GB2505927A

GB2505927A - Cleaner head

Info

Publication number: GB2505927A
Application number: GB201216487A
Authority: GB
Inventors: Kyle Toole
Original assignee: Dyson Technology Ltd
Current assignee: Dyson Technology Ltd
Priority date: 2012-09-14
Filing date: 2012-09-14
Publication date: 2014-03-19
Anticipated expiration: 2032-09-14
Also published as: GB201216487D0; JP5681769B2; JP2014057860A; GB2505927B

Abstract

A cleaner head comprises an agitator (3, fig 1), a drive assembly (4, fig 1) for driving the agitator (3, fig 1), and a control assembly 5 for powering on and off the drive assembly (4, fig 1). The control assembly 5 includes an actuator 18 and one or more pawls 16, 17. The actuator 18 moves to a first position when the cleaner head is lifted from a cleaning surface and to a second position when the cleaner head is placed onto the cleaning surface. The drive assembly (4, fig 1) is powered off when the actuator 18 is in the first position and powered on when the actuator 18 is in the second position. The or each pawl 16, 17 is pivotally attached to the actuator 18 and is moveable between an unlock position and a lock position. The pawl 16, 17 permits movement of the actuator 18 from the first position to the second position when in the unlock position, and prevents movement when in the lock position. The pawl 16, 17 moves to the lock position when the cleaner head is inverted and returns to the unlock position when the cleaner head is righted.

Description

Cleaner Head The present invention relates to a cleaner head for a cleaning appliance.

The cleaner head of a cleaning appliance, such as a vacuum cleaner or floor sweeper, often includes an agitator driven by a drive assembly. In order to improve safety, the cleaner head may include a mechanism for powering off the drive assembly should the cleaner head be lifted from the cleaning surface. A common type of mechanism comprises an actuator that projects below the underside of the cleaner head. When the cleaner head is lifted from the cleaning surface, the actuator is biased downwards, causing the drive assembly to power off When the cleaner head is placed onto the cleaning surface, the actuator is pushed upwards, causing the drive assembly to power on.

A problem with this type of mechanism is that a user may inadvertently depress the actuator when attempting to remove trapped debris from the cleaner head. Schemes for preventing accidental depression of the actuator are known but are often complex and/or suffer from reliability problems.

The present invention provides a cleaner head comprising an agitator, a drive assembly for driving the agitator, and a control assembly for powering on and off the drive assembly, thc control asscmbly comprising an actuator and one or morc pawls, whercin: the actuator is moveable between a first position and a second position, the actuator moves to the first position when the cleaner head is lifted from a cleaning surface and moves to the second position when the cleaner head is placed onto the cleaning surface; the drive assembly is powered off when the actuator is in the first position and powered on when the actuator is in the second position; and each pawl is pivotally attached to the actuator and is moveable between an unlock position and a lock position, the pawl permits movement of the actuator from the first position to the second position when in the unlock position and prevents movement when in the lock position, and the pawl moves to the lock position when the cleaner head is inverted and returns to the unlock position when the cleaner head is righted.

The pawls therefore prevent movement of the actuator when the cleaner head is inverted. Consequently, should a user invert the cleaner head, the user will find that the actuator cannot be depressed and thus the drive assembly cannot be powered on. The user is therefore able to remove trapped debris from the cleaner head in relatively safety without fear of the agitator being accidentally powered on.

By employing pawls to lock the position of the actuator, a relatively simple yet reliable scheme is provided for locking the position of the actuator. Accordingly, the safety of the cleaner head may be improved in a cost-effective manner.

The control assembly may comprise a first pawl and a second pawl that pivot about a common axis. The first pawl then pivots clockwise and the second pawl that pivots counter-clockwise when moving from the unlock position to the lock position. This then has the advantage that one of the pawls should move to the lock position when the cleaner head is only partially inverted. For example, when the cleaner head is inverted in a clockwise direction, the first pawl should move to the lock position ahead of the second pawl. Conversely, as the cleaner head is inverted in a counter-clockwise direction, the second pawl should move to thc lock position ahead of thc first pawL In moving to the lock position when the cleaner head is partially inverted, the safety of the cleaner head is improved.

