Patent Publication Number: US-6217641-B1

Title: Dust container for a vacuum cleaner

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a dust container having a bag of air pervious material with an opening covered by a plate, the plate being provided with an opening through which dust laden air flows into the bag. 
     Dust containers of the type mentioned above are known and are currently used in vacuum cleaners to achieve a hygienic handling of the dust being collected. There are, however, a large number of different types of dust containers on the market. Each type of dust container suits one or several models of vacuum cleaners, the plate of each dust container being shaped such that it should solely suit the particular model or models that the dust container is intended for. In order to prevent the wrong dust container from being inserted into the vacuum cleaner or to prevent the vacuum cleaner from being started without a dust container, the vacuum cleaner is usually provided with sensing means connected to the electric circuit of the vacuum cleaner. The sensing means prevents dust from flowing into the fan unit and to the outlet filter, which is normally placed after the fan unit, if a dust container is not inserted. Such sensing means could be a micro switch sensing the presence of the plate or the dust container, pneumatic sensors, see GB 1494310, which are blocked by the plate when the wrong dust container is inserted or electromagnetic sensors (including optical methods) for sensing identification means on or within the dust container, see EP-A-790030. 
     However, all these methods have certain deficiencies. Micro switches indicate the presence of the dust container, but do not indicate whether the correct dust container is used. Pneumatic sensors and, in particular, the flow paths within the plate of the dust container, are sensitive to disturbances because of their small dimensions. Electromagnetic sensors are comparatively complicated and, thus, rather expensive. 
     Accordingly, there is a need in the art for a dust container that is simple to manufacture and enables the vacuum cleaner to identify the dust container so as to permit the vacuum cleaner to be started only when the correct dust container has been placed in the correct position in the vacuum cleaner. The present invention is directed to such a dust container. 
     SUMMARY OF THE INVENTION 
     It therefore would be desirable, and is an advantage of the present invention, to provide a dust container for a vacuum cleaner having contacts electrically connected to an electric circuit that permits the vacuum cleaner to be activated only when an electrical connection is established between the contacts. The dust container includes a bag of air pervious material having an opening formed therein. A plate covers the opening in the bag. The plate has an opening formed therein and includes an electrical conductor for establishing an electrical connection between the contacts of the vacuum cleaner. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where: 
     FIG. 1 shows a broken-away view of a vacuum cleaner having a dust container disposed therein; and 
     FIG. 2 is a perspective view of the dust container. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     It should be noted that in the detailed description which follows, identical components have the same reference numerals, regardless of whether they are shown in different embodiments of the present invention. It should also be noted that in order to clearly and concisely disclose the present invention, the drawings may not necessarily be to scale and certain features of the invention may be shown in somewhat schematic form. 
     FIG. 1 shows a shell  10  of a vacuum cleaner  50  having a chamber  11  that in a traditional manner communicates with a fan unit, not shown. The chamber  11  has a front wall  12  with an opening  13  through which a dust container  14  can be partly inserted. The dust container  14  comprises a plate  15 , preferably a multilayered cardboard plate, that is connected to a filter bag  16  of air pervious material. The plate  15  has an inlet opening  17 , which is partly covered by a flexible sealing membrane  18  having a central opening  19 . When inserted into the vacuum cleaner  50 , the plate  15  of the dust container frictionally engages a shoulder  20  partly surrounding the plate  15 . 
     A cover  21  is pivotably connected to the shell  10 . The cover  21  is provided with an inlet sleeve  22 , which is connected to a hose  23  of the vacuum cleaner  50 . The sleeve  22  extends toward the chamber  111  in such a manner that when the cover  21  is closed, a free end of the sleeve  22  extends through the opening  19  in the flexible membrane  18 , and the membrane  18  seals against the sleeve  22 . The cover  21  is also provided with a wall  24  that supports contact means  25  comprising two pins  26 ,  27  extending in the same direction as the sleeve  22 . The pins  26 ,  27  are connected to electric conductors of a cable  28 , which is connected to an electric circuit  29  of the vacuum cleaner  50 . The cable  28  directs a small electric control current from the electric circuit  29  to the pins  26 ,  27 . The circuit  29  is arranged such that a fan unit (not shown) will start only if there is an electrical connection between the two pins  26 ,  27 , i.e., only if the control current flows between the pins  26 ,  27 . 
     In order to achieve said electrical connection between the pins  26 ,  27 , an electrical conductor  30 , such as aluminum foil, or a thread, strip or layer of another electrically conductive material is arranged between upper and lower layers  15   a,    15   b  of the plate  15 , and the upper layer  15   a  is provided with an opening  31 . When the cover  21  is closed and the dust container  14  is inserted in the vacuum cleaner  50 , the two pins  26 ,  27  will abut the conductor  30 , thereby establishing an electrical connection between the two pins  26 ,  27 , and permitting the fan unit to be started. The small control current directed to the two pins  26 ,  27  should be of such character that there is no danger to the operator. 
     The conductor  30  is sized to cover the area of the plate  15  delimited by the pins  26 ,  27  when the cover  21  is closed and the pins  26 ,  27  contact the plate  15 . The conductor  30  can be made larger than is shown, which would permit the two pins  26 ,  27  to be separated from each other and to extend through separate openings in the upper layer  15   a.  By positioning the two pins  26 ,  27  (and the corresponding openings in the container layer  15   a ) at different positions on the plate  15  it is thus possible to create several different contact patterns for different types of vacuum cleaners with associated dust containers. 
     It should be appreciated that in another embodiment of the present invention, the conductor  30  is disposed between the lower layer  15   b  and the shell  10  of the vacuum cleaner  50 . In this embodiment, aligned openings are formed in the upper and lower layers  15   a,    15   b  to permit the contact pins  26 ,  27  to extend through the plate  15  and contact the conductor  30 . 
     Although the preferred embodiments of this invention have been shown and/or described, it should be understood that various modifications and rearrangements of the parts may be resorted to without departing from the scope of the invention as disclosed and claimed herein.