Patent Publication Number: US-10321795-B2

Title: Surface cleaning apparatus with debris ejector

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 15/606,066, filed May 26, 2017, now U.S. Pat. No. 9,554,953, which is a continuation of U.S. patent application Ser. No. 14/973,844, filed Dec. 18, 2015, now U.S. Pat. No. 9,687,128, issued Jun. 27, 2017, which claims the benefit of U.S. Provisional Patent Application No. 62/097,699, filed Dec. 30, 2014, all of which are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Surface cleaning apparatuses, such as vacuum cleaners are configured for cleaning a wide variety of common household surfaces such as bare flooring, including tile, hardwood, laminate, vinyl, and linoleum, as well as carpets, rugs, countertops, stove tops and the like. Vacuum cleaners have a suction source for generating a suction force at a nozzle in contact with the surface to be cleaned, and a system for separating and collecting debris (which may include dirt, dust, hair, and other debris) from a working airstream for later disposal. Typical systems include cyclonic separation systems, centrifugal separation systems, bulk separation systems, or filter bag systems. For non-bag systems, the collection system includes a unit or module in which debris is collected and that is removed from the vacuum cleaner for emptying collected debris. 
     BRIEF DESCRIPTION OF THE INVENTION 
     According to one aspect of the invention, a surface cleaning apparatus includes a separating and collection assembly having a housing defining a collection chamber adapted to receive debris and having a debris outlet at a lower end thereof, a cover assembly at an upper end of the housing and comprising at least one pre-motor filter, a door at the lower end of the housing selectively closing the debris outlet, a debris ejector reciprocally moveable within the housing, and a push rod operably coupleable to the debris ejector to displace the debris ejector relative to the debris outlet, wherein the at least one pre-motor filter comprises an opening accommodating the push rod and sized for vertical displacement of the push rod relative to the at least one pre-motor filter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING(S) 
       In the drawings: 
         FIG. 1  is a schematic view of a surface cleaning apparatus; 
         FIG. 2  is a front perspective view of a surface cleaning apparatus according to a first embodiment of the invention; 
         FIG. 3  is a rear perspective view of the surface cleaning apparatus from  FIG. 2 ; 
         FIG. 4  is a partial exploded view of the surface cleaning apparatus from  FIG. 2 ; 
         FIG. 5  is a cross-sectional, perspective view of a collection assembly for the surface cleaning apparatus from  FIG. 2  having a debris ejector; 
         FIG. 6  is an exploded view of the collection assembly from  FIG. 5 ; 
         FIGS. 7A-7C  are perspective views of a push rod for the debris ejector of the collection assembly from  FIG. 5  showing the extension of the push rod; and 
         FIGS. 8-9  are quarter-section views of the collection assembly from  FIG. 5  showing the operation of the debris ejector. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention relates to debris disposal in surface cleaning apparatus, such as, but not limited to, vacuum cleaners, steam cleaners, extraction cleaners, or combinations thereof. 
       FIG. 1  is a schematic view of various functional systems of a surface cleaning apparatus  10  in the form of a steam/vacuum cleaner according to a first embodiment of the invention. While referred to herein as a steam/vacuum cleaner, some aspects of the apparatus can alternatively be configured as a vacuum cleaner without steam capability, a hand-held device, or as an apparatus having a hand-held accessory tool connected to a canister or other portable device by a hose. Additionally, the surface cleaning apparatus can be configured to have additional capability, including scrubbing, sweeping, and/or extraction capability. 
     As used herein, the term “steam” includes a liquid, such as but not limited to water or solutions containing water (like water mixed with a cleaning chemistry, fragrance, etc.), converted to a gas or vapor phase. The liquid can be boiled or otherwise converted to the gas or vapor phase by heating or mechanical action like nebulizing. The steam can be invisible to the naked eye, in the form of a visible mist formed when the gas or vapor condenses in air, or combinations thereof. 
