Filter assembly for a vacuum cleaner

A filter assembly for a removable dirt separation system is disclosed. The filter assembly includes a wall support attached to a wall of the dirt separation system and a screen panel having a number of screen elements. The filter assembly further includes a filter element which is selectively releasable from the screen panel. The screen panel and filter element can be selectively secured to the wall support. A fine particle separation chamber is at least partially defined by the screen elements and the filter element. A portion of the walls of a dirt cup within the dirt separation system is formed by the filter assembly. A method of operating a filter assembly for a removable dirt separation system is also disclosed.

TECHNICAL FIELD

Generally, this invention relates to vacuum cleaners. In particular, the invention relates to a removable dirt separation system for a vacuum cleaner. Moreover, the invention relates to a filter assembly for a bagless vacuum cleaner.

BACKGROUND OF THE INVENTION

Upright vacuum cleaners are well known in the art. Typically, these vacuum cleaners include an upper housing pivotally mounted to a vacuum cleaner foot. The foot is formed with a nozzle opening defined in an underside thereof and may include an agitator mounted therein for loosening dirt and debris from a floor surface. A motor and fan may be mounted to either the foot or the housing for producing suction at the nozzle opening. The suction at the nozzle opening picks up the loosened dirt and debris and produces a flow of dirt-laden air which is ducted to the vacuum cleaner housing.

In conventional vacuum cleaners, the dirt laden air is ducted into a filter bag supported on or within the vacuum cleaner housing. Alternatively, bagless vacuum cleaners duct the flow of dirt-laden air into a dirt separation system having a dirt cup which filters the dirt particles from the airflow before exhausting the filtered airflow into the atmosphere. Various dirt separation systems have been used on bagless vacuum cleaners to separate the dirt particles from the airflow. For example, some vacuum cleaners have dirt cups with outer walls comprising a filter material. Locating the filter material along the outer walls has the distinct advantage of permitting the use of a large amount of filter material similar to the amount of material in a filter bag. However, such vacuum cleaners have a disadvantage of not permitting the operator to view the accumulated material within the dirt cup. Other vacuums, place the filter element in an interior portion of the dirt cup. Such dirt cups do not take advantage of the larger surface available on the outer wall of the dirt cup. In addition, placing the filter internally in the dirt cup does not allow the operator to view the filtered air flow which exits the filter. Additionally, other vacuum cleaners have a filter assembly comprising a filter screen and filter element forming a lid of the dirt cup. A disadvantage to this type of dirt cup is that the filter assembly must be removed to empty the accumulated particles in the dirt cup. An additional disadvantage to this type of dirt cup is that the fine particles which accumulate between the filter element and screen cannot be removed from the filter assembly without removing and disassembling the filter assembly.

What is needed therefore, is a dirt separation system that overcomes the above-mentioned drawbacks.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the present invention, there is provided a filter assembly for a removable dirt separation system. The filter assembly includes a wall support attached to a wall of the dirt separation system and a screen panel having a number of screen elements. The filter assembly further includes a filter element which is selectively releasable from the screen panel. The screen panel and filter element can be selectively secured to the wall support. A fine particle separation chamber is at least partially defined by the screen elements and the filter element. A portion of the walls of a dirt cup within the dirt separation system is formed by the filter assembly.

In accordance with a second aspect of the present invention, there is provided a method of operating a filter assembly for a removable dirt separation system. The method includes the step of attaching a wall support to a wall of the dirt separation system. The method further includes the step of securing a screen panel having a number of screen elements to a filter element. The method still further includes the step of positioning the screen panel and filter element proximate to the wall support. The method yet further includes the step of forming a portion of the wall of a dirt cup within the dirt separation by a securing the screen panel and filter element to the wall support.

DETAILED DESCRIPTION

Referring now toFIG. 1, there is shown an upright vacuum cleaner10which incorporates the features of the present invention therein. Vacuum cleaner10includes a vacuum cleaner foot12and a vacuum cleaner housing14pivotally connected to the foot12. The foot12has a nozzle opening13formed in an underside thereof for suctioning of dirt particles from a floor surface. In addition, an agitator (not shown) may be provided within the nozzle opening to assist in removing dirt particles from the floor surface.

Referring now toFIG. 2, there is shown the vacuum cleaner ofFIG. 1, with a dirt separation system30removed from a cavity16formed within the housing14. The cavity16may either be a bag housing formed to contain a conventional filter bag, an adaptation thereof, or a cavity specifically adapted to receive the dirt separation system30. The cavity16has an inlet18in fluid communication with the nozzle opening13defined in the foot12and an outlet20for exhausting filtered air from the cavity16. The inlet18further has a deflector19attached thereto to direct airflow within the dirt separation system30.

