Abstract:
A floor care apparatus includes a cannister assembly, a nozzle assembly, and a suction generator that draws air, dust, dirt and debris from a carpet or rug to be cleaned through the nozzle assembly to a collection vessel. A rotary agitator carried on the nozzle assembly is driven by a motor in either a rearward bottom-dead-center direction when the floor care apparatus is being pulled rearward or a forward bottom-dead-center direction when the floor care apparatus is being pushed forward by an operator. In this way, the bottom-dead-center portion of the agitator engaging the underlying nap of a carpet or rug being cleaned is moving in the direction of movement of the floor care appliance so that the nap is always brushed from the bottom to the top and dirt and debris is lifted from the nap where it is entrained in the airstream being drawn into the apparatus by the suction generator to provide efficient and effective deep cleaning action.

Description:
[0001]    This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/397,573 filed Jul. 22, 2002. 
     
    
     
       TECHNICAL FIELD  
         [0002]    The present invention relates generally to the floor care field, and, more particularly, to a floor cleaning apparatus having a reversible rotary agitator for providing deep cleaning action for the nap of a rug or carpet being cleaned.  
         BACKGROUND OF THE INVENTION  
         [0003]    Upright floor care apparatus in all of their designs and permutations have become increasingly popular over the years. Upright vacuum cleaners, for instance, generally incorporate a nozzle assembly which rides on wheels over the floor surface to be cleaned and a canister assembly that is pivotally connected to the nozzle assembly. The canister assembly includes an operating handle that is manipulated by an operator to move the vacuum cleaner to and fro across the floor. The canister assembly also includes a dirt collection vessel comprising either a bag-like filter or a dirt cup that may include a cyclonic separation chamber and filter combination. The dirt collection vessel traps dirt and debris while substantially clean air is exhausted by an electrically operated fan that is driven by an onboard motor. It is this fan and motor arrangement that generates the drop in air pressure necessary to provide the desired cleaning action.  
           [0004]    In most upright vacuum cleaners sold today, a rotary agitator is also provided in the nozzle assembly. The rotary agitator includes tufts of bristles, brushes, beater bars or the like to beat dirt and debris from the nap of a carpet being cleaned while the pressure drop or vacuum is used to force air entrained with this dirt and debris into the nozzle of the vacuum cleaner. Powerhead assemblies for canister vacuum cleaners similarly include a nozzle assembly including a rotary agitator and a motor for driving the agitator as do extractors which have also become very popular in recent years. Extractors use a cleaning solution in combination with a rotary agitator for scrubbing action and a suction generator to draw off the dirt and solution from the carpet or rug being cleaned.  
           [0005]    In all of these floor cleaning apparatus, it is desirable to provide still more efficient deep cleaning action. To achieve this end, the nap of the carpet or rug being cleaned should be scrubbed from the bottom to the top so that dust and dirt is continually moved up out of the carpet or rug. This is not achieved in state of the art floor cleaning apparatus where the agitator is rotated in a single direction. As illustrated in FIG. 7, the prior art agitator is rotated in a clockwise direction. Assuming the forward end of the floor care apparatus is to the right side of the drawing figure, it should be appreciated that the agitator is being driven in a rearward bottom-dead-center direction (note action arrow A). Accordingly, as the floor care apparatus is pulled rearward by the operator (note action arrow B), the agitator engages the nap of the carpet or rug being cleaned and scrubs dirt and debris upwardly from the bottom to the top of the nap (note action arrow C) where it may be drawn directly into the floor care apparatus and collected. Accordingly, good deep cleaning action is provided when the floor care apparatus is moved in the rearward direction.  
           [0006]    In contrast, when the floor care apparatus is pushed forward away from the operator (note action arrow D), rotation of the agitator in the rearward bottom-dead-center direction serves to scrub dirt and debris downward along the nap from the top to the bottom (note action arrow E) thereby potentially grinding some dirt and debris into the jute J of the rug or carpet. Thus, it should be appreciated that when the floor care apparatus is moved in the forward direction, the desired deep cleaning action is no longer being provided.  
