CN116367762A - Suction tool - Google Patents

Abstract

A suction tool for a vacuum cleaner comprising: an outlet for connection to the vacuum cleaner; a main inlet in fluid communication with the outlet through a main suction passage; and an auxiliary inlet in fluid communication with the outlet through an auxiliary suction passage. The auxiliary suction channel includes a flow restriction movable between first and second configurations in which the flow restriction obstructs air flow through the auxiliary suction channel to a greater extent than in the first configuration. The flow restrictor is configured to move to the second position in response to pressure within the main suction passage falling below a predetermined threshold.

Description

suction tool

Background technique

Suction tools for vacuum cleaners come in many different forms but all have an inlet for dirty air to enter the tool and an outlet for the air to exit the tool and enter the vacuum cleaner ( The suction channel provides fluid communication between the inlet and the outlet, eg via a wand or a hose. In some tools, the suction channel includes a suction chamber in which a rotating brush bar protrudes slightly beyond the inlet for agitating the surface to be cleaned.

Some suction tools include an auxiliary inlet in communication with the outlet through an auxiliary suction channel through which a second airflow can flow through the tool. This can perform many different functions. For example, the auxiliary suction channel can form a discharge channel through which air can enter the cleaning head, preventing the pressure inside the tool from becoming too low due to clogging of the main inlet (which could cause the tool to "limpet" to the surface to be cleaned , or apply undue pressure to the vacuum motor of the vacuum cleaner to which the tool is attached). As another example, airflow through the auxiliary suction channel may be used to drive a turbine to rotate the brush bar, or to cool components such as a motor used to drive the brush bar.

It is known to include valves in the auxiliary flow channel, which close when the pressure inside the tool is relatively high and open when the pressure inside the tool is relatively low, so that flow through the auxiliary suction channel only occurs under certain conditions (for example, only Flow through the discharge occurs when the pressure inside the cleaning head is so low that settling is more likely). However, when the pressure drops low enough, the opening of the secondary runner can cause a decrease in the machine's pick-up performance. Additionally, when the pressure drop inside the tool is due to a blockage in the primary suction channel, opening the secondary suction channel reduces the likelihood of clearing the blockage with suction alone.

Contents of the invention

According to a first aspect of the present invention, there is provided a suction tool for a vacuum cleaner, the suction tool comprising:

outlet for connection to a vacuum cleaner;

a main inlet in fluid communication with the outlet through the main suction channel; and

an auxiliary inlet in fluid communication with the outlet through the auxiliary suction channel,

in:

the auxiliary suction passage includes a flow restriction movable between first and second configurations, the flow restriction obstructing air flow through the auxiliary suction passage to a greater extent in the second configuration than in the first configuration; and

The flow restrictor is configured to move to the second position in response to pressure within the main suction passage falling below a predetermined threshold.

When the suction tool is pushed firmly against the surface in order to perform a particularly thorough cleaning, the pressure in the main suction channel may drop below a threshold value. In this case, moving the restrictor to a more restricted position maximizes the pressure differential between the inside and outside of the suction tool by reducing or eliminating airflow into the tool through the auxiliary suction channel, thereby increasing the flow into the main suction channel. Inlet air velocity and thus improved pick-up performance.

Alternatively or additionally, the pressure in the main suction channel may drop below a threshold when the main suction channel is blocked (eg after suctioning a large piece of debris). In this case, movement of the flow restrictor to a more restricted position can maximize the pressure differential between the inside and outside of the suction tool, improving the chances of the blockage being cleared and passed through the tool without user intervention.

The suction means may comprise a rotatable brush bar, the auxiliary suction channel being associated with the drive mechanism of the brush bar.

For example, the auxiliary suction channel may pass over or through a component of the drive mechanism. This may allow airflow through the auxiliary suction channel to drive the brush bar (eg via a turbine).

As an alternative, the auxiliary suction channel may be a discharge channel arranged to provide airflow to the suction means in order to prevent "settling".

The drive mechanism may include a motor, and the auxiliary suction path may be routed through or adjacent to the motor so that air traveling through the auxiliary suction path may cool the motor.

Where the brushbar is driven by a motor, the motor is usually more prone to overheating than the other drive components. An auxiliary suction path routed through or close to the electric motor can thus be particularly effective in preventing short-term overheating of the drive.

Alternatively or additionally, the auxiliary suction path may be routed through or close to a different part of the drive mechanism, such as a gearbox, or an entirely different part, such as a bearing rotatably supporting the brush bar.

