GB2553013A

GB2553013A - Vacuum cleaner

Info

Publication number: GB2553013A
Application number: GB1703156.8A
Authority: GB
Inventors: Anthony Denny Bassett Alexander; Chengling Zhang
Original assignee: Conta sro
Current assignee: Conta sro
Priority date: 2016-08-16
Filing date: 2017-02-27
Publication date: 2018-02-21
Anticipated expiration: 2037-02-27
Also published as: CN107752900A; CN107752900B; GB2553013B; GB201703156D0

Abstract

A vacuum cleaner comprises an upright body 10 pivotally connected at its lower end to a wheeled floor-engaging head 20 having a suction mouth 13 on its underside. A motor and fan unit 11 draw air into the cleaner from the suction mouth 13 into a dirt and dust separation unit 12 located in the body 10. A displaceable actuator 18 can be used to set the height of the suction mouth 13 relative to a floor surface being cleaned, wherein displacement of the actuator 18 further selectively reduces the speed of rotation of the fan by the motor 11 as the height of the suction mouth relative to the floor surface being cleaned is reduced. Similarly the speed of rotation of the fan is increased as the height of the suction mouth in increased relative to the floor surface.

Description

(54) Title of the Invention: Vacuum cleaner Abstract Title: A vacuum cleaner (57) A vacuum cleaner comprises an upright body 10 pivotally connected at its lower end to a wheeled floor-engaging head 20 having a suction mouth 13 on its underside. A motor and fan unit 11 draw air into the cleaner from the suction mouth 13 into a dirt and dust separation unit 12 located in the body 10. A displaceable actuator 18 can be used to set the height of the suction mouth 13 relative to a floor surface being cleaned, wherein displacement of the actuator 18 further selectively reduces the speed of rotation of the fan by the motor 11 as the height of the suction mouth relative to the floor surface being cleaned is reduced. Similarly the speed of rotation of the fan is increased as the height of the suction mouth in increased relative to the floor surface.

1/4

FIG. 1

2/4

FIG.2

3/4

FIG. 3

4/4

L

FIG.4

Vacuum Cleaner

This invention relates to a vacuum cleaner.

As from September 2017, European Union Directives require that the motor power of vacuum cleaners is restricted to 900 Watts. Product marking is also to be introduced concerning, among other things, the annual energy consumption (AE) of the cleaner: this has to be indicated on the product as a grade in the range of A (best) to G (poorest). The energy consumption is a product of the dust pick up (DPU) performance of the cleaner and the motor power needed to achieve this DPU. The standard test procedure whereby the energy efficiency grade of a vacuum cleaner is determined involves evaluation of the DPU performance for one or both of the following two types of floor surfaces, with the cleaner operating at its maximum continuous motor power:

• Carpet • Hard floor with crevices

In the case of general purpose vacuum cleaners arranged for cleaning both of the above types of floor surfaces, the value on which the AE energy consumption is based is the sum of 50% of the observed values for the respective floor types. It must be noted that, although the test procedure involves determination of DPU efficiency in hard-floor cleaning with maximum motor power, correct features of nozzle design enable the DPU hard floor performance can be maintained at the same level even at lower power settings.

EP2452600 discloses a general purpose or so-called upright vacuum cleaner comprising an upright body portion pivotally connected at its lower end to a wheeled floor-engaging head portion for partial rotation forwardly and rearwardly about a transverse axis. Either the head or body portion encloses a motor and fan unit. The body portion encloses means for separating and collecting the dirt and dust that is drawn into the cleaner by the motor and fan unit. An upstanding handle is provided at the upper end of the body for guiding and maneuvering the cleaner. The head portion comprises a suction mouth on its underside, through which air is drawn into the cleaner by the fan from the floor surface being cleaned. A rotary agitator brush is mounted across the suction mouth to beat and sweep the floor surface in the region of the airflow into the cleaner. The rotary agitator brush is either driven by the fan motor or by a separate motor in the head.

Hitherto, the only control function available in upright cleaners is the setting of the height of the suction mouth relative to the floor surface in dependence on the type of floor being cleaned. This is normally effected by raising or lowering a pair of wheels of the head portion by actuating a rotary knob or slider to adjust a cam which supports the wheels. In this manner, the height of the suction mouth above the floor surface can be set by the user, and also the contact between the agitator brush and the floor can be set by the user. Sometimes, the wheels are lowered to raise the height of the suction mouth when the body of the cleaner is pivoted upwardly from its operative position into a parked position and vice-versa.

