EP3225144B1

EP3225144B1 - Vacuum cleaner

Info

Publication number: EP3225144B1
Application number: EP17162677.3A
Authority: EP
Inventors: Bin Xu; Davide Barlotti
Original assignee: Conta sro
Current assignee: Conta sro
Priority date: 2016-03-31
Filing date: 2017-03-23
Publication date: 2019-02-20
Anticipated expiration: 2037-03-23
Also published as: CN107280577B; CN107280577A; EP3225144A1

Description

This invention relates to a vacuum cleaner having reduced noise emission characteristics.
A problem with all vacuum cleaners is that they emit noise, which is annoying for the user and other people within the vicinity of the cleaner. The main source of noise in a vacuum cleaner is the motor and fan unit which creates an airflow through the cleaner from the suction nozzle to the exhaust. The motor and fan unit creates noise by virtue of vibration from the motor and by pulsed airflow through the fan. Turbulence in the airflow through the vacuum cleaner can also cause further noise. Considering that the motor and fan unit is the main noise source, it is logical to attempt to confine noise originating from this unit to the enclosure in which the motor and fan unit is housed. A problem with this is that the enclosure must have an air inlet and an air outlet and hence noise from inside the enclosure can escape through the air inlet and/or air outlet. This means restricting noise emission both upstream and downstream of the motor/fan unit.
Methods of reducing or preventing noise emission upstream of the fan have been disclosed in CN203555698U and WO2014/135192 . Vacuum cleaners conventionally incorporate a pre-motor" filter located upstream of the motor and fan unit and downstream of the filter bag or other dust separator. The purpose of this filter is to prevent particles still in the airstream downstream of the filter bag or other separator from entering the motor and fan unit and possibly causing damage. In canister cleaners, this typically comprises a filter medium, such as foam, mounted in a frame detachable from the cleaner for maintenance of the filter (i.e. cleaning or replacement of the filter medium). The filter frame normally comprises a grille on which the filter medium is replaceably fitted, and is mounted on the bulkhead separating the chamber in which the filter bag or other dust separator is housed from the motor and fan unit. In conventional vacuum cleaners a considerable proportion of the noise generated by the motor and fan unit escapes upstream through the pre-motor filter to enter the environment in which the cleaner is operating. A vacuum cleaner according to the preamble of claim 1 is already known e.g. from WO-A-2014056686 .
We have now devised a vacuum cleaner having reduced noise emission characteristics.
In accordance with the present invention, there is provided a vacuum cleaner having:

an inlet;
an outlet;
an airflow passageway extending between the inlet and outlet, the passageway having a flow axis;
a fan for creating an airstream along the passageway from the inlet to the outlet; and
a baffle device,

a first set of baffles extending across the passageway; and
a second set of baffles extending across the passageway at a point located downstream of the first set of baffles, the baffles of each set being separated from each other by elongate openings, each baffle having:
- a longitudinal upstream surface directed towards the inlet which is inclined relative to the flow axis; and
- a longitudinal downstream surface directed towards the outlet which is inclined relative to the flow axis,

In use, air flowing the along the passageway initially impacts the inclined upstream surfaces of the upstream set of baffles, which act to smoothly separate and distribute the airflow through the elongate openings therebetween. The laminar airflow through the openings in the upstream set of baffles then impacts the inclined upstream surfaces of the downstream set of baffles, which act to smoothly separate and distribute the airflow through the elongate openings therebetween. Although the transposed alignment of the baffles of the upstream and downstream sets of baffles prevents air from flowing axially of the passageway between opposite sides of the baffle device, the profile of the upstream surface of each baffle helps to minimise disruption of the airflow and reduces resistance, so that very little pressure drop is created across the baffle device and suction power is not compromised.
Sound propagating upstream of the passageway from the fan or other noise source impacts the inclined downstream surfaces of the downstream set of baffles, which act as reflectors to scatter and reflect the sound back towards the noise source and to prevent it from propagating upstream. In this manner, the baffle device acts to substantially reduce the noise that is emitted by the vacuum cleaner.
Each baffle may have:

a pair of longitudinal upstream surfaces directed towards the inlet which are inclined in opposite directions relative to the flow axis and which diverge in the downstream direction; and
a pair of longitudinal downstream surfaces directed towards the outlet which are inclined in opposite directions relative to the flow axis and which converge in the upstream direction.

