EP2042072A2

EP2042072A2 - Vacuum cleaner

Info

Publication number: EP2042072A2
Application number: EP08253105A
Authority: EP
Inventors: Hitoshi Suzuki
Original assignee: Toshiba Corp; Toshiba Consumer Electronics Holdings Corp; Toshiba Home Appliances Corp
Current assignee: Toshiba Corp; Toshiba Lifestyle Products and Services Corp
Priority date: 2007-09-28
Filing date: 2008-09-23
Publication date: 2009-04-01
Anticipated expiration: 2028-09-23
Also published as: EP2042072A3; EP2042072B1

Abstract

An upstream-side hose 11 is in the contracted state when in the natural length and can be stretched by an external force, and, at least when in the contracted state, can be accommodated in an extension pipe unit 6. The upstream part of the upstream-side hose 11 is connected to the downstream part of the extension pipe unit 6. A downstream-side hose 12, of which the contractive property when exposed to a negative pressure from a motor fan is smaller than that of the upstream-side hose 11, is connected to the downstream part of the upstream-side hose 11. A securing means 33 that is capable of maintaining the upstream-side hose 11 in the extended state is provided. When cleaning is performed, the securing means 33 maintains the upstream-side hose 11 in the extended state. Ease of cleaning is facilitated by preventing contraction of the upstream-side hose 11 due to negative pressure from the motor fan 2 or other force during cleaning. When stowing away the vacuum cleaner, the entire length of the pipe assembly 4 can be minimized by stowing the upstream-side hose 11 in the contracted state in the extension pipe unit 6, enabling the vacuum cleaner to be stowed easily and neatly.

Description

FEILD OF THE INVENTION

The present invention relates to a vacuum cleaner provided with a pipe assembly to be communicatively linked with the intake side of a motor fan.

BACKGROUND OF THE INVENTION

One of conventionally known examples of vacuum cleaners is disclosed in Japanese Laid-open Patent Publication No. 2006-255305 . The vacuum cleaner described in Japanese Laid-open Patent Publication No. 2006-255305 has a cleaner main body that incorporates a motor fan. A pipe assembly is removably connected to the cleaner main body so as to communicate with the intake side of the motor fan. The pipe assembly has a slender, cylindrical hose unit to be connected to the cleaner main body; a slender, cylindrical extension pipe unit to be connected to the distal end of the hose unit; and a floor brush that is adapted to be connected to the distal end of the extension pipe unit and serve as a suctioning member. The hose unit is formed of a flexible material, such as synthetic resin, to have a pleated shape and can be bent in the axial direction. When the vacuum cleaner is stowed away, the cleaner main body is stood upright, and a part of the extension pipe unit is hooked in a recess formed at the lower part of the cleaner main body.
Typically, the hose unit of a vacuum cleaner having a structure described above is substantially long to facilitate the cleaning operation and has to be wound around the extension pipe unit or the cleaner main body when the vacuum cleaner is stowed away. This results in difficulties in stowage of the vacuum cleaner, such as not being unattractive in appearance and occupying an excessively large space.
In order to solve these problems, an example of a vacuum cleaner that can be stowed more easily and neatly is disclosed in Japanese Laid-open Patent Publication No. 2006-326093 . The hose unit of this vacuum cleaner is elastic and in a contracted state when in its natural length so that the hose unit is in a contracted state when stowed.
However, when performing cleaning with this vacuum cleaner, it is necessary to keep holding the hose unit in the extended state against the constant contracting force. Therefore, should the floor brush become stuck to the surface being cleaned, in other words the floor surface, due to a negative pressure from the motor fan or encounter other similar circumstances resulting in an increased degree of vacuum, the hose unit becomes contracted by the negative pressure and impairs cleaning efficiency.
In order to solve the above problems, an object of the invention is to provide a vacuum cleaner that can be conveniently and neatly stowed away as well as facilitate ease of performing cleaning.

