Filter shaker system and method

An air filter cleaning system comprises a filter shaker plate having a top surface and a bottom surface, a motor mount extending from the top surface of the filter shaker plate, a motor mounted on the motor mount, a first filter clamp configured to be positioned adjacent to a first side of the filter shaker plate, and a second filter clamp configured to be positioned adjacent to a second side of the filter shaker plate.

BACKGROUND

The present patent application relates generally to a cleaning apparatus. More specifically, the present patent application relates to a mechanical air filter cleaning system and method that can be structured for use in a cleaning apparatus.

Industrial and commercial floors are cleaned on a regular basis for aesthetic and sanitary purposes. There are many types of industrial and commercial floors ranging from hard surfaces, such as concrete, terrazzo, wood, and the like, which can be found in factories, schools, hospitals, and the like, to softer surfaces, such as carpeted floors found in restaurants and offices. Different types of floor cleaning equipment, such as scrubbers and sweepers, have been developed to properly clean and maintain these different floor surfaces.

A typical scrubber is a walk-behind or drivable, self-propelled, wet process machine that applies a liquid cleaning solution from an onboard cleaning solution tank onto the floor through nozzles fixed to a forward portion of the scrubber. Rotating brushes forming part of the scrubber rearward of the nozzles agitate the solution to loosen dirt and grime adhering to the floor. The dirt and grime become suspended in the solution, which is collected by a vacuum squeegee fixed to a rearward portion of the scrubber and deposited into an onboard recovery tank.

Scrubbers can be very effective for cleaning hard surfaces. Unfortunately, debris on the floor can clog the vacuum squeegee, and thus, the floor should be swept prior to using the scrubber. Consequently, sweepers are commonly used to sweep a floor prior to using a scrubber. A typical sweeper is a self propelled, walk-behind or drivable dry process machine which picks debris off a hard or soft floor surface without the use of liquids. The typical sweeper has rotating brushes which sweep debris into a hopper or “catch bin,” Combination scrubber-sweepers have been developed that provide the sweeping and scrubbing functionality in a single unit.

Sweeper systems typically utilize a filter assembly to filter the “dirty” air that is suctioned into the hopper. The filter in the filter assembly typically comprises a conventional pleated panel filter.

One method for cleaning traditional pleated panel filters involves using mechanical vibration. This can be accomplished by vibrating the filter frame and consequently the filter media, using a “comb” to move or flick the individual pleats, or mechanically vibrating the filter media through direct contact. The latter has a detrimental effect on the pleated filter media because vibration between the media and any contacting part will wear holes in the media, which allows for dirty air to pass therethrough.

PowerCore® air filters produced by the Donaldson Company are a compact style of air fitter that was originally designed for engine air intake systems in automotive/vehicle applications. Unlike conventional pleated panel filters where a sheet of filter media is folded and the bends in the media are perpendicular to the flow of air, the PowerCore® filters contain a series of small flutes made from folded filter media that are closed on one end and are parallel to the flow of air. Dirty air enters one flute, passes through the wall of the flute and the clean air exits the other side of the filter through one of the adjacent flutes. These small flutes allow a larger amount of filter media to be packaged in the same amount of space occupied by a conventional panel filter. The advantage is that a smaller sized filter will contain the same amount of filtering area.

As of today, the only known means to clean fluted filters is with pulsed air. Particularly, the pulsed air system uses an air compressor to supply compressed air to a series of nozzles that are controlled by a solenoid valve. These nozzles are positioned over the clean side of the filter and the solenoid valve pulses short bursts of compressed air into the filter to push dust back out of the filter i.e., direction of the pulsed air flow is opposite the flow of air through the filter during normal operation).

OVERVIEW

In an example, an air filter cleaning system can be provided that includes a filter shaker plate having a top surface and a bottom surface, a motor mount extending from the top surface of the filter shaker plate, a motor mounted on the motor mount, a first filter clamp configured to be positioned adjacent to a first side of the filter shaker plate, and a second filter clamp configured to be positioned adjacent to a second side of the filter shaker plate.

In an example, an air filter cleaning system can be provided that includes a filter shaker plate having a top surface and a bottom surface, a motor mount extending from the top surface of the filter shaker plate, a motor mounted on the motor mount, a first filter clamp configured to be positioned adjacent to a first side of the filter shaker plate, and a second filter clamp configured to be positioned adjacent to a second side of the filter shaker plate. The filter shaker plate can include a plurality of slots extending between the top surface and the bottom surface. The motor can include at least one eccentric configured to impart vibration to the filter shaker plate.