           [0007]    The present invention addresses this shortcoming by reversing the drive direction of the agitator so that whether the floor care apparatus is being pushed forward or pulled rearward, the agitator is rotating in the necessary direction to provide efficient and effective deep cleaning action, i.e., dirt and debris are being scrubbed and brushed upwardly from the bottom to the top of the nap and into the airstream being drawn into the floor care cleaning apparatus.  
         SUMMARY OF THE INVENTION  
         [0008]    In accordance with the purposes of the present invention as described herein, an improved deep cleaning floor care apparatus is provided. The floor care apparatus may take the form of an upright vacuum cleaner, a canister vacuum cleaner with a powerhead, or even an extractor. The floor care apparatus includes a cannister assembly, a suction generator, and a nozzle assembly. The nozzle assembly includes a housing that defines an agitator cavity, an agitator mounted in the agitator cavity for rotation in a forward bottom-dead-center direction and rearward bottom-dead-center direction, and a drive motor for driving the agitator in either the forward or rearward direction. In addition, an actuator for controlling operation of the drive motor and rotation direction of the agitator may be carried on either the cannister assembly or the nozzle assembly.  
           [0009]    As a result, as the agitator is pushed or pulled through the nap of the underlying carpet or rug, the agitator is rotating in the necessary direction to provide efficient deep cleaning action so that the nap is brushed and scrubbed from the bottom toward the top and dirt and debris is directed by the agitator up out of the carpet or rug and into the airstream being drawn into the floor care apparatus by the suction generator. That dirt and debris is then trapped in the dust collector resulting in a cleaner carpet or rug.  
           [0010]    In one embodiment, for example, a moveable hand grip is slidably mounted to a control handle for directing the forward and rearward rotation of the agitator and direction of movement of the nozzle assembly. As force is exerted on the hand grip by an operator, the hand grip slides along a stem of the control handle. A forward thrust moves the hand grip forward forcing the closure of a forward switch and the application of a voltage signal to a controller. Similarly, a reverse thrust exerted on the hand grip moves the hand grip rearward opening the forward switch and forcing the closure of a rearward switch and the application of a voltage signal to the controller. The status of the switches is monitored by the controller.  
           [0011]    In accordance with another aspect of the present invention, the controller is programmed to drive the drive motor in either of the forward bottom-dead-center direction and the rearward bottom-dead-center direction upon receipt of a signal from the actuator. More specifically, the controller may be programmed upon a change of state of the actuator signal to remove power from the drive motor and to reapply power to the drive motor such that the agitator is rotated in a different direction. In one embodiment, the reapplication of power to the drive motor is delayed by the controller for between 0.1 second and 1.0 second to allow the agitator rotating in the forward direction to slow significantly, if not stop, before power is reapplied to drive the agitator in the rearward direction and vice versa. In addition, the power reapplied to the agitator drive motor may be incrementally increased using a ramp or step function, or the like, to a normal operating level in order to reduce arcing and inrush current peaks.  
           [0012]    In accordance with the broadest teachings of the present invention, the floor cleaning apparatus described generally above may be an upright vacuum cleaner or extractor, or a canister type vacuum cleaner or extractor equipped with a powerhead incorporating a power driven agitator as are well known in the art. In either instance, the agitator drive motor may be positioned coaxially with the agitator including within the agitator. Alternately, the nozzle assembly may include a belt and pulley assembly or even a gear drive connecting a remotely positioned drive motor to the agitator as is also well known in the art.  
           [0013]    In addition, the canister assembly in either instances, includes a collection vessel comprising either a bag-like filter or a dirt cup that may but does not necessarily have to include a cyclonic separation chamber and filter combination. The collection vessel traps dirt and debris while substantially clean air is exhausted by an electrically operated fan that is driven by an onboard motor. More specifically, the dust collector may take a number of forms including any type of dust cup, dirt cup or other container which is reusable and may be removed from the floor care apparatus to allow the dumping of dirt and debris into a garbage can or other waste receptacle. Of course, the dust collector may also take the form of a replaceable dust bag which is disposed in a garbage can when filled and replaced with a new bag as needed.  