SUMMARY OF THE INVENTION

A vacuum cleaner according to the present invention includes a pipe assembly to be connected to the cleaner main body so as to communicate with the intake side of the motor fan. The pipe assembly comprises an extension pipe unit, an upstream-side hose, a downstream-side hose, and a securing means. At least an upstream part of the upstream-side hose is connected to the extension pipe unit. The upstream-side hose is in the contracted state when in the natural length and can be extended by an external force, and, at least when in the contracted state, can be accommodated in the extension pipe unit. The downstream-side hose is connected to the downstream part of the upstream-side hose and has contractive property that is smaller than that of the upstream-side hose when exposed to a negative pressure from the motor fan. The securing means is capable of maintaining the upstream-side hose in the extended state. When cleaning is performed, the securing means maintains the upstream-side hose in the extended state. Ease of cleaning is facilitated by preventing contraction of the upstream-side hose due to negative pressure from the motor fan or other force during cleaning. When stowing away the vacuum cleaner, the entire length of the pipe assembly can be minimized by stowing the upstream-side hose in the contracted state in the extension pipe unit, enabling the vacuum cleaner to be stowed easily and neatly. The terms "upstream" and "downstream" mentioned above as well as in the explanation hereunder respectively refer to "upstream" and "downstream" with respect to the direction in which the air is suctioned from the outside into the cleaner main body.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a partially cutaway perspective view of a pipe assembly of a vacuum cleaner according to an embodiment of the present invention, illustrating the state in which the pipe assembly is contracted.
Fig. 2 is a partially cutaway perspective view of the aforementioned pipe assembly, illustrating the state in which hoses of the pipe assembly are contracted.
Fig. 3 is a partially cutaway perspective view of the aforementioned pipe assembly, illustrating the state in which a downstream-side hose of the pipe assembly is extended.
Fig. 4 is a partially cutaway perspective view of the pipe assembly, illustrating the state in which the aforementioned hoses are extended.
Fig. 5 is a perspective view of the pipe assembly in the contracted state.
Fig. 6 is a perspective view of the pipe assembly in the fully extended state.
Fig. 7 is a perspective sectional view of the pipe assembly secured in the contracted state by a first lock means thereof.
Fig. 8 is a perspective sectional view of the pipe assembly, illustrating the state in which the pipe assembly is released from the contracted state secured by the aforementioned first lock means.
Fig. 9 is a perspective sectional view of the pipe assembly, illustrating the state in which a securing means of the pipe assembly enables a downstream-side extension pipe to hold the downstream-side hose of the hose unit in a contracted state in the extension pipe unit.
Fig. 10 is a perspective sectional view of the downstream-side extension pipe, illustrating the state in which the downstream-side extension pipe is movable as a result of being released from the first lock means.
Fig. 11 is a perspective sectional view illustrating how the movement of the downstream-side extension pipe results in the securing means releasing the downstream-side hose.
Fig. 12 is a sectional view illustrating a state in which a connector portion is in contact with the securing means when the hoses are extended.
Fig. 13 is a sectional view illustrating a state in which the connector portion enables the securing means to function when the hoses are extended.
Fig. 14 is a sectional view illustrating a state in which the connector portion is caught by the securing means when the hoses are extended.
Fig. 15 is a perspective view illustrating the vacuum cleaner in a stowed state.
Fig. 16 is a perspective view illustrating the state in which the vacuum cleaner is in use.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Next, the structure of a vacuum cleaner according to an embodiment of the present invention is explained hereunder, referring to Figs. 1 to 16.
Referring to Figs. 15 and 16, a cleaner main body 1 incorporates a motor fan 2 and is adapted to suction up dust and dirt together with intake air generated by driving the motor fan 2 and collect the suctioned dust and dirt into a dust collector, which is not shown in the drawings. The dust collector may be a removable dust collection pack or a dust collecting device, such as a dust collecting cup.
The cleaner main body 1 has a main body suction port 3 for suctioning up the air from the outside. A pipe assembly 4 is removably attached to the main body suction port 3. The cleaner main body 1 is also provided with wheels for enabling the cleaner main body 1 to travel over a surface to be cleaned, such as a floor surface.
As illustrated in Figs. 1 to 6, the pipe assembly 4 includes a hose unit 5 and an extendable extension pipe unit 6. The downstream end of the hose unit 5 is connected to the main body suction port 3, and the upstream end of the hose unit 5 is connected to the extension pipe unit 6. A floor brush 7 serving as a suctioning member is removably connected to the upstream end of the extension pipe unit 6.
The hose unit 5 includes an upstream-side hose 11 constituting the upstream part of the hose unit 5 and a downstream-side hose 12 connected to the downstream part of the upstream-side hose 11. The hoses 11,12 are communicatively linked with each other through a coupling portion serving as a connector portion. In the case of the present embodiment, a hose joint 13, which is a connecting pipe, serves as the connector portion, i.e. the coupling portion. The total length of the hose unit 5 may be, for example, approximately 430 mm in the fully contracted state, and approximately 800 mm in the fully extended state.
The upstream-side hose 11 is formed of a flexible, elastic material, such as elastomer or other appropriate resin, in a slender cylindrical shape. The upstream-side hose 11 has a pleated shape with a pleated portion 11a formed into a spiral. When the upstream-side hose 11 is in its natural length, in other words under no external force, there is nearly no space between the pleats of the pleated portion 11a, in other words, the upstream-side hose 11 is in a contracted state in the axial direction. By applying an external force in the axial direction, the upstream-side hose 11 is stretched, with the space between the pleats of the pleated portion 11a being expanded. Therefore, by continuously applying the external force in the axial direction, the upstream-side hose 11 can be maintained in the extended state. When the upstream-side hose 11 is thus maintained in the extended state, the upstream-side hose 11 is biased in the contracting direction, i.e. such a direction as to return to its natural length.
The length of the entire upstream-side hose 11, at least in the contracted state, is shorter than the length of the entire extension pipe unit 6 in the contracted state. In other words, when both the upstream-side hose 11 and the extension pipe unit 6 are in the contracted state, the entire upstream-side hose 11 can be accommodated in the extension pipe unit 6. In the case of the present embodiment, the entire upstream-side hose 11 can be accommodated in the extension pipe unit 6 regardless of whether the upstream-side hose 11 is in the contracted state or in the fully extended stated. A cylindrical flange unit 15 is fitted and secured in the upstream end of the upstream-side hose 11, and the upstream end of the hose joint 13 is fitted and secured in the downstream end of the upstream-side hose 11. The flange unit 15 is a hose slide flange that serves as a sliding portion and is capable of sliding in the axial direction inside the upstream end portion of the extension pipe unit 6. Therefore, the upstream part of the upstream-side hose 11, in other words the upstream part of the hose unit 5, is capable of sliding in the axial direction in the extension pipe unit 6.
The flange unit 15 is formed of a rigid material, such as synthetic resin, and includes a flange unit main body 15a and a flange 15b. The flange unit main body 15a has a substantially cylindrical shape and serves as the main body of the sliding portion fitted in the upstream end of the upstream-side hose 11. The flange 15b serves as a flange of the sliding portion and projects in the radial direction from the distal end, i.e. the upstream end, of the cylindrical outer face of the flange unit main body 15a.
A flange stopper protrusion 15c in the shape of a solid cylinder projects in the radial direction from the cylindrical outer surface of the flange unit main body 15a. The flange stopper protrusion 15c serves as a stud portion of the sliding portion and is adapted to be caught against the cylindrical inner surface of the upstream part of the upstream-side hose 11. In the state where the flange stopper protrusion 15c is caught against the cylindrical inner surface of the upstream part of the upstream-side hose 11, the flange unit main body 15a is affixed to the cylindrical inner surface of the upstream part of the upstream-side hose 11 by means of, for example, an adhesive agent. The downstream end portion of the flange unit main body 15a is gradually tapered in the downstream direction.
The flange 15b has an outer diameter greater than that of the upstream-side hose 11 and is formed along the entire circumference of the flange unit main body 15a. The rim of the flange 15b faces the cylindrical inner surface of the upstream part of the extension pipe unit 6. By fitting a packing 15d, which is a sealing member, around the rim of the flange 15b, the upstream-side hose 11 and the cylindrical inner surface of the extension pipe unit 6 can be connected and made airtight. An upstream-side stopper face 15e in the shape of a flat ring is formed at the distal end of the flange 15b. When the flange unit 15 slides in the extension pipe unit 6 towards the upstream end, the upstream-side stopper face 15e serves as a stopper, which is an upstream-side (distal end-side) contact face. Similarly, the flange unit 15 is provided with a downstream stopper face 15f in the shape of a flat ring that is formed at the base end, i.e. the downstream end, of the flange 15b and serves as a stopper, in other words a downstream-side (base end-side) contact face, when the flange unit 15 slides in the extension pipe unit 6 in the downstream direction.