DETAILED DESCRIPTION

Generally speaking, the present patent application relates to a mechanical air filter cleaning system and method. More specifically, the present patent application provides an air filter cleaning system that can be incorporated into a cleaning apparatus, such as a sweeper or combination sweeper-scrubber, to conveniently and adequately clean an air filter. In part, the present patent application solves the problem of removing dust trapped in the flutes of an air filter through the use of mechanical vibration that can be in direct contact with the filter media and can be applied generally parallel to the filter media surface. The air filter cleaning system of the present patent application can be configured for use on any vacuum-type machine that utilizes an air filter. However, for purposes of example and not limitation, the air filter cleaning system of the present patent application will be described as applied to a combination sweeper-scrubber system.

FIGS. 1 and 2are top and bottom perspective views, respectively, of an example of a sweeper-scrubber30that can utilize an air filter cleaning system in accordance with the present patent application. As illustrated inFIGS. 1 and 2, the sweeper-scrubber30can include a sweeper system32for sweeping a floor surface and a scrubber system34for scrubbing the floor surface. Thus, as will be discussed in further detail below, the sweeper-scrubber30can be operable to sweep dirt and debris from the floor surface, apply a liquid cleaning solution from an onboard cleaning solution tank onto the floor being cleaned, and agitate the cleaning solution. Suction means can then be used to draw the cleaning solution into an onboard recovery tank.

Providing a floor cleaning system having both a sweeper system32and a scrubber system34can allow the operator to perform both “dry” and “wet” cleaning with the same system. These sweeping and scrubbing modes can be operated either separately or simultaneously depending upon the type of cleaning required.

As further illustrated inFIGS. 1 and 2, the sweeper-scrubber30can include a chassis36supporting a machine body37and having a forward end38and a rearward end40joined by sides42. The chassis36can be supported by one or more floor engaging front wheels44and one or more rear steerable wheels46. The one or more rear steerable wheels46can be operatively connected to a steering wheel48through the chassis36. Alternatively, the chassis36can be supported by one or more front steerable wheels and one or more floor engaging rear wheels.

A driver seat50can be supported by the machine body37rearward of the steering wheel48for use by an operator of the sweeper-scrubber30. The operator can sit on the driver seat50to operate the steering wheel48and foot operated control pedals52, such as a brake and an accelerator, supported above a chassis top surface54.

In operation, a nozzle can apply a liquid cleaning solution from an onboard cleaning solution tank onto the floor being cleaned. The cleaning solution can be gravity fed through the nozzle, or alternatively pumped out of the cleaning solution tank through the nozzle. The cleaning solution applied onto the floor can then be agitated by one or more ground engaging scrub brushes56. In an example, the scrub brushes56together form a portion of a scrub deck assembly59of the scrubber system34adjacent to a bottom surface of the chassis36. As illustrated inFIGS. 1 and 2, the outside scrub brushes56and associated skirts57can protrude from the side of the sweeper-scrubber30to improve scrubbing close to walls and other obstacles.

As illustrated inFIGS. 1 and 2, the ground engaging scrub brushes56can have substantially parallel axes of rotation that are generally perpendicular to the floor surface. The scrub brushes56can be rotatably driven by a suitable motor, and can be configured to agitate the cleaning solution sprayed onto the floor surface to dislodge dirt and grime adhered thereto. In addition to the scrub brushes56, the scrubber system34can further include a floor engaging vacuum squeegee assembly58positioned proximal the chassis rearward end40. The agitated cleaning solution and suspended dirt and grime can be drawn off the floor through the squeegee assembly58and into the recovery tank for disposal.

The squeegee assembly58can be coupled to a squeegee support bracket60pivotally fixed relative to the chassis36, and can be moved between an operating position and a stored position (when not in use). The squeegee assembly58, which can be operable to dry the floor being cleaned by the sweeper-scrubber30, can include a forward arcuate squeegee blade62nested within a rearward arcuate squeegee blade64. In an example, the nested squeegee blades62and64can extend substantially across the width of the sweeper-scrubber30and can define a crescent shaped vacuum zone66. The squeegee blades62and64can be formed from any flexible material that can sealingly engage the floor, including elastomeric materials such as rubber, plastic, or the like.

The forward squeegee blade62can be configured to collect the cleaning solution on the floor, and can include notches in its floor engaging edge which allows the cleaning solution to enter the vacuum zone66. The rearward squeegee blade64can include a continuous floor engaging edge in order to prevent the escape of the cleaning solution rearwardly from the vacuum zone66.

