Abstract:
A vacuum cleaner assembly comprising a main housing, a primary filter system, and a secondary filter system. The main housing includes an inlet and an outlet. The primary filter system filters the air prior to being exhausted outwardly through the outlet. The secondary filter system is placed in downstream airflow from the primary filter system and provides additional filtering of the air prior to being exhausted to atmosphere.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. Ser. No. 09/302,212 filed Apr. 29, 1999, now U.S. Pat. No. 6,174,350, which is a continuation in part of U.S. Ser. No. 09/298,137, filed Apr. 16, 1999, now U.S. Pat. No. 6,162,287. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a vacuum cleaner of the type for household use. 
     2. Description of the Prior Art 
     Water bath vacuum cleaners typically include a main housing with a removably attached water bath pan. An intake opening in the water bath pan matingly engages an inlet in the main housing of the vacuum cleaner to allow dust and dirt entrained air to be ingested by a vacuum force through the inlet into the area defined by the water bath pan. The primary advantage of the water bath filter is that vacuum efficiency is not compromised as more dirt and dust is accumulated in the water bath, and no further filtering is viewed as necessary. The dust and dirt are trapped in the water bath as the incoming air is directed into the water bath pan and circulated within. Traditional filtering media allow the flow of air through the filtering media to be impeded by the accumulation of the dirt and dust that has collected thereon. However, just as traditional filter media will allow very tiny microscopic particles to escape capture, the water bath and separator may also fail to capture all of the very small or microscopic particles that are light enough to remain suspended in the air as the air is circulated in the water bath pan. 
     High efficiency filters, or HEPA rated filters, are used on vacuum cleaners in industrial and residential applications. These filters are made up of filter media with very tiny openings that are designed to capture the smallest microscopic particles that most traditional filter media or methods are incapable of capturing. The major drawback to the use of these types of filters is that due to the small size of the openings in the filter media, they capture all of the dirt and debris that hits them thereby clogging up very quickly, and requiring cleaning or replacement very often. For this reason, some vacuum cleaning products try to combine the HEPA rated filter with a more conventional dry filter media. The conventional dry filter media will capture the larger particles of dirt and debris, and the HEPA rated filter will only capture the smaller particles that escape the conventional dry filter media. The overall efficiency of the vacuum cleaner (and the conventional dry filter media) is affected as the air is redirected and routed through the additional filter. Also, the full area of the high efficiency filter is not utilized because the air is typically directed through a small opening in the main housing of the vacuum cleaner, which concentrates the flow of air on the portion of the high efficiency filter that is directly in front of the opening. 
     SUMMARY OF THE INVENTION AND ADVANTAGES 
     The present invention relates to a vacuum cleaner assembly comprising a main housing having an inlet and an outlet. A motor is disposed within the main housing between the inlet and the outlet for providing motive force to a cooling fan, a blower, and a separator. The cooling fan is mounted within the main housing above the motor to circulate cooling air around the motor. A baffle is mounted within the main housing for directing the cooling air around the motor, and to filter the air that is circulated around the motor before that air is exhausted. The blower is mounted within the main housing below the motor for drawing air into the inlet and exhausting air outwardly through the outlet. The separator is mounted below the blower for circulating the air and water within a water bath and providing, in combination with the water bath, a primary filter for filtering the air prior to exhausting the air outwardly through the outlet. A second filter assembly including a high efficiency filter, known as a HEPA rated filter, for filtering microscopic dust and dirt particles that escape the separator and water bath and may be disposed after both the water bath and the separator and before the outlet to atmosphere for additional filtering of the air prior to being exhausted. The second filter assembly may also include a third filter comprising a carbon impregnated filter of a reticulated foam or similar material for absorbing or trapping odors drawn from the air, including smoke and fish odors. The second filter and the carbon impregnated filter are disposed in a recess which is integral with the main housing allowing for direct and efficient flow of the air through the water bath, separator, second filter, and carbon impregnated filter. In an alternative embodiment, the second filter can be a non-HEPA filter used in combination with the carbon impregnated filter. 
