Filter assembly for a vacuum cleaner

A vacuum cleaner includes a motor, a housing enclosing the motor, and a fan driven by the motor for producing a vacuum. A canister is removably attached to the front end of the housing and has an intake nozzle for the reception of foreign matter, liquid and air drawn into the canister is response to the vacuum developed by the fan. A filter assembly includes a filter for filtering foreign matter from the air entering the canister. The assembly also includes a filter housing for housing the filter. The assembly further includes means for removably and positively securing the filter to the filter housing to allow the filter and the filter housing to form an integral unit.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates generally to portable vacuum cleaners, more 
particularly to, a vacuum cleaner capable of operating with both air and 
liquid. 
2. Description of Related Art 
Currently, there exists portable vacuum cleaners which pick up or vacuum 
solid or liquid material. These portable vacuum cleaners are frequently 
referred to as "wet-dry" vacuum cleaners. Typically, such vacuum cleaners 
include a filter assembly to filter or resist the passage of dirt through 
a passageway to the motor. 
In the conventional wet-dry vacuum cleaner, the filter includes an integral 
framework formed by a plurality of ribs with a sealing flange at one end. 
An air permeable filter member is disposed within the framework. The 
filter fits within a filter housing and a sealing ring or gasket is 
disposed between the sealing flange of the filter and a corresponding wall 
or sealing portion of a filter housing to form a friction fit between the 
gasket, filter and filter housing. 
One disadvantage of the above vacuum cleaner is that there is no provision 
for positively locking the filter to a filter housing. Another 
disadvantage is that the gasket may be dislodged, during assembly of the 
vacuum cleaner. If this happens, liquid may leak past the gasket and 
contact the motor which is undesirable. Still another disadvantage is that 
no guiding means exists for ensuring that a seal is properly formed 
between the filter, gasket and filter housing during assembly. A further 
disadvantage is that the filter and filter housing cannot be removed as an 
integral unit from the bowl for cleaning. A still further disadvantage of 
the above vacuum cleaner is that the operator cannot see through the 
canister to determine how much liquid and/or dirt is contained within the 
canister. 
It is, therefore, one object of the present invention to provide means for 
ensuring that the seal is properly formed between the filter, gasket and 
filter housing during assembly. 
It is another object of the present invention to provide means for 
positively locking the filter to a filter housing. 
It is a further object of the present invention to provide a filter and 
filter housing which can be removed as one unit from the vacuum cleaner 
for cleaning. 
It is a still further object of the present invention to provide a filter 
which can be removably separated from a filter housing to permit cleaning. 
It is another object of the present invention to provide a means for the 
operator to determine the amount of liquid and/or dirt contained within 
the canister. 
SUMMARY OF THE INVENTION 
Accordingly, the present invention is a filter assembly for a vacuum 
cleaner. The vacuum cleaner includes a motor, a housing enclosing the 
motor, and a fan driven by the motor for producing a vacuum. A canister is 
removably attached to the front end of the housing and has an intake 
nozzle for the reception of foreign matter, liquid and air drawn into the 
canister in response to the vacuum developed by the fan. The assembly 
includes means for filtering foreign matter from the air and means for 
housing the filtering means. The assembly further includes means for 
removably and positively securing the filtering means to the filter 
housing means to allow the filtering means and the filter housing means to 
form an integral unit. 
One advantage of the present invention is that the filter is positively 
locked to a filter housing by a pair of locking tabs which fit into 
corresponding slots on the sealing ring. Another advantage of the present 
invention is that alignment pins are provided to move the filter within 
the filter housing during assembly of the canister to the vacuum cleaner 
housing such that a seal is properly formed between the sealing flange of 
the filter assembly, gasket and the filter housing to prevent liquid from 
leaking past the gasket. A further advantage of the present invention is 
that the filter and filter housing can be removed as one unit from the 
vacuum cleaner for cleaning. A still further advantage of the present 
invention is that the filter can be removably separated from the filter 
housing to permit cleaning. 
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.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, a vacuum cleaner 10 incorporating the present 
invention is shown. The vacuum cleaner 10 comprises a central housing 12 
having a canister 14 affixed to a front end thereof and a handle 16 formed 
near the back end thereof. The handle 16 is configured to be grasped by 
the hand of a person using the vacuum cleaner 10 for the cleaning of 
upholstery, rugs, as well as in the dusting of flat surfaces such as the 
top of a table. 
