GB2150014A

GB2150014A - Vacuum cleaner nozzles

Info

Publication number: GB2150014A
Application number: GB08428956A
Authority: GB
Inventors: Hans Wessel
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-11-23
Filing date: 1984-11-16
Publication date: 1985-06-26
Also published as: NL8401109A; IT1176035B; DE3342321A1; IT8420518A0; FR2555037A1; GB8428956D0

Abstract

A thread lifting device fitted adjacent a nozzle suction orifice is in the form of a strip (1,6 and 7) and is arranged transversely to the normal direction of movement with bristles (2,5 and 9) which slope towards the orifice at an angle in the range 25 to 35 DEG to the vertical, assuming the nozzle is cleaning a horizontal surface. The bristles on a backing strip of polyamide 6.6, are of circular section with a diameter in the range 0.2 to 0.3 mm. <IMAGE>

Description

SPECIFICATION Improvements relating to vacuum cleaner nozzles The invention relates to vacuum cleaner nozzles and is concerned with thread lifting devices which are often secured adjacent the suction orifice.

Such thread pickups or thread lifters can be arranged in front of and/or behind the suction orifice in relation to the usual direction of motion over a surface. They are generally in the form of brushes whose bristles are set at a slant, pointing towards the suction orifice.

Often they are spring-mounted or have means for adjusting their amount of downward projection depending upon the depth of the pile being cleaned. They may be in single strips, or in rows, continuous or with gaps, or even in separate bundles of bristles. Thread lifters can also be constructed of strips of elastic material such as rubber, with smooth or profiled edges, in the style of a comb, or with studs.

There are also thread lifters of synthetic thermoplastics material with a brushlike structure formed by injection-moulding. However, the bristles are generally too stiff and their action too harsh. Dirt accumulation is often substantial so that they become ineffective, and the force required to push the vacuum cleaner nozzle is considerably increased.

Thread lifters in a fabric resembling a pile carpet are inadequate: the pile is too straight and there is no self-cleaning. They are prone to premature dirt accumulation and are not sufficiently rigorous in their action.

Thread lifters made from a slanting brush velour textile fabric are much better, but in order to keep the pushing force within reasonable limits, there has to be a restriction in their working widths, usually below 60 to 70 mm.

There are two tests which are used to assess the efficiency of thread lifters.

In the first test, two synthetic viscous flocks, such as carded cotton wadding, are applied to a test surface 200 mm long and with a width determined by the working width of the nozzle or appliance + 50 mm. The material is worked into the surface by a rake operated lengthwise and across. The nozzle is then moved in a straight line centrally over the test surface.

The recognizable cleaned width is evaluated in millimetres and divided by the number of forward and backward strokes taken to clear it completely of threads, any fibres adhering to the nozzle being regarded as having been removed. The higher the resultant number, the better is the thread lifter in this mode of use.

In the second test, 95 swabs are applied in a staggered fashion to each of two test carpets (one being 100% nylon, the other being 100% wool velour), and are then rolled in with steel rollers. The test surface is 700 X 1000 mm.

Cleaning is then carried out by moving the nozzle in zig-zag fashion over such surface.

The time required for cleaning, including the time required for removing any cotton wadding sticking to the nozzle, is evaluated in seconds. Under 36 sec. is very good, and more than 180 sec. is very inefficient.

It is very difficult to find a thread pickup which performs well in both tests. The 60-70 mm wide thread lifters of slanting brush velour referred to above generally only achieve an inefficient rating in the first test mainly because of their small width. The brush velour requires an unacceptably high pushing force if made any wider.

The aim is therefore to find a thread lifter which, when fitted to a vacuum cleaner nozzle, renders that nozzle efficient on a wide variety of textile floorings in normal commercial use. Thus it should work equally well with deep pile, short pile and looped fabrics, fully or part synthetic materials and also natural materials such as wool velour; it should also not leave behind any traces of dirt on sensitive fabric or dark fabrics of uniform colour.

According to the present invention there is provided a thread lifter for a vacuum cleaner nozzle comprising a support strip from which project bristles of a diameter in the range 0.2 to 0.3 mm and with an incline in the range 25 to 35 to the normal to the strip, the slope being towards the nozzle orifice when the strip is secured adjacent thereto.

The bristle thickness is preferably 0.24 mm and the incline 30 .

The support strip may be a woven band into whose weave portions of the bristles are incorporated. Alternatively, the bristles may be integrally moulded with the support strip, or the support strip may be of a thermoplastics material in which the bristles are anchored. This may be done by adhesive or welding.