     Accordingly, the present invention will utilize the separator and water bath filter to capture the larger particles of dirt and debris prior to routing the air through the second, HEPA rated or non-HEPA rated filter to capture microscopic particles that escape the water bath, and finally through the carbon impregnated filter to absorb or trap odors. The recess for the high efficiency filter is located integrally to the main housing allowing the air to flow directly from the water bath canister through the second filter and the carbon impregnated filter with minimal redirection of the air and no noticeable impact on the primary filter. This will allow the air to flow smoothly through the series of filters. The second filter assembly will not be overly clogged because the separator and water bath will capture the majority of the larger dust and dirt particles before the air goes through the second filter assembly. The recess is designed to allow the majority of the surface area of the high efficiency filter to be in the direct line of airflow thereby the overall efficiency of the vacuum cleaner is maximized. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: 
     FIG. 1 is a perspective view of the vacuum cleaner assembly, partially broken away and in cross section; 
     FIG. 2 is an exploded perspective view of the vacuum cleaner assembly; 
     FIG. 3 is an elevational view of the vacuum cleaner main housing shown with the second filter seated in the recess defined by the housing; 
     FIG. 4 is an exploded perspective view of the second filter assembly including a five sectioned HEPA rated filter and a carbon impregnated reticulated foam filter; 
     FIG. 5 is an exploded perspective view of the second filter assembly including a nine sectioned HEPA rated filter and a carbon impregnated reticulated foam filter; 
     FIG. 6 is an exploded perspective view of the second filter assembly including a filter that is not HEPA rated and a carbon impregnated reticulated foam filter; and 
     FIG. 7 is a cross-section along lines  7 — 7  of FIG.  2 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views a vacuum cleaner assembly is generally shown at  10 . The vacuum cleaner assembly  10  includes a main housing  12  having an inlet  14  and an outlet  16 . A motor  17   a  is supported by support rings  18  within the main housing  12  between the inlet  14  and the outlet  16  for providing motive force to a cooling fan  17   b , a blower  17   c , and a separator  22 . The cooling fan  17   b  is mounted within the main housing  12  above the motor  17   a  to circulate cooling air around the motor  17   a . A baffle  19  surrounds the motor  17   a  to direct the cooling air around the motor  17   a  and to filter the cooling air prior to being exhausted. The blower  17   c  is mounted within the main housing  12  below the motor  17   a  for drawing air into the inlet  14  and exhausting air outwardly through the outlet  16 . The separator  22  is mounted below the blower  17   c  for circulating the air and a water bath  20  within a water bath pan  36  and providing, in combination with the water bath  20 , a primary filter for filtering the air prior to exhausting the air outwardly through the outlet  16 . 
     Vacuum cleaners using a water bath  20  filter are known to those skilled in the art as described in U.S. Pat. No. 5,096,475, which is hereby incorporated by reference to this specification. 
     A second filter assembly  24  is secured to the main housing  12  and preferably includes a high efficiency filter  100  or  100   a , known as a HEPA rated filter, for filtering microscopic dust and dirt particles that escape the separator  22  and water bath  20  and is disposed after both the water bath  20  and the separator  22  and before the outlet  16  for additional filtering of the air prior to being exhausted. The differences between filter  100  and filter  100   a  are shown in FIGS. 4 and 5. The filter  100  has compartments sectioned along five sets of ribs  102 , and made preferably of sheet polypropylene. The filter  100   a  has compartments sectioned along nine sets of ribs  103 . The ribs maintain the integrity of the filter against air pressure and other environmental effects and are preferably made from hot melt glue, although stamped aluminum and plastic ribs are alternatives. 
     In another alternative embodiment, the second filter assembly  24  can include a filter that is not HEPA rated  101 , as shown in FIG.  6  and combined in the description as discussed below and shown in FIG.  6 . 
     As a further alternative, a third filter  110  can be included as shown in FIGS. 4,  5  and  6  which comprises a carbon impregnated reticulated foam filter  110  for absorbing or trapping odors and is disposed in the air flow after the second filter  100 ,  100   a  or  101  and before the outlet  16  to atmosphere. The second filter  100 ,  101 , or  100   a  and the carbon impregnated filter  110  are secured together by glue or some equivalent means into a molded styrene frame  112  with a sealing gasket  114  associated with one edge of the frame  112 . This is shown in section in FIG. 7 where the filter of FIG. 2 is shown with the non-HEPA rated filter configuration of filter  101 , but which could just as readily be shown with the HEPA rated filter configurations of  100  or  100   a  inserted for the filter  101 . The surface area of the frame  112  adjacent the main housing  12  is at least five times larger than the surface area of the main housing  12  outlet. Preferably, the surface area of the frame  112  adjacent the main housing is nine times larger than the surface area of the main housing  12  outlet. The main housing  12  defines a recess  26  and the second filter assembly  24  is seated in that recess  26  with the sealing gasket  114  sealing against the main housing  12  at surface  115  to force the air to the outlet  16  through the second filter assembly  24 . 
