GB2049855A - A vacuum cleaner bag and duct assembly - Google Patents

Abstract

A vacuum cleaner bag and duct assembly has a rigid vacuum duct element (40), adapted to be coupled to the output port (43) of a vacuum cleaner (20), is coupled to a disposable porous bag (25) by way of a unitary duct element (47, 48) of a semi-rigid plastics material. The semi- rigid duct element has corrugations (48) at the portion thereof joining the rigid duct element (40), to impart flexibility. The rigid duct element (40) passes through and is secured sealingly to the porous outer vacuum cleaner bag (30). <IMAGE>

Description

SPECIFICATION A vacuum cleaner bag and duct assembly This invention relates to a vacuum cleaner bag assembly, and is particularly directed to improvements in the duct assembly employed for coupling the vacuum outlet of a vacuum cleaner to the inner disposable porous bag of such a cleaner.

In the upright type of vacuum cleaner, a vacuum cleaner body has wheels for movement along a floor, the body being pivotally connected to an upwardly extending handle. In such a vacuum cleaner, it is known for the vacuum duct of the cleaner body to be coupled to the inner disposable porous bag by way of a flexible duct. In order to protect the inner disposable bag, as well as to support it, an outer porous bag generally surrounds it, is suspended at its upper end from the handle, and has a lower hole through which the flexible duct sealingly extends. A closure on the outer bag gives access to the inner bag wherein dust is collected.

In such a vacuum cleaner the flexible duct is generally fabricated from a number of components.

A conventional construction is shown in Figure 1 of the drawings, wherein the body of the vacuum cleaner is indicated by 20 and a rigid coupling element for the flexible duct is indicated by 21. The rigid element 21 has a mounting flange 22 fixed to the body 20 by screws 23. In some uses this coupling is made so that it may be readily released by the user. The element 21 may be made of a conventional rigid plastics material.

Further, in conventional equipment, the inner porous bag 25 is releasably coupled to a generally rigid duct 26, which may also be of a plastics material. As an example, the free end of the duct 26 may have a peripheral groove 27 so that the opening in the bottom of the disposable bag 25 permits the duct 26 to be extended into the bag and a helical spring 28 to be fitted over the end of the bag and folded at the groove 27.

Further, the rigid coupling element 21 sealingly passes through the lower aperture in the porous outer bag 30 which supports and protects the inner bag. It is also necessary to employ a flexible coupling between the end of the rigid duct 26 and the rigid coupling element 21. This flexibility is required to simplify release of the inner bag as well as to reduce wear and abrasion of the bag in this region of the assembly. In the past, the flexible coupling was in the form of a flexible tube 35 of a further material, generally a farbric or flexible fabric sheet sewn or heat sealed into tubular form, and fitted over the adjoining ends of the rigid duct 21 and the rigid element 26.In order to hold the flexible tube 35 in position, a further groove 36 was provided in the lower end of the rigid element 26, and a twisted wire ring 37 was employed extending around the flexible tube 35 to hold it in contact with the rigid rigid element 26 at the groove 36. In this type of connection, a wire is generally manually wrapped around the flexible tube at the proper location, with the ends of the wire being twisted together effectively to reduce the inner dimension of the aperture defined thereby, in accordance with conventional practice.

A similar seal was provided between the flexible tube 35 and the rigid element 21, and the flexible tube 35 was also generally sewn or heat sealed to the outer bag 30, so that the same twisted wire ring 38 could be employed to hold the tube 35 in the bag 30 to the element 21, as shown in Figure 1.

While the above described assembly generally serves its intended function, the flexible tubes are subject to wear, and fabrication of the duct and bag assembly, including the outer bag, was inefficient and time consuming, hence increasing the cost of the equipment.

The invention is therefore directed to the provision of a bag duct assembly for a vacuum cleaner that largely overcomes the above disadvantages of conventional constructions.

According to this invention, there is provided a vacuum cleaner bag duct assembly having a first rigid vaccum duct end portion for connecting the assembly to a vacuum outlet of the cleaner, a second duct end portion for communicating with the interior of an inner vacuum cleaner bag, and a third flexible intermediate duct portion joining the said first and second portions, whereby the first duct portion may pass sealingly through a wall of an outer bag, the said second and intermediate portions comprising a unitary duct of a semi-rigid plastics material with the intermediate portion being convoluted, the free end of the intermediate portion being shaped to extend over the adjoining end of the said first portion. As a consequence, the -fabrication of a separate flexible intermediate tube is no longer required, and the life of this portion of the assembly is increased.The duct assembly of the invention may be made readily by automatic machinery.