The housing 12 contains a source of suction or fan 17 which may also be 
referred to as a blower or impeller, and an electric motor 18 coupled by a 
shaft 19 to the fan 17. Rotation of the shaft 19 by the motor 18 imparts 
rotation to the fan 17 to create a partial vacuum and the accompanying 
suction which draws air and foreign matter into the canister 14. The motor 
18 is powered by a power source such as batteries 20. A switch 21 is 
positioned on the upperside of the handle 16 for convenient engagement by 
means of the thumb of a person utilizing the vacuum cleaner 10. Operation 
of the switch 21 provides for the coupling of electric power from the 
batteries 20 to the motor 18 for activation of the motor 18. Electric 
wiring 22 connects the batteries 20 by the switch 21 to the motor 18. 
Referring to FIG. 2, the canister 14 incorporates a nozzle 23 which opens 
into a storage chamber 24. The storage chamber 24 is used for the 
collection of any liquid and dirt which may be drawn by suction or vacuum 
into the vacuum cleaner 10. The canister 14 is removably attached to the 
forward end of the housing 12 by means of a latch member 25 or the like. 
Referring to FIG. 3, the canister 14 includes a generally rectangular 
window portion 26 formed on the top or upper forward surface thereof. The 
canister 14 has a generally opaque or cloudy appearance. The window 
portion 26 is substantially clear or transparent to allow the operator to 
visually see the liquid and/or dirt entering the storage chamber 24. The 
window portion 26 is formed with a wall thickness less than the wall 
thickness of the remaining portion of the canister 14. Preferably, the 
window portion 26 has a wall thickness of 1.5 mm while the remaining 
portion of the canister 14 has a wall thickness of 2.5 mm. Also, the 
window portion 26 has a high polish on both sides of its wall. The 
remaining portion of the canister 14 is textured and tinted in color to 
further provide the window portion 26 with its transparent effect. 
When the vacuum cleaner 10 is in an upright operative position, the window 
portion 26 allows the operator to determine the amount of liquid and/or 
dirt in the storage chamber 24 of the canister 14. The rearward end of the 
window portion 26 acts as a fill line such that no further liquid and/or 
dirt should enter the canister 14 to prevent overfilling of the storage 
chamber 24. 
Within the canister 14, a filter assembly 27 according to the present 
invention is removably disposed. The filter assembly 27 comprises a filter 
housing, generally indicated at 28, having a deflecting surface 29 to 
deflect any incoming liquid which flows from the nozzle 23 away from the 
flow of the air stream, and a filter, generally indicated at 30, disposed 
within a generally rectangular cavity 32 formed in a filter housing 28. 
Referring to FIGS. 2, 4 and 7, the filter housing 28 includes openings 34 
which allow the air to flow from the storage chamber 24 into the interior 
of the filter housing 28. The openings 34 are located at positions to 
prevent the flow of liquid stored in the storage chamber 24 from flowing 
into them. The openings 34 allow air to flow from the intake nozzle 23 
into and through the fan 17. A passageway 36 is formed within the filter 
housing 28 and communicates with the openings 34 and the cavity 32. The 
filter housing 28 further includes an end flange 38 extending radially 
outwardly at one end or the opening of the cavity 32. A gasket or sealing 
ring 40 is removably molded about the end flange 38. Preferably, the 
gasket 40 is made of a thermo-elastic material which provides some 
flexibility and resiliency. The gasket 40 has an interior portion 41 
extending radially inwardly to partially cover the end flange 38 of a 
filter housing 28. The gasket 40 also has a sealing lip 42 extending 
radially outwardly from its outer surface 44 which frictionally engages 
the interior surface 45 of the canister 14 as illustrated in FIG. 2. When 
the sealing flange 42 is seated against the interior surface 45 of the 
canister 14 when the vacuum cleaner 10 is assembled, liquid is prevented 
from flowing past the filter housing 28 to the fan 17. 
Referring to FIGS. 4 and 7, the filter housing 28 also includes a pair of 
locking tabs 46 extending axially outwardly from the end flange 38. One of 
the locking tabs 46 is disposed on one side of the cavity 32 and the other 
locking tab 46 is disposed on the other side of the cavity 32. The locking 
tabs 46 are integrally formed with the end flange 38, both of which are 
made of a plastic material having some flexibility and resiliency. The 
free end 48 of the locking tabs 46 includes a protrusion 50 extending 
radially outwardly. 