The brush strip may be hollow and the auxiliary suction channel may extend into the brush strip.

An auxiliary suction path extending into the brush strip may allow the suction path to reach components of the drive mechanism housed inside the brush strip, eg for cooling.

Alternatively, the auxiliary suction means may remain on the outside of the brush bar.

The flow restriction may be configured to substantially close the auxiliary flow channel when in the second configuration.

As noted above, the effect of the flow restriction becoming more restrictive when the pressure drops low enough can be amplified if the flow restriction substantially closes the secondary flow passage.

Alternatively, the flow restrictor may be configured to allow air to flow through the auxiliary flow channel when in the second configuration.

While this may reduce the effectiveness of the flow restriction device compared to an arrangement that substantially closes the auxiliary flow passage when in the second configuration, in some cases this reduction may be acceptable in order to maintain the function of the auxiliary suction passage. sacrifice. For example, where the auxiliary suction channel cools the brush-strip motor, a slight (but still minimal) compromise in pick-up can be beneficial in order to ensure that the brush-strip motor is still sufficiently cooled to withstand relatively long periods of high-intensity cleaning .

Optionally:

the current limiting device is movable from the first configuration to the second configuration through the intermediate configuration;

When in the intermediate configuration, the restrictor blocks air flow through the auxiliary suction passage to a greater extent than in the first configuration but less than in the second configuration; and

The flow restrictor is configured to move from the first position to the intermediate position in response to the pressure in the main suction passage falling below the upper predetermined threshold, and to move from the first position to the intermediate position in response to the pressure in the main suction passage falling below the lower predetermined threshold. The middle position is moved to the second position.

In other words, the obstructiveness of the flow restrictor may gradually increase as the pressure in the main suction channel gradually decreases. This can allow the flow through the auxiliary suction channel to more closely match the needs of the cleaning head. For example, when the pressure in the main suction channel begins to drop, which may indicate that the user is pushing the tool harder against the surface for a more thorough cleaning, the proportion of flow through the main inlet rather than the auxiliary inlet can be increased if the main suction channel The lower the medium pressure drops, the user may be pushing the tool extra hard against the surface and the tool may respond by further increasing the proportion of airflow through the main suction inlet. This can happen continuously or as a series of steps.

Alternatively, the current limiting device may have two discrete positions and switch between the two positions at a specific single threshold.

The primary and secondary suction channels may intersect and form a common suction channel extending to the outlet.

This can reduce the complexity of the piping within the suction tool. Furthermore, by choosing where the primary and secondary suction paths meet, the flow of air through the two channels can be varied.

For example, the primary suction channel may comprise a suction chamber, and the secondary suction channel may intersect the primary suction channel at the suction chamber.

Due to its relatively large cross-sectional area, the pressure within the suction chamber can generally be higher than the pressure elsewhere in the main suction channel. Therefore, the auxiliary suction opening that discharges to this area means that a relatively small proportion of the airflow through the tool flows through the auxiliary suction channel.

Alternatively, the main suction channel may comprise a suction chamber and the auxiliary suction channel may intersect the main suction channel downstream of the suction chamber.

Due to its relatively narrow cross-sectional area, the portion of the main flow path upstream of the pumping chamber is generally at a lower pressure than the pumping chamber. Therefore, the auxiliary suction openings that discharge to this area mean that a relatively large proportion of the air flow through the tool flows through the auxiliary suction channels.

The flow restrictor is biasable to a first position and is movable to a second position against said bias by air flowing through the auxiliary suction passage.

For example, the flow restrictor may comprise a deformable element that narrows in an upstream direction and defines a central bore, the deformable element being configured to be deformed inwardly by air flowing through the auxiliary suction path, thereby reducing the cross-sectional area of the central bore.

This may allow the flow restriction device and tool as a whole to be advantageously simple, thus reliable or easy to assemble, advantageously compact and/or advantageously lightweight.

As another example, the flow restricting device may include a valve element movable relative to the valve seat, and when the flow restricting device is in the second position, the positions of the respective surfaces of the valve member and the valve seat are closer together than when the flow restricting device is in the first position. near.

Compared to arrangements that rely on more complex interactions (e.g. the behavior of elastically deformable elements may be influenced by changes in shape and/or stiffness, and/or by harmonic influences), this may allow Or appropriate selection of the strength of the components responsible for biasing advantageously defines the behavior of the flow limiting device conveniently and/or predictably.

