EP0269592A2

EP0269592A2 - Multi-layer outer and inner filter dust bag arrangement for a vacuum cleaner

Info

Publication number: EP0269592A2
Application number: EP87850336A
Authority: EP
Inventors: Dexter K. Lehman; Martin E. Wiese
Original assignee: Electrolux AB
Current assignee: Electrolux AB
Priority date: 1986-11-28
Filing date: 1987-11-05
Publication date: 1988-06-01
Also published as: EP0269592A3

Abstract

A dust bag arrangement for a vacuum cleaner comprises a dual paper throwaway filter dust bag (24) located within and spaced from an outer triple filter bag (20). The outer bag comprises an inner layer (30) of latex-impregnated filter material, a middle layer (26) in the form of a filter flannel batt such as fiberglass, and an outer layer (28) of a support cloth material, such as cotton cloth. The dirt laden air entering the inner layer of the dual layer throwaway paper filter bag passes through both layers and the space between the paper filter bag and the outer bag and penetrates through the triple-layer outer bag to be expelled into the room atmosphere in a cleaned condition. The filter bag arrangement traps and retains more than 99% of the dirt, debris and bacteria that goes into the vacuum cleaner.

Description

In the housekeeping of hospitals and other health care institutions it is important that sanitary conditions are meticulously maintained. Furthermore, it is necessary to maintain the hospital bacteriologically clean to the greatest extent possible. It is therefore important that a very efficient cleaning device be utilized to trap all bacteria drawn into the machine and the machine must not contaminate the atmosphere by exhaust turbulence. A number of vacuum cleaning machines and methods have been used prior to the present invention in hospitals and the like for removing minute dirt and dust particles from air streams. However, in order to satisfy the sanitary requirements of hospitals and other health institutions, at least 99% of the particulate material should be trapped in the filter bag while maintaining a satisfactory air flow rate through both the air paper dust bag and the air pervious outer bag. A vacuum cleaner machine of the type shown in U.S. Patent No. 3,971,643 to Hufton has proved to be less than ideal, and, in addition, the present invention constitutes a further improvement over U.S. Patent 4,116,648 to Busch.
It is an object of the present invention to provide a filtering system for a suction type vacuum cleaner for use in hospitals and other health institutions, which traps and retains more than 99% of the bacteria drawn into the machine and still maintains itself as an efficient operating vacuum cleaning device.
It is a principle feature of the present invention to provide a multi-layer outer filter bag assembly as well as utilizing a disposable two-layered inner filter bag that removes both large and minute particles of dust and dirt from a moving air stream.
It is a further object of the present invention to provide a filtering system with an extremely high efficiency that provides an efficient barrier for preventing the re-introduction of particulate matter of 0.3 micron diameter or larger into the atmosphere air present in the room.
It is another object of the present invention to provide a suction type vacuum cleaner which has low noise characteristics that make it suitable for hospital applications.
It is another oject of the present invention to provide a filter bag system for an upright vacuum cleaner which has an outer bag provided with triple filtration for bacteria control in a medically aseptic environment, while substantially preventing harmful bacteria from being passed through the system to thereby become airborne.
It is a further feature of the present invention to provide a topfill, multi-layer throwaway paper dust bag for the present sanitary vacuum cleaner.
In order that the present invention may be more clearly understood, it will now be disclosed in greater detail with reference to the acoompanying drawings, wherein:

Fig. 1 is a rear perspective view of an upright vacuum cleaner showing both an inner throwaway bag and an outer permanent cloth bag constructed in accordance with the teachings of the present invention;
Fig. 2 is an enlarged sectional view taken along the lines 2-2 of Fig. 1;
Fig. 3 is a cross sectional view taken along the lines 3-3 of Fig. 2; and
Fig. 4 is a sectional view taken along the lines 4-4 of Fig. 2.

