Patent Publication Number: US-7210197-B2

Title: Nozzle assembly with air flow acceleration channels

Description:
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/457,432 filed on Mar. 25, 2003. 

   TECHNICAL FIELD 
   The present invention relates generally to the floor care equipment field and, more particularly, to a nozzle assembly for a suction cleaning device equipped with channels for directing and accelerating the flow of air toward the intake opening of the nozzle assembly. The invention also relates to upright vacuum cleaners, power heads and nozzle attachments incorporating such a feature. 
   BACKGROUND OF THE INVENTION 
   Floor care cleaning equipment including upright and canister vacuum cleaners as well as power nozzles and nozzle attachments for such vacuum cleaners as well as extractors are all very well known in the art. Each of these devices incorporates a suction generator for drawing an airstream into an intake opening in the nozzle. Dust, dirt and debris from an underlying surface such as a carpet, rug or bare floor become entrained in the airstream and are drawn into the intake opening. The dust, dirt and debris are separated from the airstream in the vacuum cleaner and collected in a dirt collecting vessel such as a cup, container or bag and the clean air is then subjected to final filtration before being exhausted into the environment. 
   Whether the cleaning equipment in question operates utilizing cyclonic airflow principles or is non-cyclonic or utilizes a bag or a cup, the velocity of the airstream being drawing into the intake opening has a significant effect on the cleaning efficiency of the device. Specifically, the greater the velocity of the airstream being drawn into the intake opening, the greater the capacity of that airstream for carrying dirt into the device and toward the dirt collection vessel. 
   The present invention relates to a nozzle assembly for a suction cleaning device incorporating structures adapted to accelerate the airstream as it approaches the intake opening and thereby increase cleaning efficiency. 
   SUMMARY OF THE INVENTION 
   In accordance with the purposes of the present invention as described herein, an improved nozzle assembly is provided for a suction cleaning device. That nozzle assembly includes a body having an edge and a bottom wall. The bottom wall includes an intake opening and a portion extending between the edge and the intake opening. At least one channel is provided in that portion. That channel extends at least partially between the edge and the intake opening. That channel also has a cross-sectional area deceasing in a direction extending from the edge toward the intake opening whereby air drawn through the channel is accelerated as the air approaches the intake opening. 
   In one possible embodiment the channel includes a top wall and a pair of converging sidewalls. Thus, the channel may be a substantially truncated V-shape. 
   In any of the possible embodiments the channel includes a first end adjacent the edge and a second end adjacent the intake opening. The first end has a width W 1  and the second end has a width W 2  where W 1 &gt;W 2 . Similarly, the first end may have a depth D 1  and the second end may have a depth D 2  where D 1 &gt;D 2 . 
   In accordance with still another aspect of the present invention, multiple channels may be provided. In such a structure each of those channels may include a top wall and a pair of converging sidewalls. Thus, each of the channels may be a substantially truncated V-shape. 
   Each of the channels may include a first end adjacent the edge and a second end adjacent the intake opening. As noted above, the first end has a width W 1  and the second end has a width W 2  where W 1 &gt;W 2 . Additionally, the first end may have a depth D 1  and the second end may have a depth D 2  where D 1 &gt;D 2 . 
   The portion may have an overall width W 3  and the first ends of the multiple channels have a total combined width W 4  where W 4  is between about 40% to about 60% of W 3 . The second ends of the multiple channels have a total combined width W 5  where W 5  is between about 22% to about 42% of W 3 . 
   In accordance with yet another aspect of the present invention, a method is provided for increasing cleaning efficiency of a nozzle assembly including an intake opening. That method includes the step of providing an air inlet channel in the nozzle assembly for delivering air to the intake opening. Additionally, the method includes the step of accelerating air traveling through the air inlet channel as it approaches the intake opening. This is accomplished by gradually reducing the cross sectional area of the air inlet channel as it approaches the intake opening. 
   In accordance with yet another aspect of the present invention, an upright vacuum cleaner is provided. That upright vacuum cleaner includes a nozzle assembly having a bottom wall defining an intake opening and a canister assembly pivotally connected to the nozzle assembly. A suction generator is mounted in either the nozzle assembly or the canister assembly. Similarly, a dirt collection vessel is mounted in either the nozzle assembly or the canister assembly. 
   The nozzle assembly is characterized by having at least one channel in the bottom wall thereof in communication with the intake opening. That at least one channel has a cross sectional area decreasing in a direction extending toward the intake opening. Of course, the upright vacuum cleaner may also include a rotary agitator in the intake opening. Such an agitator rotates relative to the nozzle assembly and brushes, bristles, beater bars, wipers and/or other structures contained thereon sweep and beat dirt and debris from an underlying surface such as the nap of a carpet being cleaned. 
