Patent Publication Number: US-8533903-B2

Title: Dirt cup assembly with a pre-filter having a plurality of ribs

Description:
TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION 
     This invention relates to the floor care equipment field and, more particularly, to a floor cleaning apparatus incorporating a dirt collection assembly including both ribs/vanes in the dirt collection chamber to reduce air turbulence and a dump door for easy and convenient emptying of the dirt cup. 
     BACKGROUND OF THE INVENTION 
     Upright and canister vacuum cleaners equipped with dirt collection assemblies comprising a dirt cup with a tangentially directed inlet and an axially directed outlet are well known in the art. Such a dirt cup provides for cyclonic air flow which utilizes centrifugal force to provide more efficient and effective cleaning of dirt and debris from the air stream. 
     After a certain period of use the dirt collection chamber in the dirt cup fills with debris and it becomes necessary to empty the dirt cup. Many operators do not enjoy handling the dirt cup and are uncomfortable during the emptying operation. Such operators typically want to minimize any potential contact with the dirt and debris held in the dirt cup. In order to address this concern, it is known in the art to provide a dirt cup with a hinged bottom wall or dump door as disclosed, for example, in U.S. Pat. No. 7,640,624 owned by the Assignee of the present invention. Advantageously, the dump door allows the operator to handle the dirt cup without opening the dirt compartment until the cup is positioned over a garbage can or other receptacle. The dump door is then opened and the dirt and debris in the dirt cup drops under the force of gravity into the underlying garbage receptacle. It should be appreciated that such a dirt cup with a dump door is user friendly, is considered generally more sanitary than other approaches and is a desirable feature. 
     As noted above, a cyclonic vacuum cleaner utilizes centrifugal force to help separate dirt and debris from the air stream. More specifically, the air stream enters the dirt cup through a tangentially directed inlet and flows rapidly in a cyclonic path around the cylindrical sidewall of the dirt cup. Dirt particles in the air stream move under the resulting centrifugal force produced by this cyclonic movement toward and against the cylindrical sidewall. There the particles slow due to the frictional contact with the sidewall and gradually drop toward the bottom of the dirt cup where they are collected. 
     It has been found that under certain operating conditions and in certain circumstances the air flow at the bottom of the dirt cup develops an elliptical component. At the same time the air stream typically maintains sufficient velocity to entrain some particles of dirt and debris. Thus, particle backflow may be produced where dirt and debris from the bottom of the cup is lifted back toward the top thereby reducing the overall cleaning efficiency of the vacuum cleaner. 
     In order to address this concern it is known to reduce turbulence in and particle backflow from the bottom of the dirt cup by positioning vanes or fins on the bottom wall or the outer cylindrical sidewall of the dirt cup as disclosed in, for example, U.S. Pat. Nos. 6,616,721 and 6,810,557. Positioning fins or vanes along the outer sidewall is not the most desirable solution since these vanes are in the path of particle concentration. As a result, the air stream and entrained particles impact the vanes with a high force. Often that force is sufficient to cause substantial airflow turbulence and particle scatter toward the center of the dirt cup where some of the particles have a tendency to be lifted toward the airstream outlet leading from the dirt collection chamber. This can adversely affect the cleaning efficiency of the vacuum cleaner. 
     While the positioning of the vanes or fins in the dirt cup along the bottom wall but spaced from the sidewall avoids this problem, such vanes are not compatible with a dirt cup with a hinged bottom wall or dump door. This is because these vanes would engage the sidewall of the dirt cup and prevent the bottom wall/dump door from opening completely thereby interfering with the dirt dumping or cup emptying operation. 
     The present invention relates to a vacuum cleaner incorporating a novel dirt collection assembly equipped with both a dump door and fins or vanes to reduce turbulence and particle back flow so as to allow more efficient cleaning operation. Thus, the present invention relates to the first floor cleaning apparatus to both incorporate and benefit fully from these two, previously incompatible features. 
     SUMMARY OF THE INVENTION 
     In accordance with the purposes of the invention as described herein, a floor cleaning apparatus is provided. That apparatus comprises a housing including a nozzle assembly and a canister assembly. The nozzle assembly includes a suction inlet. Both a suction generator and a dirt collection assembly are carried on the housing. The dirt collection assembly includes a dirt cup having a substantially cylindrical sidewall and a bottom wall defining a primary dirt collection chamber as well as a tangentially directed air stream inlet. In addition, the dirt collection assembly includes a shroud concentrically received within the sidewall in the dirt collection chamber. The shroud includes an air stream outlet, an air flow guide between the air stream outlet and the bottom wall and at least one rib or fin projecting from the shroud and, more particularly the air flow guide, toward the bottom wall. The at least one rib is positioned so as to reduce air turbulence in the dirt collection chamber between the air flow guide and the bottom wall. 