The downstream-side hose 12 is formed of a flexible, elastic material, such as elastomer or other appropriate resin, in a slender cylindrical shape having an inner diameter and an outer diameter greater than those of the upstream-side hose 11, respectively. The downstream-side hose 12 has a pleated shape with a pleated portion 12a formed into a spiral. A core wire (not shown) for retaining the shape of and limiting contraction of the pleated portion 12a is attached to the inner side of the pleated portion 12a. When the downstream-side hose 12 is at the natural length, the core wire maintains the space between the pleats of the pleated portion 12a at a specified distance that is greater than 0, in other words at such a distance that the downstream-side hose 12 is not completely contracted. When an axial external force is applied, the core wire allows the space between the pleats of the pleated portion 12a to be expanded, thereby enabling the downstream-side hose 12 to be extended. Therefore, compared with the upstream-side hose 11, the downstream-side hose 12 is less prone to being contracted by an external force or a negative pressure from the motor fan 2. In other words, the contractive property of the downstream-side hose 12 when exposed to an external force or a negative pressure from the motor fan 2 is smaller than that of the upstream-side hose 11. As a result, when the space between the pleats of the pleated portion 12a is in a compressed state so that the length of the downstream-side hose 12 is shorter than its natural length, the downstream-side hose 12 is biased in such a direction as to extend, i.e. return to its natural length. The downstream-side hose 12 may have extendibility equivalent to that of the upstream-side hose 11.
The downstream-side hose 12 has such a length that at least a part of the downstream-side hose 12 can be accommodated in the extension pipe unit 6 when the upstream-side hose 11 is in the contracted state. In the case of the present embodiment, the length of the entire downstream-side hose 12 is greater than that of the upstream-side hose 11. When the downstream-side hose 12 is in the contracted state, the upstream part of the downstream-side hose 12 is accommodated in the extension pipe unit 6, and the downstream part of the downstream-side hose 12 is constantly exposed from the downstream end of the extension pipe unit 6. The downstream part of the hose joint 13 is fitted and secured in the upstream end portion of the downstream-side hose 12. The downstream end portion of the downstream-side hose 12 is fitted and secured in a substantially cylindrical clamp unit 17, which serves as a detachable part for removably attaching the downstream-side hose 12 to the main body suction port 3. A hose securing ring 18 having an annular shape is attached around a middle portion of the downstream-side hose 12, between the clamp unit 17 and the hose joint 13. The hose securing ring 18 serves as a secured portion that is secured to the extension pipe unit 6 when the upstream-side hose 11 is in the contracted state.
As illustrated in Fig. 16, the clamp unit 17 has a clamp button 17a exposed to the outside. The clamp button 17a serves as an operating element so that the clamp unit 17 can be disengaged from the main body suction port 3 by operating the clamp button 17a.
As illustrated in Figs. 2, 6, and other drawings, the hose securing ring 18 is the portion that is secured to the downstream end of the extension pipe unit 6 when the upstream-side hose 11 is in the contracted state. The hose securing ring 18 is formed of a rigid material, such as synthetic resin, and integrally fixed to the downstream-side hose 12. As illustrated in Figs. 10 and 11, a tooth-shaped stopper protrusion (not shown) protruding towards the center axis is formed at the distal end, i.e. the upstream end, of the hose securing ring 18 and serves as a secured portion stopper protrusion. A stopper recess 18a serving as a stopper is formed at the base end, i.e. the downstream end, of the hose securing ring 18.
The stopper protrusion is provided around the cylindrical outer surface of the downstream-side hose 12 and fitted between two pleats of the pleated portion 12a to prevent unintentional displacement of the hose securing ring 18 from the downstream-side hose 12 in the axial direction.
The stopper recess 18a is the portion at which the hose securing ring 18 catches the extension pipe unit 6 when the hose securing ring 18 is secured to the downstream end of the extension pipe unit 6. The stopper recess 18a has a groove-like shape formed along the entire circumference of the base end portion of the hose securing ring 18.
As illustrated in Figs. 7 to 9 and Figs. 12 to 14, the hose joint 13 includes a substantially cylindrical upstream-side cylindrical portion 13a, a substantially cylindrical downstream-side cylindrical portion 13b, a radially extending joint collar portion 13c, and a pair of projecting guide portions 13d. The upstream-side cylindrical portion 13a is located at the upstream side, i.e. the distal end portion, and serves as an upstream-side connector portion, i.e. an upstream-side coupling portion. The downstream-side cylindrical portion 13b is located at the downstream side, i.e. the base end portion, and serves as a downstream-side connector portion i.e. a downstream-side coupling portion. The joint collar portion 13c is in the shape of a collar, in other words an annular flange, around the entire middle portion of the hose joint 13, between the upstream-side cylindrical portion 13a and the downstream-side cylindrical portion 13b, and serves as a sliding contact portion. As is true with the joint collar portion 13c, each projecting guide portion 13d is also formed on the aforementioned middle portion between the two cylindrical portion 13a,13b and project straight in the radial direction. The projecting guide portions 13d together serve as a protruding guided portion, which is a portion to be guided.
The upstream-side cylindrical portion 13a has an outer diameter smaller than the inner diameter of the upstream-side hose 11 and is provided with a protruding portion 13e (see Fig. 1) in the shape of a solid cylinder protruding from the cylindrical outer surface of the upstream-side cylindrical portion 13a. The protruding portion 13e serves as an upstream-side connecting and stopping portion to be caught on the cylindrical inner surface of the downstream part of the upstream-side hose 11. In the state where the protruding portion 13e is caught on the cylindrical inner surface of the downstream part of the upstream-side hose 11, the upstream-side cylindrical portion 13a is affixed to the cylindrical inner surface of the downstream part of the upstream-side hose 11 by means of, for example, an adhesive agent. The upstream end portion of the upstream-side cylindrical portion 13a is gradually tapered in the upstream direction.
The downstream-side cylindrical portion 13b has an outer diameter that is smaller than the inner diameter of the downstream-side hose 12 and greater than the outer diameter of the upstream-side cylindrical portion 13a, and an inner diameter that is greater than that of the upstream-side cylindrical portion 13a. Therefore, the hose joint 13 is radially enlarged in a step-like manner at its middle portion, which is the portion continuously connecting the cylindrical portions 13a,13b in the axial direction. The downstream-side cylindrical portion 13b is provided with a protruding portion 13f (see Fig. 1) in the shape of a solid cylinder protruding from the cylindrical outer surface of the downstream-side cylindrical portion 13b. The protruding portion 13f serves as a downstream-side connecting and stopping portion to be caught on the cylindrical inner surface of the upstream part of the downstream-side hose 12. In the state where the protruding portion 13f is caught on the cylindrical inner surface of the upstream part of the downstream-side hose 12, the downstream-side cylindrical portion 13b is affixed to the cylindrical inner surface of the upstream part of the downstream-side hose 12 by means of, for example, an adhesive agent. The downstream end portion of the downstream-side cylindrical portion 13b is gradually tapered in the downstream direction.
The joint collar portion 13c has such a diameter that its rim faces the cylindrical inner surface of the extension pipe unit 6 with a slight gap therebetween. The upstream end face of the joint collar portion 13c is gradually tapered in the upstream direction.
The distal end portion of each projecting guide portion 13d projects from the cylindrical outer surface of the hose joint 13, and by fitting these distal end portions to the inner surface of the extension pipe unit 6, the projecting guide portions 13d guide sliding movement of the hose unit 5 in the axial direction of the extension pipe unit 6. Each projecting guide portion 13d is a boss of which at least the downstream side of the distal end portion does not have a corner, in other words is formed in a curved surface. In the case of the present embodiment, the entire distal end portion of each projecting guide portion 13d is formed in a substantially spherical shape. Furthermore, each projecting guide portion 13d projects further from the cylindrical outer surface of the hose joint 13 in the radial direction than does the joint collar portion 13c.
As illustrated in Figs. 1 to 9, the extension pipe unit 6 includes an upstream-side extension pipe 21, which is an inner pipe, and a downstream-side extension pipe 22, which is an outer pipe. The upstream-side extension pipe 21 is an extension pipe portion located at the upstream side, and the downstream-side extension pipe 22 is an extension pipe portion connected to the downstream part of the upstream-side extension pipe 21. As the downstream part of the upstream-side extension pipe 21 is fitted in the upstream part of the downstream-side extension pipe 22 and is capable of sliding therein in the axial direction, the extension pipe unit 6 can be contracted or extended by sliding these extension pipes 21,22 relative to each other. The extension pipe unit 6 is provided with an extension/contraction clamp 23, which is disposed on the upper side of the extension pipe unit 6, and also with hose clamps 24,24, which are provided at laterally opposing locations with respect to the center axis of the extension pipe unit 6. The extension/contraction clamp 23 serves as a first lock means, which is an extension/contraction operating portion for maintaining the extension pipe unit 6 in either the fully contracted state or the fully extended state. The hose clamps 24,24 together serve as a second lock means, which is a supporting means for securing the hose unit 5 to the extension pipe unit 6. The total length of the extension pipe unit 6 may be, for example, approximately 610 mm in the fully contracted state, and approximately 870 mm in the fully extended state.