   In accordance with yet another aspect of the present invention a power head is provided. That power head comprises a nozzle assembly having a bottom wall defining an intake opening. Additionally, the power head includes a rotary agitator carried on the nozzle assembly and extending at least partially across the intake opening. At least one channel in the bottom wall is provided in communication with the intake opening. That channel has a cross sectional area decreasing in a direction extending toward the intake opening. 
   Finally, the invention includes a nozzle attachment. That nozzle attachment comprises a nozzle body having a bottom wall defining an intake opening and at least one channel in the bottom wall in communication with the intake opening. That channel has a cross sectional area decreasing in a direction extending toward the intake opening. Accordingly, air passing through the channel is accelerated as it is drawn into the intake opening. The accelerated air has the capability of entraining more dirt and debris and thereby increases the cleaning efficiency of the vacuum cleaner for a suction generator having a particular size motor. 
   Still other objects of the present invention will become readily apparent to those skilled in this art from the following description wherein there is shown and described a preferred embodiment of this invention simply by way of illustration of one 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 drawing incorporated in and forming a part of the specification, illustrates several aspects of the present invention, and together with the description serves to explain certain principles of the invention. In the drawing: 
       FIG. 1  is a perspective view of a nozzle assembly clearly illustrating the bottom wall thereof, the intake opening defined by the bottom wall, an edge of the nozzle assembly and the margin of the bottom wall extending between the edge and the intake opening; 
       FIG. 2  is a detailed plan view illustrating the bottom wall of the nozzle assembly shown in  FIG. 1  including the channels extending from the edge to the intake opening; 
       FIG. 3  is an inverted front elevational view illustrating the nozzle assembly of  FIGS. 1 and 2  incorporating the features of the present invention; 
       FIG. 4  is a perspective view illustrating an upright vacuum cleaner incorporating the nozzle assembly of the present invention; and 
       FIG. 5  is a perspective view of a canister vacuum cleaner including a power head an nozzle attachment both incorporating the features of the present invention. 
   

   Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawing. 
   DETAILED DESCRIPTION OF THE INVENTION 
   Reference is now made to  FIG. 1  showing the nozzle assembly of the present invention generally designated by reference numeral  10 . The nozzle assembly  10  includes a body  12  having a bottom wall  14  that defines an intake opening  16 . The body  12  also includes an edge  18  illustrated as the front or leading edge. The bottom wall  14  also includes a portion  20  extending between the edge  18  and the intake opening  16 . 
   In the illustrated embodiment, two rotary agitators  22 ,  24  are carried on the nozzle assembly  10  and extend across the intake opening  18 . During operation of the vacuum cleaner the rotary agitators  22 ,  24  are rotated relative to the nozzle assembly  10 . Tufts of bristles  26  project from the agitators  22 ,  24 . As the agitators  22 ,  24  rotate, the bristle tufts  26  engage the nap of an underlying rug or carpet and beat dirt and debris from that carpet. Air is drawn by a suction generator into the intake opening  16 . Dirt and debris loosened from the rug or carpet becomes entrained in that airstream and is drawn through the intake opening  16  into a dirt collection vessel such as a cup or bag where it is collected for disposal. 
   As should be appreciated, the cleaning efficiency of the vacuum cleaner is largely determined by two factors: (1) the effectiveness of the bristle tufts  26 , beater bars, wipers or other associated structure or structures to free dirt and debris from a rug or carpet, and (2) the speed and volume of the airstream which determines the effectiveness of the airstream to entrain dust, dirt and debris and draw it into the vacuum cleaner. The present invention serves to increase the speed of the airstream and, consequently, maximize the load carrying capacity of the airstream. In this way the cleaning efficiency of the vacuum cleaner may be significantly enhanced. 
   In order to improve the cleaning efficiency of the nozzle assembly  10 , a series of channels  28  are provided in the portion  20  of the bottom wall  14 . The channels  28  include a top wall  30  and a pair of opposing sidewalls  32 . As further illustrated the channels  28  include a first end  34  adjacent the front edge  18  of the nozzle assembly  10  and a second end  36  adjacent the inlet opening. Thus, each channel  28  extends uninterrupted from the edge  18  to the intake opening  16 . Further, it should be appreciated that the sidewalls  32  converge in a direction moving from the edge  18  toward the intake opening  16 . Thus, the cross sectional area of each channel  28  decreases in a direction extending from the edge  18  toward the intake opening  16 . Accordingly, air being drawn into the first end  34  of each channel  28  must pass through an ever narrowing space and as a result that air is accelerated as it approaches the second end  36  and passes into the intake opening  16 . The resulting accelerated airstream has the capability of entraining both a greater volume and weight of dust, dirt and debris which is then drawn into the floor cleaning device with increased cleaning efficiency. 
   While substantially truncated V-shaped channels  28  are illustrated in  FIGS. 1 and 2 , it should be appreciated that substantially any channel shape providing a cross-sectional area decreasing in a direction toward the intake opening could be utilized. 