When cleaning hard floors, it is desirable to have the wheels raised, so that the suction mouth is positioned close to the floor, whereby the airflow draws dirt and dust from the floor surface and any floor crevices. When cleaning carpets, it is desirable to have the wheels lowered, so that the suction mouth is raised above the carpet surface to a position where rotation of the agitator brush is not severely impeded by the carpet pile. Sometimes, a number of different raised positions may be provided, so that the user can select the height of the head commensurate with the depth of the pile of the carpet being cleaned.

The standard test procedure on which the energy efficiency grade for a general purpose vacuum cleaner is based involves determining the DPU efficiency for the two above-mentioned floor types and calculating an AE annual energy consumption.

In a practical use situation, it is to be expected that performance of a vacuum cleaner is consistent with the results of the test on which the efficiency grade is based. It must also be acknowledged that the height setting of the head of the vacuum cleaner in a practical use situation must be appropriate for the floor type to achieve a level of efficiency commensurate with the efficiency grade according to the test.

The object of the present invention is to provide a general purpose vacuum cleaner which has good DPU values for both hard floors and crevices and which can be repeatably configured by the user for cleaning either floor type in a way which is incomplex and which avoids the possibility of accusations of fraudulent action on the part of the manufacturer in achieving the advertised DPU values.

With the above objectives in mind, we have now devised an improved vacuum cleaner.

In accordance with the present invention, there is provided a vacuum cleaner comprising an upright body portion pivotally connected at its lower end to a wheeled floor-engaging head portion for partial rotation forwardly and rearwardly about a transverse axis, the head portion comprising a suction mouth on its underside, the cleaner further comprising a fan and a motor arranged to rotate the fan to draw air into the cleaner from the suction mouth into means in the body portion for separating and collecting dirt and dust that is drawn into the cleaner, and a displaceable actuator for setting the height of the suction mouth relative to a floor surface being cleaned, wherein displacement of the actuator further selectively reduces the speed of rotation of the fan by the motor as the height of the suction mouth relative to the floor surface being cleaned is reduced and vice-versa.

As stated above, hard floor cleaning is best performed with the suction mouth lowered, whereas carpet cleaning is best performed with the suction mouth raised. However, during hard floor cleaning, the suction mouth is positioned so close to the floor surface that a comparable DPU value can be achieved at a lower motor power setting. Hence, since the AE annual energy consumption during a hard floor test is a product of the DPU and the average specific energy consumption during the hard floor cleaning test, the overall AE annual energy consumption (on which the cleaner’s energy efficiency rating of A to G is based), is lowered. Also, since the power is reduced automatically when the head is lowered and vice-versa, there is no doubt that the test is being performed under the correct conditions and in a way which can be repeated by the user during use.

The actuator may be displaceable to reduce the speed of rotation of the fan when the head is below a predetermined height of the head relative to the floor. The speed of rotation of the fan may be constant when the head is above said predetermined height or it may be variable.

In some cleaning applications, it may be desirable for the user to have the fan rotating at an increased or full speed when the head is in close proximity to the ground. Thus, the actuator may displaceable to bring the head into a position at or adjacent said predetermined height in which the speed of rotation of the fan by the motor is increased.

Preferably the actuator is displaceable between positions which are respectively labelled as being suitable for each floor type, so that the tester and user can be in no doubt where to position the actuator for hard floor and carpet cleaning.

The actuator may be arranged to index or latch at a plurality of positions defining respective heights of the suction mouth relative to the floor.

The actuator may comprise a formation which is arranged to operate an electrical switch to reduce the speed of rotation of the fan when the head is lowered and viceversa.

Preferably a rotary agitator brush is mounted across the suction mouth, the actuator being arranged to selectively reduce the speed of rotation of the agitator as the height of the suction mouth relative to the floor surface being cleaned is reduced and vice-versa. When performing hard floor cleaning the agitator brush is not needed to achieve a good DPU and thus stopping or reducing the speed of rotation of the agitator brush helps to save power and hence improves the overall AE annual energy consumption.

In one embodiment, the agitator may be driven by the fan motor, the speed of rotation of the agitator being reduced by disconnecting or partially decoupling the agitator from the motor.

In an alternative embodiment, the agitator may be driven by an agitator motor, the speed of rotation of the agitator being reduced by disconnecting or reducing the power applied to the agitator motor.

A seal may extend around the suction mouth to modify the flow of air into the suction mouth when the head is lowered in a way which improves the DPU. The actuator may be arranged to selectively lower the seal as the height of the suction mouth relative to the floor surface being cleaned is reduced and vice-versa.

The speed of rotation of the or each motor may be varied by varying the current waveform of the electrical supply to the motor, for example using phase control. However, other methods of varying the speed could be used, such as varying the configuration of the motor windings.

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 bottom view of an upright vacuum cleaner in accordance with the present invention;

Figure 2 is a schematic sectional view along the line II - II of Figure 1;

Figure 3 is a side view of an actuator cam of the vacuum cleaner of Figure 1; and

Figure 4 is schematic circuit diagram of the vacuum cleaner of Figure 1.