Each pawl may engage a respective notch in the cleaner head when in the lock position.

This then prevents the pawl from slipping from the lock position should an excessive tbrce be applied to the actuator. By reducing the chances of the pawls slipping, the safety of the cleaner head is further improved.

Each pawl may have a first end that is pivotally attached to the actuator, and a second free end that has a mass greater than that of the first end. As a result, the centre-of-mass of each pawl is positioned closer to the free end of the paw]. When the cleaner head is inverted, each pawl is then subjected to a larger moment of force that encourages the pawl to move to the lock position. The same is true when the cleaner head is subsequently righted, i.e. a larger force encourages each pawl to return to the unlock position. The pawls are therefore more sensitive to movement of the cleaner head.

The drive assembly may comprise an electric motor or an air turbine and a transmission for transmitting torque generated by the motor or turbine to the agitator. The control assembly may then comprise a switch or valve for controlling the flow of electric current to the motor or the flow of air through the turbine. The actuator then acts upon the switch or valve such that that the motor or turbine is powered off when the actuator is in the first position and powered on when the actuator is in the second position.

The present invention fnrther provides a cleaner head comprising an agitator, a drive assembly, and a control assembly, the drive assembly comprising an electric motor and a transmission for transmitting torque generated by the motor to the agitator, and the control assembly comprising a switch, an actuator and one or more pawls, wherein: the actuator is moveable between a first position and a second position, the actuator moves to the first position when the cleaner head is lifted from a cleaning surface and moves to the second position when the cleaner head is placed onto the cleaning surface; the switch is opcncd whcn the actuator is in thc first position and closed when the actuator is in the second position; the motor is powered off when the switch is open and powered on when the switch is closed; and each pawl is pivotally attached to the actuator and is moveable between an unlock position and a lock position, the pawl permits movement of the actuator from the first position to the second position when in the unlock position and prevents movement when in the lock position, and the pawl moves to the lock position when the cleaner head is inverted and returns to the unlock position when the cleaner head is righted.

In order that the present invention may be more readily understood, embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is an exploded view of a cleaner head in accordance with the present invention; Figure 2 is an exploded view of a control assembly of thc cleaner head; Figure 3 is an exploded view of part of the control assembly; Figure 4 is a sectional view of the control assembly, wherein an actuator of the control assembly is in a first position; Figure 5 is a sectional view of the control assembly, wherein the actuator is in a second position; Figure 6 is a sectional view of the control assembly in an inverted position, wherein the actuator is in the first position and pawls of the control assembly are in a lock position; and Figurc 7 is a sectional vicw of an altemative control assembly in accordance with thc prcscnt invention, wherein the actuator is in the second position.

The cleaner head I of Figure 1 comprises a housing 2 within which an agitator 3, a drive assembly 4, and a control assembly 5 arc mounted.

The agitator 3 comprises an elongate body 6 to which bristles, flicker strips or other means 7 for agitating a cleaning surface are attached. This type of agitator is generally referred to as a brush bar or bcatcr bar. However, alternative types of agitator might equally bc used. By way of example, thc agitator 3 could comprise rotary discs of thc type described in US2012/0144621. One end of the agitator 3 is mounted to a bushing 8 seated within a removable cap 9. The opposite end of the agitator 3 is mounted to a transmission 11 forming part of the drive assembly 4.

The drive assembly 4 comprises an electric motor 10 and a transmission 11 for transmitting torque generated by the motor 10 to the agitator 3.