In use, air flowing the along the passageway initially impacts the upstream set of baffles, with the diverging longitudinally extending upstream surfaces acting to smoothly separate and distribute the airflow through adjacent elongate openings therebetween. The laminar airflow through the openings in the upstream set of baffles then impacts respective baffles of the downstream set, with the diverging longitudinally extending upstream surfaces acting to smoothly separate and distribute the airflow through adjacent elongate openings therebetween.
The upstream and/or downstream surfaces of the baffles may be U or V shaped.
The fan may be mounted downstream of the baffle device.
The vacuum cleaner may comprise a filter bag or other separation device for separating dirt and dust from the airstream.
The separation device may be mounted upstream of the baffle device.
The separation device may be mounted in a chamber disposed inside the vacuum cleaner, the baffle device being disposed across an opening in a wall of the chamber. The baffle device may be detachable from the vacuum cleaner, to allow the device to be removed, replaced or cleaned.
The baffles of each set may lie in the same plane as each other and may extend parallel to each other.
The baffle device may comprise a baffle assembly having an upstream baffle member and a downstream baffle member which are detachably connected to each other and which respectively define the upstream and downstream set of baffles.
The baffle assembly may comprise an upstream filter disposed between the upstream baffle member and the downstream baffle member.
The baffle assembly may comprise a downstream filter disposed downstream of the downstream baffle member. The downstream filter may be disposed in a frame of the baffle assembly.
The width of the baffles of the upstream set of baffles may be at least equal to the width of the elongate openings between the baffles of the downstream set of baffles.
The width of the baffles of the downstream set of baffles may be at least equal to the width of the elongate openings between the baffles of the upstream set of baffles.
In one embodiment, the upstream surfaces of the downstream set of baffles may be co-planar with the downstream surfaces of the upstream set of baffles.
In an alternative embodiment, the upstream surfaces of the downstream set of baffles may be separated from the downstream surfaces of the upstream set of baffles to define a planar void therebetween.
An embodiment of the present invention will now be described by way of an example only and with reference to the accompanying drawings, in which:

Figure 1 is a perspective view from the front and above of a vacuum cleaner in accordance with the present invention, with some parts shown cut away;
Figure 2 is a part sectional view along the line ii-ii of Figure 1;
Figure 3 is a front perspective view of a baffle assembly of the vacuum cleaner of Figure 1; and
Figures 4A to 4D are sectional views along the line iv-iv of Figure 3.

Referring to Figures 1 and 2 of the drawings, there is shown the body of a so-called canister vacuum cleaner comprising a housing 10 which defines a front chamber 11 in which a filter bag or other dust separation device (not shown) is housed. The upper wall of the front chamber 11 comprises a lid 12, which is shown partly cut away in Figure 1, so that the chamber 11 can be seen. An inlet port 13 is provided on the lid 12 for coupling to the proximal end of an elongate flexible hose (not shown). The distal end of the flexible hose is connected to a tubular wand which is arranged for selectively coupling to detachable cleaning tools and heads, perhaps via one or more extension tubes. The underside of the inlet port 13 comprises a formation 14 adapted to sealingly engage an inlet of the filter bag or other dust separation device.
The housing 10 also defines a rear chamber 15 in which a motor and fan unit 16 is disposed. The rear chamber 15 is separated from the front chamber 11 by a bulkhead 17 that forms the rear wall of the front chamber 11. An opening is provided in the bulkhead between the rear chamber 15 and the front chamber 11, a grille 18 extending across the opening. A baffle assembly 19 in accordance with the present invention is detachably fitted inside the front chamber 11 over the grille 18.
In use, when the motor and fan unit 16 is energised, air is drawn from the surface being cleaned through the cleaning tool or head and along the wand and flexible hose to the inlet port 13. Air then enters the inlet of the filter bag or other dust separation device, where any dirt or dust entrained in the airflow is separated and retained. The lid 12 of the front chamber 11 can be opened to remove, clean, replace or empty the filter bag or other dust separation device.
Air leaving the filter bag or other dust separation device exits the chamber 11 through the grille 18 into the rear chamber 15, where it is drawn by the motor and fan unit 16. Clean air then leaves the vacuum cleaner through an exhaust outlet 20 on the housing 10. Hitherto, noise created by the motor and fan unit propagate out of the rear chamber through the grille 18 into the front chamber 11. As will be described hereinafter, the baffle assembly 19 acts to substantially reduce the noise that propagates into the front chamber 11 from the motor and fan unit 16.
Referring also to Figures 3 and 4A of the drawings, the baffle assembly 19 comprises first upstream and second downstream baffle members 21A, 21B which are detachably connected to each other and which are similar in construction. Each baffle member e.g. 21A comprises a rectangular peripheral frame e.g. 22A and a plurality of elongate baffles e.g. 23A extending between opposite sides of the frame e.g. 22A. The baffles e.g. 23A extend parallel to each other and are spaced apart to provide elongate openings, through which air can flow. Each baffle e.g. 23A is substantially V-shaped in section and comprises an apex facing upstream perpendicular to the plane of the baffle member e.g. 21A in the same direction as the other baffles 23A, 23B, and a pair of divergent wings which extend downstream from the apex.
The frame 22B of the downstream baffle member 21B is dimensioned to fit closely inside the frame 22A of the upstream baffle member 21A, the members being held together by snap engagement of respective parts. The baffles 23A, 23B of the upstream and downstream baffle members 21A, 21B are staggered with respect to each other such that the baffles 23A of the upstream baffle member 21A are disposed directly in front of respective elongate openings in the downstream baffle member 21B. Likewise, the baffles 23B of the downstream baffle member 21B are disposed directly behind respective elongate openings in the upstream baffle member 21A. The width of the upstream and downstream baffles 23A, 23B are at least equal to the width of the elongate openings in the downstream and upstream baffle members 21B, 21A. A planar void may be disposed between the upstream and downstream baffles 23A, 23B.
The baffle assembly 19 snap engages with the front wall of the bulkhead 17 over the grille 18, with the apexes of the baffles 23A, 23B being directed into the front chamber 11. In use, air flowing out of the front chamber 11 initially impacts the apexes of the upstream baffles 23A, with the wings of the baffles 23A acting to smoothly separate and distribute the airflow through adjacent elongate openings therebetween. The laminar airflow through the openings in the upstream baffle 21A then impacts the apexes of respective downstream baffles 23B, with the wings of the baffles 23B again acting to smoothly separate and distribute the airflow through adjacent elongate openings therebetween. Although air is unable to flow directly between the front and rear chambers 11,15 through the baffle assembly 19, the V-shape of the baffles 23A, 23B helps to minimise disruption of the airflow and reduces resistance, so that very little pressure drop is created between the front and rear chambers 11,15 and suction power is not compromised.
Sound propagating from the motor and fan unit 16 out of the rear chamber 15 impacts the inclined downstream surfaces of the baffles 23A, 23B, which act as reflectors to scatter and reflect the sound back towards the motor and fan unit 16 and to prevent it from propagating into the front chamber 11. In this manner, the baffle assembly 19 acts to substantially reduce the noise that propagates into the front chamber 11 from the motor and fan unit 16.
Referring to Figure 4B of the drawings, a thick foam or fibrous filter 24 may be fitted inside the frame 22B of the downstream baffle member 21B to prevent any fine dirt and dust in the airflow from entering the motor and fan unit 19.
Referring to Figure 4C of the drawings, a thin filter 25 may be fitted inside the planar void disposed between the upstream and downstream baffles 23A, 23B to prevent any coarse dirt and dust in the airflow from entering the motor and fan unit 19. The upstream and downstream baffle members 21A, 21B can be separated to allow the filter 25 to be removed, replaced or cleaned.
Referring to Figure 4D of the drawings, the baffle assembly 19 may comprise both the filter 24 of Figure 4B and the filter 25 of Figure 4C.
The baffle assembly 19 of the present invention is simple and inexpensive in construction, yet provides the vacuum cleaner with a substantially reduced noise level.