     The surface cleaning apparatus  10  includes a steam generation system  24  for producing steam from liquid, a liquid distribution system  26  for storing liquid and delivering the liquid to the steam generation system  24 , a steam delivery system  28  for delivering steam to a surface to be cleaned, and a vacuum collection system  60  for creating a partial vacuum to suck up liquid and debris (which may include dirt, dust, hair, and other debris) from a surface to be cleaned and collecting the debris from a working airstream for later disposal. 
     The steam generation system  24  can include a steam generator  30  for producing steam from liquid. The steam generator  30  can include an inlet  32  and an outlet  34 , and a heater  36  between the inlet  32  and outlet  34  for boiling the liquid. Some non-limiting examples of steam generators  30  include, but are not limited to, a flash heater, a boiler, an immersion heater, and a flow-through steam generator. The steam generator  30  can be electrically coupled to a power source  38 , such as a battery or by a power cord plugged into a household electrical outlet. 
     The liquid distribution system  26  can include at least one supply tank  40  for storing a supply of liquid. The liquid can comprise one or more of any suitable cleaning liquids, including, but not limited to, water, compositions, concentrated detergent, diluted detergent, etc., and mixtures thereof. For example, the liquid can comprise a mixture of water and concentrated detergent. The liquid distribution system  26  can further include multiple supply tanks, such as one tank containing water and another tank containing a cleaning agent. 
     The liquid distribution system  26  can comprise a flow controller  42  for controlling the flow of liquid through a fluid conduit  44  coupled between an outlet port  46  of the supply tank  40  and the inlet  32  of the steam generator  30 . An actuator  48 , such as a trigger, can be provided to actuate the flow controller  42  and dispense liquid to the steam generator  30 . 
     In one configuration, the liquid distribution system  26  can comprise a gravity-feed system and the flow controller  42  can comprise a valve  50 , whereby when valve  50  is open, liquid will flow under the force of gravity, through the fluid conduit  44 , to the steam generator  30 . The actuator  48  can be operably coupled to the valve  50  such that pressing the actuator  48  will open the valve  50 . The valve  50  can be mechanically actuated, such as by providing a push rod with one end coupled to the actuator  48  and another end in register with the valve  50 , such that pressing the actuator  48  forces the push rod to open the valve  50 . Alternatively, the valve  50  can be electrically actuated, such as by providing an electrical switch between the valve  50  and the power source  38  that is selectively closed when the actuator  48  is actuated, thereby powering the valve  50  to move to an open position. 
     In another configuration, the flow controller  42  can comprise a pump  52  that distributes liquid from the supply tank  40  to the steam generator  30 . The actuator  48  can be operably coupled to the pump  52  such that pressing the actuator  48  will activate the pump  52 . The pump  52  can be electrically actuated, such as by providing an electrical switch between the pump  52  and the power source  38  that is selectively closed when the actuator  48  is actuated, thereby activating the pump  52 . 
     The steam delivery system  28  can include at least one steam outlet  54  for delivering steam to the surface to be cleaned, and a fluid conduit  56  coupled between an outlet  34  of the steam generator  30  and the at least one steam outlet  54 . The at least one steam outlet  54  can comprise any structure, such as a perforated manifold or at least one nozzle; multiple steam outlets can also be provided. In use, the generated steam exits the outlet  34  of the steam generator  30  by pressure generated within the steam generator  30  and, optionally, by pressure generated by the pump  52 . The steam flows through the fluid conduit  56 , and out of the at least one steam outlet  54 . 
     A cleaning pad  58  can be removably attached over the steam outlet  54  to the surface cleaning apparatus  10 . In use, the cleaning pad  58  is saturated by the steam from the steam outlet  54 , and the damp cleaning pad  58  is wiped across the surface to be cleaned to remove debris present on the surface. The cleaning pad  58  can be provided with features that enhance the scrubbing action on the surface to be cleaned to help loosen debris on the surface. The cleaning pad  58  can be disposable or reusable, and can further be provided with a cleaning agent or composition that is delivered to the surface to be cleaned along with the steam. For example, the cleaning pad  58  can comprise disposable sheets that are pre-moistened with a cleaning agent. The cleaning agent can be configured to interact with the steam, such as having at least one component that is activated or deactivated by the temperature and/or moisture of the steam. In one example, the temperature and/or moisture of the steam can act to release the cleaning agent from the cleaning pad  58 . 