A motor-fan unit26is positioned either in a lower portion of the housing14or the foot12and is adapted to generate an airflow from the nozzle opening13to the outlet20. In one type of vacuum cleaner, the motor-fan unit26is positioned between the nozzle opening13and the inlet18such that the low pressure at the fan inlet creates a suction in the nozzle opening13. This suction draws the loosened dirt from floor surface into nozzle opening13and creates a flow of dirt-laden air which travels through the motor-fan unit26. The flow of dirt-laden air is blown upwardly through the inlet18through the dirt separation system30, through the outlet20and exhausted from the vacuum cleaner10. The air which reaches the motor-fan unit26has not been filtered either by the dirt separation system30or a bag prior to reaching the fan, hence these vacuum cleaners are generally referred to as “dirty air” units.

Alternatively, the motor-fan unit26may be positioned downstream from the outlet20such that the low pressure at the fan inlet creates a an airflow that draws low pressure air from the nozzle opening13to the outlet20via the inlet18and dirt separation system30. The air which reaches the motor-fan unit has been filtered by the dirt separation system30prior to reaching the fan, hence these vacuums are generally referred to as “clean air” units. The air which exits the motor-fan unit26is then exhausted from the vacuum cleaner10. It should be appreciated that the dirt separation system30may be used in either a dirty air unit or a clean air unit without deviating from the scope of the invention. Additionally, it is well known in the art to provide a final filter24for filtering the airflow prior to exhausting the airflow from the vacuum cleaner10.

The vacuum cleaner housing14further includes a catch22which hangs down from an upper portion27of the housing14. The catch22is adapted to cooperate with a latch assembly80of the dirt separation system30to secure the dirt separation system30to the upper housing14. The details of the latch assembly80and lid assembly40are described in greater detail below in reference toFIGS. 6,7A,7B,8A,8B, and8C.

The housing14further includes a base portion28having a U-shaped groove29defined therein. The U-shaped groove29cooperates with a U-shaped extension32which extends downwardly from the lower edge of the dirt separation system30. A lateral portion25of the U-shaped extension32fits within the U-shaped slot29to provide front to rear location of the dirt separation system30relative to the housing14. The longitudinal portions31(seen inFIGS. 5A and 5B) of the of the extension32provide left to right location of the dirt separation system30relative to the housing14. It should be appreciated that the cooperation of the single U-shaped extension32with the single U-shaped groove29provides precise location of the dirt separation system30relative to the housing14both in a left to right orientation and a front to rear orientation.

Referring now toFIG. 3, there is shown a top view of the dirt separation system30with a lid assembly40removed to show the interior of a dirt cup100defined within the dirt separation system30. The dirt cup100is defined by a floor33, a number of wall panels34,35,36, and a filter assembly50. An inlet opening38is defined in the wall panel36to allow the dirt laden airflow to enter the dirt separation system30. While the filter assembly50is described herein as a single flat wall, the scope of this invention is intended to cover every configuration wherein the filter assembly50is used to form a first portion of the walls of the dirt cup100including circular walls, arcuate walls, triangular walls, flat walls, outwardly angled walls, inwardly angled walls and any combination thereof which are used to form a first portion of the walls of the dirt cup100within the removable dirt separation system30. Additionally, it should be appreciated that floor33is not required to form the dirt cup100as angled walls, such as the filter assembly50could converge to form a dirt cup100without a floor.

It should be appreciated, that a second portion of the walls of the dirt cup, including the walls34,35, and36are translucent to allow for the viewing of material which may accumulate within the dirt cup100. However, only a second portion, i.e. excluding the first portion formed by the filter assembly50need be translucent to allow for the viewing of the contents of the dirt cup100. The dirt separation system30further includes translucent walls134,135and136for viewing air which flows through filter assembly50and through a dirt duct120(shown inFIG. 5B). The dirt separation system30yet further includes a left lateral extension37and a right lateral extension39which may be used to manipulate the dirt separation system30when the dirt separation system30is removed from the housing14of the vacuum cleaner10.

Referring now toFIG. 4A, there is shown an exploded view of the filter assembly50which forms a first portion of the side walls of the dirt cup100within the dirt separation system30. The filter assembly50includes a screen panel52, a filter element54, and wall support56. The screen panel52includes screen elements53which coarsely filter the dirt laden airflow which exit the dirt cup100(shown inFIG. 3) The screen panel52further includes lateral sealing members58, an upper sealing member60, a lower sealing member62, and screen support members61. The lateral sealing members58seal the filter panel to adjacent portions of the walls34,36(shown inFIG. 3) which form the dirt cup100so as to prevent airflow from bypassing the screen elements53. The upper sealing member60seals with the lid assembly40to seal the upper portion of the of the dirt cup100(shown inFIG. 5B). The lower sealing member62seals with the floor33(shown inFIG. 3) to seal the lower portion of the dirt cup100.