The upstream-side extension pipe 21 includes a first extension pipe portion 26 and a second extension pipe portion 27, both of which have a slender cylindrical shape. The first extension pipe portion 26 forms the upstream part of the upstream-side extension pipe 21, and the second extension pipe portion 27 is connected to the downstream end of the first extension pipe portion 26 so as to form the downstream part of the upstream-side extension pipe 21.
Formed at the upstream end of the first extension pipe portion 26 is a brush clamping unit 26a serving as a suctioning member connector to which the floor brush 7 is removably attached. An upstream-side slide restricting face 26b serving as an upstream-side slide restricting portion is formed on the cylindrical inner surface of the portion that integrally continues from the brush clamping unit 26a. The first extension pipe portion 26 also includes a projecting clip 26c, which is located downstream of the brush clamping unit 26a and projects from the underside of the first extension pipe portion 26. The projecting clip 26c serves as a pipe assembly clipping portion for clipping the pipe assembly 4 to the cleaner main body 1 in the stowed state. The first extension pipe portion 26 also has the radially projecting raised stopper portion 26d that is formed along the entire circumference of the cylindrical outer surface of the downstream part of the first extension pipe portion 26 and serves as a second extension pipe stopper, i.e. the portion for preventing detachment of the second extension pipe portion.
The brush clamping unit 26a has a clamp cover 26e and a brush clamp button 26f, which is exposed to the outside from the clamp cover 26e, so that the floor brush 7 can be removed from the upstream-side hose 21 by operating the brush clamp button 26f.
As the diameter of the brush clamping unit 26a is smaller than that of the base end of the first extension pipe portion 26, the upstream-side slide restricting face 26b is in the shape of a step that is formed along the cylindrical inner surface of the first extension pipe portion 26 and projects towards the center axis. Therefore, as illustrated in Figs. 1 and 2, upon the upstream-side stopper face 15e of the flange unit 15 coming into contact with the upstream-side slide restricting face 26b during sliding motion of the hose unit 5, the sliding position, in other words the sliding distance in the upstream direction, of the hose unit 5 is limited.
The projecting clip 26c extends from the cylindrical outer surface of the first extension pipe portion 26 in an L-like shape when viewed from a side, with the distal end of the projecting clip 26c bent in the upstream direction. As illustrated in Fig. 15, the distal end portion of the projecting clip 26c can be engaged in a groove portion 28, which is a pipe stopper recess formed in the bottom of the cleaner main body 1 and serves as a pipe stopper groove portion, so that the pipe assembly 4 is secured to the cleaner main body 1.
Referring again to Figs. 1 to 9, the raised stopper portion 26d projects from the cylindrical outer surface of the first extension pipe portion 26. Therefore, upon the upstream end of the second extension pipe portion 27 coming into contact with the raised stopper portion 26d, the sliding position of the second extension pipe portion 27 in the upstream direction is limited so that detachment of the second extension pipe portion 27 in the upstream direction is prevented.
The axial length of the second extension pipe portion 27 is greater than that of the first extension pipe portion 26. Furthermore, as illustrated in Figs. 7 and 8, a step portion 27a projecting towards the center axis is formed along the cylindrical inner surface of the upstream part of the second extension pipe portion 27 and serves as a portion for preventing detachment of the downstream part of the first extension pipe portion 26. A hole in which the extension/contraction clamp 23 can be engaged is formed at a plurality of locations on the upper side of the cylindrical outer surface of the second extension pipe portion 27. For example, as illustrated in Figs. 1, 2, 7, and 8, a hole 27b and a hole 27c may respectively be formed near the upstream end and the downstream end of the second extension pipe portion 27. The cylindrical inner surface of the downstream end portion of the second extension pipe portion 27 is slanted so that the inner diameter thereof is gradually increased. A guide groove 27d extending along the entire axial length of the second extension pipe portion 27 is formed at each lateral side of the cylindrical inner surface of the second extension pipe portion. The guide grooves 27d,27d serve as a fitting guide in which the projecting guide portions 13d of the hose joint 13 of the hose unit 5 can be fitted. A detachment preventing step 27e raised in the radial direction is formed along the cylindrical outer surface of the downstream part of the second extension pipe portion 27 and serves as a portion for preventing detachment of the downstream part of the downstream-side extension pipe.
Upon the downstream end of the first extension pipe portion 26 coming into contact with the step portion 27a, the sliding position of the first extension pipe portion 26 in the downstream direction is limited so that detachment of the first extension pipe portion 26 in the downstream direction is prevented. As the step portion 27a projects further inward than does the downstream end portion of the first extension pipe portion 26, the step portion 27a limits the sliding position of the upstream-side hose 11 of the hose unit 5 in the upstream direction when the downstream stopper face 15f (see Figs. 1 and 2) of the flange unit 15 of the upstream-side hose 11 comes into contact with the step portion 27a. Thus, the step portion 27a also serves as a hose unit stopper, i.e. hose unit detachment preventing portion, for preventing inadvertent detachment of the hose unit 5.
The holes 27b,27c are both through holes that extend towards the center axis thereof so as to pass through the wall of the second extension pipe portion 27. An extended or contracted state of the first and second extension pipe portions 26,27 is fixed as a result of a part of the extension/contraction clamp 23 being caught in either hole 27b or 27c. To be more specific, in the state where a part of the extension/contraction clamp 23 is caught in the hole 27b, the extension pipe unit 6 is maintained at its fully contracted state. In the state where a part of the extension/contraction clamp 23 is caught in the hole 27c, the extension pipe unit 6 is maintained at its fully extended state.
In the state where the distal ends of the projecting guide portions 13d of the hose unit 5 are respectively engaged in the guide grooves 27d,27d, the guide grooves 27d,27d are capable of guiding sliding movement of the hose unit 5 in the axial direction of the extension pipe unit 6. Furthermore, each guide groove 27d is formed so that its outer shape parallels that of its inner grooved shape and protrudes outward.
Upon a part of the extension/contraction clamp 23 connected to the downstream-side extension pipe 22, as well as other relevant parts, coming into contact with the detachment preventing step 27e, the sliding position of the downstream-side extension pipe 22 in the downstream direction is limited so that detachment of the downstream-side extension pipe 22 in the downstream direction is prevented.
The downstream-side extension pipe 22 permits the downstream part of the second extension pipe portion 27 of the upstream-side extension pipe 21 to be inserted and slide therein in the axial direction so that the extension pipe unit 6 can be contracted or extended. An insertion hole 22a (see Figs. 7 and 8) is formed in the upper side of the downstream-side extension pipe 22. The insertion hole 22a is a clamp insertion hole serving as a stopper insertion hole for enabling the extension/contraction clamp 23 to secure the downstream-side extension pipe 22 to the upstream-side extension pipe 21 in the state where the downstream-side extension pipe 22 is either extended or contracted. The extension/contraction clamp 23 is provided on the upper side of the cylindrical outer surface of the downstream-side extension pipe 22, at a location downstream of the insertion hole 22a. Also provided on the upper side of the cylindrical outer surface of the downstream-side extension pipe 22 is an attachment portion 22b (see Figs. 1 and 2), which is located downstream of the extension/contraction clamp 23. A manual operation handle 31 is attached to the attachment portion 22b and serves as an operating portion by which various selection including the operation mode of the motor fan 2 is carried out.
As illustrated in Figs. 1 to 6, the hose clamps 24,24 mentioned earlier are provided at the downstream part of the downstream-side extension pipe 22, at laterally opposing locations with respect to the center axis of the downstream-side extension pipe 22. As illustrated in Figs. 5, 6, and other drawings, a guiding recess 22c is formed at each lateral side of the downstream-side extension pipe 22 at a location opposite each other with respect to the center axis of the downstream-side extension pipe. The guiding recesses 22c extend in the axial direction and together serve as a guide fitting portion. Furthermore, as illustrated in Figs. 1 to 4, a hose joint stopper 22d (hereinafter referred to as "the stopper 22d") is inserted and secured in the downstream-side extension pipe 22, at a location downstream of the guiding recesses 22c. The stopper 22d is a substantially cylindrical detachment prevention tube serving as a detachment prevention member.
The insertion hole 22a serves to support the upstream-side extension pipe 21 and the downstream-side extension pipe 22 at a fixed axial position by receiving therein a part of the extension/contraction clamp 23 in the state where the insertion hole 22a is aligned with either one of the holes 27b,27c of the second extension pipe portion 27 of the upstream-side extension pipe 21.