As illustratedFIGS. 1 and 2, one or more side disk brooms68can be rotatably mounted proximal the chassis forward end38and forward of the ground engaging agitation brushes56. The side disk brooms68can be driven by a suitable motor controlled by control circuitry. Each side broom68can be rotatable about a substantially vertical axis proximal one of the chassis sides42, and can be configured to convey debris towards a centerline of the chassis36for pick-up by a main sweeper broom69. In an example, the main sweeper broom69can be rotatable about a substantially horizontal axis. As illustrated inFIGS. 1 and 2, each side broom68can extend radially from its vertical axis past one side42of the chassis36in order to sweep the floor along a wall or other vertical or angled surface. Similar to the squeegee assembly58, the side brooms68can be vertically movable between an operating position and a storage position.

Adjacent to the main sweeper broom69, a debris collection chamber70located within the machine body37can be provided that is configured to collect the debris thrown generally forward by the main sweeper broom69. In operation, the main sweeper broom69can sweep the debris forward into the debris collection chamber70for pick-up. Dust entrained air in the main sweeper brush compartment and the debris collection chamber70can then be filtered through an air filter cleaning system.

FIG. 3is a front perspective view of the sweeper-scrubber30with a front lift cover72in an open position and providing access to an air filter cleaning system74. As illustrated inFIG. 3, the air filter cleaning system74can be positioned within an air filter compartment76. When the front lift cover72is lowered to a closed position, the air filter compartment76and the front lift cover72can define an enclosed chamber. A gasket78can be provided to form a seal between the air filter compartment76and the front lift cover72in the closed position.

As illustrated inFIG. 3, a vacuum fan80can be coupled to the front lift cover72and configured to draw air from the debris collection chamber70through the air filter cleaning system74when the front lift cover72is in the closed position. Particularly, the filtered air can be suctioned through the vacuum fan80and routed through internal passageways formed within the front lift cover72. The front lift cover72can include one or more vents82that are configured to exhaust the filtered air out of the sweeper-scrubber30. In an example, the sweeper-scrubber30can include one or more exhaust chambers84positioned adjacent to the forward end38. When the front lift cover72is in the closed position, the one or more vents82can be positioned so as to deliver the filtered air into the one or more exhaust chambers84. The filtered air can escape through one or more gaps formed between the front lift cover72and the machine body37.

FIG. 4is an enlarged perspective view of the air filter cleaning system74positioned within the air fitter compartment76and coupled to an air fitter86. The air filter86can include an air filter frame87and air filter media89disposed therein. As illustrated inFIG. 4, the air filter cleaning system74can include a filter shaker plate88and a filter shaker motor92. With reference toFIGS. 4 and 5, the filter shaker motor92can include a motor shaft having one or more eccentric weights91coupled thereto. When a single eccentric weight91is mounted on one end of the filter shaker motor92, or when two substantially equal eccentric weights91are mounted on opposing ends of the filter shaker motor92and not aligned on the same side of the motor shaft, they can impart a rocking motion upon the filter shaker motor92. When two eccentric weights91are positioned on opposing sides of the filter shaker motor92and aligned on the same side of the motor shaft, they can impart a generally cylindrical movement of the filter shaker motor92. As the motor shaft rotates, the one or more eccentric weights91can cause the filter shaker motor92to vibrate. Any suitable filter shaker motor92can be utilized, such as an electric motor or a hydraulic motor.

The air filter cleaning system74can include a motor mount94extending from a top surface95of the filter shaker plate88that is configured to hold the filter shaker motor92. The motor mount94can include first and second flanges96and98extending therefrom that can be generally perpendicular to the motor shaft and generally aligned with a center of gravity of the filter shaker motor92. The air filter cleaning system74can also include a first filter clamp100configured to be positioned adjacent to a first side102of the filter shaker plate88and a second filter clamp104configured to be positioned adjacent to a second side106of the filter shaker plate88. The first and second flanges96and98can be coupled to the first and second filter clamps100and104with suitable fastening members to position the filter shaker plate88above the air filter86. The filter shaker plate88, the motor mount94, the first and second flanges96and98, and the first and second filter clamps100and104can be formed from any suitable material, such as various metals, plastics, or the like.

In an example, the air filter cleaning system74can include first and second clamp securing members108and110configured to secure the first and second filter clamps100and104to posts111within the air filter compartment76. As illustrated inFIG. 4, the first and second clamp securing members108and110can be T-handles having an internally threaded connection that is configured to engage an externally threaded post111. However, any suitable connection means can be used in place of a threaded connection.