The control assembly 5 is responsible for powering on and off the drive assembly 4. In particular, the control assembly S powers off the drive assembly 4 when the cleaner head 1 is lifted from the cleaning surface, and powers on the drive assembly 4 when the cleaner head 1 is placed onto the cleaning surface.

Referring now to Figures 2 to 6, the control assembly S comprises a easing 13 that houses a switch 14, an actuator subassembly 15, and a pair of pawis 16,17.

The switch 14 controls the supply of electric current to the motor 10. When the switch 14 is open, the motor 10 is powered off Conversely, when the switch 14 is closed, the motor 10 is powered on. The switch 14 takes the form of a microswitch that is biased open.

The actuator subassembly 15 comprises an actuator 18, a torsion spring 19, and a roller 20.

The actuator 18 is pivotally attached to the casing 13 at one end. The actuator 18 is then pivotally moveable between a first position (Figure 4) and a second position (Figure 5).

The actuator 18 is responsible for actuating the switch 14. When the actuator 18 is in the first position, the switch 14 is opened. Conversely, when the actuator 18 is in the second position, the switch 14 is closed. The torsion spring 19 biases the actuator 18 into the first position, and the roller 20 is rotatably attached to a lower part of the actuator 18.

The actuator 18 projects through openings in the casing 13 and the housing 2, and projects beyond the underside of the cleaner head 1. When the cleaner head I is lifted from the cleaning surface, as illustrated in Figure 4, the actuator 18 is biased by the spring 20 into the first position. The switch 14 is therefore opened and the motor 10 is powered off When the cleaner head 1 is placed onto the cleaning surface, as illustrated in Figure 5, the cleaning surface pushes the actuator 18 upwards against the biasing force of the spring 20 and thus the actuator 18 moves to the second position. The switch 14 is then closed and the motor 10 is powered on.

The roller 20 contacts the cleaning surface when the cleaner head 1 is placed onto the cleaning surface. Consequently, as the cleaner head I is manoeuvred forwards and backwards, the roller 20 rotates so as to support the actuator 18 above the cleaning surface.

Turning now to the pawls 16,17, each of the pawls 16,17 is pivotally mounted to an upper part of the actuator 18. Each pawl 16,17 pivots between an unlock position and a lock position. When the cleaner head 1 is righted (i.e. when the cleaner head 1 is correctly oriented for use on a cleaning surface), as illustrated in Figure 4, each pawl 16,17 is in the unlock position. When in the unlock position, the pawls 16,17 permit movement of the actuator 18 from the first position to the second position, as illustrated in Figure 5. When thc cleaner hcad 1 is inverted, as illustratcd in Figurc 6, each pawl 16,17 moves to thc lock position. Morc particularly, thc free end of each pawl 16,17 falls under the force of gravity. When in the lock position, each pawl 16,17 engages with a respective notch 21,22 in the surface of the casing 13. The pawls 16,17 then prevent movement of the actuator 18 from the first position to the second position.

In particular, when a downward force (referring now to Figure 5) is applied to the actuator 18, the force is transmitted by the pawls 16,17 to the casing 13. Consequently, the actuator 18 is prevented from moving to the second position. When the cleaner head I is subsequently righted, the pawls 16,17 return to the unlock position. Again, the free end of each pawl 16,17 falls under the force of gravity. With the pawls 16,17 in the unlock position, the actuator 18 is again peimitted to move from the first position to the second position.

The pawis 16,17 therefbre prevent movement of the actuator 18 when the cleaner head 1 is inverted. Consequently, should a user invert the cleaner head 1, the user will find that the actuator 18 cannot be depressed and thus the motor 10 cannot be powered on.

Accordingly, the user may remove trapped debris from the cleaner head I in relatively safety without fear of the agitator 3 being accidentally powered on.