     The vacuum collection system  60  can include a suction nozzle  62 , a suction source  64  in fluid communication with the suction nozzle  62  for generating a working airstream, and a separating and collection assembly  66  for separating and collecting debris from the working airstream for later disposal. Some examples of separating and collection assemblies  66  include, but are not limited to, a cyclone separator, a centrifugal separator, or a bulk separator. The collection assembly  66  can further be configured to separate liquid from the working air; however, as described below most or all of the liquid is separated from the working airstream prior to entering the collection assembly  66 , and so any remaining liquid would be imperceptible and would not require any special features directed to separating and collecting liquid. As perceived by a user of the surface cleaning apparatus  10 , the separating and collection assembly  66  separates and collects only dry debris. 
     The suction source  64 , such as a motor/fan assembly, is provided in fluid communication with the separating and collection assembly  66 , and can be positioned downstream or upstream of the separating and collection assembly. The suction source  64  can be electrically coupled to the power source  38 . An electrical switch between the suction source  64  and the power source  38  can be selectively closed by the user upon pressing a power button (not shown), thereby activating the suction source  64 . 
     The vacuum collection system  60  can also be provided with one or more additional filters  68  upstream or downstream of the separating and collection assembly  66  or the suction source  64 . Optionally, an agitator  70  can be provided adjacent to the suction nozzle  62  for agitating debris on the surface to be cleaned so that the debris is more easily ingested into the suction nozzle  62 . Some examples of agitators  70  include, but are not limited to, a rotatable brushroll, dual rotating brushrolls, or a stationary brush. 
     The surface cleaning apparatus  10  shown in  FIG. 1  can be used to effectively remove debris (which may include dirt, dust, hair, and other debris) from the surface to be cleaned in accordance with the following method. The sequence of steps discussed is for illustrative purposes only and is not meant to limit the method in any way as it is understood that the steps may proceed in a different logical order, additional or intervening steps may be included, or described steps may be divided into multiple steps, without detracting from the invention. 
     To perform steam cleaning, the cleaning pad  58  is attached to the surface cleaning apparatus  10 , over the steam outlet  54 , the supply tank  40  is filled with liquid, and the steam generator  30  is coupled to the power source  38 . Upon actuation of the actuator  48 , liquid flows to the steam generator  30  and is heated to its boiling point to produce steam. The steam exits the steam outlet  54  and passes through the cleaning pad  58 . As steam passes through the cleaning pad  58 , a portion of the steam may return to liquid form before reaching the floor surface. The steam delivered to the floor surface can sanitize the surface when exposed for a predetermined amount of time before returning to liquid form. As the damp cleaning pad  58  is wiped over the surface to be cleaned, debris is loosened or solubilized, and excess liquid, dirt and debris on the surface are absorbed by the cleaning pad  58 . 
     To perform vacuum cleaning, the suction source  64  is coupled to the power source  38 . The suction source  64  draws in debris-laden air through the suction nozzle  62  and into the separating and collection assembly  66  where the debris is substantially separated from the working air. The air flow then passes the suction source  64 , and optionally through any additional filters  68 , prior to being exhausted from the surface cleaning apparatus  10 . The separating and collection assembly  66  can be periodically emptied of debris. Likewise, the optional filters  68  can periodically be cleaned or replaced. The suction source  64  may also draw in liquid through the suction nozzle  62  and most or all of the liquid is separated from the working airstream prior to entering the collection assembly  66 . 
     In some cases, the debris (which may include dirt, dust, hair, and other debris) may not easily empty from the collection assembly  66 . In accordance with one aspect of the invention, the separating and collection assembly  66  can be provided with a debris ejector that applies force to accumulated debris in order to eject it from the collection assembly  66 . 
