VACUUM CLEANER HOSE

Abstract: A vacuum cleaner hose comprising a flexible shell of plastics material which is provided with one slectric wire or several wires secured to the shell all along their length. The electric wire (15) comprises a core of soft non-conductive material about which one filament or several filaments of conductive material are helically wound.

Description: Vacuum cleaner hose This invention relates to a vacuum cleaner hose comprising a flexible shell of plastics material which is provided with one electric wire or several wires secured to the shell all along their length- Hoses of the above type are previously known and are used when it is desired to operate the vacuum cleaner by means of control devices which are disposed on a handle connected to the hose, for instance in order to start or stop the vacuum cleaner motor or to change the speed of the motor. This type of hoses can also be used to transmit electric energy from the motor fan unit to an electrically driven tool, for instance a brush roller, in a nozzle which is connected to the hose. In certain applications the wire embedded in the hose also serves the purpose of forming a reinforcing element preventing radial deformation of the hose. For instance U.S. patent 4,203,476 shows a hose which is built up by a strip of plastics, one half of the strip in adjacent turns overlapping the other half. The strip has a ridge facing the outside of the hose, and the side of the ridge facing the interior of the hose is provided with a groove in which a reinforcing electric wire is inserted, the groove being covered by the underlying part of the strip. A drawback of this type of arrangement is that the hose will be very stiff, depending on the overall double thickness of the strip and the use of a homogenous single wire. This stiffness easily causes damages to the hose after it has been bent several times. Another drawback is that the electric wire is placed in the outer parts of the hose, i.e. the parts which are most exposed to mechanical strain, and this causes a risk for the wire becoming uncovered in case the hose is damaged. A further example of a hose of the above type is described in German OS 30 01 529. The hose described in this publication is built up by a plastics strip of a particular shape so as to form a cavity in which an electric wire is inserted in such a way that it is freely movable. This movability is achieved because one edge of the strip has several wall portions which after applying the wire on the strip will enclose the wire. The cavity forms a closed profile which makes the hose rigid in the radial direction. In order to make the hose flexible only the outer wall of the second, U-shaped, edge of the strip is glued to the close profile being created by the first edge. Thus, the two edge parts can move comparatively freely relative to one another. A drawback of this type of hose, in addition to the complicated shape of the strip and corresponding difficulties in the manufacture, is that the hose cannot withstand bending stresses to the desired extent. The object of this invention is to provide a hose which does not have the above drawbacks and this is achieved by the invention as defined in the following claims. An embodiment of the invention will now be described with reference to the accompanying drawing in which Fig. 1 is a perspective view of a vacuum cleaner with hose and Fig. 2 is a longitudinal section of the hose shown in Fig. 1. The vacuum cleaner shown in Fig. 1 comprises a hood 10 enclosing a motor fan unit and a dust bag. The hood is via a hose 11 and a connection 12 connected to a tubular shaft 13 having a nozzle 14 in its outer end. The hose 11 is provided with an electric wire 15 (Fig. 2) which connects a control means 16 on the connection 12 to an electric source via the electric means in the hood 10. The end of the hose 11 facing the hood can be provided with a connection, not shown, or with a device which is operated by induction in order to make it possible to easily remove the hose from the hood. The hose 11 comprises one strip or several strips 17 of plastics which are wound helically so that a first edge 18 of the strip overlaps the second edge 19 of the strip, the two edges being joined by a U-shaped part 20 which extends radially from the hose. The surface of the first edge 18 which faces the interior of the hose comprises a generally flat part 18a, whose outer end continues into an outer, short side wall 18b and whose inner end continues into an inner, longer side wall 18c. The surface 18d facing the outside of the hose is generally plane. The parts 18a, 18b and 18c together form a groove, whose side walls converge radially outwards. The second edge 19 comprises a ridge which is formed by a flat surface 19a continuing into an inner, short side wall 19b and an outer, longer side wall 19c. The surface 19d facing the interior of the hose is generally flat and forms together with a flat surface 19e at the outside of the hose a tongue 19f which continues into the U-shaped part 20. The flat surface 19a is divided by a recess 21 in which which the electric wire 15 is placed. The wire 15 is fixed to the recess 21 by means of glue 22 and in the same way the side walls 18b, 19b, 18c, 19c and the flat parts 18a and 19a, respectively, are fixed to one another. The wire 15 consists of several filaments which are twisted and/or helically wound about a core of non-conductive soft material. Preferably, the wire com¬ prises in known manner a comparatively thick core of synthetic material about which several metal filaments are twisted.

Claims: Claims 1. A vacuum cleaner hose comprising a flexible shell of plastics material which is provided with one electric wire or several wires secured to the shell all along their length, characterized in that the electric wire (15) comprises a core of soft non-conductive material about which one filament or several filaments of 5 conductive material are helically wound. 2. A vacuum cleaner hose according to Claim 1, characterized in that the flexible shell comprises one strip or several helically wound strips (17) whose edges (18,19) in adjacent turns overlap one another, at least one of the edge parts (18) having a recess (21) in which the wire (15) is placed. 103. A vacuum cleaner hose according to Claim 1 or Claim 2, characteriz¬ ed in that the wire (15) is fastened to the shell by a glue (22). 4. A vacuum cleaner hose according to any preceding claim, character¬ ized in that the strip or strips has a profile comprising a first and a second edge part (19 and 18, respectively) which are connected to one another by a U-shaped 15 intermediate part (20), the first edge part (19) comprising a ridge with a recess (21) to accomodate the wire or wires (15) whereas the second edge part (18) has a surface (18a) overlapping the ridge, the first and the second edge part being connected to one another along the entire overlapping surface. 5. A vacuum cleaner hose according to Claim 4, characterized in that 20 the second edge part (18) has a groove opening into the interior of the hose, the side walls (18b, 18c) of the groove converging radially outwards and the ridge of the first edge part (19) having side walls of corresponding shape. 6. A vacuum cleaner hose according to Claim 5, characterized in that one (18b) of the side walls of the groove has a radial extension which is less than 25 that of the other side wall (18c). 7. A vacuum cleaner hose according to any preceding claim, character¬ ized in that the U-shaped intermediate part (20) has a height which is about the same as the width of the edge parts (18,19). 8. A vacuum cleaner hose according to any preceding claim, character- 30 i z e d in that the core consists of synthetic fibres.

Inventors: LEETE MICHAEL WILLIAM, RICHARDSON RONALD IAN, LEETE, MICHAEL, WILLIAM, RICHARDSON, RONALD, IAN
Applicants: ELECTROLUX AB, AKTIEBOLAGET ELECTROLUX
Application year: 1985
Main classification: A47L9
IPC codes: A47L9