The screen support members61provide structural support for screen elements53. The screen elements53may be formed of a number of different materials such as metal or synthetic mesh or screens, cloth, foam, a high-density polyethylene material, apertured molded plastic or metal, or any other woven, non-woven, natural or synthetic coarse filtration materials without affecting the concept of the invention. In addition, the screen panel52includes a number of slots63adapted to receive an number of tabs64of the filter element54. In addition, the screen panel52includes a pair of latching elements65adapted to engage an pair of hooks66(best seen inFIGS. 5A and 5B) defined in the wall support56.

The filter element54includes a compressible sealing member55bonded to the outer edges of a filter material57. The filter material57provides a fine filtration of the dirt laden airflow which passes through the screen elements53. The filter material57includes a first inner layer formed of a melt-blown polypropylene, a second middle layer formed of a spun-bond polyester and an outer third layer formed of an expanded polytetrafluoro-ethylene (ePTFE) membrane. The ePTFE outer layer provides non-stick properties to the filter material57and allows any dirt or dust accumulated on the filter element54to be easily displaced therefrom. Although the filter material57is shown and described as having three layers, it is understood that the filter material may include any number of layers or be formed of any number of materials such as a micro-glass or a melt-blown polyester without affecting the concept of the invention. The sealing member55includes the tabs,64which are adapted to be received within the slots63of the screen panel52.

The wall support56includes the hooks66which are adapted to engage the latching members65of the screen panel52. In addition, the wall support56includes screw bosses67,68adapted to receive the fasteners, such a screws60and70(shown inFIGS. 5A and 5B) to secure the wall support56to the dirt separation system30.

Referring now toFIG. 4B, there is shown assembled filter assembly50. It should be appreciated that the wall support56is secured to the structure of the dirt separation system30, which is not shown inFIGS. 4A and 4B. To assemble the filter assembly50, the screen panel52is first secured to the filter element54by engaging the tabs64of the filter element54to the slots63of the screen panel52. To complete the assembly of the filter assembly50, the combined screen panel52and filter element54is secured to the wall support56by engaging the latching members65of the screen panel52to the hooks66of the wall support56. It should be appreciated that the screen panel52, filter element54, and wall support56are configured such that when the screen panel52is engaged with the wall support56, the compressible sealing element55of the filter element54is compressed between the screen panel52and the wall support56to form a seal which prevents airflow from by-passing the filter material57of the filter element54.

Once assembled, a fine particle separation chamber72is defined between the screen panel52and the filter element54. In operation, fine particles which pass through the screen elements53, but not through the filter material57are trapped within the fine particle separation chamber72. A pair of fine particle exit openings74are defined through the assembled screen panel52and filter element54. Fine particles may be emptied from the fine particle separation chamber72via the fine particle exit opening74without removing the filter assembly50from the dirt separation system30. It should be appreciated that a lid assembly40seals the upper area110proximate the exit openings74to prevent fine particles from escaping the dirt separation system30during operation (seeFIG. 5B).

Referring now toFIG. 5A, there is shown a view of the assembled screen panel52and filter element54prior to being secured to the wall support56to form the filter assembly50within the dirt separation system30. The assembled screen panel52and filter element54are slid downwardly into the dirt separation system30in the general direction of arrow90. A guide rail92is provided within the dirt separation system30to allow lateral alignment of the assembled screen panel52and filter element54within the dirt separation system30. Furthermore, an extension93of the guide rail92extends across the bottom of the dirt separation system30and cooperates with the lower sealing member62of the screen panel52to prevent particles from flowing around the screen elements53of the screen panel52. Once the lower portion62has engaged the extension93, the combined screen panel52and filter element54are secured to the wall support56by rotating the screen panel52and filter element54in the general direction of arrow94. Rotation of the combined screen panel52and filter element54causes the latching members65of the screen panel52to engage the hooks66of the wall support56and secure the combined screen panel52and filter element54to the wall support56to form the filter assembly50(as shown inFIGS. 3 and 5B). It should be appreciated that rotating the combined screen panel52and filter element54against the wall support56compresses the compressible sealing element55between the screen panel52and the wall support56. Compressing the sealing element55between the screen panel52and the wall support56seals the area around the filter material57and prevents airflow through the filter assembly50from bypassing the filter material57(as described above).