The free end of each paw! 16,17 has a mass greater than that of the opposite end to which the actuator 18 is attached. As a result, the centre-of-mass of each pawl 16,17 is positioned closer to the free end of the pawl 16,17. When the cleaner head 1 is inverted, each pawl 16,17 is then subjected to a larger moment of force that encourages the paw! 16,17 to move to the lock position. The same is true when the cleaner head 1 is subsequently righted, i.e. a larger force encourages each paw! 16,17 to return to the unlock position. The pawls 16,17 are therefore more sensitive to movement of the cleaner head 1. In the present embodiment, the greater mass is achieved by enlarging the free ends of the pawls 16,17. However, alternative or additional means may be used to achieve the greater mass.

Thc control assembly 5 comprises two pawls 16,17. Whcn thc clcancr hcad 1 is invcrted, onc of the pawls 16 pivots clockwise and the other paw! 17 pivots counter-clockwise. This then has the advantage that one of the pawls 16,17 moves to the lock position when the cleaner head I is only partially inverted. For example, if the cleaner head 1 is rotated clockwise by, say, 100 degrees, the first pawl 16 moves to the lock position. Conversely, if the cleaner head I is rotated counter-clockwise by 100 degrees, the second pawl 17 moves to the lock position. The pawls 16,17 therefore prevent movement of the actuator 18 fixnn the first position to the second position after the cleaner head I has been rotated through 100 degrees. By preventing movement of the actuator 18 when the cleaner head is only partially inverted, the safety of the cleaner head 1 is fbrther improved.

S

The pawls 16,17 pivot about an axis of rotation that extends longitudinally through the cleaner head 1. Consequently, the pawls 16,17 are most sensitive to movement of the cleaner head 1 when rotating to the left or right (i.e. when the cleaner head 1 rotates about its longitudinal axis). Conceivably, however, a user may tilt the cleaner head 1 forwards or backwards (i.e. rotate the cleaner head 1 about its lateral axis). If the cleaner head I were tilted backwards by, say, 90 degrees, it is unlikely that the pawls 16,17 would move to the lock position. As a result, the agitator 3 would continue to rotate and present a danger to the user. Accordingly, the control assembly 5 may comprise pawls that rotate about different axes of rotation. This then has the benefit that the control assembly 5 is more sensitive to movement of the cleaner head I about different axes of rotation. For example, in addition to the two pawls 16,17 that pivot about an axis that extends longitudinally through the cleaner head 1, the control assembly 5 may comprise a thrther two pawls that pivot about an axis that extends laterally through the cleaner head 1. The first pair of pawls 16,17 are then sensitive to rolling of the cleaner head I about its longitudinal axis, whilst the second pair of pawls are sensitive to pitching of the cleaner head 1 about its lateral axis.

In spite of the aforementioned advantages in having two or more pawls 16,17, the control assembly S could conceivably have a single pawl that moves to the lock position whcncvcr the cleaner head 1 is inverted.

When in the lock position, each of the pawls 16,17 engages a respective notch 21,22.

The notches 21,22 ensure that the pawls 16,17 do not slip from the lock position should an excessive force be applied to the actuator 18. Nevertheless, there may be instances for which the notches 2 1,22 arc unnecessary. For example, although the pawls 16,17 may slip when a force is applied to the actuator 18, the force required to cause the pawls 16,17 to slip may be relatively large and thus not regarded as a problem.

Alternatively, slipping of the pawls 16,17 may be averted by some other means. For example, the surface of the casing 13 may be covered with a layer of rubber or some other nonslip material.

The roller 20 supports the actuator 18 above the cleaning surface as the cleaner head I is manocuvrcd forwards and backwards. Without the roller 20, the actuator 18 would directly contact the cleaning surface and may mark or otherwise damage the cleaning surface. Nevertheless, the roller 20 is not essential to the general operation of the control assembly 5 and may therefore be omitted. For example, the roller 20 may be omitted when the cleaner head I is intended to be used on surfaces for which marking is not regarded as a problem, e.g. carpeted surfaces. Alternatively, the part of the actuator 18 that contacts the cleaning surface may be shaped and/or the spring constant of the torsion spring 19 may be set so as to reduce the risk of marking.