The attachment portion 22b extends in the axial direction and has a groove-like shape because it is surrounded by a rib portion 22e, which is a portion raised from the cylindrical outer surface of the downstream-side extension pipe 22. The attachment portion 22b is provided with a pair of protrusions 22f,22f in the shape of a solid cylinder protruding upward. The protrusions 22f,22f are spaced apart in the axial direction of the downstream-side extension pipe 22 and collectively serve as an operating portion securing means for attaching the manual operation handle 31 to the downstream-side hose 22.
As illustrated in Figs. 5 and 6, the guiding recesses 22c extend straight along the entire length of the downstream-side extension pipe 22. When the extension pipe unit 6 is in the contracted state, the outer side of each guide groove 27d of the upstream-side extension pipe 21 is slidably fitted in the corresponding guiding recess 22c so that the guiding recesses 22c guide axial sliding movement of the upstream-side extension pipe 21 along the downstream-side extension pipe 22. When the extension pipe unit 6 is in the extended state, each guiding recess 22c is communicatively linked with the downstream end of the corresponding guide groove 27d and receives the distal end portion of each respective projecting guide portion 13d (Figs. 1 to 3) of the hose unit 5 so that the guiding recesses 22c guide sliding movement of the hose unit 5 in the axial direction of the extension pipe unit 6. Therefore, as illustrated in Fig. 3, the guiding recesses 22c, the guide grooves 27d of the second extension pipe portion 27 of the downstream-side extension pipe 22, and the projecting guide portions 13d of the hose joint 13 together constitute a guide portion 32 for guiding sliding movement of the hose unit 5 along the extension pipe unit 6. Furthermore, as illustrated in Figs. 9 to 11, an opening 22g is formed near the downstream end of each guiding recess 22c. Each opening 22g serves as a supporting means insertion portion, i.e. a clamp insertion portion, in which a part of each hose clamp 24 can be inserted and projected into the corresponding guiding recess 22c. As illustrated in Figs. 12 to 14, a stopper face 22h, which is a flat surface, is formed on the downstream end of each guiding recess 22c and serves as a guide stopper for limiting the sliding position of the corresponding projecting guide portion 13d of the hose joint 13.
Each stopper face 22h constitutes the downstream terminal end of each guiding recess 22c. As a result of each projecting guide portion 13d of the hose joint 13 coming into contact with the corresponding stopper face 22h, the maximum distance of extension of the hose unit 5 (see Fig. 1) in the axial direction is limited. A space S in which the corresponding projecting guide portion 13d of the hose joint 13 can be fitted is formed between each stopper face 22h and the corresponding opening 22g.
The stopper 22d is disposed inside the downstream part of the downstream-side extension pipe 22 in such a manner that the upstream end of the stopper 22d faces the downstream end of the second extension pipe portion 27 of the upstream-side extension pipe 21 with a slight gap therebetween. The upstream end face of the stopper 22d is substantially flush with the stopper faces 22h so that the upstream end face of the stopper 22d and the stopper faces 22h together limit the sliding position of the projecting guide portions 13d of the hose joint 13.
As illustrated in Fig. 15, the manual operation handle 31 includes a handle portion 31a, which projects towards the downstream end of the extension pipe unit 6 so as to enable an operator to hold it when performing cleaning. The handle portion 31a is provided with selection buttons 31b and an infrared transmitting unit 31c. The selection buttons 31b are a plurality of operation buttons for setting the driving mode of the motor fan 2 incorporated in the cleaner main body 1 or other functions in a desired operation mode. The infrared transmitting unit 31c is a communication means that serves as a signal transmitting unit for transmitting a signal generated by operation of a selection button 31b to the cleaner main body 1 or the floor brush 7.
As illustrated in Figs. 1 to 4, the extension/contraction clamp 23 has an extension/contraction clamp main body 23a, which extends in the axial direction of the downstream-side extension pipe 22 and serves as the main body of the extension/contraction operating portion. Each lateral end portion of the extension/contraction clamp main body 23a is pivotally attached to each lateral side of the downstream-side extension pipe 22 by a shaft. As illustrated in Figs. 7 and 8, a coil spring 23c is provided between the cylindrical outer surface of the downstream-side extension pipe 22 and the extension/contraction clamp main body 23a, at a location surrounded by a base end 23b, i.e. the end facing towards the downstream end of the downstream-side extension pipe 22, and the two lateral ends, which are fixed to the downstream-side extension pipe 22 by the shafts. The coil spring 23c is a biasing means that serves as an extension/contraction operating portion biasing means for biasing the base end 23b of the extension/contraction clamp 23 upward. A stopper protrusion 23e protruding towards the center axis of the downstream-side extension pipe 22 and serving as a stopper tooth is formed on the distal end 23d of the extension/contraction clamp main body 23a, i.e. the end facing towards the upstream end of the downstream-side extension pipe 22.
The base end 23b of the extension/contraction clamp main body 23a is an operated portion, i.e. a portion to be pressed when the extension/contraction clamp 23 is being operated. To be more specific, by pressing the base end 23b towards the downstream-side extension pipe 22 against the biasing force of the coil spring 23c, the extension/contraction clamp main body 23a pivots so that the distal end 23d thereof moves away from the downstream-side extension pipe 22. As a result, the stopper protrusion 23e retreats into the insertion hole 22a and becomes disengaged from the hole 27b or the hole 27c, enabling the upstream-side extension pipe 21 and the downstream-side extension pipe 22 to slide relative to each other so that the extension pipe unit 6 can be extended or contracted. By releasing the base end 23b from the pressing force, the biasing force of the coil spring 23c causes the extension/contraction clamp main body 23a to pivot so that the distal end 23d moves towards the downstream-side extension pipe 22. As a result, the stopper protrusion 23e becomes fitted and engaged in either the hole 27b or the hole 27c, whichever is aligned with the insertion hole 22a, thereby locking sliding action for contraction or extension of the upstream-side extension pipe 21 and the downstream-side extension pipe 22, in other words locking the upstream-side extension pipe 21 and the downstream-side extension pipe 22 in such a state as to be unable to slide for extension or contraction.
As illustrated in Figs. 1 to 4 and 9 to 14, each hose clamp 24 has a hose clamp main body 24a, which extends in the axial direction of the downstream-side extension pipe 22. The hose clamp main bodies 24a of the hose clamps 24,24 together serve as the main body of the supporting means. Each lateral end of each hose clamp main body 24a is pivotally attached to each lateral side of the downstream-side extension pipe 22 by a shaft. A coil spring 24c is provided between the cylindrical outer surface of the downstream-side extension pipe 22 and each hose clamp main body 24a, at a location surrounded by a base end 24b, i.e. the end facing towards the downstream end of the downstream-side extension pipe 22, and the two lateral ends, which are fixed to the downstream-side extension pipe 22 by the shafts as described above. The coil spring 24c is a biasing means that serves as a supporting means biasing means for biasing the base end 24b of the hose clamp 24 upward. The base end 24b of each hose clamp main body 24a projects further downstream of the downstream end of the downstream-side extension pipe 22. A stopper claw 24d, which has a claw-like shape when viewed from a side, projects from each base end 24b and serves as a stopping and stopper means. A hose clamp claw portion 24f protruding towards the center axis of the downstream-side extension pipe 22 and serving as a supporting means stopper claw is formed on the distal end 24e of each hose clamp main bodies 24a, i.e. the end facing towards the upstream end of the downstream-side extension pipe 22.
The stopper claw 24d serves to catch the hose securing ring 18. The distal end portion of the stopper claw 24d is bent in the downstream direction so as to be capable of fitting in the stopper recess 18a of the hose securing ring 18.
The hose clamp claw portions 24f are inserted through the openings 22g of the downstream-side extension pipe 22 so as to protrude into the downstream-side extension pipe 22. Each hose clamp claw portion 24f has a slanted face 24g formed on the upstream part of the hose clamp claw portion 24f so as to gradually slant from the upstream end to the downstream end of the hose clamp claw portion 24f towards the center axis of the downstream-side extension pipe 22. The slanted faces 24g together serve as a pushing contact face, i.e. a contact face. A flat catching face 24h serving as a securing means catching portion is formed on the downstream end of each hose clamp claw portion 24f. Therefore, each hose clamp claw portion 24f has a substantially triangular shape when viewed from a side. The stopper claws 24d, the hose clamp claw portions 24f, the hose securing ring 18, and other relevant elements together constitute a securing means 33, which is capable of maintaining the upstream-side hose 11 in the extended state.
As a result of the downstream end of the second extension pipe portion 27 coming into contact with the slanted faces 24g when the extension pipe unit 6 is in the fully contracted state, the hose clamps 24 are maintained in such a state that the hose clamp main bodies 24a have pivoted against the biasing force of their respective coil springs 24c in such a direction that the base ends 24b move towards the cylindrical outer surface of the downstream-side extension pipe 22, in other words the state in which the stopper claws 24d are fitted in the stopper recesses 18a of the hose securing ring 18. Therefore, the securing means 33 has not only a function of an upstream-side hose supporting means for supporting the upstream-side hose 11 in the fully extended state but also a function of a downstream-side hose supporting means for supporting the portion of the downstream-side hose 12 that is upstream of the hose securing ring 18 in the fully contracted state.
