GB2323422A

GB2323422A - Coiled tubing

Info

Publication number: GB2323422A
Application number: GB9705940A
Authority: GB
Inventors: Geoffrey Martin Brewin
Original assignee: Vax Ltd
Current assignee: Vax Ltd
Priority date: 1997-03-21
Filing date: 1997-03-21
Publication date: 1998-09-23
Also published as: GB9705940D0

Abstract

A flexible suction hose for a cleaning appliance of the kind comprising a reservoir for a cleaning liquid and a cleaning head connected to such flexible suction hose, has loosely assembled thereon a length of tubing (10) made from a flexible plastics material and formed into a coil (12), for the supply of cleaning liquid from the reservoir to the clearing head, and the tubing (10) has within it a separate resilient member such as a spring coil (15) whereby the axial length of the coil (12) of tubing is resiliently extensible and contractible along the length of the hose to facilitate the connection of the tubing to the cleaning head when an extension tube is attached between the hose and the cleaning head. The resilient member (15) is wire of stainless steel or coated.

Description

Title: "Coiled tubing" Description of Invention This invention relates to coiled tubing, particularly tubing made of relatively soft plastics materials such as used in cleaning apparatus of the kind for cleaning a surface by the application of a cleaning liquid to the surface and removal of the cleaning liquid from the surface by suction, in order to convey such cleaning liquid from a reservoir in a body of the appliance and along the length of flexible suction hose to a cleaning head at the free end of such hose.

In some cases the cleaning head may be attached directly to a fitting at the end of the flexible cleaning hose, particularly where the cleaning head is of a type intended for use on upholstery or curtains. More usually, a rigid extension tube is connected to such fitting at the end of the flexible hose and the cleaning head is releasably connected at the end of such extension tube, particularly where the cleaning head is of a kind intended for application to the floor.

Interchangeable cleaning heads may be provided whereby the same cleaning apparatus can be used for conventional dry suction cleaning or for wet process cleaning as and when required.

Various arrangements have been proposed for the physical association of the liquid supply tubing with the flexible suction hose, including arranging the tubing within the hose, with an appropriate connector at the end fitting; arranging the tubing in a substantially non-detachable manner externally of the suction hose; arranging the tubing for releasable assembly with the suction hose. However, such known arrangements do not cope satisfactorily with the variable length of connection between the body of the appliance and the cleaning head according to whether one or more extension tubes are attached to the free end of the flexible hose.

One way in which it has been attempted to cope with this variation is to form the tubing into a loose coil which is wound around the flexible hose such that the axial length of the coil can be expanded and contracted over the length of the flexible hose and any extension tube connected thereto. However, when the tubing is made of the relatively soft plastics materials conventionally employed, the coil has relatively little elasticity and does not easily contract onto the length of the flexible hose, contraction being hindered by the corrugated nature of the external surface of the hoses currently in use. Even if the tubing, when new, exhibits a degree of resilience sufficient to hold the coil of tubing in an axially contracted state on the flexible suction hose, in practice, particularly if the cleaner is used with warm cleaning solution, the coil soon loses such elasticity.

In order to obviate this problem, in accordance with the invention we provide a length of tubing made from a flexible plastics material and formed into a coil, wherein the tubing has within it a separate resilient member whereby the axial length of the coil is resiliently extensible and contractible.

The resilient member typically comprises a coil of resilient material, the turns of which are dimensioned in correspondence to the turns of the coil of tubing.

The resilient member may be formed from any appropriate metallic wire. Preferably, stainless steel is used, but alternatively it would be possible to use any other material which is relatively inert with respect to the liquid for which the tubing is intended to be used. Alternatively, the resilient member may be made of a wire of appropriate resilient material sheathed in a protective coating.

Whilst such tubing in accordance with the invention may have applications other than in connection with the delivery of cleaning liquid from a reservoir to a cleaning head in a cleaning appliance of the type previously mentioned, from a further aspect of the invention we provide a cleaning appliance of the kind comprising a flexible suction hose to which a cleaning head is connected, a reservoir for a cleaning liquid, and a length of tubing extending from said reservoir to said cleaning head, wherein said tubing is made from a flexible plastics material and is formed into a coil which extends loosely around such suction hose, and wherein the tubing has within it a separate resilient member whereby the axial length of the coil is resiliently extensible and contractible along the length of the hose.

In accordance with a further aspect of the invention we provide a flexible suction hose for a cleaning appliance of the kind comprising a reservoir for a cleaning liquid and a cleaning head connected to such flexible suction hose, wherein said hose has loosely assembled therein a length of tubing made from a flexible plastics material and formed into a coil, wherein the tubing has within it a separate resilient member whereby the axial length of the coil is resiliently extensible and contractible along the length of the hose.