The actuator 18 is pivotally attached to the casing 13 and thus pivots between the first position and the second position. Alternatively, the actuator 18 may be configured to move in a different way between the first and second positions. For example, the actuator 18 may translate vertically up and down between the first and second positions.

In the embodiment described above, the switch 14 is biased open. The actuator 18 then depresses the switch 14 when moving to the second position in order to close the switch 14. Equally, however, the switch 14 may be biased closed. In this instance, the actuator 18 depresses the switch 14 when moving to the first position in order to open the switch 14. As a further alternative, the switch 14 may be unbiased, e.g. a latched switch. Thc actuator 18 may then actuate the switch 14 on moving from the first position to the second position in order to close the switch 14, and then actuate the switch 14 on moving from the second position to the first position in order to open the switch 14. Irrespective of the manner in which the switch 14 is actuated, the switch 14 is open when the actuator 18 is in the first position and the switch 14 is closed when the actuator 18 is in the second position.

Figure 7 illustrates an alternative control assembly 5' incorporating many of the alternative features described in the preceding paragraphs. The same reference numerals have been used to designate the various features of the control assembly 5'.

However, in order to distinguish the alternative control assembly 5' from that described above, the reference numerals have been suffixed with an apostrophe. In the alternative control asscmbly 5', the actuator 18' movcs vcrticaHy up and down bctwccn the first and second positions. The actuator 1 is shown in the second position in Figure 7. The actuator 18' is again biased in the first position by means of a spring 19' (this time, a coil spring). Rather than being biased open, the switch 14' is biased closed. The switch 14' is therefore closed in Figure 7 and thus the motor 10 is powered on. When the cleaner head 1 is lifted from the cleaning surface, the spring 19' biases the actuator 18' downwards. A horizontal arm forming part of the actuator 18' then depresses the switch 14' to open the switch and power off the motor 10. The control assembly 5' comprises a single pawl 16' which, like the embodiment described above, is pivotally attachcd to thc actuator 18'. Whcn thc cleancr hcad I is invcrted, thc pawl 16' pivots to the lock position and engages a notch 21' in the casing 13'.

In view of the above, the actuator 14 may be said to be moveable between a first position and a second position. The actuator 14 moves to the first position (e.g. under the biasing force of a spring 19) when the cleaner head 1 is lifted from the cleaning surface, and moves to the second position when the cleaner head I is placed onto the cleaning surface. The switch 14 is then opened (and the motor 10 is powered off) when the actuator 18 is in the first position, and the switch 14 is closed (and the motor 10 is powered on) when thc actuator 14 is in the second position. The pawl or pawls 16,17 thdll permit movcmcnt of the actuator 18 from the first positioll to the second position when in the unlock position, and prevent movement when in the lock position.

In cach of the cmbodimcnts dcscribcd abovc, the drive asscmbly 4 comprises an clcctric motor 10, and thc control asscmbly 5 compriscs a switch 14 for controlling the supply of electric current to the motor 10. Alternatively, the drive assembly 4 may comprise an air turbine for generating the torque necessary to drive the agitator 3. Drive assemblies having an air turbine are now well known. By way of example, the cleaner head of the DCI2 vacuum cleaner sold by Dyson Limited, as well as the mini turbine head sold by Dyson Limited as an accessory for removing pet hair, each include a drive assembly having an air turbine. The turbine would then be powered by air drawn through the cleaner head I. The control assembly 5 may then comprise a valve or other means for controlling the flow of air through the turbine. For example, the valve may have an open position in which air is permitted to flow through the turbine, and a closed position in which air is prevented fix,m flowing through the turbine. Alternatively, the value may operate as a bleed such that, when in the open position, air is drawn through the bleed in preference to the turbine. When in the closed position, the valve covers the bleed and air is again drawn through the turbine.