     Further describing the invention, a hinge is provided connecting the bottom wall to the sidewall of the dirt cup. A releasable latch mechanism secures the bottom wall to the side wall in a closed position so as to seal the dirt collection chamber during vacuum cleaner operation. When the dirt collection chamber fills with dirt and debris or the operator desires to empty dirt and debris from the dirt cup, the dirt cup is removed from the housing and positioned overlying a garbage receptacle. The latch mechanism is then released and the bottom wall or dump door swings open about the hinge and dirt and debris is emptied from the dirt cup into the underlying garbage receptacle under the force of gravity. Significantly, the ribs or fins for reducing turbulence do not in any way interfere with the hinged movement of the bottom wall or dump door. 
     In the following description there is shown and described several different embodiments of the invention, simply by way of illustration of some of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings incorporated herein and forming a part of the specification, illustrate several aspects of the present invention and together with the description serve to explain certain principles of the invention. In the drawings: 
         FIG. 1  is a perspective view of an upright vacuum cleaner constructed in accordance with the teachings of the present invention; 
         FIG. 2  is a detailed cross sectional view of the dirt collection assembly of the vacuum cleaner illustrating the bottom wall or dump door in the closed position; 
         FIG. 3  is a view similar to  FIG. 2  but illustrating the bottom wall or dump door in the open position so as to allow emptying dirt and debris from the dirt collection assembly; 
         FIG. 4  is a detailed perspective view of a portion of the shroud that is concentrically received within the dirt collection chamber and clearly illustrating the airflow guide and the projecting ribs or fins that reduce air turbulence in the dirt collection chamber; 
         FIG. 5  is a detailed cross sectional view of the shroud showing the channel underlying the air flow guide; and 
         FIG. 6  is a schematical illustration of a canister vacuum cleaner constructed in accordance with the teachings of the present invention. 
     
    
    
     Reference will now be made in detail to the present preferred embodiment of the invention, examples of which are illustrated in the accompanying drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION 
     Reference is now made to  FIG. 1  illustrating the floor care apparatus of the present invention in the form of an upright vacuum cleaner  10 . The upright vacuum cleaner  10  has a housing  12  comprising a nozzle assembly  14  and a canister assembly  16 . As is known in the art, the nozzle assembly  14  and canister assembly  16  are pivotally connected together. Further, the nozzle assembly includes a suction inlet  18 . A rotary agitator  20  is mounted on the nozzle assembly  14  adjacent the suction inlet  18 . The rotary agitator  20  may be equipped with bristles, tufts, wipers or other projecting cleaning structures (not shown) in a manner known in the art. 
     The canister assembly  16  includes an operating handle  22  by which the operator may control the movement of the vacuum cleaner  10  during the cleaning operation. A control switch  24  allows the operator to turn the vacuum cleaner on and off. Wheels  26  provided on the housing  12  allow the vacuum cleaner  10  to be moved smoothly across the floor. Both a suction generator  28 , such as a fan and motor assembly, and a dirt collection assembly  30  are carried on the housing  12 . In the illustrated embodiment the canister assembly  16  includes an internal compartment  32  for receiving the suction generator  28  and an opening  34  for receiving and holding the dirt collection assembly  30 . Conduits, not shown, connect the suction inlet  18  with the dirt collection assembly  30  and the dirt collection assembly with the suction generator  28 . 
     During vacuum cleaner operation, the operator manipulates the vacuum cleaner using the handle  22 . Specifically, the operator pivots the canister assembly  16  relative to the nozzle assembly  14  so that the handle  22  moves from the storage position illustrated in  FIG. 1  to an oblique, operating position. The operator is then able to move the vacuum cleaner  10  smoothly across the floor being cleaned as the canister assembly  16  freely pivots relative to the nozzle assembly  14 . 
     During this movement, the rotary agitator  20  rotates at high speeds so as to brush and lift dirt and debris from an underlying carpet. That dirt and debris becomes entrained in the air stream being drawn into the suction inlet  18  of the vacuum cleaner  10  by the suction generator  28 . The air stream with the entrained dirt and debris is then delivered to the dirt collection assembly  30  where dirt and debris are removed from the air stream and collected for later disposal. Clean air is then discharged from the dirt collection assembly  30  and drawn over the motor of the suction generator  28  so as to provide cooling. The air stream is then directed through a final filter (not shown) before being exhausted back into the environment through the exhaust port  36 . 