           [0014]    In accordance with another aspect of the present invention, a method of cleaning a nap of a carpet or rug using a floor care apparatus having a power driven agitator is provided. The method comprises the steps of rotating the agitator in a forward bottom-dead-center direction as the floor care apparatus is pushed forward by an operator, and rotating the agitator in a rearward bottom-dead-center direction as the floor care apparatus is pulled rearward by an operator. In this way, the agitator is always rotating toward the direction of movement of the floor care apparatus at its bottom-dead-center position so as to provide more efficient deep cleaning action. Specifically, the nap of the carpet or rug being cleaned is always being brushed from the bottom toward the top so that the agitator is moving dirt and debris into the airstream being drawn into the floor care apparatus by the suction generator as shown in FIGS. 3 a  and  3   b . The method may be alternatively described as including the steps of sensing operator input to determine a direction of desired nozzle assembly movement, and driving the agitator in a desired direction of the nozzle assembly movement.  
           [0015]    In accordance with still another aspect of the present invention, a floor cleaning apparatus includes a nozzle assembly including an agitator cavity and at least one rotary agitator mounted for rotation in the agitator cavity. That rotary agitator is rotated in a first direction as the floor care apparatus is pushed forward by an operator and in a second direction as the floor care apparatus is pulled rearward by an operator. The floor cleaning apparatus also includes a cannister assembly connected to the nozzle assembly, a suction generator, a drive motor for driving the at least one agitator, and an actuator for controlling operation of the drive motor and rotation direction of the at least one agitator. In accordance with the broad teaching of the present invention, the suction generator, the at least one agitator, and the drive motor may each be carried on one of the nozzle assembly and cannister assembly.  
           [0016]    In the following description there is shown and described one possible 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 DRAWING  
       [0017]    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 the principles of the invention. In the drawing:  
         [0018]    [0018]FIG. 1 is a perspective view of a floor care apparatus, in this instance an upright vacuum cleaner, constructed in accordance with the teachings of the present invention;  
         [0019]    [0019]FIG. 2 is a schematic block diagram showing the control circuit that controls the application of electrical power to the agitator motor depending upon the direction in which the floor care apparatus is being pushed or pulled by the operator;  
         [0020]    [0020]FIGS. 3 a  and  3   b  are schematical views illustrating the present invention and, more particularly, how the agitator is driven depending upon the direction of movement of the floor care apparatus so as to provide the desired deep cleaning action whether that apparatus is being pushed S forward or pulled rearward by the operator;  
         [0021]    [0021]FIG. 4 is a schematic block diagram showing an alternate embodiment of the present invention which utilizes a drive arrangement incorporating a belt and pulley assembly;  
         [0022]    [0022]FIG. 5 is a schematic block diagram showing another alternate embodiment of the present invention which utilizes a drive arrangement incorporating a gear drive assembly;  
         [0023]    [0023]FIG. 6 is a cross-sectional view through the nozzle assembly of the vacuum cleaner showing the agitator and agitator drive arrangement;  
         [0024]    [0024]FIG. 6 a  is a detailed cross-sectional view through the agitator; and  
         [0025]    [0025]FIG. 7 is a schematical view of the prior art showing the cleaning action of the agitator as the floor care apparatus is being pushed forward and pulled rearward by the operator.  
         [0026]    Reference will now be made in detail to the present invention, an example of which is illustrated in the accompanying drawing. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0027]    Reference is now made to FIG. 1 showing a preferred embodiment of a floor care apparatus  10  of the present invention. It should be appreciated that while an upright vacuum cleaner  10  is illustrated, embodiments of the present invention also include different upright vacuum cleaners and extractors, and canister vacuum cleaners and extractors equipped with a powerhead incorporating a power driven agitator such as shown, for example, in U.S. Pat. No. 6,148,474 which is owned by the assignee of the present invention and is incorporated herein by reference.  