The invention will now be described by way of example, with reference to the drawing, in which: Figure 1 is a part cross-sectional view of a portion of a known vacuum cleaner duct and bag assembly; Figure 2 is a part cross-sectional view of a portion of a vacuum cleaner duct and bag assembly in accordance with the invention; Figure 3 is an enlarged view of a duct of Figure 2, with the elements thereof extending linearly; and Figure 4 is a section on the plane VI-VI of Figure 3.

Referring to the drawing, the known arrangement of Figure 1, and its disadvantages, have been discussed above. The following disclosure is therefore directed to the arrangement in accordance with the invention as illustrated in Figures 2, 3 and 4. As in the known arrangement, a rigid duct element 40 is fixed to the vacuum cleaner body 20, by screws 23. Alternatively a quick release coupling may be provided between the rigid element 40 and the body. The rigid duct element 40 is preferably of a plastics material, for example polystyrene or ABS, and it may be made by conventional means for example injection moulding.The considerations for providing the element 40 with rigidity conform to those of the past, i.e. the requirements for firmly holding the bag structure to the vacuum cleaner body, and for providing an element which can be formed readily to extend sealingly through the lower aperture in the outer bag 30.

The rigid element 40 has a ridge 41 extending around its periphery, adjacent the open end 42 thereof, i.e. the end away from the mounting flange 43. A further ridge 44 also extends transversely of the element 40 spaced from the ridge 41.

The duct assembly in accordance with the invention is further composed of a semi-rigid element 46 which is a unitary plastics element, i.e.

formed as a single piece, of semi-rigid plastics material. This choice of material is necessary, since one end portion 47 thereof must have sufficient rigidity to be readily releasably coupled to the porous inner bag 25, while the other end portion 48 must be sufficiently flexible that the inner bag will be flexibly mounted at its lower end.

It has been found that blow moulding materials, for example ethylene vinyl acetate EVA, ethylene vinyl acetate, low density polyethylene, high density polyethylene, polypropylene, polyalamer, polyvinylchloride, krayton, hytrel, urethane and surlyn are suitable for this purpose.

The end portion 47 has a groove 50 extending transversely therearound adjacent the open end 51. This groove serves the same function as the groove 27 of the known structure illustrated in Figure 1, i.e. to permit releasable coupling between the inner bag 25 and-the duct element.

Thus, as in the arrangement of the prior art, Figure 2 illustrates an elastic annular element 28 in the form of a coil spring having its ends joined together, for holding the inner bag 25 onto the end portion 47. If desired, the extreme end of the end portion 47 may be inclined, as indicated at 52, further to simplify assembly of the inner bag on the end of the duct element.

The remainder of the rigid element 40 has generally straight lateral walls extending axially of the duct. This portion of the structure has adequately thick walls to withstand the suction of the cleaner, and is also adequately rigid that it will not collapse due to the forces acting thereon from the holding spring 28. The thickness may be for example about 0.109".

The other end portion 48 is flexible, for example by being provided with corrugations along its length as shown. This portion 48 has a reduced wall thickness, for example of 0.03", to enhance its flexibility without risking collapse as a result of the suction applied in use.

The open end of the duct portion 48 has an internal peripheral groove 55, Figure 3, for receiving the ridge 41 on the end of the rigid portion 40, Figure 2. The rigid portion 40 is not shown in Figure 3. This simplifies understanding of the invention, but does not represent an actual step in the formation of the bag and duct assembly, since the two plastics elements 40 and 46 are assembled prior to fixing of the outer bag to them.

The ridge 44 on the rigid element 40 may abut the and of the flexible duct portion 48, Figure 2, to inhibit forcing of the flexible duct over the rigid duct element 40 beyond a desired extent.

Immediately adjacent the open end of the duct portion 48 the lateral side walls thereof are generally straight, i.e. free of corrugations, in order to enable the open end of the duct portion 48 to be snapped over the open end of the rigid duct element 40, Figure 2.