     Reference is now made to  FIGS. 2 and 3  which illustrate the dirt collection assembly  30  of the present invention in detail. The dirt collection assembly  30  includes a dirt cup  38  having a substantially cylindrical sidewall  40  and a bottom wall  42  defining a primary dirt collection chamber  44 . The bottom wall or dump door  42  is pivotally connected to the sidewall  40  by means of a hinge  41 . A releasable latch mechanism  43 , opposite the hinge  41 , secures the bottom wall/dump door  42  in the closed position illustrated in  FIG. 2  thereby sealing the dirt collection chamber  44 . The latch mechanism  43  is released to open the bottom wall/dump door  42  and allow emptying of dirt and debris from the dirt cup  38  under the force of gravity. Air entrained with dirt and debris is delivered to the primary dirt collection chamber  44  through a tangentially directed air stream inlet  46  provided in the sidewall  40 . 
     A shroud  50  is concentrically received within the sidewall  40  in the dirt collection chamber  44 . The shroud  50  includes a partition  52 , an airflow guide  54 , a sieve section  56  provided between the partition  52  and airflow guide  54  and multiple ribs, fins or vanes  58  (four are illustrated) projecting from the airflow guide  54  (see also  FIG. 4 ). The partition  52  of the shroud  50  abuts and seals against the cylindrical sidewall  40  of the dirt cup  38  thereby forming the top wall of the dirt collection chamber  44 . The sieve section  56  of the shroud  50  includes multiple apertures that define the air stream outlet of the dirt collection chamber  44 . Here it should be appreciated that the primary dirt collection chamber  44  defined by the cylindrical sidewall  40 , bottom wall  42  and shroud  50  functions as the primary separation stage of the dirt collection assembly  30 . 
     As illustrated in  FIGS. 2-5 , the airflow guide  54  is an annular, disc-shaped projection. A channel  60  is formed by the lower surface  62  of the air flow guide  54 , the bottom wall  64  and the depending lip  66  of the shroud  50 . The channel  60  functions to redirect any rising air currents adjacent the ribs  58  downwardly and outwardly so as to maintain debris and dirt particles in the bottom section of the dirt cup  38  below the air flow guide  54  and away from the sieve section  56 . 
     Each rib or vane  58  depending from the air flow guide  54  is tapered from a proximal end adjacent the air flow guide  54  to a distal end away from the air flow guide  54 . Further, the distal end of each rib/vane  58  includes rounded corners which aid in reducing turbulence. While the ribs/vanes  58  of the illustrated embodiment are all the same size and shape, it should be appreciated that the ribs/vanes may have different shapes and/or be of different sizes. 
     The shroud  50  also includes a tubular, cylindrical or slightly tapering support  70  that is connected to the depending lip  66 . The bottom edge  72  of the support  70  abuts the bottom wall  42  of the dirt cup  38 . A plurality of secondary cyclones  74  are provided in a second section of the dirt cup  38  on the side of the partition  52  opposite the dirt collection chamber  44 . Each secondary cyclone  74  includes a vortex chamber  76  having a cylindrical sidewall  77 , a tangentially oriented or directed inlet  78 , an axially directed clean air discharge outlet  80  and a fine particle discharge outlet  82 . As should be appreciated, the clean air discharge outlet  80  is at a first end while the fine particle discharge outlet  82  is provided at a second opposite end. Fine particles are discharged from each secondary cyclone  74  through the fine particle discharge  82  into an underlying conduit  84  with converging sidewalls. The particles travel through the conduit  84  to a secondary dirt collection chamber  86  formed within the cylindrical support  70 . Simultaneously, clean air stripped of the fine dust particles travels axially through the clean air discharge outlet  80  into a clean air manifold  88  formed between the partition  90  and a lid  92  that closes the open end or top of the dirt cup  38 . Here it should be appreciated that the dirt cup  38  may be formed by two sections  94 ,  96  that are joined together adjacent the partition  52 . The lid  92  includes an outlet port  98  that is connected by a conduit (not shown) to the intake or suction side of the suction generator  28 . The lid  92  also includes a handle  100  that is pivotally connected to the lid and allows one to conveniently hold and carry the dirt collection assembly  30  when it is removed from the opening  34  of the canister assembly  16  for emptying or any other purpose. 
     During operation, the rotary agitator  20  brushes the nap of an underlying carpet so as to loosen dirt and debris. That dirt and debris is then entrained in the airstream being drawn into the vacuum cleaner  10  by the suction generator  28 . The airstream with entrained dirt and debris is then delivered vie a conduit (not shown) to the tangentially directed inlet  46  of the dirt collection assembly  30 . The airstream then enters the primary dirt collection chamber  44  moving around the cylindrical sidewall  40  in a cyclonic path (note action arrows A in  FIG. 2 ). As a result, dirt and debris entrained in that airstream moves under the influence of centrifugal force toward and against the sidewall  40 . As the dirt and debris slows under the frictional forces produced by contact with the sidewall  40 , the dirt and debris falls through the gap G between the airflow guide  54  and the sidewall  40  toward the bottom wall  42  of the dirt cup  38  (see action arrows B in  FIG. 2 ). Dirt and debris collects in the bottom of the dirt cup  38  adjacent the bottom wall  42 . Advantageously, the ribs/vanes  58  depending downwardly from the airflow guide  54  along the lip  66  and support  70  of the shroud  50  reduce the air turbulence in the bottom of the dirt cup  38  below the airflow guide  54 . Further, any rising air currents are redirected by the channel  62  below the airflow guide  54  back toward the sidewall  40  and the downwardly directed air currents identified by action arrows B. Together the ribs/vanes  58  and the channel  62  formed by the airflow guide  54  function to maintain dirt and debris in the bottom of the dirt cup so as to enhance cleaning efficiency. 