         [0028]    The upright vacuum cleaner  10  includes a nozzle assembly  16  and a canister assembly  18  pivotally connected to the nozzle assembly. The canister assembly  18  further includes a control handle  20  and a hand grip  22 . A power switch  24  is provided for turning the vacuum cleaner on and off. Of course, electrical power is supplied to the vacuum cleaner  10  from a standard electrical wall outlet through a cord (not shown) as is known in the art.  
         [0029]    In the present preferred embodiment, the hand grip  22  is slidably mounted to a stem  21  of the control handle  20 . As forces are exerted on the hand grip  22  by an operator, the hand grip  22  slides along the stem  21  as shown by action arrows E in FIG. 1. A forward thrust moves the hand grip  22  forward toward the cannister assembly  18  forcing closure of a forward switch  23  and the application of a voltage signal (Vcc) generated by a power supply (not shown) to a first pin of controller  27 . Similarly, a reverse thrust exerted on the hand grip  22  moves the hand grip rearward away from the cannister assembly  18  opening the forward switch and forcing closure of a rearward switch  25  and the application of the voltage signal (Vcc) to a second pin of controller  27 . Dependent upon the desired direction of movement of the nozzle assembly  16  as indicated by the open/closed states of the forward and rearward switches  23  and  25 , the voltage signal (Vcc) generated by a power supply (not shown) is selectively applied to the first or second pins of controller  27 .  
         [0030]    As shown in FIG. 2, the controller  27  in turn generates an output signal (SI) which is applied to and directs the operation of relay  29  and agitator motor  40 . In the present preferred embodiment, the electrical power is converted from AC to DC by converter  31 . The DC power is applied to the agitator motor  40  through relay  29  such that the motor and agitator  38  are rotated as illustrated in FIG. 3 a  in a forward bottom-dead-center direction (see action arrow F) when the nozzle assembly  16  is pushed forward (see action arrow G) or are rotated as illustrated in FIG. 3 b  in a rearward bottom-dead-center direction (see action arrow H) when the nozzle assembly is pulled rearward (see action arrow I) depending upon the open/closed states of the switches  23  and  25 .  
         [0031]    Preferably, the controller is programmed to monitor the open/closed states of the switches  23  and  25  and to generate the output signal (SI) which operates relay  29  accordingly. The controller  27  is further programmed to remove the DC power provided through relay  29  to the drive motor  40  and to reapply power to the drive motor such that the agitator is rotated in a different direction upon a change in state of the switches  23  and  25 . In other words, when the operator of the vacuum cleaner  10  desires to change the direction of movement of the vacuum cleaner  10  by actuating the hand grip  22 , the controller  27  generates a different output signal (SI) causing the removal and reapplication of DC power to the agitator motor  40  through relay  29 .  
         [0032]    In one preferred embodiment, the reapplication of power to the drive motor  40  is delayed by the controller  27  for between 0.1 second and 1.0 second to allow the agitator  38  rotating in the forward direction to slow significantly, if not stop, before DC power is reapplied to drive the agitator  38  in the rearward direction and vice versa. It should be noted that the DC power reapplied to the agitator drive motor  40  may be incrementally increased using a ramp or step function, or the like, to a normal operating level in order to reduce arcing and inrush current peaks.  
         [0033]    A pair of rear wheels  26  (partially shown) are provided at a lower portion of the cannister assembly  18  and a pair of front wheels  27  are provided on the nozzle assembly  16 . Together, these wheels  26 ,  27  support the vacuum cleaner  10  for movement across the floor. To allow for convenient storage of the vacuum cleaner  10 , a foot latch (not shown) may function to lock the canister assembly  18  in an upright position as shown in FIG. 1. When the foot latch is released, the canister assembly  18  may be pivoted relative to the nozzle assembly  16  as the vacuum cleaner  10  is manipulated to-and-fro to clean the floor.  
         [0034]    In the present preferred embodiment, the canister assembly  18  includes a cavity adapted to receive and hold a collection assembly or vessel  12 . A detailed description of the dust collection vessel  12  of the present preferred embodiment may be found in PCT Application PCT/US01/47401, entitled Cyclonic Vacuum Cleaner with Filter and Filter Sweeper, filed Nov. 13, 2001. Although described as accessible from the front of the vacuum cleaner  10  in the noted PCT application, the dust collection vessel  12  may likewise be accessible from the rear of the vacuum cleaner  10 . In accordance with the broad teaching of the present invention, the dust collection vessel may alternatively include a bag-like filter to receive dirt and debris as is also well known in the art.  