Referring to Fig. 1, an upright vacuum cleaner of the type which is well known is shown, and is referred to generally by the reference numeral 10. The vacuum cleaner comprises a base 12 supported on a plurality of wheels 14 and is provided with a generally vertically disposed handle 16. The wheels facilitate the movement of the vacuum cleaner over the surface to be cleaned and a motor driven fan (not shown) is mounted in housing 18 on the base 12. The fan operating within the housing provides a suction or a vacuum which is necessary for picking up dust and dirt from a rug or carpet to be cleaned.
The upright vacuum cleaner is provided with an outer filter bag referred to generally by the reference numeral 20, and has a rear opening capable of being opened and closed by means of a zipper fastener 22. An air-impervious inlet tube 21 connects an inner throwaway paper filter bag 24 to the discharge outlet of the vacuum cleaner. Consequently, the air being discharged from the motor driven fan is directed into the interior of the throwaway dust bag.
As seen in Fig. 2, the inner throwaway paper dust bag which is installed over the throat of the inlet tube is for trapping large particles of dirt and debris, with respect to the outer paper filter. The outer paper filter layer is designed to trap minute particles which are airborne and conducted through the paper filter bag arrangement. The dual filter paper dust bag is spaced within an outer filter bag arrangement which is a triple-layer bag in which the inner layer is constituted of a latex-impregnated filter material, and the middle layer is a filter batt, such as fiberglass, while the outer layer is constituted of a support cloth material, which may be a cotton cloth having a thread count that permits the escape of air through its interstices. Thus, a two-layer throwaway paper bag is placed within the three-layer outer filter bag assembly.
Fig. 3 is a cutaway view showing the triple-layer outer bag assembly in a stepped form in which the fiberglass or flannel batt filter 26 is shown positioned between the outer cloth bag 28 which is air pervious, and the innermost latex-impregnated filter 30.
In Fig. 4 the two-layer paper throwaway bag filter is shown in which the inner layer 32 is illustrated as secured to the outer layer 34.
As seen in Fig. 2, the dirty air stream passes through an air impervious tube 21 (not shown) and enters the space 36 within the dual-layer paper filter bag showing layers 32 and 34. The contaminated air passes through the paper layers 32 and 34 thereby impacting and trapping a good deal of the dirt, debris and bacteria, and then the air stream passes into air space 38 located between the dual paper filter and the triple-layer outer bag assembly, and thereafter penetrates through the triple-layer outer bag assembly constituting layers 30, 26 and 28 to thereby be propelled into the atmosphere in a cleaned condition, leaving behind the bacteria, dirt and debris that remains impacted on the layer of the triple outer bag assembly.
It is submitted that the present filter arrangement for a vacuum cleaner meets the filter system criteria required in hospitals and other health care facilities, and it is to be noted that the present filtering system has an efficiency in the order of 99.94%, and therefore provides an efficient barrier for preventing the re-introduction of particulate matter that has been sucked up from the floor of the building from beeing expelled into the atmosphere room air. Furthermore, the above-described filter bag system, together with a highly efficient vacuum system, makes the present arrangement suitable for hospital or other health institution applications.
While this invention has been disclosed and described with reference to a single embodiment, it is apparent that variations and modifications may be made therein within the true spirit and scope of the invention as defined in the following claims.

Claims

1. A multi-layer filter bag arrangement for an upright vacuum cleaner apparatus of the type used in hospitals and other health care facilities, said vacuum cleaner having an air discharge outlet, characterized in that said filter bag arrangement is provided with an inner two-layer disposable pater bag (24) and an outer triple-ply filter bag (20), the latter including an inner layer (30) of filter material, an intermediate filter batt layer (26) and an outer layer (28) of support cloth material, whereby air flows from said air discharge outlet through said two-layer paper bag and through said inner, intermediate and outer layers of said triple-ply outer filter bag to the room atmosphere in a cleaned condition whereby dirt, dust and bacteria remains impacted on the layers of said filter bag arrangement.

2. A multi-layer filter bag arrangement as claimed in claim 1, characterized in that said intermediate layer (26) of said outer filter bag (20) is a batt material of fiberglass.

3. A multi-layer filter bag arrangement as claimed in claim 1, characterized in that said inner layer (30) of said triple-ply outer filter bag (20) is fabricated of a latex-impregnated material.

4. A multi-layer filter bag arrangement as claimed in laim 1, characterized in that said dirt-laden airstream traverses at least five separate layers of filters arranged concentrically in order to expell clean air to the room atmosphere.