Referring to Figures 1 and 2 of the drawings, there is shown a so-called upright vacuum cleaner comprising an upright body portion 10 pivotally connected at its lower end to a wheeled floor-engaging head portion 20 for partial rotation forwardly and rearwardly about a transverse axis A. The body portion 10 encloses a motor and fan unit 11 and a separator 12 for separating and collecting the dirt and dust that is drawn into the cleaner by the motor and fan unit 11. An upstanding handle (not shown) is provided at the upper end of the body 10 for guiding and maneuvering the cleaner.

The head portion 20 comprises an elongate transversely extending suction mouth 13 on its underside, through which air is drawn into the cleaner by the motor and fan unit 11 ffrom the floor surface being cleaned. A rotary agitator brush 14 is mounted across the suction mouth for rotation about an axis which extends longitudinally thereof. The rotary agitator brush 14 is driven by a DC agitator motor (not shown) in the head 20. A depending seal 21 extends along opposite sides and opposite ends of the suction mouth.

A rotary actuator 18 is disposed on the upper surface of the head 20. The actuator 18 rotates a cam 17 about a vertical axis. Referring also to Figure 3 of the drawings, the cam 17 comprises an enlarged body having radially projecting shoulder at its upper end. The underside of the shoulder defines a ramped cam surface which is profiled to provide a plurality of camming positions P1 to P4. The positions P2 to P4 are disposed progressively closer to the lower end of the cam 17, whereas position P2 is positioned further away from the lower end of the cam 17 than position P1.

The head 20 is supported on the floor surface by a pair of front wheels 15 and a pair of rear wheels 16. The front wheels 15 are mounted at the front a chassis 24, which is pivoted at its rear to the head 20. A cam follower 19 extends upwardly from the chassis 24 and rests against the profiled surface of the cam 17. It will be appreciated that the wheels 15 on chassis 24 are thus urged downwardly by the cam follower 19 as the actuator 18 is turned in the clockwise direction, thereby progressively raising the height of the suction mouth 13 relative to the floor surface as the cam follower 19 moves from positions P2 to P4. Likewise, the wheels 15 on chassis 24 are also urged downwardly by the cam follower 19 as the actuator 18 is turned in the counter clockwise direction, thereby slightly raising the height of the suction mouth 13 from its position at P2.

Referring to Figure 4 of the drawings, live and neutral power conductors L, N extend from a plug of the cleaner (not shown) that is arranged for insertion into an electrical mains power outlet socket. A switch S1 comprises a first terminal connected to the live conductor L and a second terminal. The first and second terminals of switch S1 can be selectively closed and opened for turning the cleaner on and off. The motor 31 of the motor and fan unit 11 is connected via a speed control circuit 30 between the second terminal of switch S1 and the neutral conductor N.

A second switch S2 comprises a first terminal connected to the second terminal of switch S1 and a second terminal. The second switch also comprises third and fourth terminals connected to the speed control circuit 30. The first and second terminals of switch S2 can be selectively closed and opened. The third and fourth terminals of switch S2 are also selectively closed and opened in unison. The DC agitator motor 33 is connected via a mains rectifier circuit 32 between the second terminal of switch S2 and the neutral conductor N.

The cam 17 comprises a radially projecting formation 22 which opens switch S2 when the cam 17 is turned to position P2 and which closes switch S2 when at positions P1, P3 and P4. It will be appreciated that the head 20 is at its lowest position relative to the floor when the cam 17 is at position P2. In this position, switch S2 is open so that no power is applied to the DC agitator motor 33 once the switch S1 is closed. Also, switch S2 configures the speed control circuit 30 to apply a reduced current to the motor 31 of the motor and fan unit 11. When the cam 17 is turned to any of positions P1, P3 and P4, S2 is closed so that no power is applied to the DC agitator motor 33 via rectifier 32. Also, switch S2 configures the speed control circuit 30 to apply full current to the motor 31 of the motor and fan unit 11.

It will be apparent that the following characteristics are therefore achieved by simply turning the actuator 18:

Position	Fan Motor Power	Agitator Motor	Suction mouth	Mode
P1	Full	On	Lowered	Unspecified
P2	Reduced	Off	Fully lowered	Hard floor
P3	Full	On	Raised	Short carpet
P4	Full	On	Fully raised	Long carpet

The cleaner is labelled to clearly indicate that position P2 of the actuator 18 is for hard floor cleaning and that position P3 and P4 are for carpet cleaning. Position P1 allows unspecified cleaning using the agitator 14 when the suction mouth 13 is lowered.