The flow restrictor may include a deformable channel extending through the neutral pressure zone, the deformable channel being configured to be crushed under the ambient pressure of the neutral pressure zone to move the deformable channel to the second position.

This may allow the flow limiting device to have a particularly simple mode of operation and/or be less susceptible to clogging.

According to a second aspect of the invention there is provided a suction tool for a vacuum cleaner, the suction tool comprising:

outlet for connection to a vacuum cleaner;

a main inlet in fluid communication with the outlet through the main suction channel; and

an auxiliary inlet in fluid communication with the outlet through the auxiliary suction channel,

in:

the auxiliary suction passage includes a flow restriction movable between first and second configurations, the flow restriction obstructing air flow through the auxiliary suction passage to a greater extent in the second configuration than in the first configuration; and

The flow restrictor is configured to move to the second position in response to air flow through the auxiliary suction passage exceeding a predetermined threshold.

According to a third aspect of the present invention, there is provided a vacuum cleaner comprising the suction tool as described above.

Features described above in relation to the first aspect of the invention apply equally to each of the second and third aspects of the invention and vice versa.

Description of drawings

The invention will now be described with reference to the accompanying drawings, in which:

1 is a perspective view of a stick vacuum cleaner according to a first embodiment of the present invention;

Figure 2 is a bottom perspective view of the cleaning head of the vacuum cleaner of Figure 1;

Figure 3 is a cross-sectional view through the cleaning head of the vacuum cleaner of Figure 1;

Figure 4 is a rear perspective view of the cleaning head of Figures 1 and 2, with the top cover removed;

Figure 5 is a perspective view of the current limiting device of the first embodiment;

Figure 6 is a cross-sectional view of a flow restricting device of a second embodiment of the present invention; and

7 is a rear perspective view of a cleaning head of a third embodiment of the present invention, with the top cover removed.

Detailed ways

Corresponding reference numerals indicate corresponding features throughout the description and drawings.

Figure 1 shows a vacuum cleaner 2 according to a first embodiment of the invention. The vacuum cleaner 2 of this embodiment is a stick vacuum cleaner comprising a hand-held vacuum cleaner 4 which can be attached to a suction implement in the form of a cleaning head 6 by means of an elongated rigid stick 8 . The hand-held vacuum cleaner 4 includes a vacuum motor (not shown) powered by a battery pack 10 and a dirt separator 12 with an inlet 14 at its front. The hand-held vacuum cleaner 4 is not subject matter of the present invention and therefore will not be described in detail.

The cleaning head 6 is shown in more detail in FIGS. 2 to 4 . The cleaning head 6 has an outlet 20 connected by the wand 8 to the hand-held vacuum cleaner 4 by means of a wheeled hinged neck 21 and a main inlet in the form of an opening 22 in a floor 24 touching the ground. The main suction channel 26 extends from the main inlet 22 to the outlet 20 and includes a suction chamber 28 within which is disposed a hollow rotatable brush bar 30 . A cap 32 extends over the top of the cleaning head.

In addition to the main inlet 22 and the main suction channel 26 , the cleaning head 6 has an auxiliary inlet in the form of a grid 40 and an auxiliary suction channel 42 . In this particular case, an auxiliary inlet 40 is provided in the right side wall of the cleaning head 6 , the auxiliary suction channel 42 being associated with the drive mechanism 44 of the brush bar 30 . More specifically, the auxiliary suction channel 42 enters the right side of the brush bar 30, flows through the cantilevered motor support 45 of the drive mechanism, then flows through the motor 46 of the drive mechanism 44 that drives the brush bar 30, and flows through the brush bar 30. The pipe 47 enters the end chamber 49. Auxiliary suction channel 42 then runs upwards and rearwards in the end chamber, passes through straight pipe 50 in space 51 below top cover 32, and connects with suction channel downstream of suction chamber 28 at hole 53 shortly before outlet 20 26 intersect. Thus, the final portion 52 of the fluid path through the cleaning head 6 extending from the point where the primary and secondary suction channels 26 and 42 intersect to the outlet 20 (and through the neck 21 ) is the common suction channel.

Auxiliary suction channel 42 includes a flow restriction, which in this embodiment is located within straight tube 50 . FIG. 5 shows an isolated current limiting device 60 . In this embodiment, the flow limiting means takes the form of a deformable element 62, in this case made of elastic rubber. The flow restrictor has an annular boss 63 that seals inside the straight tube 50 , and a protrusion 65 that narrows in the upstream direction and defines a central bore 64 .

