it is also conceivable to injection mold only the cooling unit and two contacts. The triac will then be attached to the cooling unit for subsequent soldering with the contacts. 
   Moving the control electronics of the vacuum cleaner into the structural unit of the operating elements  12  also offers the possibility of variably to structure the apparatus. More particularly, it would be possible to select, with the same control electronics, an unchanging wiring principle for apparatus of a manufacturing series. A given type of apparatus is then defined by the applied combination of operating keys. For different manufacturing series of vacuum cleaners middle pieces  12   b  of the same width or the same size may be combined with larger or smaller switching keys  12   a ,  12   c  of the same width, the electronics of the middle piece  12   b  defining the type of apparatus.