These and other aspects of the invention will now be described by way of example with reference to the accompanying drawings wherein: FIGURE 1 illustrates a coil of tubing in accordance with the invention; FIGURE 2 illustrates a suction hose for a vacuum cleaner having a coil of tubing in accordance with the invention assembled thereon; and FIGURE 3 illustrates the suction hose of Figure 2 with an extension tube connected at its free end, and the coil of tubing extended over such extension tube.

As shown in Figure 1, the invention comprises a length of tubing 10 formed from a relatively soft plastics material such as polyethylene, polypropylene or nylon so as to be substantially flexible. Typically, the internal diameter of the tubing may be of the order of 5 mm, and the wall thickness of the order of 1 mm, where the tubing is to be used for the supply of a cleaning liquid from a reservoir in a cleaning apparatus to a cleaning head which is connected to the apparatus by means of flexible suction hose in conventional manner.

The tubing 10 is formed into a coil 12 which is so dimensioned as to fit loosely over such a suction tube, typically the turns of the coil having a radius of curvature of the order of 5 cm. The overall length of the tubing may typically be between 3 and 4 metres.

In accordance with the invention, the tubing contains a coil of spring wire 15 such that the coil 12 of tubing then is resiliently extensible and assumes a natural axial length of approximately 1 to 1.5 metres, but can be stretched longitudinally up to, say, 2.5 metres.

The spring coil 15 may be formed of any appropriate resilient wire, particularly stainless steel or any other appropriate material which will be substantially non-reactive relative to the cleaning liquid to be used. Alternatively, the wire may be covered by a protective sheath of an appropriate plastics material in order to isolate it from the liquid flowing in the tubing.

The coil tubing 12 as illustrated in Figure 1 may be formed in various ways. For example, the tubing 10 may be formed by extrusion, and the wire 15 may be introduced at the point of extrusion, the tubing 10 containing the wire then being formed into large, non-resilient coils for storage purposes, lengths of the tubing then being withdrawn from such storage coil and passed between rollers so as to impart the require curvature to the wire in order to form the tubing 10 into the resilient coil 12, which is then severed into individual lengths.

Alternatively, pre-cut lengths of wire may be introduced into pre-cut lengths of tubing before they are formed into a resilient coil in the same manner.

Figure 2 shows the coil 12 of tubing 10 as loosely assembled on a flexible vacuum cleaner hose 20. At one end, the tubing 10 is provided with a fitting 17 whereby it is coupled to a liquid outlet duct on the main body of the cleaning appliance, whereas at the other end it is provided with a nozzle 18 whereby it may be plugged into a corresponding orifice on a cleaning head (not shown), mounted on an end fitting 22 at the free end of the hose 20.

In Figure 3, the hose 20 has connected thereto a rigid tubular extension 25 which itself terminates in an end fitting 26 for the reception of the cleaning head, the coil 12 of tubing 10 being stretched over the extension tube 25 so as to reach the cleaning head.

When the extension tube 25 is to be removed, the tubing 10 is unplugged from the cleaning head and the coil 12 allowed to contract, by virtue of the coil spring 15, to its natural length over the suction hose 20, so that the extension tube 25 can be removed from the end fitting 22 of the suction hose.

Claims

CLAIMS:

1. A length of tubing made from a flexible plastics material and formed into a coil, wherein the tubing has within it a separate resilient member whereby the axial length of the coil is resiliently extensible and contractible.

2. A length of tubing as claimed in Claim 1 wherein the resilient member comprises a coil of resilient matelial, the tums of which are dimensioned in correspondence to the tums of the coil of tubing.

3. A length of tubing as claimed in Claim 1 or Claim 2 wherein the resilient member is formed from a metallic wire.

4. A length of tubing as claimed in Claim 3 wherein the resilient member is folmed from stainless steel wire.

5. A length of tubing as claimed in Claim 3 wherein the wire is sheathed in a protective coating.

6. A flexible suction hose for a cleaning appliance of the kind comprising a reservoir for a cleaning liquid and a cleaning head connected to such flexible suction hose, wherein said hose has loosely assembled thereon a length of tubing made from a flexible plastics material and fowled into a coil, wherein the tubing has within it a separate resilient member whereby the axial length of the coil is resiliently extensible and contractible along the length of the hose.

7. A cleaning appliance of the kind comprising a flexible suction hose to which a cleaning head is connected, a reservoir for a cleaning liquid, and a length of tubing extending from said reservoir to said cleaning head, wherein said tubing is made from a flexible plastics material and is foimed into a coil which extends loosely around such suction hose, and wherein tlle tubing has within it a separate resilient member whereby the axial length of the coil is resiliently extensible and contractible along the length of the hose.