To hold the outer bag on the duct assembly, Figures 2 and 3, a twisted wire may be wrapped around the bag, in the region between the ridges 41 and 44 of the rigid duct element 40. The twisted wire 56 is held in this position by a pair of spaced peripheral ridges 57 and 58, on opposite sides of the twisted wire 56.

As shown in Figure 4, in a preferred embodiment, the duct assembly is generally oval in cross-section. It will be apparent that this is a matter of design, and the invention is not limited to such configuration.

In the fabrication of the duct assembly, the rigid duct element 40 may be formed by injection moulding, or by other conventional process. The unitary semi-rigid element 46 may be formed conventionally by blowing material in a die to form a tube of the desired configuration, and then straightening the formed element to remove it from the injection moulding die. Such moulding of the elements may be effected-on automatic machines. Thereafter, the flexible duct portion may be snapped into position on the rigid duct element, with the duct assembly extending to the open end of the outer porous bag, the bag at this time being inside out. The wire 56 may then be assembled around the inside out outer bag at the proper location, and manually twisted for sealing and positive holding of the outer bag onto the duct assembly. The assembly is then completed by returning the outer bag to extend over the duct element 46, as it would be used.

It is apparent that the structure of the invention may be more readily, rapidly and economically fabricated than the assemblies employed in the past, and that the wear of the assembly is improved. There is much less wear resulting from abrasion, for example from gravel or other rough material that may be picked up by the vacuum cleaner. In addition, the bag and duct assembly is readily adaptable to the use of a porous plastics outer bag, that may be sealed together either from one or more plastics sheets.

Claims (10)

1. A vacuum cleaner bag duct assembly having a first rigid vacuum duct end portion for connecting the assembly to a vacuum outlet of the cleaner, a second duct end portion for communicating with the interior of an inner vacuum cleaner bag, and a third flexible intermediate duct portion joining the said first and second portions, whereby the first duct portion may pass sealingly through a wall of an outer bag, the said second and intermediate portions comprising a unitary duct of a semi-rigid plastics material with the intermediate portion being convoluted, the free end of the intermediate portion being shaped to extend over the adjoining end of the said first portion.

2. The assembly of claim 1 wherein the said free end is shaped to snap over the adjoining end of the said first portion.

3. The assembly of claim 2 wherein the said adjoining end has a first external peripheral ridge, and the said free end has an internal groove receiving the first ridge, and second and third spaced transverse outer ridges, whereby the outer bag may be fixed to the intermediate portion between the second and third ridges.

4. The assembly of claim 2 wherein the free end of the said second portion has a transverse groove for connecting to the inner bag.

5. The assembly of any preceding claim wherein the said first portion is of a plastics material.

6. The assembly of any preceding claim wherein the semi-rigid material is one of the following: ethylene vinyl acetate, low density polyethylene, high density polyethylene, polypropylene, polyalamer, polyvinylchloride, krayton, hytrel, urethane and surlyn.

7. A vacuum cleaner bag and duct assembly comprising a first rigid vacuum duct for connecting the assembly to the vacuum outlet of the cleaner, the rigid duct having a transverse external first ridge on one end, a semi-rigid plastics second duct having an internal groove on one end receiving the first ridge, and second and third spaced transverse ridges externally on the said one end of the second duct, the region of the second duct adjacent the said one end thereof having transverse corrugations to impart flexibility to the second duct, the other end of the second duct having substantially straight side walls in the axial direction, and an external transverse groove, an inner disposable bag having an aperture through which the said other end of the second duct extends, releasable securing means holding the inner bag in the said external groove in the said other end of the second duct, a porous outer bag having an aperture through which the said one end of the second duct extends, and nonreleasable holding means holding the outer bag adjacent the aperture therein between the second and third ridges, the outer bag being folded back upon itself in the region of the second and third ridges to enclose the inner bag.

8. The assembly of claim 7 wherein the said means holding the inner bag comprises a helical spring and the said means holding the outer bag comprises a twisted wire.

9. A vacuum cleaner having an assembly according to any of claims 1 to 8.

10. A vacuum cleaner bag duct assembly constructed and arranged substantially as herein described and shown in the drawing.