The flow limiting device 60 is movable between a first configuration (as shown in FIG. 5 ) to a second configuration. In the second configuration, the narrower end of the deformable element 62 is crushed inwardly and the aperture 64 is squeezed closed. In the second configuration with the holes 64 closed, no or almost no air can flow through the auxiliary suction channel 42 . Thus, in the second configuration, the flow restrictor is more obstructive to the flow of air through the auxiliary suction channel 42 than in the first configuration. Due to the elastic nature of the deformable element 62, the deformable element 62 is biased in the first configuration and must be moved to the second configuration by an external force against the bias. When the external force is removed, the deformable element 62 (and thus the flow restrictor 60 as a whole) springs back to the first configuration.

The flow restrictor 60 is configured to move from the first configuration to the second configuration in response to the air pressure within the main suction passage 26 falling below a threshold. More specifically, when the pressure in the primary suction passage 26 is above a threshold, then relatively less air is drawn through the secondary suction passage 42 . When the pressure in the main suction channel 26 starts to drop, more air is sucked through the secondary suction channel. When the pressure in the primary suction channel 26 drops below a threshold, sufficient air is drawn through the secondary suction channel 42, which deforms the deformable element 62 against the bias provided by its elastic properties. The holes 64 then snap into place, the flow restrictor 60 is in the second configuration, and no more air passes through the auxiliary suction channel 42 .

With the flow restriction 60 in the second configuration, the pressure differential across the deformable element 62 keeps the aperture 64 closed. However, when the pressure within the main suction channel rises sufficiently, the resilient bias of the deformable element 62 causes the aperture 64 to open again and the flow restrictor to return to the first configuration.

The flow limiting device 60 according to the second embodiment of the present invention, for example, can replace the flow limiting device 60 in the straight pipe 50 of the cleaning head 6 of the first embodiment, as shown in FIG. 6 . The flow restrictor 60 of the present embodiment has a valve element 70 movable along a main axis 72 relative to a valve seat 74 .

Like the current limiting device 60 of the first embodiment, the current limiting device 60 of this embodiment has a first configuration and a second configuration. Figure 6 shows the current limiting device 60 in a first configuration. With the flow restrictor 60 in the second configuration, the valve element 70 abuts against the valve seat 74 . With the flow restrictor 60 in the first configuration, air can flow through the relatively wide gap between the valve element 70 and the valve seat 74 . However, the valve element 70 abuts against the valve seat 74 and the gap is completely closed. Accordingly, like the flow restriction of the first embodiment, the flow restriction 60 is more obstructive to flow through the auxiliary suction channel in the second configuration than in the first configuration.

The current limiting device 60 of this embodiment, like the current limiting device 60 of the previous embodiments, is biased in the first configuration. In this case, the flow restrictor 60 includes a compression spring 76 located around the main shaft 72 and held between the valve seat 74 and the valve element 70 . In use, when the pressure in the primary suction passage 26 is relatively high, air in the secondary suction passage 42 can simply flow through the valve element and then past the valve seat. However, when the pressure in the primary suction passage 26 drops below that air flows through the secondary suction passage 42 fast enough that the valve element is forced toward the valve seat 74 (i.e., the flow restrictor 60 moves from the first configuration to the second configuration).

However, the current limiting device 60 of the present embodiment does not move abruptly and completely from the first configuration to the second configuration as in the first embodiment. In this case, the current limiting device 60 moves from the first configuration to the second configuration through an intermediate configuration. In the intermediate configuration, the flow restrictor 60 is more restrictive on airflow through the auxiliary suction channel 42 than in the first configuration, but less restrictive than in the second configuration.

In this particular embodiment, the flow restricting device 60 moves through successive configurations, any of which may be referred to as intermediate configurations. When the pressure in the primary suction passage 26 is above the upper threshold, the flow through the secondary suction passage 42 is too slow to move the valve element 70, as described above. Once the pressure in the primary suction passage 26 drops below the upper threshold, the air in the secondary suction passage 42 moves fast enough to move the valve member 70 toward the valve seat 74 . However, this compresses the spring 76, which acts to prevent further movement of the valve element 70. The continued reduction in pressure in the primary suction passage 26 accelerates the airflow in the secondary suction passage 42 , which moves the valve member 70 closer to the valve seat 74 . This causes further compression of the spring 76 , thereby increasing the force forcing the valve element 70 off the valve seat such that the valve element still does not reach the valve seat 74 . Once the pressure in the primary suction passage 26 drops further, below the lower threshold, the air velocity through the secondary suction passage 26 is sufficient to force the valve element 70 against the valve seat 74 . The current limiting device 60 then reaches the second configuration.