       FIG. 2  is a front perspective view of a surface cleaning apparatus  10  which embodies the various functional systems according to the first embodiment of the invention. For purposes of description related to the figures, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” “inner,” “outer,” and derivatives thereof shall relate to the invention as oriented in  FIG. 1  from the perspective of a user behind the surface cleaning apparatus  10 , which defines the rear of the surface cleaning apparatus  10 . However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. 
     The surface cleaning apparatus  10  comprises an upper housing  12  mounted to a lower cleaning foot  14  which is adapted to be moved across a surface to be cleaned. The housing  12  and the foot  14  may each support one or more components of the various functional systems discussed with respect to  FIG. 1 . The upper housing  12  generally comprises a main support section  72  with the separating and collection assembly  66  on a front portion thereof for separating and collecting debris, and optionally some amount of liquid, from a working airstream for later disposal. A motor cavity  74  is formed at an upper end of the support section  72 , above the collection assembly  66 , and contains the motor/fan assembly  64  ( FIG. 1 ) positioned therein in fluid communication with the collection assembly  66 . The foot  14  includes suction nozzle  62  that is in fluid communication with the suction source in the motor cavity  74 , through the collection assembly  66 . 
     An elongated handle  76  can project from the main support section  72 , with a handle grip  78  provided on the end of the handle  76  to facilitate movement of the surface cleaning apparatus  10  by a user. The actuator  48  can be provided on the handle grip  78 . A coupling joint  80  is formed at an opposite end of the housing  12  and moveably mounts the foot  14  to the housing  12 . In the embodiment shown herein, the foot  14  can pivot up and down about one axis relative to the housing  12 . The coupling joint  80  can alternatively comprise a universal joint, such that the foot  14  can pivot about at least two axes relative to the housing  12 . 
     The foot  14  of the surface cleaning apparatus  10  can comprise a housing adapted to be moved over the surface to be cleaned and which can mount the cleaning pad  58 , generally described with respect to  FIG. 1 . The housing includes a removable pad mounting plate  94  provided on the bottom of the foot  14  for mounting the cleaning pad  58  to the foot  14 . The foot  14 , at least one steam outlet  54  ( FIG. 1 ), and the fluid conduit  56  coupled between the steam generator  30  ( FIGS. 1 and 9 ) and the steam outlet  54  can extend at least partially through the coupling joint  80 . At least a portion of the conduit  56  can be flexible to accommodate for the movement of the coupling joint  80 . 
     The foot  14  can further include a working air conduit between the suction nozzle  62  and the collection assembly  66 , which can extend though the coupling joint  80  and include an external conduit  82  connected between the coupling joint  80  and the collection assembly  66 . The external conduit  82  can be a flexible hose or a rigid conduit. In addition to the cleaning pad  58 , the foot  14  can be provided with one or more additional agitators, such as, but not limited to, a stationary or rotating brush positioned adjacent the suction nozzle  62 , edge brushes, a squeegee, or combinations thereof. 
       FIG. 3  is a rear perspective view of the surface cleaning apparatus  10 . The supply tank  40  is supported on a rear portion of the main support section  72  for storing a supply of liquid. The housing  12  has a window  84  which allows the user to view the supply tank  40  and ascertain the level of liquid within the supply tank  40 . A filter assembly  86  is supported on a rear portion of the main support section  72 , below the supply tank  40 , for filtering the liquid passing out of the supply tank  40 . A heater cavity  88  is formed at a front, lower end of the support section, below the collection system, and contains the steam generator  30  ( FIG. 1 ) positioned therein in fluid communication with the supply tank  40 , through the filter assembly  86 . Cord wraps  90  are provided on the rear portion of the upper housing  12 , below and above the supply tank  40 , and store the power cord  38  (shown in  FIG. 1 ) which can plugged into a household electrical outlet to provide power to various components of the surface cleaning apparatus, such as but not limited to the steam generator  30  and the suction source  64 . The foot  14  is detachably mounted to the upper housing  12  by a latch  92  provided on the rear of the coupling joint  80 . 