As is apparent from the above table, hard floor cleaning is performed with the suction mouth 13 lowered, whereas carpet cleaning is performed with the suction mouth 13 raised. During hard floor cleaning, the suction mouth 13 is positioned so close to the floor surface that a comparable DPU value can be achieved at the lower motor power setting. Also, the agitator motor 33 is not energised when performing hard floor cleaning. Hence, since the AE annual energy consumption during a hard floor test is a product of the DPU and the average specific energy consumption during the hard floor cleaning test, the overall AE annual energy consumption (on which the cleaner’s energy efficiency rating of A to G is based), is lowered because of the reduced fan motor power and the cessation of the agitator motor 33. Also, since the power is reduced automatically when the head is lowered and vice-versa, there is no doubt that the energy rating test is being performed under the correct conditions and in a way which can be repeated by the user during use.

A vacuum cleaner in accordance with the present invention is extremely energy efficient and provides easy setting of respective optimum power levels for hard floor or carpet cleaning and unquestionable compliance with its marked energy efficiency grade.

Claims

1. A vacuum cleaner comprising an upright body portion pivotally connected at its lower end to a wheeled floor-engaging head portion for partial rotation forwardly and rearwardly about a transverse axis, the head portion comprising a suction mouth on its underside, the cleaner further comprising a fan and a motor arranged to rotate the fan to draw air into the cleaner from the suction mouth into means in the body portion for separating and collecting dirt and dust that is drawn into the cleaner, and a displaceable actuator for setting the height of the suction mouth relative to a floor surface being cleaned, wherein displacement of the actuator further selectively reduces the speed of rotation of the fan by the motor as the height of the suction mouth relative to the floor surface being cleaned is reduced and viceversa.

2. A vacuum cleaner as claimed in claim 1, in which the actuator is displaceable to reduce the speed of rotation of the fan when height of the head relative to the floor is below a predetermined height.

3. A vacuum cleaner as claimed in claim 2, in which the actuator is displaceable to increase the speed of rotation of the fan when the height of the head relative to the floor is above said predetermined height.

4. A vacuum cleaner as claimed in claim 3, in which the speed of rotation of the fan is constant when the height of the head relative to the floor is increased above said predetermined height.

5. A vacuum cleaner as claimed in claim 3, in which the speed of rotation of the fan increases when the height of the head relative to the floor is increased from said predetermined height.

6. A vacuum cleaner as claimed in any preceding claim, in which the actuator is displaceable to bring the head into a position at or adjacent said predetermined height in which the speed of rotation of the fan is increased.

7. A vacuum cleaner as claimed in any preceding claim, in which the actuator is displaceable between positions which are respectively labelled as being suitable for each floor type.

8. A vacuum cleaner as claimed in any preceding claim, in which actuator is arranged to index or latch at a plurality of positions defining respective heights of the suction mouth relative to the floor.

9. A vacuum cleaner as claimed in any preceding claim, in which a rotary agitator brush is mounted across the suction mouth, the actuator being arranged to selectively reduce the speed of rotation of the agitator as the height of the suction mouth relative to the floor surface being cleaned is reduced and vice-versa.

10. A vacuum cleaner as claimed in claim 9, in which the speed of rotation of the agitator is reduced to zero.

11. A vacuum cleaner as claimed in claim 9 or 10, in which the agitator is driven by the fan motor, the speed of rotation of the agitator being reduced by disconnecting or partially decoupling the agitator from the motor.

12. A vacuum cleaner as claimed in claim 9 or 10, in which the agitator is driven by an agitator motor, the speed of rotation of the agitator being reduced by disconnecting or reducing the power applied to the agitator motor.

13. A vacuum cleaner as claimed in any preceding claim, in which a seal extends around the suction mouth.

14. A vacuum cleaner as claimed in claim 13, in which the actuator is arranged to selectively lower the seal as the height of the suction mouth relative to the floor surface being cleaned is reduced and viceversa.

15. A vacuum cleaner as claimed in any preceding claim, in which the

5 speed of rotation of the motor is varied by varying the current waveform of the electrical supply to the motor.

16. A vacuum cleaner as claimed in any preceding claim, in which the actuator comprises a formation which is arranged to operate an

10 electrical switch to reduce the speed of rotation of the fan when the head is lowered and vice-versa.

17. A vacuum cleaner as claimed in claim 9, in which the actuator comprises a formation which is arranged to operate an electrical

15 switch to reduce the speed of rotation of the fan and to reduce the speed of rotation of the agitator when the head is lowered and viceversa.

18. A vacuum cleaner as claimed in any preceding claim, in which the

20 actuator comprises a ramped camming surface which displaces at least one supporting wheel of the head.

Intellectual

Property

Office

Application No: GB1703156.8 Examiner: Mr Rhodri Evans