Referring to FIG. 5, the filter 30 comprises a generally rectangular 
framework 52 made from a plurality of interconnected ribs. An air 
permeable filter member 54 is disposed within the framework 52 and secured 
thereto. The filter 30 also includes a sealing flange 56 extending 
radially outwardly from one end or the opening of the framework 52. A pair 
of slots 58 are formed in the sealing flange 56 of the filter 30 and 
aligned with the locking tabs 46 of the filter housing 28 such that the 
locking tabs 46 may be disposed in the slots 58 when the sealing flange 56 
seats against the gasket 40 to removably and positively secure the filter 
30 to the filter housing 28 to allow the filter 30 and filter housing 28 
to form an integral unit. 
The filter 30 further includes a plurality of alignment posts or pins 60 
extending axially outwardly from the sealing flange 56. Preferably, there 
is an alignment pin 60 for each side of the sealing flange 56. The 
alignment pins 60 contact a front face 62 of the housing 12 during 
assembly as illustrated in FIG. 2. 
Referring to FIG. 8, an alternate embodiment of the filter assembly 27 is 
shown. Preferably, the alignment pins 60 are formed on the front face 62 
of the housing 12 and extend axially outwardly toward the filter 30. It 
should be appreciated, however, that the alignment pins 60 may be formed 
as "bumps" or protrusions on the front face 62 of the housing 12. 
Referring to FIGS. 2 and 8, the canister 14 includes a pair of laterally 
spaced locator ribs 63 which operatively coact with the filter housing 28 
to prevent the filter housing 28 from being "pushed" or moved too far 
within the canister 14 toward the nozzle 23. The locator ribs 63 have a 
generally inverted "V" shaped configuration to form a point 64 which 
engages the filter housing 28 and resists or prevents further movement of 
the filter housing 28 inwardly into the canister 14. 
If the filter housing 28 and filter 30 are disposed within the canister 14, 
when canister 14 is attached to the housing 12, the alignment pins 60 will 
move the filter 30 and filter housing 28 inwardly into the canister 14 
until the locator ribs 63 prevent further movement of the filter housing 
28. The filter 30 continues to move within the cavity 32 of a filter 
housing 28 until the locking tabs 46 are disposed in the slots 58 of the 
sealing flange 56 to ensure that a proper seal is formed between the 
sealing flange 56 of the filter 30, interior portion 41 of the gasket 40 
and end flange 38 of the filter housing 28. Additionally, if the filter 30 
is secured to the filter housing 28 prior to assembly, the alignment pins 
60 will move the filter assembly 27 until positively located or stopped by 
the locator ribs 63 to properly seat the gasket 40 such that the sealing 
lip 42 frictionally engages the interior surface 45 of the canister 14. 
The filter 30 also includes a pull tab member 66 extending axially 
outwardly from the bottom of the framework 52. The pull tab member 66 is 
adapted to be grasped by the thumb and forefinger of a person and pulled 
axially to deflect the locking tabs 46 and separate the filter 30 from the 
filter housing 28 to permit removal of the filter 30 for cleaning or the 
like. 
In operation, during assembly of the vacuum cleaner 10, the locking tabs 46 
are deflected radially inwardly and disposed in the slots 58 of the 
sealing flange 56. Once the protrusion 50 is past the sealing flange 56, 
the locking tabs 46 return to their original undeflected position to 
prevent separation between the filter 30 and filter housing 28. The 
sealing flange 56 abuts the interior portion 41 of the gasket 40. The 
filter 30 is removably and positively secured to the filter housing 28 
such that the two form an integral unit or assembly 27. The filter 
assembly 27 is placed within the canister 14. The canister 14 is removably 
secured to the housing 12. When this occurs, the alignment pins 60 slides 
the filter assembly 27 within the canister 14 until located or stopped by 
the locator ribs 63. When the canister 14 is finally secured in place to 
the housing 12, the sealing lip 42 of the gasket 40 frictionally engages 
the interior surface 45 of the canister 14. 
The present invention has been described in an illustrative manner. 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. 
Obviously, many modifications or variations of the present invention are 
possible in light of the above teachings. Therefore, within the scope of 
the appended claims, the present invention may be practiced otherwise than 
as specifically described.