Suction tube arrangement for a vacuum cleaner

Abstract

The present disclosure relates to a suction tube arrangement for a vacuum cleaner, comprising an inner tube (19) and an outer tube (21) which is slideable from a resting position in relation to the inner tube against the force of an elastic element (35). The inner and outer tubes each comprise a peripheral tube opening which openings are mutually offset in the resting position and which overlap by the outer tube sliding in relation to the inner tube thereby forming a bypass opening. A latch (25) is provided, moveable between a locked and an unlocked position, wherein the latch in the locked position blocks the sliding of the outer tube in relation to the inner tube (19) at the resting position.

Description

Field of the invention

[0001] The present disclosure relates to a suction tube arrangement for a vacuum cleaner, comprising an inner tube and an outer tube, which is slideable from a resting position in relation to the inner tube against the force of an elastic element. The inner and outer tubes each comprise a tube opening, and those openings are mutually offset in the resting position and overlap by the outer tube sliding in relation to the inner tube thereby forming a bypass opening into the suction tube arrangement.Technical background

[0002] One example of a suction tube arrangement of this kind is shown in DE-2815196-A1. This suction tube arrangement serves to reduce the negative pressure in the suction tube if a vacuum cleaner nozzle becomes stuck e.g. on a rug in a case where the negative pressure in the nozzle is too high. Then, the user pushes against the force of the elastic element sliding the inner and outer tubes relative to each other and forms a bypass opening into the suction tube. This reduces the negative pressure in the nozzle such that the nozzle becomes released.

[0003] Document WO2016 / 087833 A1 discloses a vacuum cleaner in which an air bleed valve may be provided which permits the suction provided at a cleaning tool nozzle to be reduced. The document discloses a vacuum cleaner for lifting and collecting matter from surfaces, wherein at least one air-bleed orifice is provided in a wall portion to reduce suction at the nozzle. An air-permeable porous material is disposed to obturate the orifice, which porous material permits the passage of bypass air through the orifice but restricts the airflow rate therethrough. The porous material is preferably an open cell foam membrane. The orifice may be provided in a vacuum cleaner wand tube which serves as a vacuum conduit between the nozzle and a vacuum cleaner body in which the suction motor is provided.

[0004] One problem with such arrangement is that the lowering of the pressure makes deep cleaning of for instance a rug inefficient. This has recently been addresses by instead lowering the motor speed electronically when sensing that the nozzle becomes stuck, and by providing the option to electronically disable this function. This, however, is a relatively complex solution adding costs to the vacuum cleaner as a whole.Summary of the invention

[0005] One object of the present invention is therefore to provide a suction tube arrangement for a vacuum cleaner that can allow a deep cleaning function in a cost-efficient manner. This object is achieved by means of a suction tube arrangement as defined in claim 1. More specifically, in a suction tube arrangement of the initially mentioned kind, there is provided a latch, moveable between a locked and an unlocked position, wherein the latch in the locked position blocks the sliding of the outer tube in relation to the inner tube at the resting position. This allows the user to easily disable the negative pressure reducing function with cost-efficient means in cases where a deep cleaning functionality is needed.

[0006] An air flow may pass from the outer tube to the inner tube or vice versa, the inner and outer tubes forming a telescopic tube section.

[0007] Alternatively, the inner tube may pass through the outer tube. Then, the outer tube may be connected to a handle, offset from the connection between the inner tube and the outer tube along the direction of the inner tube center axis.

[0008] The handle may be angled 10-80 degrees in relation to the inner tube center axis, more preferably between 25-65 degrees to provide an ergonomic grip on the handle. The elastic element may be a helical spring arranged between the handle and the inner tube being compressed by the handle moving from the resting position in relation to the inner tube.

[0009] The latch may be slidable sideways on the outer tube between the locked and unlocked positions.

[0010] The latch may be located on the top side of the outer tube. If the outer tube is connected to a handle, the latch may be located less than 60 mm from the end of the handle, such that it can be reached by the user with the thumb of the hand holding the handle.

[0011] A flexible sealing lip may be provided attached to the outer tube, which sealing lip covers an opening of the inner tube in the resting position. The outer periphery of the inner tube may be covered by a mesh supporting the sealing lip at the opening. Typically, a suction tube arrangement as defined above comprises a connection to a flexible tube part at one end and a connection to a rigid tube on the other.