     FIG. 2 shows an exploded view of the vacuum cleaner assembly  10 . The second filter assembly  24  is secured in position by a rear cover  28  which is removably attached to the main housing  12  via screws to cover the opening of the recess  26  and secure the second filter assembly  24  in position. The rear cover  28  includes a stowage device  30  for stowing an electrical cord. A foam seal  34  is disposed between the assembly  24  and the rear cover  28  to cushion and sound deaden that area of the vacuum as well as further prevent air from escaping anywhere other than via the outlet  16 . The second filter assembly  24  has smaller openings to capture particles passing through the separator  22  and water bath  20 . In the preferred embodiment, the second filter assembly  24  includes a HEPA rated filter  100  or  100   a  for capturing tiny microscopic dust and dirt particles. 
     Reuseable washable HEPA rated filter media, such as a pleated GORE-TEXtm material, can also be used as the second filter  100  or  100   a . Preferably, the reuseable washable filter media would be used as a HEPA rated filter, although if the particulate penetration size of the media selected were greater, the filter media would not be a HEPA rated filter, such as is the case with filter  101 . Reuseable washable filter media would be advantageous in this device because it can be washed and reused along with or intermittently with the disposal of the water bath  20  from the water bath pan  36  after use. 
     The vacuum cleaner assembly  10  includes a water bath pan  36  for containing the water bath  20 . The water bath pan  36  presents a first opening  38  which is disposed directly below the main housing  12  which has a bottom opening  39  that corresponds to the first opening  38  in the water bath pan  36 . A foam seal  40  forms a sealed engagement between the water bath pan  36  and the bottom opening  39  of the main housing  12 . The water bath pan  36  also includes a second opening  42  which corresponds to a tubular member extending from an inlet face plate  44 . The foam seal  40  forms a sealed engagement between the second opening  42  in the water bath pan  36  and the inlet face plate  44 . The inlet face plate  44  is mounted to the main housing  12  at the inlet  14  and allows attachments to be connected in direct communication with the inlet  14 . 
     The motor  17   a  is centrally supported by support rings  18  in the main housing  12  above the bottom opening  39 . The separator  22  is attached to the motor  17   a  below the blower  17   c  and extends downwardly through the bottom opening  41  in the main housing  12  and the first opening  38  in the water bath pan  36 . The separator  22  is rotated by the motor  17   a  for circulating the air within the water bath pan  36  and for drawing the dust and dirt entrained air, along with water from the water bath  20 , within the separator  22  for further capture of debris in the water bath  20  and to direct, by centrifugal force, the water and any remaining dirt or dust back outward into the water bath pan  36  for additional separation as it is drawn within the separator  22  again. As the dust, dirt, and water are forced outward from the separator by centrifugal force, the filtered air is drawn upward out of the separator  22  outwardly through the second filter assembly  24 . 
     A dolly  46  is positioned below the water bath pan  36 . The water bath pan  36  attaches to the main housing  12  with at pair of latches  47  to secure the water bath pan  36  to the main housing  12 . The main housing  12  attaches to the dolly  46  and is held securely in place by a latch which is released upon activation of a release button  49 . An interlock switch  48  is mounted to the main housing  12  and detects the presence of the water bath pan  36  when the dolly  46  is assembled to the main housing  12 . The dolly  46  includes a seat  51  for the main housing and casters  50  are mounted to the dolly  46  to provide movable support for the vacuum cleaner assembly  10 . The vacuum cleaner assembly  10  also includes a top cover  52  with a handle attached to the top of the main housing  12  to close off the top and cover the motor  17   a , cooling fan  17   b , support rings  18 , and blower  19 . The top cover  52 , main housing  12 , and dolly  46  when assembled enclose all inner components of the vacuum cleaner assembly  10 . 
     The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. 
     Modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, wherein reference numerals are merely for convenience and are not to be in any way limiting, the invention may be practiced otherwise than as specifically described.