Abstract:
A handheld cleaning appliance includes a dirty air inlet, a clean air outlet and separating apparatus for separating dirt and dust from an airflow in an airflow path leading from the air inlet to the air outlet. The cyclonic separator is arranged in a generally upright orientation. A base surface of the main body and a base surface of the cyclonic separator together form a base surface of the appliance for supporting the appliance on a surface. By providing a base surface of the appliance which is made up of the base surface of the main body and the base surface of the cyclonic separator, the appliance is provided with a substantial base surface on which the appliance can be stably and reliably supported. This is also achieved without substantially increasing the size of the appliance as a whole.

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application is a national stage application under 35 USC 371 of International Application No. PCT/GB2007/002540, filed Jul. 6, 2007, which claims the priority of United Kingdom Application Nos. 0614235.0 and 0618492.3, filed Jul. 18, 2006, and Sep. 20, 2006, respectively, the contents of which prior applications are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The invention relates to a handheld cleaning appliance particularly, but not exclusively, to a handheld vacuum cleaner. More particularly, the invention relates to a handheld cleaning appliance having a cyclonic separator. 
     BACKGROUND OF THE INVENTION 
     Handheld vacuum cleaners are well known and have been manufactured and sold by various manufacturers for several years. Typically, a handheld vacuum cleaner comprises a casing which houses a motor and fan unit for drawing air into the cleaner via an inlet, and a separation device such as a filter or bag for separating dirt and dust from the incoming airflow. An example of such a vacuum cleaner is shown in GB 1207278. 
     Handheld vacuum cleaners have more recently been developed to incorporate cyclonic separation systems which are capable of removing larger items of debris from the airflow before removing finer particles using a filter or other barrier means. An example of such a device is sold by Black &amp; Decker under the trade name DUSTBUSTER®. These vacuum cleaners are generally elongate in shape with a handle at or near a first end and a dirty air inlet located at the end remote from the handle. The cyclonic separator is therefore commonly arranged generally in a horizontal direction. This can affect the performance of the cyclonic separator or its capacity to collect dirt and dust. 
     A further example of a handheld vacuum cleaner incorporating a cyclonic separator is shown in GB2035787A. In this arrangement, the cyclonic separator is arranged in an upright configuration and has a base surface on which the appliance can be supported. However, the base surface of the cyclonic separator is relatively small in comparison to the appliance as a whole and the appliance is therefore relatively unstable when balanced on the base surface of the cyclonic separator. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a handheld cleaning appliance incorporating a cyclonic separator which is oriented in a generally upright configuration for improved capacity and performance, the appliance being more convenient and stable to store on a flat surface. 
     The invention provides a handheld cleaning appliance comprising a main body, a dirty air inlet, a clean air outlet and a cyclonic separator for separating dirt and dust from an airflow located in an airflow path leading from the air inlet to the air outlet, the cyclonic separator being arranged in a generally upright orientation, wherein a base surface of the main body and a base surface of the cyclonic separator together form a base surface of the appliance for supporting the appliance on a surface. 
     By providing a base surface of the appliance, which is made up of a base surface of the main body and a base surface of the cyclonic separator, the appliance is provided with a substantial base surface on which the appliance can be stably and reliably supported. This is also achieved without substantially increasing the size of the appliance as a whole. 
     Preferably, the base surface of the main body and the base surface of the cyclonic separator are each substantially planar. More preferably, the base surface of the main body lies adjacent the base surface of the cyclonic separator. Still more preferably, the base surface of the main body lies in the plane of the base surface of the cyclonic separator. 
     In a preferred embodiment, the main body includes a motor and/or battery unit arranged above the base surface of the main body. In this arrangement, the centre of gravity of the motor and/or battery unit passes through the base surface of the main body which enhances the stability of the main body when it is supported on the base surface thereof. More preferably, the motor and/or battery unit is arranged immediately above the base surface of the main body for further enhancing the stability of the main body. 
     It is also preferred that the width of the base surface of the main body is at least one half of the width of the cyclonic separator. This provides further increased stability of the base surface of the appliance. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       An embodiment of the invention will now be described with reference to the accompanying drawings, in which: 
         FIG. 1  shows a handheld cleaning appliance according to the invention; 
         FIG. 2  is a side view of the appliance of  FIG. 1 ; 
         FIG. 3  is a longitudinal cross section through the cyclonic separating apparatus forming part of the appliance of  FIG. 1 ; 
         FIG. 4  is a side view similar to  FIG. 2  but with the main body shown in section; and 
         FIG. 5  is a rear view of the appliance of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 and 2  show a handheld vacuum cleaner  10 . The handheld vacuum cleaner  10  has a main body  12  which houses a motor and fan unit (not shown). The main body  12  also includes a power source  14  such as a battery. A handle  16  is provided on the main body  12  for manipulating the handheld vacuum cleaner  10  in use. A cyclonic separator  100  is attached to the main body  12 . A dirty air inlet  18  extends from a portion of the cyclonic separator  100  remote from the main body  12 . A brush tool  22  is slidably mounted on the distal end of the dirty air inlet  18 . A set of exhaust vents  24  are provided on the main body  12  for exhausting air from the handheld vacuum cleaner  10 . 