The height of the tips is the bristles above the strip is preferably in the range 2 to 2.5 mm, 2.2 mm being considered best.

Generally, the bristles will be in rows, with a spacing, normal to the bristle incline, in the range 2.5 to 3.5 mm, with 3 mm being the optimum.

The preferred material for the bristles is polyamide 6.6.

For a better understanding of the invention some embodiments will now be described, by way of example, with reference to the accompanying drawing, in which: Figure 1 is a cross-section of a thread lifter of woven construction, Figure 2 is an end view of a thread lifter of injection-moulded plastics material, Figure 3 is a cross-section of a thread lifter with bristles embedded in a support strip, and Figure 4 is a perspective view of a thread lifter.

The thread lifter of Figure 1 comprises a woven support band 1 with bristles incorporated into the weave. They slope in the direction of the arrow 3, towards the nozzle orifice when the band is fitted, and are in pairs, being the limbs of a U-shaped member whose central base portion 4 is embedded in the band 1. The bristles are of circular section with a diameter in the range 0.2 to 0.3 mm, 0.24 mm being particularly suitable. The incline of the bristles 2 to the normal to the band is between 25 to 35 , the optimum value of having been found to be 30 . The height H of the tips of the bristles above the band 1 is in the range 2 to 2 5 mm, 2.2 mm having proved to be most effective. The spacing A of the two bristles 2 normal to their incline is 2.5-3.5 mm, with 3 mm being considered best.Particularly with the preferred dimensions, such a lifter is most efficient at picking up threads and does not require a substantial effort to push it over almost any surface.

The same dimensions and general arrange.

ment apply to Figure 2, but here bristles 5 are integrally moulded with a backing strip 6, the material preferably being polyamide 6.6.

In Figure 3 the dimensions and general arrangement are again similar, but here a support strip 7 of thermoplastics material has bores 8 whose size and incline correspond to those of bristles 9. These are inserted in the bores and either stuck by adhesive to the underside 10 of the strip, which may be locally countersunk as shown, or welded to it.

In order to ease fixing any of the thread lifters described to the nozzle body, a tab 11 on which there are no bristles is provided at both ends of the strip or band, as indicated in Figure 4. Also on the left-hand side, this Figure shows bristles 12 with those of one row aligned behind those of the other row, with reference to the direction of slope, while on the right-hand side bristles 13 of one row are staggered with respect to bristles of the other row. Both arrangements are possible.

It is assumed that the strip is fixed to an under surface of the nozzle which is horizontal when the nozzle is cleaning a horizontal surface. The bristles will then be between 25 to 35 to the vertical. However, if the strip is to be fitted to an angled surface, the bristles will have their angle range correspondingly altered with respect to the strip to keep within the specified range to the vertical.

Claims

1. A thread lifter for a vacuum cleaner nozzle comprising a support strip from which project bristles of a diameter in the range of 0.2 to 0.3 mm and with an incline in the range 25 to 35 to the normal to the strip, the slope being towards the nozzle orifice when the strip is secured adjacent thereto.

2. A thread lifter as claimed in Claim 1, wherein the bristle thickness is 0.24 mm.

3. A thread lifter as claimed in Claim 1 or 2, wherein said incline is 30 .

4. A thread lifter as claimed in Claim 1.2 or 3. wherein the support strip is a woven band into whose weave portions of the bristles are incorporated.

5. A thread lifter as claimed in Claim 1,2 or 3, wherein the bristles are integrally moulded with the support strip.

6. A thread lifter as claimed in Claim 1.2 or 3, wherein the support strip is of a thermoplastics material in which the bristles are anchored.

7. A thread lifter as claimed in Claim 6, wherein the bristles are anchored by adhesive.

8. A thread lifter as claimed in Claim 6, wherein the bristles are anchored by welding.

9. A thread lifter as claimed in any preceding claim, wherein the height of the tips of the bristles above the support strip is in the range 2-2.5 mm.

10. A thread lifter as claimed in Claim 9, wherein said height is 2.2. mm.

11. A thread lifter as claimed in any preceding claim, wherein the bristles are in rows.

12. A thread lifter as claimed in Claim 11.

wherein the row spacing, normal to the bristle incline, is in the range 2.5-3.5 mm.

13. A thread lifter as claimed in Claim 12, wherein said spacing is 3 mm.

14. A thread lifter as claimed in any preceding claim, wherein said bristles are of polyamide 6.6.

15. A vacuum cleaner nozzle with a thread lifter as claimed in any preceding claim fitted adjacent the suction orifice.