The catching faces 24h serve to respectively catch the projecting guide portions 13d of the hose joint 13 in the state where the hose unit 5 is extended to its the maximum length so that the upstream-side hose 11 of the hose unit 5 is maintained in the extended state.
As illustrated in Figs. 15 and 16, the floor brush 7 has a casing 35, which is longer in a lateral direction, and a communicating pipe 36 pivotally and rotatably attached to the rear portion of the casing 35.
The casing 35 has a suction opening (not shown in the drawings), which is formed at the bottom of the casing 35 facing the floor surface. A rotary brush serving as a rotary cleaning body, for example, may be rotatably attached to the suction opening.
The communicating pipe 36 is connected to the casing 35 in such a manner that the communicating pipe 36 is capable of pivoting vertically or laterally, or rotating circumferentially. The distal end of the communicating pipe 36 is located inside the casing 35 and communicates with the suction opening. Therefore, by fitting the base end of the communicating pipe 36 in the brush clamping unit 26a so as to be engaged with the brush clamp button 26f, the communicating pipe 36 is connected to the extension pipe unit 6 in an airtight state.
Next, functions of the embodiment described above are explained hereunder.
In the stowed state of the vacuum cleaner illustrated in Fig. 15, the cleaner main body 1 is placed on the floor in an upright position with the front side and the rear side of the cleaner main body 1 facing upward and downward, respectively. With the projecting clip 26c of the extension pipe unit 6 of the pipe assembly 4 engaged in the groove portion 28, which is formed in the bottom of the cleaner main body 1, the pipe assembly 4 is clipped to the cleaner main body 1.
The components of the pipe assembly 4 are in the state described below. In the state where the extension pipe unit 6 is in the fully contracted state, and, in the state where the upstream part of the hose unit 5 has slid to the upstream part of the extension pipe unit 6 by the maximum distance, the upstream-side hose 11 in its natural length, i.e. the fully contracted state, is accommodated in the first extension pipe portion 26 of the upstream-side extension pipe 21 of the extension pipe unit 6. A part of the upstream part of the downstream-side hose 12 is accommodated in a compressed state in the second extension pipe portion 27 of the upstream-side extension pipe 21 of the extension pipe unit 6, and the downstream part of the downstream-side hose 12 is exposed from the downstream end of the downstream-side extension pipe 22 of the extension pipe unit 6.
To be more specific, the stopper protrusion 23e of the extension/contraction clamp 23, which is disposed on the downstream-side extension pipe 22 of the extension pipe unit 6, is fitted through the insertion hole 22a into the hole 27b of the second extension pipe portion 27 of the upstream-side extension pipe 21, thereby engaging the two extension pipes 21,22 with each other. The hose clamp claw portions 24f of the hose clamps 24 respectively project through the openings 22g into the guiding recesses 22c. In this state, the downstream end of the downstream-side extension pipe 22 are in contact with the slanted faces 24g of the hose clamp claw portions 24f of the hose clamps 24 and thereby presses the distal ends 24e of the hose clamps 24 upward against the biasing force of the coil springs 24c. As a result, the stopper claws 24d of the hose clamp main bodies 24a are retained in the stopper recess 18a of the hose securing ring 18 of the hose unit 5. In the state where the upstream-side hose 11 of the hose unit 5 is contracted to its natural length, the upstream-side stopper face 15e of the flange unit 15 is in contact with the upstream-side slide restricting face 26b of the first extension pipe portion 26 of the upstream-side extension pipe 21 of the extension pipe unit 6, and the stopper claws 24d of the hose clamp main bodies 24a are respectively retained in the stopper recess 18a. Therefore, the portion of the downstream-side hose 12 that is upstream of the hose securing ring 18 is accommodated in the downstream-side extension pipe 22 of the extension pipe unit 6 in an axially compressed state.
When cleaning is performed, by pulling the pipe assembly 4 upward, the projecting clip 26c of the extension pipe unit 6 becomes disengaged from the groove portion 28 of the cleaner main body 1. Then, the extension/contraction clamp 23 is operated to extend the extension pipe unit 6, and the hose unit 5 is pulled in the downstream direction to extend the hose unit 5.
To be more specific, the pipe assembly 4 is shifted from the state illustrated in Fig. 7 to the state illustrated in Fig. 8. This is done by pressing the base end 23b of the extension/contraction clamp 23 towards the downstream-side extension pipe 22 against the biasing force of the coil spring 23c in order to cause the stopper protrusion 23e to retreat from the hole 27b so that the downstream-side hose 12, which has been in the compressed state, extends to return to its natural length. As a result of the extension of the downstream-side hose 12, the flange unit 15 at the distal end of the upstream-side hose 11 pushes the downstream-side extension pipe 22 in the upstream direction so that, as illustrated in Figs. 9 to 11, the downstream end of the downstream-side extension pipe 22 becomes detached from the slanted faces 24g of the hose clamp claw portions 24f of the hose clamps 24, and the biasing force of the coil springs 24c causes the hose clamp main bodies 24a to simultaneously pivot in such a direction that the distal ends 24e of the respective hose clamp main bodies 24a move towards downstream-side extension pipe 22. As a result, the base ends 24b of the hose clamp main bodies 24a move away from the downstream-side extension pipe 22, and the hose clamp claw portions 24f become disengaged from the stopper recess 18a of the hose securing ring 18, thereby releasing the hose unit 5, and the part of the downstream-side hose 12 near the hose securing ring 18 becomes exposed from the downstream end of the downstream-side extension pipe 22 of the extension pipe unit 6.
Then, the upstream-side extension pipe 21 and the downstream-side extension pipe 22 are held and pulled in opposite directions to extend the extension pipe unit 6 to its maximum length. In this state, the insertion hole 22a of the downstream-side extension pipe 22 is aligned with the hole 27c of the upstream-side extension pipe 21, and the base end 23b of the extension/contraction clamp 23 is returned by the biasing force of the coil spring 23c, in other words pivoted towards the cylindrical outer surface of the downstream-side extension pipe 22 so that the stopper protrusion 23e becomes engaged in the hole 27c. By pulling the hose unit 5 in the downstream direction in this state, the upstream-side hose 11 of the hose unit 5 slides inside the first extension pipe portion 26 of the upstream-side extension pipe 21 of the extension pipe unit 6 while the projecting guide portions 13d of the hose joint 13 are respectively guided by the guide grooves 27d of the second extension pipe portion 27, until the stopper face 15f of the flange unit 15 comes into contact with the upstream end of the step portion 27a of the second extension pipe portion 27.
Thereafter, by pulling the hose unit 5 further in the downstream direction, the projecting guide portions 13d of the hose joint 13 slide in the respective guide grooves 27d and further in the guiding recesses 22c in the downstream direction. As a result, because the flange 15b is stopped by the step portion 27a, the upstream-side hose 11 is extended to a length that is nearly the same as the total length of the axial dimensions of the second extension pipe portion 27 and the downstream-side extension pipe 22, and, as illustrated in Figs. 12 to 14, comes into contact with the slanted faces 24g of the hose clamp claw portions 24f of the hose clamps 24 in the state where the hose clamp claw portions 24f of the hose clamps 24 respectively project through the openings 22g into the guiding recesses 22c. As a result of the projecting guide portions 13d sliding further in the guiding recesses 22c in the downstream direction, the projecting guide portions 13d push the slanted faces 24g upward against the biasing force of the coil springs 24c and move over the slanted faces 24g into the spaces S. Thereupon, the biasing force of the coil springs 24c causes the hose clamp main bodies 24a to pivot in such a direction that their distal ends 24e return to the regular positions. Furthermore, as the upstream-side hose 11 is biased in such a direction as to return to the natural length, the projecting guide portions 13d rest on the catching faces 24h of the hose clamp main bodies 24a so that the upstream-side hose 11 is maintained in the extended state, in other words in the state when in use as illustrated in Fig. 16.
Therefore, by extending the extension pipe unit 6 and pulling the hose unit 5 in the downstream direction, the upstream-side hose 11 is stretched into the extended state, and a biasing force in such a direction as to contract the pipe assembly 4 is stored.
Then, after placing the cleaner main body 1 on the floor and connecting the power supply plug to an electrical outlet (not shown), the operator holds the handle portion 31a of the manual operation handle 31 and activates the motor fan 2 in a desired driving mode by operating the various selection buttons 31b to transmit signals from the infrared transmitting unit 31c to a control unit in the cleaner main body 1. By placing and moving the floor brush 7 back and forth over the floor, dust and dirt on the floor are suctioned through the suction opening by means of a negative pressure generated by operation of the motor fan 2.
The suctioned dust and dirt are suctioned up together with the air from the suction opening of the floor brush 7 through the communicating pipe 36 into the upstream-side extension pipe 21, the downstream-side extension pipe 22, the upstream-side hose 11, the downstream-side hose 12, and into the main body suction port 3 sequentially, and further into the dust collector, in which the dust and dirt are separated from the air and trapped therein. The air is suctioned into the motor fan 2, from which it is discharged as the exhaust air to the outside of the cleaner main body 1.