To remove the assembled screen panel52and filter element54, the above described operation is reversed. The latching members65of the screen panel52are disengaged from the hooks66of the wall support56. Disengaging the latching members65from the hooks66releases the compression on the sealing element55and allows the combined screen panel52and filter element54to be rotated back in the direction of arrow95. The assembled screen panel52and filter element54can then be removed from the other components of the dirt separation system30by lifting the assembled screen panel52and filter element54out in the general direction of arrow91. The filter element54may then be cleaned or replaced. To clean the filter element54, the filter element54may be knocked against a waste container, brushed, or bent along its vertical or horizontal axis to dislodge any fine particles which may have accumulated on the filter material57.

Referring now toFIG. 5B, there is shown the dirt separation system30fully assembled and positioned within the housing14as shown inFIG. 1, with the translucent front panels34and134removed for clarity of description. It should be appreciated that the filter assembly50divides the dirt separation system30into the dirt cup100and the dirt duct120. The dirt duct120directs the airflow which exits the filter assembly50toward an exit opening122defined in an orifice plate124at the bottom of the dirt separation system30. In addition, a flow directing vane126helps direct the air from the filter assembly50to the exit opening122. In addition to its flow directing function, the vane126provides support to the center of the wall support56to reduce deflection of the filter assembly50during operation.

The dirt cup100is generally defined by the walls34,35, and36along with the floor33and the screen panel52of the filter assembly50(as shown inFIG. 3) whereas the dirt duct120is generally defined by the walls134,135, and136and the wall support56of the filter assembly50. The wall34forms a first translucent viewing panel for viewing the material which accumulates within the dirt cup100whereas the wall134forms a second translucent viewing panel for viewing the filtered air flow which exits the filtered assembly50and flows through the dirt duct120. In the embodiment shown, the second translucent viewing panel134is an extension of the first translucent viewing panel34. In addition, the translucent walls34,35,36,134,135, and136maybe be formed out of continuous translucent panel.

It should be appreciated that the dirt duct120could be formed to either side, or rear of the dirt cup100, or on multiple sides if more than one portion of the walls the dirt cup100were defined by the filter assembly50. Such a dirt duct could encompass the entire area around the dirt cup100and direct air to an exit of the dirt separation system30. Such an exit may be defined on any outer surface of the dirt separation system, including but not limited to the bottom, sides, rear, front, lid or combination thereof.

The lid assembly40prevents air from exiting from an upper opening of the dirt cup100. In particular, a lid element42seals the upper opening of the dirt cup100. The upper opening of the dirt cup is defined by the upper portion of the walls34,35, and36along with the upper sealing member60of the screen panel52(seeFIG. 3). In addition, the lid element42seals the area110above the filter assembly50. The area110is in fluid communication with the fine particle separation chamber72(seeFIG. 3) via the fine particle exit openings74. Thus, the lid element42seals both the dirt cup100and the fine particle separation chamber72to prevent larger particles from exiting the dirt cup100and smaller particles from exiting the fine particle separation chamber72.

In operation, the dirt separation system30takes a dirt laden airflow from the inlet18, through the inlet opening38generally in the direction of arrow130. This dirt laden airflow is directed toward the filter assembly50by the deflector19of the inlet18. The deflector19could also be incorporated into the dirt separation system30. Directing the airflow toward the filter assembly50increases the pressure at the screen panel53which increases airflow through the filter assembly50. In addition, directing the airflow toward the screen panels53of the filter assembly50helps to remove large particles which may accumulate on the screen panels53and block airflow into the filter assembly50. Additionally, because the dirt-laden air stream is flowing from the confined area of the inlet18into the relatively large area of the cup100, the dirt cup100acts like an expansion chamber where the airflow expands and reduces its velocity. This expansion and reduced velocity allows the relatively heavy dirt particles and other relatively heavy debris to separate and fall from the dirt laden airflow. These large particles collect in the dirt cup100whereas the fine particles are directed through the screen elements53of the screen panel52.

The dirt laden airflow is then directed through the filter material57where the fine particles are filtered out. These fine particles are then collected within the fine particle separation chamber72. After passing through the filter material57, the filtered airflow exits the filter assembly50in the general direction of arrow132in the duct120toward the outlet opening122. The flow directing vane126assists in directing the filtered airflow in the duct120toward the exit opening122. It should be appreciated that one advantage of the present invention is that the filtered airflow in the duct120may be viewed via the second translucent panel134.