         [0035]    The canister assembly  18  further carries a suction generator or fan  33  and suction fan drive motor  34 . Together, the suction fan  33  and its cooperating drive motor  34  function to generate a vacuum airstream for drawing air, dust, dirt and debris from a surface to be cleaned through the nozzle assembly  16  to the collection vessel  12 . While the suction fan  33  and suction fan drive motor  34  are illustrated as being carried on the canister assembly  18 , it should be appreciated that one or both could likewise be carried on the nozzle assembly  16  if desired.  
         [0036]    The nozzle assembly  16  includes a nozzle housing  35  that defines an agitator cavity  36  that receives a rotating agitator  38 . The agitator  38  shown is rotatably mounted in the agitator cavity  36  and driven by a motor  40  and cooperating gear drive  42 . In the present preferred embodiment, the motor  40  and gear drive  42  are coaxial with and housed within the agitator  38  as is described in greater detail below (see FIGS. 6 and 6 a ). While the vacuum cleaner of the present preferred embodiment is described with the agitator motor  40  positioned coaxially with and held within the agitator  38 , a remotely positioned motor  93  in either the nozzle assembly  16  or the canister assembly  18  described above may utilize a drive arrangement incorporating a belt and pulley assembly  99  as shown schematically in FIG. 4 and/or a gear drive assembly  97  as shown schematically in FIG. 5 in any manner desired to drive an agitator  95 .  
         [0037]    In the illustrated vacuum cleaner  10 , the scrubbing action of the rotary agitator  38  and the negative air pressure created by the suction fan  33  and drive motor  34  cooperate to brush and beat dirt and dust from the bottom of the nap of the carpet being cleaned to the top and then to draw the dirt and dust laden air from the agitator cavity  36  to the dust collection vessel  12 . Specifically, the dirt and dust laden air passes serially through a suction inlet defined by the nozzle housing  35  and hose and/or an integrally molded conduit in the nozzle housing  35  and/or canister assembly  18  as is generally known in the art. Next, the dirt and dust laden air is delivered into the dust collection vessel  12  which serves to trap the suspended dirt, dust and other particles inside while allowing the now clean air to pass freely through to the suction fan  33  and ultimately to the environment through an exhaust port  50 .  
         [0038]    Reference is now made to FIGS. 6 and 6 a  which show the mounting of the agitator motor  40  and associated gear drive  42  coaxially with and within the agitator  38  in detail. As shown, the agitator  38  is mounted for rotation relative to the nozzle assembly  16 . Specifically, a first end of the agitator  38  includes an end cap  52  which is supported on bearings  54  on a stub shaft  55  held in mounting block  56  keyed into slot  58  in the side of the nozzle housing  35 . An end cap  60  at the opposite end of the agitator  38  is supported on bearings  62  mounted on the housing  64  of the motor  40 . As should be appreciated, the motor  40  is fixed to the nozzle housing  35  by means of the mounting block  66  fixed to the motor housing  64  and keyed in the slot  68  in the side of the nozzle housing.  
         [0039]    The motor  40  drives a shaft  70  including gear teeth  72 . The drive shaft  70  extends through a bearing  74  held in the hub  76  of the planetary gear set carrier  78 . In the most preferred embodiment a fan  80  is keyed or otherwise secured to the distal end of the drive shaft  70 .  
         [0040]    The planetary gear set carrier  78  includes three stub shafts  82  that each carry a planetary gear  84 . Each of the planetary gears  84  include teeth that mesh with the gear teeth  72  of the drive shaft  70 . Additionally, the planetary gears  82  mesh with the teeth of an annular gear  86  that is fixed to the agitator motor housing  64  by pin or other means. Thus, it should be appreciated that as the drive shaft  70  is driven by the motor  40 , the planetary gears  84  are driven around the annular gear  86 , thereby causing the planetary gear set carrier  78  to rotate.  