[0012] The present invention also considers a suction tube arrangement for a vacuum cleaner, the arrangment comprising an inner tube and an outer tube, which is slideable from a resting position in relation to the inner tube against the force of an elastic element, wherein the inner and outer tubes comprise tube openings which are mutually offset in the resting position and which overlap by the outer tube sliding in relation to the inner tube thereby forming a bypass opening. The arrangement comprises a flexible sealing tab attached to the outer tube, which covers an opening of the inner tube in the resting position. The outer periphery of the inner tube may be covered by a mesh at the opening for supporting the sealing tab. This provides very tight sealing in the resting position.

[0013] The present invention further considers a vacuum cleaner comprising a suction tube arrangement as defined above.Brief description of the drawings

[0014] Fig 1 illustrates one example of a vacuum cleaner. Fig 2 illustrates an upright- or stick-type vacuum cleaner. Fig 3 shows a suction arrangement according to an example of the present invention with a handle. Fig 4A shows a perspective view of the handle in fig 3. Fig 4B shows the handle with a partially removed outer tube. Figs 5A and 5B show a cross section through the handle in fig 3 in closed and open positions. Figs 6A and 6B show the latch in two different views. Detailed description

[0015] The present invention relates to a suction tube arrangement for vacuum cleaners, for instance a vacuum cleaner as illustrated in fig 1. This vacuum cleaner 1 comprises a main housing 3 comprising a motor, a fan and a dust separation device hidden therein. The motor is driven by a battery or by a connection via a cord to a power outlet. The motor is connected to the fan which provides a strong air flow from a nozzle 5 via a suction tube arrangement 7, 9 through a dust separation device in the housing 3 and to the ambient space through an air outlet 11 in the housing 3. In general, a dust separation device is used, which for instance may be a dust bag, a filter, a cyclone, or a combination thereof.

[0016] In the case illustrated in fig 1, the housing 3 is configured to be moveable on the floor by rolling, while the user maneuvers the nozzle 5 and the suction tube. The suction tube arrangement comprises a flexible tube part 9 leading from the housing 3 on the floor to a rigid tube 7, leading to the nozzle 5, which often rests on the floor for floor cleaning.

[0017] The present invention is however useful also in an upright- or stick-type vacuum cleaner 1' such as illustrated in fig 2, only having a stiff tube 27 leading from the nozzle 5 to a handle 8 and where the housing 3 is fitted on this stiff tube. In both cases the user moves the nozzle around by pushing and pulling the rigid tube 7, 27 in different directions, sometimes also lifting the nozzle 5 from the floor.

[0018] The above-mentioned basic vacuum cleaner designs are well known as such. Recent initiatives such as regulations has sought to reduce the power used in a vacuum cleaner, for instance by limiting the maximum electric power used. By e.g. clever nozzle designs it has been possible to maintain or even improve the vacuum cleaner's dust removing efficiency despite lowered maximum motor power. This has partly been achieved by making the inner space in the nozzle greater, and by making the outer boundaries of the nozzle to provide a tighter seal between this inner space and the ambient room. While this works very smoothly in most cases, for instance on hard floors, some circumstances may lead to problems.

[0019] For instance, when vacuum cleaning a thick rug, the nozzle may in some cases become stuck on the rug and may be difficult to move. A firm movement by the user in that case may even move the rug as a whole rather than cleaning the same.

[0020] The present invention illustrates a suction tube arrangement function that deals with this problem, and it is possible to inactivate this function if desired in order to provide a deep-cleaning effect, for instance in a thick rug.

[0021] Fig 3 shows a suction arrangement according to an example of the present invention with a handle 23. In general, the suction tube arrangement 17 comprises an inner tube 19 and an outer tube 21 which are mutually slideable along the center axis of the inner tube 19. The outer tube 21 may thus slide from a resting position in relation to the inner tube 19 against the force of an elastic element.

[0022] As will be shown, a sliding motion by the outer tube 21 in relation to the inner tube 19 causes a bypass air flow to be opened and closed, to change the negative pressure in the vacuum cleaner nozzle.

[0023] In the illustrated case, the inner tube 19 provides a connection between a rigid tube 7 and a flexible tube 9 as described before in connection with fig 1. The outer tube 21 encloses a part of the inner tube 19 and is connected to a handle 23 that the user holds when using the vacuum cleaner. Expressed differently, the inner tube 19 passes through the outer tube 21. However, other configurations are possible. For instance, the inner and outer tubes could form a telescopic tube section where suction air passes from one part to the other. In a vacuum cleaner of the type shown in fig 2, a corresponding arrangment may be formed between the housing 3 and the nozzle 5.