While the flow restriction 60 of the first embodiment prevents air from flowing through the auxiliary suction passage 42, the flow restriction 60 of the present embodiment does not. The valve element 70 is provided with a set of through holes 78 which allow some air to pass along the auxiliary suction passage even if the valve element 70 is pressed against the valve seat 74 . Therefore, the auxiliary suction channel 42 of this embodiment is never completely closed.

Figure 7 shows a cleaning head 6 according to a third embodiment of the invention, which is a modification of the first embodiment, so only the differences are described here. In this embodiment, the flow restrictor 60 is formed by a part of the straight pipe 50 itself. In this embodiment, the top cover (not shown) has a hole therethrough, which ensures that the space 51 through which the straight pipe 50 passes forms a neutral pressure zone (i.e. a region under ambient pressure), and the portion of the straight pipe 50 is formed by Made of resilient elastic material, the flow limiting device 60 is formed in the form of a deformable channel. When the pressure in the main suction passage 26 is relatively high and the pressure in the straight pipe 50 is relatively high, the deformable passage 60 has a general pipe shape (ie, occupies the first configuration). However, when the pressure in the main suction passage 26 drops, the pressure in the straight tube 50 also drops and the deformable passage 60 begins to be crushed by the ambient pressure. This in turn reduces the cross-sectional area available for air flow inside the deformable channel 60, so the channel becomes more obstructive. A further reduction in pressure results in further crushing of the deformable channel 60 until it closes completely. The increase in pressure within the main suction channel 26 has the opposite effect, allowing the deformable channel to spring back to its original shape, increasing the cross-sectional area within the deformable channel.

It will be appreciated that various modifications may be made to the embodiments described above without departing from the scope of the invention as defined in the appended claims. For example, a deformable element may be shaped such that it moves from a first configuration to a second configuration through one or more intermediate configurations. As another example, in a modification of the second embodiment, the valve element may not be provided with a through hole, so that the auxiliary suction channel may be completely closed in the second configuration.

Claims (9)

1. A suction tool for a vacuum cleaner, the suction tool comprising:

an outlet for connection to a vacuum cleaner;

a primary inlet in fluid communication with the outlet through a primary suction channel; and

an auxiliary inlet in fluid communication with the outlet through an auxiliary suction channel,

wherein:

the auxiliary suction channel comprising a restriction movable between a first and a second configuration, the restriction blocking air flow through the auxiliary suction channel to a greater extent in the second configuration than in the first configuration; and also

The flow restriction device is configured to move to a second position in response to the pressure within the primary suction channel falling below a predetermined threshold;

wherein the flow restricting device is biased to a first position and is movable against the bias to a second position by air flowing through the auxiliary suction channel;

wherein the flow restriction means comprises a deformable element narrowing in an upstream direction and defining a central aperture, the deformable element being configured to be deformed inwardly by air flowing through the auxiliary suction path, thereby reducing the cross-sectional area of the central aperture.

2. The suction tool of claim 1, wherein the suction tool comprises a rotatable brush bar, the auxiliary suction channel being associated with a drive mechanism of the brush bar.

3. The suction tool of claim 2, wherein the drive mechanism includes a motor through or near which the auxiliary suction path is routed so that air traveling through the auxiliary suction path can cool the motor.

4. A suction tool according to any preceding claim, wherein the brush bar is hollow, the auxiliary suction channel extending into the brush bar.

5. A suction tool according to any preceding claim, wherein the flow restricting means is configured to substantially close the auxiliary flow channel when in the second configuration.

6. A suction tool according to any preceding claim, wherein the primary suction channel and the secondary suction channel intersect and form a common suction channel extending to the outlet.

7. The suction tool of claim 6, wherein the primary suction channel comprises a suction chamber, the secondary suction channel intersecting the primary suction channel at the suction chamber.

8. The suction tool of any one of claims 1 to 6, wherein the primary suction channel comprises a suction chamber, the secondary suction channel intersecting the primary suction channel downstream of the suction chamber.

9. A vacuum cleaner comprising a suction tool according to any one of the preceding claims.

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