     While dirt and debris are deflected by the channel  62  back toward the bottom wall  42  of the dirt cup  38 , relatively clean air flows around the outer edge of the airflow guide  54  toward the sieve section  56 . That clean air travels through the plurality of apertures in the sieve section  56  up along the outer surface of the conduit  84  toward the partition  102  (see action arrows C in  FIG. 2 ). The airstream then travels around the lower, truncated cone portions of the secondary cyclones  74  and is redirected by the air deflector  104  upwardly between the secondary cyclones  74  to the tangentially oriented or directed inlets  78  by which the airstream enters the secondary cyclones  74  (see action arrow D in  FIG. 2 ). 
     As the airstream enters the vortex chambers  76  of each secondary cyclone  74  it swirls in a cyclonic path around the cylindrical sidewall  77  so that any remaining fine dust particles are moved toward and through the fine particle discharge outlets  82 . The particles then fall through the conduit  84  into the secondary dirt collection chamber  86  inside the support  70  where they are maintained and collected (see action arrow E in  FIG. 2 ). Simultaneously, clean air now devoid of those fine particles travels through the axially directed clean air discharge outlet  80  of each secondary cyclone  74  into the clean air manifold  88  before passing through the outlet port  98  (note action arrows F in  FIG. 2 ). From there, the clean air travels through a conduit (not shown) to the intake or suction side of the suction generator  28 . The airstream then travels over the motor of the suction generator  28  to provide cooling. Next the airstream passes through a final filter to remove any remaining dust particles and carbon scavenged from the brushes of the motor before being exhausted through the exhaust port  36  back into the environment. 
     The operator can quickly and conveniently empty the dirt collection assembly. Specifically, the operator lifts the handle  100  to release the dirt collection assembly  30  from the opening  34  in the canister assembly  16 . The operator then carries the dirt collection assembly  30  by means of the handle  100  to a garbage receptacle. While holding the dirt collection assembly  30  over the garbage receptacle, the operator releases the latch  43 . Gravity then causes the bottom wall or dump door  42  to swing completely open about the hinge  41  and dirt and debris falls from the dirt cup  38 . More specifically, dirt and debris from both the primary dirt collection chamber  44  and the secondary dirt collection chamber  86  fall into the underlying garbage receptacle. Advantageously, there is no need to open the dirt cup  38  and expose the dirt contained therein to the environment until the operator is actually ready to empty the dirt cup into the garbage receptacle. Further, there is no need for the operator to come into direct contact with the dirt in the receptacle. In addition, it should be appreciated that while the dirt collection assembly  30  incorporates a series of ribs or vanes  58  that reduce turbulence in the dirt cup and increase cleaning efficiency, these ribs or vanes  58  are positioned so as to not interfere with the smooth operation of the dump door  42 . Accordingly, the clump door  42  fully opens to allow easy and convenient emptying of the dirt cup as desired. 
     After emptying the dirt cup, the operator closes the bottom wall/dump door  42  by pivoting about the hinge  41 . The resilient latch mechanism  43  functions to once again lock the bottom wall/dump door  42  in the closed position once the wall/door is properly seated against the sidewall  40 . The operator then replaces the dirt collection assembly  30  back in the opening  34  provided in the canister assembly  16  where it seats thereby placing the vacuum cleaner  10  in condition for operation. 
     The foregoing description of the preferred embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The ribs/vanes  58  could be secured to another portion of the shroud  50  instead of the air flow guide  54 . For example, the ribs/vanes  58  could be secured to the support  70  which is secured to the lip  66  and remains within the dirt collection chamber  44  when the bottom wall/dump door  42  is opened (see  FIG. 3 ). 
     As illustrated in  FIG. 6 , the invention is not limited to an upright vacuum cleaner  10  as shown in  FIG. 1 . The canister vacuum cleaner  200  of  FIG. 6  includes a canister body  202  supported on wheels  204 . The dirt collection assembly  30  of the present invention as described above is carried on the canister body. A wand and hose assembly  206  connects the canister body  202  to the nozzle assembly  208 . 
     The embodiments were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled. The drawings and preferred embodiments do not and are not intended to limit the ordinary meaning of the claims in their fair and broad interpretation in any way.