When cleaning is completed, the operator stops operation of the motor fan 2 by operating an appropriate selection button 31b, and removes the power supply plug from the electrical outlet. Thereafter, by pressing the base end portion 24b of each hose clamp 24 against the biasing force of the coil spring 24c thereof, the distal end 24e of each hose clamp main body 24a pivots so that its hose clamp claw portions 24f retreats from the corresponding opening 22g of the downstream-side extension pipe 22, thereby disengaging the corresponding projecting guide portion 13d of the hose joint 13 so that the upstream-side hose 11, which has been in the stretched state, contracts to return to its natural length. In other words, the upstream-side hose 11 slides in the extension pipe unit 6 in the upstream direction. As a result, the part of the downstream-side hose 12 of the hose unit 5 that has been exposed from the downstream end of the extension pipe unit 6 is pulled into the downstream-side extension pipe 22 of the extension pipe unit 6. At that time, as a result of the projecting guide portions 13d of the hose joint 13 being guided by the guiding recesses 22c of the downstream-side extension pipe 22 and the guide grooves 27d of the second extension pipe portion 27, the upstream-side hose 11 is in such a state that the upstream-side stopper face 15e of the flange unit 15 is in contact with the upstream-side slide restricting face 26b of the first extension pipe portion 26 of the upstream-side extension pipe 21 of the extension pipe unit 6.
In this state, the operator holds and pushes the part of the hose unit 5 that is in the proximity of the hose securing ring 18 so that the hose securing ring 18 is inserted a slight distance into the downstream-side extension pipe 22 of the extension pipe unit 6. The operator then presses the base end portion 24b of each hose clamp 24 towards the downstream-side extension pipe 22 against the biasing force of the coil spring 24c so as to hook each stopper claw 24d in the stopper recess 18a of the hose securing ring 18. While maintaining the hose clamps 24 in this state, the operator presses the base end 23b of the extension/contraction clamp 23 against the biasing force of the coil spring 23c. As a result, the stopper protrusion 23e retreats from the hole 27c of the upstream-side downstream-side extension pipe 21, enabling the extension pipe unit 6 to contract. By pushing the downstream-side extension pipe 22 in the upstream direction, in other words towards the upstream-side extension pipe 21, the hose clamps 24,24 come close to the hose joint 13 so that the part of the downstream-side hose 12 that is between the hose joint 13. and the hose clamps 24,24 is compressed. When the openings 22g of the downstream-side extension pipe 22 become aligned with the hole 27b of the second extension pipe portion 27 of the upstream-side extension pipe 21, the stopper protrusion 23e of the extension/contraction clamp 23 is fitted through the openings 22g into the hole 27b. As a result, the extension pipes 21,22 are engaged with each other, and the downstream end of the downstream-side extension pipe 22 comes into contact with the slanted faces 24g of the hose clamp claw portions 24f of the hose clamps 24 in the state where the hose clamp claw portions 24f of the hose clamps 24 respectively project through the openings 22g into the guiding recesses 22c. As a result, the downstream end of the downstream-side extension pipe 22 pushes the distal ends 24e of the respective hose clamps 24 upward against the biasing force of the coil springs 24c so that the hose clamps 24 are maintained in such a state that the stopper claws 24d of the respective hose clamp main bodies 24a are retained in the stopper recess 18a of the hose securing ring 18 of the hose unit 5.
Therefore, by performing a contracting action described above on the extension pipe unit 6, the portion of the downstream-side hose 12 that is upstream of the hose securing ring 18 is compressed so that a biasing force in such a direction as to stretch the pipe assembly 4 is stored.
In this state, the operator releases the hose clamps 24 from the continual pushing force and thereby returns the pipe assembly 4 to the contracted state. Then, by placing the cleaner main body 1 on the floor in the upright position and hooking the projecting clip 26c in the groove portion 28, the operator stows the vacuum cleaner at a desired location in the stowed state illustrated in Fig. 15.
As described above, according to the present embodiment, by holding the upstream-side hose 11 in the extended state by means of the securing means 33 when performing cleaning, it is possible to prevent contraction of the upstream-side hose 11 due to negative pressure from the motor fan 2 or other force when in operation. Therefore, the present invention facilitates ease of performing cleaning.
When stowing away the vacuum cleaner, the entire length of the pipe assembly 4 can be minimized by stowing the upstream-side hose 11 in the contracted state in the extension pipe unit 6. Therefore, the hose unit 5 can be stowed compactly and neatly, as the hose unit 5 neither occupies an unnecessarily large space nor requires to be wound around the extension pipe unit or the cleaner main body to be stowed. Furthermore, there is no need to disassemble the pipe assembly 4 or other components when stowing the vacuum cleaner. Therefore, the vacuum cleaner described above can be stowed easily and neatly.
To be more specific, the upstream-side hose 11 has larger contractive property than does the downstream-side hose 12 and is in the contracted state when in the natural length. Therefore, should there be no mechanism to maintain the upstream-side hose 11 in the extended state, the operator has to hold the upstream-side hose 11 while constantly applying an external pulling force in order to prevent contraction of the upstream-side hose 11. Furthermore, should the suction opening of the floor brush 7 become stuck to the floor surface or encounter other similar circumstances, there is the possibility of an increased degree of vacuum causing the upstream-side hose 11 to contract. According to the present embodiment, however, it is easy to provide a pipe assembly 4 that can be maintained to be extended to a sufficient length by means of the securing means 33 that is capable of securing the upstream-side hose 11 in the extended state when cleaning is performed, and can be contracted to a short length when the vacuum cleaner is stowed away.
When the upstream-side hose 11 is in the contracted state, a part of the downstream-side hose 12 is accommodated in the extension pipe unit 6. In other words, when the vacuum cleaner is stowed away, a part of the downstream-side hose 12 is also accommodated in the extension pipe unit 6 so that only the minimal necessary portion of the hose unit 5 is exposed. Therefore, the present embodiment provides a vacuum cleaner with an improved appearance when stowed.
The upstream part of the upstream-side hose 11 is capable of sliding in the extension pipe unit 6. Therefore, when extending the hose unit 5, the pipe assembly 4 can be extended to a greater extent than would be possible with a conventional structure, and, when contracting the hose unit 5, the pipe assembly 4 can be compactly arranged by effectively using the length of the extension pipe unit 6.
When the upstream-side hose 11 is in the extended state, the securing means 33 is capable of easily maintaining the upstream-side hose 11 in the extended state by catching the hose joint 13, which serves as a connector portion to connect the upstream-side hose 11 and the downstream-side hose 12 at the downstream part of the extension pipe unit 6.
Furthermore, when extending the pipe assembly 4 to prepare for cleaning operation, merely pulling the hose unit 5 from the extension pipe unit 6 after extending the extension pipe unit 6 is sufficient to cause the hose joint 13, at which the hoses 11,12 are connected, to slide in the extension pipe unit 6 so that the projecting guide portions 13d catch the respective hose clamps 24. The upstream-side hose 11 can thus be easily maintained in the extended state.
It is also easy to contract the pipe assembly 4 for stowage, because the entire upstream-side hose 11 and the portion of the downstream-side hose 12 that is upstream of the hose securing ring 18 can be easily accommodated in the extension pipe unit 6 by merely compressing the extension pipe unit 6 while the hose clamps 24 continuously engage the hose securing ring 18. Furthermore, it is also possible to use the securing means 33, which serves to maintain the upstream-side hose 11 in the extended state, as a means to maintain the downstream-side hose 12 in the contract state. Therefore, by thus using the same component for different functions, the structure can be simplified compared with a structure that requires separate means for these functions.
As disposing the securing means 33 at the downstream end of the extension pipe unit 6 enables nearly the entire length of the downstream-side hose 12 to be exposed from the downstream end of the extension pipe unit 6 when the upstream-side hose 11 is in the extended state, the length of the hose unit 5 can be utilized to its fullest extent.
As the manual operation handle 31 includes a wireless means, such as the infrared transmitting unit 31c, to transmit signals, there is no need of wiring such as in the hose unit 5 and the extension pipe unit 6, from the manual operation handle 31 to the cleaner main body 1 or the floor brush 7, and the structure of the vacuum cleaner can be simplified.
In the embodiment described above, it is not essential for the extension pipe unit 6 to have an extendable structure.
Furthermore, it is not essential for the hose unit 5 to slide in the extension pipe unit 6 in the axial direction.
The hose securing ring 18 may be disposed at a desired location on the downstream-side hose 12 in accordance with the distance by which the downstream-side hose 12 in the stowed state should be exposed from the extension pipe unit 6.
Furthermore, the structure of the securing means 33 is not limited to the description given above, provided that it is capable of maintaining the upstream-side hose 11 in the extended state. For example, the securing means 33 may be adapted to catch the hose joint 13 at a location downstream of the downstream end of the extension pipe unit 6.
The details of the vacuum cleaner are not limited to the description provided above.