       FIG. 4  is a partial exploded view of the surface cleaning apparatus  10 . In this embodiment, the pump  52  is provided in the upper housing  12 , in the heater cavity  88 , to control the flow of liquid to the steam generator  30 , also positioned in the heater cavity  88 . When the pump  52  is activated, liquid flows through the pump  52  into the steam generator  30  to be heated by the heater  36 . 
     The collection assembly  66  is shown as removed from the surface cleaning apparatus  10 . A latch assembly  95  can be provided for selectively latching the collection assembly  66  to the main support section  72 . The latch assembly  95  can cause the collection assembly  66  to move upwardly and downwardly with respect to the main support section  72 . Upward movement of the collection assembly  66  effects the latching the collection assembly  66  to the surface cleaning apparatus  10  in a position to receive debris, while downward movement of the collection assembly  66  allows the collection assembly  66  to be selectively removed from the surface cleaning apparatus  10  to be emptied. 
       FIG. 5  is a cross-sectional, perspective view of the collection assembly  66 . The collection assembly  66  comprises a housing  96  at least partially defining a single-stage cyclone chamber  98  for separating contaminants from a debris-containing working airstream and an integrally-formed debris collection chamber  100  which receives contaminants separated by the cyclone chamber  98 . The housing  96  is common to the cyclone chamber  98  and the collection chamber  100 , and includes a side wall  102 , a bottom wall  104 , and an open top defined by an upper edge  106  of the side wall  102 . The side wall  102  is illustrated herein as being generally cylindrical in shape. A handle grip  108  attached to the housing  96  can be gripped by a user to facilitate removing collection assembly  66  from the upper housing  12 . 
     The bottom wall  104  comprises a door or cover that can be selectively opened, such as to empty the contents of the collection chamber  100  through a bottom debris outlet  109  defined by a lower edge  106  of the side wall  102 . The cover  104  is pivotally mounted to the side wall by a hinge  110 . A door latch  112  is provided on the side wall  102 , opposite the hinge  110 , and can be actuated by a user to selectively release the cover  104  from engagement with the bottom of the side wall  102 . The door latch  112  is illustrated herein as comprising a latch button  114  that is pivotally mounted to the side wall  102  and biased toward the closed position shown in  FIG. 5  by a spring  116 . By pressing the upper end of the latch button  114  toward the side wall  102 , the lower end of the latch button  114  pivots away from the side wall  102  and releases the cover  104 . An annular gasket  118  can be provided between the cover  104  and the bottom edge of the side wall  102  to seal the interface therebetween when the cover  104  is closed. 
     An air inlet to the cyclone chamber  98  can be at least partially defined by an inlet conduit  120 . An air outlet from the cyclone chamber  98  can be at least partially defined by an exhaust grill  122  which guides working air out of the housing  96 . The inlet conduit  120  is in fluid communication with the suction nozzle  62  ( FIG. 4 ) and the exhaust grill  122  is in fluid communication with the suction source  64  ( FIG. 4 ). The exhaust grill  122  is positioned in the center of the cyclone chamber  98  and can depend from a bottom wall of the cover assembly  128 . 
     The exhaust grill  122  separates the cyclone chamber  98  from a passageway  124  leading to a pre-motor filter assembly  126  within a cover assembly  128  that is removably mounted to the upper edge  106  to partially close the open top. The exhaust grill  122  includes a generally cylindrical cage-like body  130  defining a plurality of openings which can be covered by a filtration media  132  that prevents at least some particles in the working airstream from entering the openings. Some non-limiting examples of the filtration media  132  is a mesh or screen, such as a nylon mesh or screen. 