     The cyclonic separator  100  is located between the main body  12  and the dirty air inlet  18 . Consequently, the cyclonic separator  100  is located between the handle  16  and the dirty air inlet  18 . The cyclonic separator  100  has a longitudinal axis  26  which extends in a generally upright direction so that the axis  26 , and therefore the cyclonic separator  100 , lies substantially parallel to the direction in which the handle  16  extends. 
     The orientation of the handle  16  is such that, when the user grips the handle  16 , the user&#39;s hand forms a fist in a manner similar to that adopted when gripping a saw. This ensures that the user&#39;s wrist is not strained more than necessary when manipulating the handheld vacuum cleaner  10  for cleaning purposes. The cyclonic separator  100  is positioned close to the handle  16  which also reduces the moment applied to the user&#39;s wrist when the handheld vacuum cleaner  10  is in use. The handle  16  carries an on/off switch  20  in the form of a trigger for turning the vacuum cleaner motor on and off. 
     The cyclonic separating apparatus  100  forming part of the handheld vacuum cleaner  10  is shown in more detail in  FIG. 3 . The cyclonic separating apparatus  100  comprises a first cyclone  102  which has a longitudinal axis X-X and a collector  105  having a wall  104 . An inlet  110  is formed in the upper portion of the wall  104 . The inlet  110  is in communication with the dirty air inlet  18  and forms a communication path between the dirty air inlet  18  and the interior of the first cyclone  102 . The air inlet  110  is arranged tangentially to the first cyclone  102  so that the incoming air is forced to follow a helical path around the interior of the first cyclone  102 . 
     A base  116  closes the collector  105  at one end of the first cyclone  102 . The base  116  is pivotably mounted on the lower end of the wall  104  by means of a hinge  118 . The base  116  is retained in a closed position (as shown  FIGS. 1 ,  2  and  3 ) by means of a catch  120  which interengages with a lip  150  located on the wall  104 . When the catch  120  is released, the base  116  will drop away from the wall  104 . 
     A shroud  121  is located inwardly of the wall  104  of the first cyclone  102 . The shroud  121  comprises a part-cylindrical, part-frustoconical wall  122  having a plurality of through-holes  123 . The shroud  121  surrounds an outlet  124  from the first cyclone  102 . The outlet  124  provides a communication path between the first cyclone  102  and a second cyclone assembly  126 . A lip  128  is provided at the base of the shroud  121 . The lip  128  has a plurality of through-holes  129  which are designed to allow air to pass through but to capture dirt and dust. 
     The second cyclone assembly  126  comprises a plurality of second cyclones  130  arranged in parallel with one another. In this embodiment, six second cyclones  130  are provided. The second cyclones  130  are arranged around the axis X-X of the first cyclone  102 . The arrangement of the second cyclones  130  is such that the second cyclones  130  are spaced equi-angularly around the axis X-X. Each second cyclone  130  has a tangentially-arranged air inlet and an air outlet (not shown) located at a first end of the respective second cyclone  130 . A cone opening  136  is located at a second end of each second cyclone  130 . The plane of the cone opening  136  of each second cyclone  130  is inclined with respect to a longitudinal axis (not shown) of the respective further cyclone  130 . The cone opening  136  of each of the second cyclones  130  is in communication with a passageway  138  defined by a wall  140  located inwardly of the shroud  121 . 
     A collector  142  is located at the lower end of the passageway  138 . The collector  142  comprises a frustoconical first portion  144  and a cylindrical second portion  146 . The interior of the collector  142  is delimited by the base  116  and the sides of the first and second portions  144 ,  146  of the collector  142 . 
     Each of the air outlets of the second cyclones  130  is in communication with a duct  150 . The duct  150  provides an airflow path from the cyclonic separating apparatus  100  into other parts of the handheld vacuum cleaner  10 . Located at the downstream end of the duct  150  is a pre-motor filter  152 . The pre-motor filter  152  comprises a porous material such as foam and can also include a fine filter material. The pre-motor filter  152  is designed to prevent any fine dust particles from entering the motor and causing damage thereto. 
     In use, when the on/off switch  20  is depressed, the motor and fan unit draws a flow of dirt-laden air into the dirty air inlet  18  and then into the cyclonic separator  100 . Dirt-laden air enters the cyclonic separator  100  through the inlet  110 . Due to the tangential arrangement of the inlet  110 , the airflow is forced to follow a helical path around the interior of the wall  104 . Larger dirt and dust particles are separated by cyclonic motion around the wall  104 . These particles are then collected at the base  116  of the first cyclone  102 . 
     The partially-cleaned airflow then flows back up the interior of the first cyclone  102  and exits the first cyclone  102  via the through-holes  123  in the shroud  121 . Once the airflow has passed through the shroud  121 , it enters the outlet  124  and from there is divided between the tangential inlets of each of the second cyclones  130 . Each of the second cyclones  130  has a diameter which is smaller than that of the first cyclone  102 . Therefore, the second cyclones  130  are able to separate smaller particles of dirt and dust from the partially-cleaned airflow than the first cyclone  102 . Separated dirt and dust exits the second cyclones  130  via the cone openings  136 . Thereafter, the separated dirt and dust passes down the passageway  138  and into the collector  142 . The separated dirt and dust eventually settles at the bottom of the collector  142  on the base  116 . 