In order to minimize the risk of the filter shaker plate88becoming dislodged as a result of vibration during operation of the filter shaker motor92, the first and second filter clamps100and104can include corresponding first and second stop members114and116that mate with the first and second clamp securing members108and110. In an example, the first and second stop members114and116can include a curved inner surface that mates with a curved outer surface of the first and second clamp securing members108and110.

FIG. 5is a perspective view of the air filter cleaning system74detached from the air filter86. The first and second filter clamps100and104can include first and second openings112and114, respectively, that are configured to receive the posts111within the air filter compartment76. The openings112and114can be opened ended, as illustrated inFIG. 5, or closed ended. When closed ended openings112and114are utilized, the openings can include an inner dimension that is larger than an outer dimension of the posts111such that the openings112and114can slide over the posts111.

As illustrated inFIG. 5, the first filter clamp100can include a first inwardly projecting flange116configured to mate with a first side117of the air filter frame87, and the second filter clamp104can include a second inwardly projecting flange118configured to mate with a second side119of the air filter frame87. The first and second inwardly projecting flanges116and118can allow the air filter cleaning system74to be coupled to the air filter frame87white avoiding any substantial contact with the filter media89prior to operation of the filter shaker motor92.

The filter shaker plate88can include a plurality of elongated slots120extending between the top surface95and a bottom surface122of the plate. The slots120can be configured to allow the free passage of air from the air fitter86through the filter shaker plate88. In addition to allowing for air flow, the slots120can be configured to decrease the rigidity of the filter shaker plate88such that the filter shaker plate88can vibrate more freely across the entire surface of the filter media89. As illustrated inFIG. 5, the filter shaker plate88can include one or more paddle members124defined between adjacent slots120. The paddle members124can have a first end126integral with the filter shaker plate88and a second free end128. The free ends128can allow for increased movement and vibration of the paddle members124relative to the remaining structure of the filter shaker plate88during operation of the filter shaker motor92.

As discussed above, the fitter shaker motor92can be configured to cause vibration of the filter shaker plate88, which in turn can “shake” the filter media89to dislodge dirt and debris that is caught within the filter media89. Over time, vibration of the filter shaker plate88can cause stress and wear, which can lead to failure of the filter shaker plate88. In an example, one or more support brackets130can be provided on the top surface95of the filter shaker plate88that are configured to increase the rigidity of the plate and minimize the risk of damage or failure. As illustrated inFIG. 5, a plurality of support brackets130can be provided that extend between the motor mount94and a first plate lip132adjacent to the first side102of the filter shaker plate88or a second plate lip134adjacent to the second side106of the filter shaker plate88.

The fitter shaker motor92can be positioned in any orientation relative to the filter shaker plate88while providing adequate vibration for cleaning the air filter86. However, in an example, the filter shaker motor92can be mounted to the motor mount94such that the motor shaft ties along an axis A that is substantially parallel to a longitudinal length L of the air filter86. Orienting the filter shaker motor92with the motor shaft generally parallel to the longitudinal length L of the air filter86can allow an increased amount of vibration at the ends of the filter shaker plate88farthest away from a center of the air filter86.

FIG. 6is an exploded perspective view of the air filter cleaning system74ofFIGS. 3-5illustrating the connection of various components. As illustrated inFIG. 6, the air filter cleaning system74can include a motor clamp140configured to secure the filter shaker motor92to the motor mount94. The motor clamp140can be sized and configured to wrap around and mate with an upper surface142of the filter shaker motor92. The motor clamp140can also include a pair of motor clamp fastening apertures144configured to align with a corresponding pair of apertures146in the first and second flanges96and98. Once the apertures are properly aligned, the motor mount clamp140can be coupled to the first and second flanges96and98with motor clamp fastening means148. In an example, the motor clamp fastening means148can include a threaded bolt150, one or more washers152, and a threaded nut154. However, any suitable fastening means can be used including, but not limited to, snap-fit connections, press-fit connections, welding, or the like.

Although the motor clamp140is illustrated and described as a single component, the clamp can alternatively comprise separate clamp components that can be independently coupled to the first and second flanges96and98. The first and second flanges96and98can also be an integral part of the filter shaker motor92.

In order to prevent rotation of the filter shaker motor92within the motor mount94, the filter shaker motor92can be provided with one or more protrusions156that are configured to be received within one or more protrusion receiving apertures158formed in the motor clamp140. Further, the motor mount94can include one or more retaining tabs160configured to mate with and engage one or more ends162of the fitter shaker motor92and prevent lateral movement of the filter shaker motor92during operation. The one or more protrusions156and one or more retaining tabs160can also function to center the filter shaker motor92on the filter shaker plate88.