To empty the accumulated dirt from the dirt separation system30, the dirt separation system30is removed from the housing14of the vacuum cleaner10, as shown inFIG. 2. The lid assembly40is then removed to unseal the upper opening of the dirt cup100and area110. The dirt separation system30may then be inverted by either grasping the right extension37or the left extension39. Once inverted, coarse particles in the dirt cup100will fall from the dirt cup100via the upper opening and fine particles will fall from the fine particle separation chamber72via the fine particle exit openings74(SeeFIG. 3). The filter assembly50may also be removed and disassembled to further remove particles from the filter assembly50as described above.

Referring now toFIG. 6, there is shown an exploded view of the latch assembly80which is positioned within the lid assembly40(seeFIGS. 7Aand7B). The latch assembly80includes a latch82, an actuator84and a biasing spring86. The latch82includes a latching surface81and an axle83integrally formed therewith. The latching surface81is the interface between the latch82and the catch22(seeFIG. 2) of the housing14. The axle83serves a pivot point for the latch82. The actuator84has a living spring85integrally formed therein which biases the actuator in the general direction of arrow99. The actuator84further has a sleeve87integrally formed therein which is adapted to fit around the axle83and allow rotation of the actuator about the axle83. The actuator84further has a latch opening88defined therethrough operable to allow the latching surface81to pass through, but prevents a lower portion89of the latch82from passing through the. latch opening88of the actuator84.

Referring now toFIGS. 8A and 8B, there is shown the lid assembly40of the dirt separation system30. The lid assembly40includes a lid element42, a cover44, and a latch assembly80. The lid element42seals the upper opening of the dirt cup100and the area110as described above. The cover44cosmetically covers an upper portion of the cavity16proximate to the catch22, as shown inFIG. 2. The latch assembly80is operable to selectively secure the lid assembly40, and thus the dirt separation system30, to the housing14. The lid assembly40further includes a pair of axle supports46to support the axle83of the latch82. The cover44further includes an actuator opening48defined therethrough.

To assemble the latch assembly80within the lid assembly40, the actuator84is secured to the latch82by placing the sleeve87of the actuator84about the axle83of the latch82and further placing the latching surface81through the latch opening88defined in the actuator84. The coils of the spring86are then slid over each end of the axle83. The assembled latch assembly is then slid through the actuator opening48, shown inFIG. 7A, until the axle83engages the axle supports46, shown inFIG. 7B. Engaging the axle83to the axle supports46secures the latch assembly80to the lid assembly40.

Referring now toFIG. 8A, there is shown the latch assembly80in a latched position wherein the latch82secures the lid assembly40to the housing14. The spring member86acts against the latch85and the lid member42to bias the latching member in the general direction of arrow99. This biasing force of the spring86maintains the latching surface81of the latch82against the catch22thereby securing the lid assembly40to the housing14. The living spring85acts against the lid member42to bias the actuator84in the general direction of arrow99. It should be appreciated, that the biasing force of the living spring85is not transferred to the latch82as the actuator84is positioned above the latch84and the latching surface81extends through the latch opening88defined in the actuator84, as shown inFIG. 7B.

Referring now toFIG. 8B, there is shown the latch assembly80in an unlatched position wherein the lid assembly is released from the housing14. To place the latch assembly in the unlatched position, the actuator84is rotated in the general direction of arrow98about the axle83. Depressing the actuator84in the general direction of arrow98overcomes the biasing force of the living spring85and moves the actuator84into contact with the latch82. Further depression of the actuator84overcomes the biasing force of the spring86and causes the latch82rotate in the general direction of arrow98about the axle83. As the latch82rotates in the general direction of arrow98, the latching surface81is moved out of contact with the catch22thereby releasing the lid assembly40from the housing14. Releasing the lid assembly40from the housing14allows the dirt separation system30to be removed from the housing14, as shown inFIG. 2.

Referring now toFIG. 8C, there is shown the latch assembly80in a return position wherein the lid assembly40is returned to the housing14, prior to reaching the latched position ofFIG. 8A. To place the latch assembly in the return position, the dirt separation system30, including the lid assembly40is rotated back into the housing14. The latch82is moved into contact with the catch22, overcoming the biasing force of the spring86to cause the latch82to rotate in the general direction of arrow98. Rotating the latch82in the general direction of arrow98allows the latch82to move past the catch22and return to the latched position shown inFIG. 8A. It should be appreciated that moving the latch82into contact with the catch22does not cause the actuator84to rotate in the general direction of arrow98. Because the actuator84does not rotate, a pinch point is not created in the actuator opening48between the actuator84and the lid42.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description is to be considered as exemplary and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.