[0024] If a handle 23 is used as shown, the handle may be offset from the connection between the inner and outer tubes 19, 21 along the direction of the inner tube center axis. The handle may be angled 10-80 degrees in relation to the inner tube center axis, more preferably between 25-65 degrees to provide an ergonomic grip on the handle when vacuum cleaning.

[0025] In the illustrated case, the outer tube 21 also includes a latch 25 that can be moved between a locked and an unlocked position as will be discussed in detail. In the locked position, the latch 25 blocks the sliding of the outer tube in relation to the inner tube at a resting position such that substantially no bypass flow is introduced in the inner tube regardless of how the handle 23 is moved.

[0026] Fig 4A shows a perspective view of the handle in fig 3 And Fig 4B shows the handle with a removed top cover. As is best seen in the enlarged portion of fig 4A, a part 26 of the latch 25 protrudes through and opening 27 the outer cover of the outer tube 21, where this protruding part 26 is slidable, trapped between the inner and outer tubes 19, 21, between two positions "I" and "O" in the direction illustrated by the arrow.

[0027] As can be seen in fig 4B, the latch 25 is configured to selectively cooperate with an abutment 29 on the inner tube 19. When in the released position "I", cf. fig 4A, the abutment 29 is aligned with a groove or channel 31, which means that the latch 25 allows a mutual linear movement between the inner and outer tubes 19, 21. However, when the latch 25 is moved to the locked position "O", the abutment 31 is instead aligned with a rib 33 on the bottom side of the latch 25, which prevents that linear movement as the rib 33 abuts the abutment 29. As shown, the latch 25 may be located on the top side of the outer tube 21 such that it is easily seen by the user and may be located less than 60 mm from the end of the handle, such that it can be reached by the user with the thumb of the hand holding the handle 23.

[0028] Figs 6A and 6B show the user-operated latch 25 in a front view as seen from the top of the tubes 19, 21 and a side view as seen along the elongation of the rib 33. As shown, the rib may be located directly below the protruding part 26 of the latch. As also indicated, there may be provided symmetrically another channel on the opposite side of the rib 33. While that channel is not active, it eliminates the risk of assembling the latch 25 in the wrong way by being symmetric along the length axis of the rib 33. The latch 25 as a whole has a roughly arc-shaped cross section across that axis to be able to slide between inner and outer tubes 19, 21. The latch may typically be formed in one piece by injection moulding a plastic material.

[0029] Figs 5A and 5B show a cross section through the handle in fig 3 when moving from the closed state at the resting position to the open position. This movement, as described above, only takes place when the latch 25 is in the unlocked position. Typically, this movement takes place as a result of the vacuum cleaner nozzle becoming stuck on a rug, for instance, due to a high negative pressure under the nozzle. When the force applied by the user on the handle 23 is large enough to compress a spring 35 or other elastic element arranged between parts of the inner and outer tubes 19, 21, those tubes begin to move mutually as illustrated in figs 5A and 5B. The spring 35 in the illustrated case is a helical spring with an axis parallel to the center axes of the inner and outer tubes 19, 21, where they are aligned, although some deviation of the spring axis may be allowed. As shown, the spring 35 is located in between the handle 23 of the outer tube 21 and a protruding portion 37 of the inner tube 19 where that tube bends. This gives a great deal of design freedom with regard to the diameter of the spring 35. An alternative would be to provide a spring with a greater inner diameter than the inner tube and a smaller outer diameter than the outer tube and to locate that spring in between the tubes 19, 21 at a location where they are parallel.

[0030] The bypass air flow established sliding motion by the outer tube 21 in relation to the inner tube 19 is best illustrated in the enlarged portions of figs 5A and 5B.