       FIG. 6  is an exploded view of the collection assembly  66 . The cover assembly  128  can define a filter chamber for the pre-motor filter assembly  126  and includes a lower filter housing  134  and an upper filter cover  136  which can be mounted to the lower filter housing  134 . The pre-motor filter assembly  126  can include one or more filters. In one non-limiting example, the pre-motor filter assembly  126  can comprise a sponge filter  138  and a pleated HEPA filter  140  arranged sequentially with respect to the direction of air flow. The lower filter housing  134  includes a central opening  142  allowing air to pass out of the exhaust grill  122  and into the sponge filter  138 . The upper filter cover  136  can have a lattice-like frame with multiple openings  144  allowing air to pass out of the pre-motor filter assembly  126 . After passing through the filter cover  136 , working air can pass to the suction source  64  (see  FIG. 4 ). 
     A first seal  146  and a second seal  148  are provided between the lower filter housing  134  and the upper filter cover  136  for providing fluid-tight interfaces therebetween. A third seal  150  can be provided on the top of the upper filter cover  136  for sealing the air path between the pre-motor filter assembly  126  and the suction source  64  when the separating and collection assembly  66  is latched on the main support section  72  (see  FIG. 4 ). 
     The collection assembly  66  further includes a debris ejector  152  that is reciprocally moveable within the housing  96 . The debris ejector  152  can eject debris through the debris outlet  109  of the housing  96  when the cover  104  is open. A retractable push rod  154  is selectively coupled to the debris ejector  152  to actuate the debris ejector  152 . When debris ejection is not required, the push rod  154  can be retracted into the collection assembly  66 . 
     The debris ejector  152  of the illustrated embodiment includes an ejector plate  156  configured to be moved vertically within the housing  96  by the push rod  154 . The ejector plate  156  can be annular and includes an inner opening  158  that accommodates the exhaust grill  122  and an outer peripheral edge  160  that can extend to the side wall  102 . The inner opening  158  can be sized such that the ejector plate  156  passes in close proximity to the exhaust grill in order to remove debris that accumulates on the mesh. 
     The debris ejector  152  can further include a push member  162  which engages with the push rod  154  to transfer the push force from the push rod  154  to the ejector plate  156 . The push member  162  can be coupled with the ejector plate  156  by a connector, shown herein as two vertical links  164  extending between the push member  162  and the ejector plate  156  and supporting the push member  162  below the ejector plate  156 . 
     In the illustrated embodiment, a stationary grill support  166  depends from the lower filter housing  134  to support the exhaust grill  122  within the housing  96  in a fixed position. The grill support  166  includes a central passage  168  to accommodate the push rod  154 . The grill support  166  can further be split to allow for the passage of the vertical links  164  as the ejector plate  156  moves relative to the exhaust grill  122  and grill support  166 . 
     The push rod  154  includes an outer member  172  and an inner member  174  that is collapsible or telescopingly received within the outer member  172  when the push rod  154  is retracted. The outer member  172  includes a generally cylindrical sleeve  176  defining a receiving space for the inner member  174  and having a flange  178  at its upper end. The inner member  174  includes a generally cylindrical shaft  180  sized to slide within the sleeve  176 , with a handle  182  at its upper end. In the retracted position, the handle  182  can be at or below the top of the cover assembly  128  (see  FIG. 5 ). 
     A spring  170  can be provided for biasing the debris ejector  152  upwardly within the housing  96 . As illustrated, the spring  170  is positioned within the central passage  168  and between the grill support  166  and the flange  178  to bias the outer member  172 , and therefore the entire debris ejector  152 , upwardly within the housing  96 , as shown in  FIG. 5 . 
     The push rod  154  can be retained in the collection assembly  66  during normal operation so that a user cannot inadvertently pull the push rod  154  out of the housing  96 . In the illustrated example, the outer member  172  of the push rod  154  is fastened to, or otherwise fixed with, the push member  162  using a fastener in the form of a screw  184 . Further, a seal  186  is provided between the push member  162  and the grill support  166  for providing a fluid-tight interface therebetween when the debris ejector  152  is in the uppermost position (see  FIG. 5 ). 