Claims

A vacuum cleaner comprising:
a cleaner main body incorporating a motor fan having an intake side; and

a pipe assembly to be connected to the cleaner main body so as to communicate with the intake side of the motor fan, wherein the pipe assembly comprises:
an extension pipe unit;

an upstream-side hose including an upstream part and a downstream part and connected to the extension pipe unit at least at the upstream part of the upstream-side hose, the upstream-side hose being adapted to be in a contracted state when in the natural length and extendable by an external force, and, at least when in the contracted state, accommodated in the extension pipe unit;

a downstream-side hose connected to the downstream part of the upstream-side hose and having contractive property that is smaller than that of the upstream-side hose when exposed to a negative pressure from the motor fan; and

a securing means capable of maintaining the upstream-side hose in an extended state.
A vacuum cleaner as claimed in claim 1, wherein:
at least a part of the downstream-side hose is accommodated in the extension pipe unit when the upstream-side hose is in the contracted state.
A vacuum cleaner as claimed in claim 1 or claim 2, wherein:
the upstream part of the upstream-side hose is capable of sliding in the extension pipe unit.
A vacuum cleaner as claimed in any one of the claims from claim 1 to claim 3, wherein:
when the upstream-side hose is in the extended state, the securing means serves to engage, at a downstream part of the extension pipe unit, a connector portion for connecting the upstream-side hose and the downstream-side hose to each other.