[0031] An opening or a set of openings 39 are provided in the inner tube 19, in the illustrated case at the bottom side thereof. In the resting position, where there is no bypass flow reducing the negative pressure in the nozzle, those openings are closed by a sealing tab 41 of the outer tube 21. The sealing tab 41 is attached at one edge 43 to the outer tube 21, such that the distal part of the sealing tab 41 extending from that edge is moveable to some extent towards and away from the center of the tubes 19, 21. The sealing tab 41 may be made from an elastic material such as silicone rubber. In this configuration the negative pressure inside the inner tube 19 makes the sealing tab stick to and substantially seal the openings 39. This reduces leaks and also noise that could otherwise occur due to the pressure gradient at such leaks. To allow a softer sealing tab material for a given opening size, a mesh 45 may be provided, covering the opening at the outer periphery of the inner tube 19 while allowing air to pass therethrough. This mesh ensures that a soft sealing tab 41 is not deformed in such a way by the negative pressure in the inner tube 19 that it is sucked into the inner tube 19.

[0032] In fig 5B, the outer tube 21 has been moved to the right in the figure while compressing the spring 35. This movement in relation to the inner tube 19 makes the sealing tab 41 slip off the opening 39 in the inner tube 19. Instead, a part of the opening is aligned with an opening 47 in the outer tube 21. This creates a bypass flow 49 letting ambient air into the inner tube 19, lowering the negative pressure in the vacuum cleaner nozzle, thereby loosen it for instance from a thick rug. It should be noted that the sealing feature disclosed in figs 5A and 5B can be used also without provision of the locking latch.

[0033] The present invention is not restricted to the above-described embodiment and may be varied and altered in different ways within the scope of the appended claims. For instance, it would be possible to provide two springs and bypass openings that are activated when the moves out of the resting position in two different directions such that both a pulling and pushing movement of the handle can create the bypass flow.

Claims

1. A suction tube arrangement for a vacuum cleaner, comprising an inner tube (19) and an outer tube (21), which is slideable from a resting position in relation to the inner tube against the force of an elastic element (35), wherein the inner and outer tubes comprise tube openings (39, 47) which openings are mutually offset in the resting position and which overlap by the outer tube (21) sliding in relation to the inner tube (19) from the resting position thereby forming a bypass opening (49), wherein a latch (25) is moveable between a locked and an unlocked position, wherein the latch in the locked position blocks the sliding of the outer tube (21) in relation to the inner (19) tube at the resting position, characterized in that an air flow passes from the inner tube to the outer tube or vice versa, the inner and outer tubes forming a telescopic tube section.

2. Suction tube arrangement according to claim 1, wherein the inner tube (19) passes through the outer tube (21).

3. Suction tube arrangement according to claim 2, wherein the outer tube (21) is connected to a handle (23), offset from the connection between the inner tube (19) and the outer tube (21) along the direction of the inner tube center axis.

4. Suction tube arrangement according to claim 3, wherein handle is angled 10-80 degrees in relation to the inner tube center axis, more preferably between 25-65 degrees.

5. Suction tube arrangement according to any of claims3-4, wherein the elastic element is a helical spring (35) arranged between the handle (23) and the inner tube (19) and is compressed by the handle (23) moving from the resting position in relation to the inner tube (19).

6. Suction tube arrangement according to any of the preceding claims, wherein the latch (25) is slidable sideways on the outer tube between the locked and unlocked positions.

7. Suction tube arrangement according to claim 6, wherein the latch (25) is located on the top side of the outer tube (21).

8. Suction tube arrangement according to claim 7, wherein the outer tube is connected to a handle (23) and the latch (25) is located less than 60 mm from the end of the handle.

9. Suction tube arrangement according to any of the preceding claims, comprising a flexible sealing lip (41) attached to the outer tube (21), which covers an opening (39) of the inner tube (19) in the resting position.

10. Suction tube arrangement according to claim 9, wherein the outer periphery of the inner tube (19) is covered by a mesh (45) at the opening (39).

11. A suction tube arrangement according to any of the claims above , comprising an inner tube (19) and an outer tube (21), which is slideable from a resting position in relation to the inner tube (19) against the force of an elastic element (35), wherein the inner and outer tubes comprise peripheral tube openings (39, 47) which openings are mutually offset in the resting position and which overlap by the outer tube sliding in relation to the inner tube thereby forming a bypass opening (49), comprising a flexible sealing lip (41) attached to the outer tube (21), which covers an opening (39) of the inner tube (19) in the resting position.

12. Suction tube arrangement according to claim 11, wherein the outer periphery of the inner tube (19) is covered by a mesh (45) at the opening (39).

13. A vacuum cleaner comprising a suction tube arrangement according to any of the preceding claims.

Images