As further illustrated inFIG. 6, the first and second filter clamps100and104can include studs164that are configured to be received within an aperture166of an isolator member168. When assembled, the studs164can be received within a corresponding pair of flange apertures170in the first and second flanges96and98. The isolator members168can be coupled between the first and second flanges96and98and the first and second filter clamps100and104with isolator fastening means172. In an example, the isolator fastening means172can include one or more washers174and a threaded nut176. The threaded nut176can be configured to engage a threaded portion of the stud164. However, any suitable fastening means can be used including, but not limited to, snap-fit connections, press-fit connections, welding, or the like.

Alternatively or additionally, isolators178can be positioned on an opposing side of the first and second flanges96and98and engage the studs164through apertures180.

The isolator members168and/or178can be configured to allow the filter shaker plate88to pivot about an axis that extends between the two studs164. The isolator members168and/or178can also allow the filter shaker plate88to move vertically along a longitudinal axis of the studs164. As previously discussed, movement of the shaker plate88can cause vibration of the filter media89, which in turn can allow removal of dirt and debris from the filter media89. In addition to the isolator members168and/or178, the first and second flanges96and98can also provide some flexibility to the filter shaker plate88and allow for vertical movement of the filter shaker plate88.

At rest, the bottom surface122of the filter shaker plate88can be positioned in close proximity to but spaced apart from the filter media89. The spacing can allow the filter shaker plate88to move farther when it starts vibrating, thus increasing the amplitude of the impact on the upper surface of the filter media89. However, the filter shaker plate88can also be positioned such that, at rest, the bottom surface122of the filter shaker plate88is in contact with the filter media89. The vertical position of the filter shaker plate88above the filter media89can be adjusted by compression of the isolator members168and/or178via the threaded nuts176. Particularly, the threaded nuts176can be tightened and loosened to adjust the vertical position of the filter shaker plate88above the filter media89(i.e. the more the threaded nuts176are tightened the closer the filter shaker plate88can be positioned with respect to the fitter media89). Thus, the isolator members168and/or178not only allow for vibratory movement of the filter shaker plate88, but they also allow for vertical adjustment of the filter shaker plate88relative to atop surface of the air filter86.

The isolator members168and/or178can be formed from any suitable material that allows for at least minimal compression. Examples of suitable materials include elastomers or rubbers such as polyisoprene, polybutadiene, polyisobutylene, polyurethane, or the like.

A benefit of the air filter cleaning system74of the present patent application is that the air filter86can be secured in place completely independent of the fitter shaker plate88. Stated alternatively, the fitter shaker plate88does not need to be installed in order to secure the air filter86in place within the air filter compartment76. Particularly, the first and second filter clamps100and104can be secured to the posts111to retain the air filter86in place prior to attachment of the filter shaker plate88. With the air filter86secured in place, the first and second flanges96and98extending from the motor mount94can then be secured to the studs164of the first and second filter clamps100and104as previously described. Alternatively, the filter shaker plate88can be pre-assembled to the first and second filter clamps100and104.

FIGS. 7A and 7Billustrate bottom and top views, respectively, of the air filter86. In an example, the filter media89can include a plurality of vertical flutes180extending between a bottom surface184of the air filter86and a top surface186of the air filter86. As illustrated inFIG. 7A, alternating flutes180can include an obstruction188positioned in the corresponding inlets to block air from flowing into those particular flutes180. With reference toFIG. 7B, the flutes180having the obstructions188in the inlets can have an open flute outlet to allow air to pass therethrough. Conversely, the flutes180that have an open inlet inFIG. 7Acan include obstructions188positioned in the corresponding outlets, as illustrated inFIG. 7B. Thus, each of the flutes180can include either an obstructed inlet or an obstructed outlet. Any suitable material can be used to form the obstructions188, including a plastic material, a glue joint, or the like.

FIG. 8is partial cross-sectional view of the air filter86taken along line8-8inFIG. 7Bdepicting air flow through the filter media89. As illustrated inFIG. 8, air flow189can enter an open flute inlet of one of the flutes180and be suctioned through an inner wall191of the filter media89and into an adjacent flute180having an open flute outlet. Thus, by providing obstructions188in adjacent flutes180, the air flow189can be forced to pass through the inner wall191of the filter media89prior to being expelled into the air filter compartment76. When the vacuum fan80is disabled and the filter shaker motor92is powered on to initiate direct vibratory contact between the filter shaker plate88and the filter media89, dirt and debris190collected in the flutes180can be forced to drop in a downward direction, as indicated by arrow192, and out of the filter media89. Cyclical vibration, continuous vibration, or a combination of the two can be used during a filter cleaning cycle.