Claims

A vacuum cleaner comprising:
an inlet (13);

an outlet (20);

an airflow passageway extending between the inlet and outlet, the passageway having a flow axis;

a fan (16) for creating an airstream along the passageway from the inlet to the outlet; and

a baffle device (19),
characterized in that the baffle device comprises:
a first set of baffles (21A) extending across the passageway; and

a second set of baffles (21B) extending across the passageway at a point located downstream of the first set of baffles, the baffles of each set being separated from each other by elongate openings,
wherein each baffle comprises:
a longitudinal upstream surface directed towards the inlet which is inclined relative to the flow axis; and

a longitudinal downstream surface directed towards the outlet which is inclined relative to the flow axis,
the baffles of the second set of baffles being transposed perpendicular to the flow axis with respect to the baffles of the first set of baffles, such that the baffles of the second set of baffles are aligned with respective elongate openings between the baffles of the first set of baffles along the flow axis and such that the baffles of the first set of baffles are aligned with respective elongate openings between the baffles of the second set of baffles along the flow axis.
A vacuum cleaner as claimed in claim 1, in which the fan is mounted downstream of the baffle device.
A vacuum cleaner as claimed in claim 1 or claim 2, in which a filter bag or other separation device for separating dirt and dust from the airstream is mounted upstream of the baffle device.
A vacuum cleaner as claimed in claim 3, in which the separation device is mounted in a chamber disposed inside the vacuum cleaner, the baffle device being disposed across an opening in a wall of the chamber.
A vacuum cleaner as claimed in any preceding claim, in which the baffles of each set lie in the same plane as each other and extend parallel to each other.
A vacuum cleaner as claimed in any preceding claim, in which the baffle device comprises a detachable baffle assembly having an upstream baffle member and a downstream baffle member which are detachably connected to each other and which respectively define the upstream and downstream set of baffles.
A vacuum cleaner as claimed in claim 6, in which the baffle assembly comprises an upstream filter disposed between the upstream baffle member and the downstream baffle member.
A vacuum cleaner as claimed in claim 6 or claim 7, in which the baffle assembly comprises a downstream filter disposed downstream of the downstream baffle member.
A vacuum cleaner as claimed in any preceding claim, in which the width of the baffles of the upstream set of baffles is at least equal to the width of the elongate openings between the baffles of the downstream set of baffles.
A vacuum cleaner as claimed in any preceding claim, in which the width of the baffles of the downstream set of baffles is at least equal to the width of the elongate openings between the baffles of the upstream set of baffles.
A vacuum cleaner as claimed in any preceding claim, in which baffle comprises:
a pair of longitudinal upstream surfaces directed towards the inlet which are inclined in opposite directions relative to the flow axis and which diverge in the downstream direction; and

a pair of longitudinal downstream surfaces directed towards the outlet which are inclined in opposite directions relative to the flow axis and which converge in the upstream direction.