   In the embodiment illustrated in  FIGS. 1–3 , the first end  34  of each channel  28  has a width W 1  and the second end  36  of each channel has a width W 2  where W 1 &gt;W 2 . While not specifically illustrated, the first end  34  of each channel  28  could have a depth D 1  while the second end  36  of each channel could have a depth D 2  where D 1 &gt;D 2 . Thus, it should be appreciated that it does not matter which channel dimensions change so long as the overall cross-sectional area of the channel decreases in a direction moving toward the intake opening  16  so as to promote acceleration of the airstream. 
   In the embodiment illustrated in  FIG. 1  five channels  28  are shown in the portion  20 . The portion  20  has a width W 3  and the first ends  34  of the multiple channels  28  have a total combined width W 4  where W 4  is between about 40% to about 60% of W 3 . Further, the second ends  36  of the multiple channels have a total combined width W 5  of between about 22% to about 42% of W 3 . 
   While five channels  28  are illustrated, it should, of course, be appreciated that substantially any other reasonable number of channels could be provided from, for example, one to perhaps  20  or more. The key is providing one or more inlet air channels  28  in the nozzle assembly  10  for freely delivering air to the intake opening  16  having a geometry adapted for accelerating the air traveling through the channels  28  as that air approaches the intake opening. 
     FIG. 4  illustrates an upright vacuum cleaner  50  incorporating the nozzle assembly  10  of the present invention. More specifically, the upright vacuum cleaner  50  includes a housing comprising the nozzle assembly  10  and a canister assembly  52  that is pivotally connected to the nozzle assembly. As illustrated the canister assembly  52  includes a control handle  54  and a hand grip  56 . A control switch  58  is provided for turning the upright vacuum cleaner on and off. Of course, electrical power is supplied to the vacuum cleaner  50  from a standard electrical wall outlet through an electrical cord  60 . 
   As is well known in the art, a pair of rear wheels (not shown) are provided on a lower portion of the canister assembly  52  and a pair of front wheels (also not shown) are provided on the nozzle assembly  10  for movement across the floor. To allow for convenient storage of the vacuum cleaner, a foot latch  62  functions to lock the canister assembly  52  in an upright position as shown in  FIG. 4 . When the foot latch  62  is released, the canister assembly  52  may be pivoted relative to the nozzle assembly  10  as the vacuum cleaner  50  is manipulated back and forth to clean the floor. 
   In the illustrated embodiment the canister assembly  52  includes a cavity adapted to receive and hold a dirt collection vessel in the form of a dirt cup  64 . A suction generator  66 , including a fan and motor assembly, may either be carried on the nozzle assembly  10  or the canister assembly  52 . In either event the suction generator  66  draws air and entrained dirt and debris into the vacuum cleaner  50 . The dirt and debris is collected from the air in the dirt cup  64  and clean air is then exhausted through a final filter (not shown) into the environment. The bagless vacuum cleaner illustrated may or may not take advantage of cyclonic technology. 
   While the illustrated vacuum cleaner  50  utilizes a dirt cup  64  as the dirt collection vessel, it should be appreciated that the vacuum cleaner could just as easily utilize a vacuum cleaner bag instead of the cup. Further, while the dirt cup  64  in the illustrated vacuum cleaner  50  is carried on the canister assembly  52 , it should be appreciated that the dirt cup or even a bag could be just as easily carried on the nozzle assembly  10  if desired. 
     FIG. 5  illustrates a canister vacuum cleaner  70  equipped with a nozzle assembly/power head  10  and alternative nozzle attachments (not shown) constructed in accordance with the teachings of the present invention and including the airflow channels  28 . More particularly the canister vacuum cleaner  70  includes a hose  76 , a wand  77  and a canister housing  78  supported on wheels  79 . The canister housing  78  includes an internal chamber  80  as well as a suction inlet  81  and exhaust outlet  83 . A suction generator  82 , in the form of a fan and motor assembly, is held in the chamber  80 . Additionally, a dirt collection vessel  84  in the form of a dust bag or dirt cup is held in the internal chamber  80  between the suction inlet  81  and the suction generator  82 . 
   The foregoing description of a preferred embodiment of the invention has 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. For example, the channels  28  may be of different sizes and shapes. Further, additional channels  68  may be provided in the bottom wall  14 . As illustrated in  FIG. 1  these channels  68  extend from the sides of the nozzle assembly  10  to the intake opening  16  at a point between the two agitators  22 ,  24 . These channels  68  function to direct air into the intake opening  16  between the agitators  22 ,  24  so as to increase the airflow in this zone and thereby enhance the capacity of that airstream to entrain dirt and carry that dirt toward the dirt collection vessel. While not apparent from the illustration, the channels  68  may also be shaped to provide a decreasing cross sectional area as those channels extend toward the intake opening  16  to aid in increasing the speed of the airstream. 
   The embodiment was 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 embodiment do not and are not intended to limit the ordinary meaning of the claims and their fair and broad interpretation in any way.