     Cleaned air then flows back up the second cyclones  130 , exits the second cyclones  130  through the air outlets and enters the duct  150 . The cleaned air then passes from the duct  150  sequentially through the pre-motor filter  152 , the motor and fan unit, and a post-motor filter before being exhausted from the vacuum cleaner  10  through the air vents  24 . 
     The first cyclone  102  and the collector  142  can be emptied simultaneously by releasing the catch  120  to allow the base  116  to pivot about the hinge  118  so that the separated dirt and dust can fall away from the cyclonic separator  100 . By positioning the cleaning appliance  10  above a suitable dirt receptacle such as a dustbin, the dirt and dust collected in the cyclonic separator can be efficiently and reliably emptied. The user may close the cyclonic separator  100  by moving the base  116  back into the closed position shown in  FIGS. 1 and 2  by hand. 
       FIG. 4  shows the vacuum cleaner  10  in side view with the main body  12  in section. The remainder of the appliance is as shown in  FIG. 2  except that the distal end of the dirty air inlet  18  and the brush tool  22  have been omitted. The main body  12  includes the handle  16  (which carries the on/off switch  20 ), an upper portion  160  and a lower portion  162 . The upper portion  160  houses the motor  164  and fan  166  by means of which dirty air is drawn into the appliance when the on/off switch is depressed. A post-motor filter  168  is also provided between the air outlet of the motor and the exhaust vents  24 . The lower portion  162  houses a plurality of battery cells  170  for powering the motor  164  when the on/off switch  20  is depressed. Suitable connections between the switch  20 , the batteries  170  and the motor  164  are provided within the main body  12 . 
     The lower portion  162  is shaped so as to include a base surface  172  which is planar and faces downwardly away from the handle  16  and away from the upper portion  164 . The lower portion  162  is also generally rectangular in shape as can be seen from  FIG. 1 . The base surface  172  of the lower portion  164  forms a base surface of the main body  12 . The motor  164  is positioned so that it lies vertically above the base surface  172  and the battery cells  170  are positioned immediately above the base surface  172 . 
     The cyclonic separator  100  also has a base surface  174  which is formed by the lowermost extremity of the base  116 . This base surface  174  of the cyclonic separator  100  in this embodiment is shaped as an annular ring as can be seen in  FIG. 3 . The annular ring defines the planar base surface  174 . Naturally, the base  116  could have been shaped so that the area inside the annular ring forming the base surface  174  was planar but this makes no difference to the invention. 
     As can be seen in  FIG. 4 , the base surface  172  of the main body  12  and the base surface  174  of the cyclonic separator  100  lie in the same plane. Together they comprise a base surface of the handheld vacuum cleaner  10 . The base surface  172  of the main body  12  lies adjacent the base surface  174  of the cyclonic separator  100  as can also be seen in  FIG. 4 . 
     The base surface of the handheld vacuum cleaner  10  provides the vacuum cleaner  10  with a surface on which the appliance can be placed at intervals between periods of use or for storage. Because the base surface extends beyond the area of one or the other of the base surface  172  and the base surface  174 , the base surface provided for the entire machine is more stable than would otherwise be the case. This is important because the handheld cleaning appliance  10  has a height which exceeds that of many known handheld vacuum cleaners due to the upright configuration of the cyclonic separator  100 . 
     The positioning of one or the other of the motor  164  and the battery cells  170  vertically above the base surface  172  of the main body  12  enhances the stability of the handheld vacuum cleaner  10  when it is placed on the base surface. This is because the centre of gravity of the motor  164  and/or the battery cells  170 , which are relatively heavy components of the handheld vacuum cleaner  10 , passes through the base surface  172  of the main body. 
     The rectangular shape of the lower portion  162  also assists in enhancing the stability of the vacuum cleaner when it is supported on the base surface formed by the base surface  172  of the main body  12  and the base surface  174  of the cyclonic separating apparatus  100 . This is because an inadvertent knock to the vacuum cleaner  10  need not cause the vacuum cleaner  10  to topple over if the width of the lower portion  162  is sufficiently wide to provide stability. As can be seen in  FIG. 5 , the width b of the lower portion  172  is approximately two thirds of the width B of the widest part of the cyclonic separator  100 , which is the collector  105 . The width b of the lower portion  172  can be as little one half of the width B of the cyclonic separator  100  if preferred. 
     The invention is not limited to the precise details of the embodiment described above. For example, the number of first and second cyclones can be varied, as can the detail of their design, such as their cone angle, axis inclination and cone opening inclination. The shape of the collector and base can be altered, as can the precise location of the hinge and catch and the location of the actuator. The location of the on/off switch may also be varied. What is important is the presence of a base surface on each of the cyclonic separator and the main body which together form a base surface for the handheld vacuum cleaner in a manner which allows the vacuum cleaner to be placed stably on a surface.