       FIGS. 7A-7C  are perspective views of the push rod  154  showing the extension of the push rod  154 . The push rod  154  can further include a lockable coupling between the members  172 ,  174  for selectively locking the push rod  154  in the extended position. The lockable coupling can include a pin  190  projecting radially from the shaft  180  the inner member  174  that engages a slot  192  in the sleeve  176  of the outer member  172 . The push rod  154  is configured so the inner member  174  moves relative to the outer member  172  between the positions illustrated in  FIGS. 7A-7C  via the sliding movement of the pin  190  in the slot  192 . The movement of the pin  190  in the slot  192  also provides a locking mechanism for securing the members  172 ,  174  in the extended position. In an alternate configuration, the slot  192  can be formed in the shaft  180  of the inner member  174  and the pin  190  can be formed on the sleeve  176 . 
     The slot  192  includes a longitudinal segment  194  and a radial segment  196  which extends radially from the upper end of the longitudinal segment  194  in a circumferential direction on the sleeve  176 . Longitudinal movement of the inner member  174  relative to the outer member  172  is controlled by the longitudinal segment  194 , and rotational movement of the inner member  174  relative to the outer member  172  is controlled by the radial segment  196 . The slot  192  further includes an end segment  198  that extends downwardly from the end of the radial segment  196  opposite the longitudinal segment  194  to selectively secure the pin  190 , thereby locking the push rod  154  in the extended position. 
       FIG. 7A  shows the push rod  154  in the retracted position. To extend the push rod  154 , a user can grip the handle  182  and pull upwardly on the inner member  174 . The pin  190  slides within the longitudinal segment  194  of the slot  192  to guide the longitudinal extension of the inner member  174  relative to the outer member  172  to the position shown in  FIG. 7B . Once the pin  190  reaches the top of the longitudinal segment  194 , the inner member  174  can be rotated such that the pin  190  slides within the radial segment  196  of the slot  192  to guide the rotation of the inner member  174  within the outer member  172 . The pin  190  can then drop into the end segment  198  of the slot  192  to lock the push rod  154  in the extended position shown in  FIG. 7C . These steps can generally proceed in the opposite order to retract the push rod  154 . 
     With reference to  FIGS. 2-5 , the surface cleaning apparatus  10  can be used to effectively remove liquid and debris (which may include dirt, dust, hair, and other debris) from the surface to be cleaned in accordance with the following method. The sequence of steps discussed is for illustrative purposes only and is not meant to limit the method in any way as it is understood that the steps may proceed in a different logical order, additional or intervening steps may be included, or described steps may proceed concurrently, or be divided into multiple steps, without detracting from the invention. 
     In operation, the surface cleaning apparatus  10  can be utilized in a vacuum only mode, a steam only mode, or a concurrent vacuum and steam mode. For vacuum cleaning, the suction source  64  is energized and draws liquid and debris-containing air from the suction nozzle  62  through a circuitous working air path which can trap and evaporate moisture before the working air enters the collection assembly  66 , where the debris and any remaining liquid are separated from the working air. Although the collection assembly  66  can be configured to separate liquid from the working air, most or all of the liquid is separated from the working air prior to entering the collection assembly  66 , and so any remaining liquid would be imperceptible. The working air, which may still contain some smaller or finer debris, then passes through the exhaust grill  122  which can separate out some additional debris. The working air, which may still contain some even smaller or finer debris, passes through the pre-motor filter assembly  126 , where additional debris may be captured. The working air then exits the collection assembly  66  and passes through the suction source  64  before being exhausted from the surface cleaning apparatus  10 . One or more additional filter assemblies may be positioned upstream or downstream of the suction source  64 . 
     For steam cleaning, the cleaning pad  58  is attached to the foot  14 , the supply tank  40  is filled with liquid, and the power cord  38  is plugged into a household electrical outlet. Upon pressing the actuator  48 , the pump  52  is activated and liquid flows from the supply tank  40 , through the filter assembly  86 , to the steam generator  30 . In the steam generator  30 , liquid is heated to its boiling point to produce steam. The generated steam exits the steam generator  30  and guided downwardly to the foot  14  towards the surface to be cleaned. As steam passes through the cleaning pad  58 , a portion of the steam may return to liquid form before reaching the floor surface. A portion of the steam delivered to the floor surface can also return to liquid form. As the damp cleaning pad  58  is wiped over the surface to be cleaned, at least some excess liquid and debris on the surface can absorbed by the cleaning pad  58 . Liquid and debris can also be removed from the surface to be cleaned by operation of the vacuum mode. 