         [0041]    As best shown in FIG. 6 a , planetary gear set carrier  78  also includes a drive ring  88  and associated rubber drive boot  87  which includes a series of spaced channels  89  that receive and engage axial ribs  91  projecting inwardly radially from the inner wall of the agitator  38 . Thus, the rotation of the planetary gear set carrier  78  is transmitted by the drive ring  88  and drive boot  87  directly to and causes like rotation of the agitator  38 . The rubber drive boot  87  provides the necessary damping to insure the smooth transmission of power to the agitator  38 . Simultaneously with the rotation of the planetary gear set carrier  78  and agitator  38 , the drive shaft  70  also drives the fan  80  at a ratio of between 4-1 to 10-1 and most preferably 6-1 with respect to the agitator  38 . The resulting rapid rotation of the fan  80  helps to move air through the agitator  38  and ensure proper cooling of the agitator motor  40  during its operation.  
         [0042]    In operation, the operator applies a force to the hand grip  22  dependent upon a desired direction of movement of the nozzle assembly  16 . If the force exerted on the hand grip  22  is in a forward direction, the forward switch  23  is closed through contact with the hand grip and the voltage signal (Vcc) is applied to the first pin of controller  27 . The controller  27  in turn generates an output signal (SI) based on the open/closed states of the switches  23 ,  25  which is applied to and directs the operation of relay  29 . In the present scenario with a forward force applied to the hand grip  22 , DC power is applied to the agitator motor  40  such that the agitator  38  is driven in the forward bottom-dead-center direction.  
         [0043]    Conversely, if the force exerted on the hand grip  22  is in a rearward direction, the rearward switch  25  is closed through contact with the hand grip and the forward switch remains open or is opened. In response to the output signal (S 1 ) of the controller  27 , relay  29  operates to direct the DC power to the agitator motor  40  such that the agitator  38  is driven in a rearward bottom-dead-center direction.  
         [0044]    Once the agitator  38  is rotating, a change in direction initiated by the operator, i.e., a change in the force exerted on the hand grip  22 , is indicated to the controller  27  by the forward and rearward switches  23  and  25 , respectively. If the agitator  38  is being driven in a forward bottom-dead-center direction and the operator exerts a rearward force on the hand grip  22 , the hand grip travels along the stem  21  of the control handle allowing the forward switch  23  to open followed by the closure of the rearward switch  25 . As the forward switch  23  opens, the voltage signal (Vcc) is removed from the first pin of controller  27  thus changing the controller input. As the rearward switch closes, the voltage signal (Vcc) is applied to the second pin of controller  27  again changing the controller input.  
         [0045]    Based on the new states of the forward and rearward switches  23  and  25 , the controller  27  stops generating the present output signal (S 1 ) thus turning the relay  29  off and removing power from the agitator motor  40 . The controller  27  may then generate a new output signal (S 1 ) either immediately or after a delay period which actuates the relay  29  to direct the DC power to the agitator motor  40  such that the agitator  38  is driven in the rearward bottom-dead-center direction. The delay established by the controller  27  may be between 0.1 second and 1.0 second to allow the agitator  38  rotating in the first direction to slow significantly, if not stop, before DC power is reapplied to drive the agitator  38  for movement in the second direction and vice versa. In this manner, overheating of the agitator motor  40  may be substantially avoided.  
         [0046]    The foregoing description of the preferred embodiment of this 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, various pressure sensing devices may be utilized to replace the forward and rearward switches which sense changes in direction initiated by an operator, or a single switch may be utilized to sense a change in direction with the agitator rotating in a normally forward bottom-dead-center direction. Additionally, different delay timing patterns may be utilized during a stop, delay, and restart sequence or application of the DC power to the agitator motor  40  may be incrementally increased over a period of time. Even further, additional switching devices such as a FET array, for example, activated by the controller output signal may be utilized to direct the DC power to the agitator motor  40 . The floor care apparatus could also be equipped with multiple agitators rather than a single agitator as illustrated.  
         [0047]    The present 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.