Irrespective of the means employed by the drive assembly 4 to generate the necessary torque (be it an electric motor or an air turbine) and the means employed by the control assembly 5 to power off and on the drive assembly 4 (be it a switch, valve or the like), the drive assembly 4 is powered off whenever the actuator 18 is in the first position and powered on whenever the actuator 18 is in the second position. The pawl or pawls 16,17 then permit movement of the actuator 18 when the cleaner head 1 is righted, and prevent movement of the actuator 18 when the cleaner head I is inverted.

By employing pawts 16,17 to lock the position of the actuator 18, a relatively simple yet reliable scheme is provided for locking the position of the actuator 18. The safety of the cleaner head I is therefore improved in a cost-effective manner.

Claims

CLAIMSI. A cleaner head comprising an agitator, a chive assembly lbr driving the agitator, and a control assembly fbr powering on and off the drive assembly, the control assembly comprising an actuator and one or more pawls, wherein: the actuator is moveable between a first position and a second position, the actuator moves to the first position when the cleaner head is lifted fltm a cleaning surface and moves to the second position when the cleaner head is placed onto the cleaning surfce; the drive assembly is powered off when the actuator is in the first position and powered on when the actuator is in the second position; and each pawl is pivotally attached to the actuator and is moveable between an unlock position and a lock position, the pawl permits movement of the actuator from the first position to the second position when in the unlock position and prevents movement when in the lock position, and the pawl moves to the lock position when the cleaner head is inverted and returns to the unlock position when the cleaner head is righted.
2. A cleaner head as claimed in claim 1, wherein the control assembly comprises a first pawl that pivots clockwise and a second pawl that pivots counter-clockwise when moving from the unlock position to the lock position.
3. A cleaner head as claimed in claim I or 2, wherein each pawl engages a respective notch in the cleaner head when in the lock position.
4. A cleaner head as claimed in any one of the preceding claims, wherein each pawl has a first end and a second opposite end, the pawl is pivotally attached to the actuator at the first end, and the second end has a mass greater than that of the first end.
5. A cleaner head as claimed in any one of the preceding claims, wherein the drive assembly comprises an electric motor or an air tuthine and a transmission fbr transmitting torque generated by the motor or turbine to the agitator, the control assembly comprises a switch or valve for controlling the flow of electric current to the motor or the flow of air through the turbine, and the actuator acts upon the switch or valve such that that the motor or turbine is powered off when thc actuator is in thc first position and powered on when the actuator is in the second position.
6. A cleaner head comprising an agitator, a drive assembly, and a control assembly, the drive assembly comprising an electric motor and a transmission for transmitting torque generated by the motor to the agitator, and the control assembly comprising a switch, an actuator and one or more pawls, wherein: the actuator is moveable between a first position and a second position, the actuator moves to the first position when the cleaner head is lifted from a cleaning surface and moves to the second position when the cleaner head is placed onto the cleaning surface; the switch is opened when the actuator is in the first position and closed when the actuator is in the second position; the motor is powered off when the switch is open and powered on when the switch is closed; and each pawl is pivotally attached to the actuator and is moveable between an unlock position and a lock position, the pawl permits movement of the actuator from the first position to the second position when in the unlock position and prevents movement when in the lock position, and thc pawl moves to the lock position when the cleaner head is inverted and returns to the unlock position when the cleaner head is righted.
7. A cleaner head as claimed in claim 6, wherein the control assembly comprises a first pawl that pivots clockwise and a second pawl that pivots counter-clockwise when moving from the unlock position to the lock position.
8. A cleaner head as claimed in claim 6 or 7, wherein each pawl engages a respective notch in the cleaner head when in the lock position.
9. A cleaner head as claimed in any one of claims 6 to 8, wherein each pawl has a first end and a second opposite end, the pawl is pivotally attached to the actuator at the first end, and the second cnd has a mass greater than that of the first end.