     Operating in the concurrent vacuum and steam mode, the steam generator  30  and suction source  64  operate concurrently such that steam delivery and suction pick-up occur at the same time, or at least partially overlap each other. With the surface cleaning apparatus  10 , the collection assembly  66  remains perceptibly dry during and after concurrent operation of the steam generator  30  and suction source  64 . 
     To dispose of collected debris and any remaining imperceptible amount of liquid, the collection assembly  66  is detached from the surface cleaning apparatus  10  using the latch assembly  95  (see  FIG. 4 ). Using the latch  112 , the cover  104  is opened under the force of gravity, and at least some accumulated debris can fall from the collection chamber  100  through the debris outlet  109  of the housing  96 . In some cases, at least some of the some accumulated debris may remain in the housing  96 . The debris ejector  152  can then be used to eject any remaining debris from the housing  96 . 
       FIGS. 8-9  are quarter-section views of the collection assembly  66  from  FIG. 5  showing the operation of the debris ejector  152 . The retractable push rod  154  is moveable between a retracted position (shown in  FIG. 5 ) in which the push rod  154  lies within the housing  96  and an extended position (shown in  FIG. 8 ) in which the push rod  154  extends from the housing  96  and is operably coupled to the debris ejector  152 . The extension of the push rod  154  can proceed as described above with respect to  FIGS. 7A-7C . When the push rod  154  is in the extended position, downward pressure on the push rod  154  displaces the debris ejector  152  relative to the debris outlet  109 , as shown in  FIG. 9 . The ejector plate  156  moves downwardly within the housing  96  and pushes any remaining debris out of the debris outlet  109 . As the ejector plate  156  moves, it may scrape the exterior of the exhaust grill  122  and remove debris that accumulates on the grill  122 . In its lowermost position, shown in  FIG. 9 , a portion of the debris ejector  152  may project through the debris outlet  109 ; as such the cover  104  cannot be closed. However, upon release of the push rod  154 , the spring  170  biases the debris ejector  152  upwardly within the housing  96  to the position shown in  FIG. 8 . The user can then retract the push rod  154  back into the housing  96  as previously described, close the cover  104 , and replace the collection assembly  66  on the surface cleaning apparatus  10 . 
     While the surface cleaning apparatus  10  is shown in  FIGS. 2-9  as a steam/vacuum cleaner, some aspects of the debris ejector  152  can alternatively be used with a vacuum cleaner without steam capability, including upright vacuum cleaners, hand-held vacuum cleaners, portable vacuum cleaners, or canister vacuum cleaners. Further, the debris ejector  152  can be used with virtually any collection assembly having a bottom dirt outlet, and is not limited to cyclonic collection assemblies. 
     The various embodiments of surface cleaning apparatus and other devices related to the invention disclosed herein provide improved debris disposal. One advantage that may be realized in the practice of some embodiments of the described apparatus is that accumulated debris can be forcefully ejected from the collection assembly. Prior collection assemblies having a bottom empty design rely on gravity alone to dispose of debris through the bottom dirt outlet. However, in some cases debris may become stuck within the assembly, requiring a user to remove it by hand or by shaking or tapping the assembly in order to remove it. Embodiments of the present invention provide a debris ejector that applies force to accumulated debris in order to eject the debris through the bottom dirt outlet. In a further advantage of some embodiments of the described invention, a telescoping push rod can be used to actuate the debris ejector; the compact design of the push rod conserves space within the collection assembly and allows the collection assembly to be easily mounted to the surface cleaning apparatus. 
     While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation. Reasonable variation and modification are possible with the scope of the foregoing disclosure and drawings without departing from the spirit of the invention which, is defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.