GB2355392A - Sensor for detecting hose attachment on vacuum cleaner - Google Patents

Abstract

A vacuum cleaner has a normally open dirty floor inlet 24 and a normally closed dirty air house inlet 61. A sensor 65 is provided for sensing the presence of the hose 90 at the hose inlet 61 and for automatically closing the floor inlet 24 when the hose 90 is present at the hose inlet. The sensor 65 can comprise a switch (112, Figs 5A-5C) or an optical device (T, R, Fig 5C).

Description

2355392 A Vacuum Cleaner The invention relates to a vacuum cleaner

particularly, but not exclusively, to a robotic vacuum cleaner.

Vacuum cleaners operable in more than one mode, ie in upright mode and in cylinder mode, are well known. In the upright mode, the cleaner operates by drawing dirty air into the cleaner by way of a cleaner head which travels across the floor or other surface to be cleaned. In the cylinder mode, the dirty air is drawn into the cleaner via a hose or a hose and wand assembly. Most cleaners which are convertible between the two modes of operation are essentially upright cleaners which have permanently attached hoses which can be brought into operation when cylinder cleaning is required. In some cases, the hose is permanently connected to the inlet to the dirt and dust separating apparatus of the cleaner and the distal. end of the hose is then stored in a hollow socket during upright cleaning so that the hose becomes pain of the dirty air inlet path during upright cleaning. Such an arrangement results in losses which are higher than is desirable during upright cleaning due to the passage of the air through a hose rather than through a smooth conduit or pipe. In other arrangements, the hose is permanently connected to the main body of the cleaner but a valve is used to select whether dirty air is drawn into the cleaner through the cleaner head or through the hose. The operation of the valve can be made dependent upon the angle of inclination of the main body of the upright cleaner as illustrated and described in EP 0 134 654B. This type of arrangement is better than the aforementioned alternative arrangement during upright cleaning because the dirty air is not required to pass through a hose. However, in such an arrangement, the airflow passage is often longer than is desirable during cylinder cleaning and, as a result, avoidable losses can occur.

Autonomous or robotic vacuum cleaners have also been proposed. Robotic vacuum cleaners operate in a manner which is different to that of both upright and cylinder cleaners. In the normal or autonomous mode of operation, the cleaner traverses the surface to be cleaned under its own power and using its own navigation system so that human intervention is not required. Dirty air is drawn into the machine through a cleaner 2 head in a manner similar to that used in upright cleaning using an upright cleaner. Robotic vacuum cleaners are shown and described in, inter alia, US 5781960 and US 5109566. The latter of these documents also indicates (see Figure 3) that a conventional suction hose can be attached to the robotic vacuum cleaner for the purpose of manual cleaning of areas which cannot be reached by the robotic cleaner. An air path changing device is provided by which the suction intake of the fan is switched to the cleaner head or to the hose. The hose connector has a sliding cover which is mechanically linked to the changing device to switch the suction intake between the cleaner head and the hose. The disadvantage of such an arrangement is that, should the sliding cover be left open without the hose being attached, the incorrect suction intake will be operative.

It is an object of the present invention to provide a vacuum cleaner which is convertible between two different modes of operation easily and conveniently and moreover is cheap to manufacture. It is a further object of the invention to provide a vacuum cleaner in which the disadvantages of the prior art are obviated.

According to the present invention, there is provided a vacuum cleaner having a normally open dirty air floor inlet and a normally closed dirty air hose inlet, and a sensor for sensing the presence of the hose at the hose inlet to close the floor inlet el ectromagnetically.

This new arrangement allows a hose, or a hose and wand assembly, to be attached directly to the dirty air hose inlet in an easy and convenient manner and enables considerable latitude in the design of the cleaner. Furthermore, there is no possibility of the hose inlet being inadvertently left open when no hose is present.

Preferred and advantageous features of the invention are set out in the subsidiary claims.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein; 3 Figure 1 is a perspective view of a robotic vacuum cleaner according to an embodiment of the invention, without a hose connected; Figure 2 is a sectional view through the vacuum cleaner of Figure 1 taken on the central axis X-X of Figure I and with a hose connected; Figure 3 is a transverse sectional view through part of the cleaner on the line Y-Y of Figure 2; Figure 4 is a block circuit diagram of the power management and navigation system of the cleaner of Figs 1 to 3; and Figures 5A to 5C show modifications to the hose inlet of the cleaner of Figures 1 to 4.

The vacuum cleaner 10 shown in the drawings has a supporting chassis 12 which is generally circular in shape and is supported on two driven wheels 14 and a castor wheel 16 (Fig 2). The chassis 12 is preferably manufactured from high-strength moulded plastics material, such as ABS, but can equally be made from metal such as alun-linium or steel. The chassis 12 provides support for the components of the cleaner 10 which will be described below. The driven wheels 14 are arranged at either end of a diameter of the chassis 12, the diameter lying perpendicular to the longitudinal axis X-X of the cleaner 10. Each driven wheel 14 is moulded from a high-strength plastics material and carries a comparatively soft, ridged band around its circumference to enhance the grip of the wheel 14 when the cleaner 10 is traversing a smooth floor. The driven wheels 14 are mounted independently of one another via support bearings (not shown) and each driven wheel 14 is connected directly to a motor (not shown) which is capable of driving the respective wheel 14 in either a forward direction or a reverse direction. By driving both wheels 14 forward at the same speed, the cleaner 10 can be driven in a forward direction. By driving both wheels 14 in a reverse direction at the same speed, the cleaner 10 can be driven in a backward direction. By driving the wheels 14 in opposite directions, the cleaner 10 can be made to rotate about its own central axis to as to effect a turning 4 manoeuvre. Other turning manoeuvres can be effected by driving the wheels at different speeds. The aforementioned method of driving a vehicle is well known and will not therefore be described any further here.

The castor wheel 16 is significantly smaller in diameter than the driven wheels 14 as can be seen from Figure 2. The castor wheel 16 is not driven and merely serves to support the chassis 12 at the rear of the cleaner 10. The location of the castor wheel 16 at the trailing edge of the chassis12, and the fact that the castor wheel 16 is swivellingly mounted on the chassis by means of a swivel joint 20, allows the castor wheel 16 to trail behind the cleaner 10 in a. manner which does not hinder the manoeuvrability of the cleaner 10 whilst it is being driven by way of the driven wheels 14. The castor wheel 16 can be made from a moulded plastics material or can be formed from another synthetic material such a Nylon.

Mounted on the underside of the chassis 12 is a cleaner head 22 which includes a suction opening 24 facing the surface on which the cleaner 10 is supported. The suction opening 24 is essentially rectangular and extends across the majority of the width of the cleaner head 22. A brush bar 26 is rotatably mounted in the suction opening 24 and a motor 28 is mounted on the cleaner head 22 for driving the brush bar 26 by way of a drive belt (not shown) extending between a shaft of the motor 28 and the brush bar 26. The cleaner head 22 is mounted on the chassis 12 by a double articulation arrangement in such a way that the cleaner head 22 is able to float on the surface to be cleaned. Details of these arrangements are described in our co-pending British Patent Application No. 98 27782.5 filed on 18 December 1998. The double articulation arrangement allows the cleaner head 22 to move freely in a vertical direction with respect to the chassis 12. This enables the cleaner head 22 to climb over small obstacles such as books, magazines, rug edges, etc. Obstacles of up to approximately 25mm in height can be traversed in this way. A flexible connection 30 is located between a rear portion of the cleaner head 22 and an inlet port 32 located in the chassis 12. The flexible connection 30 consists of a rolling seal, one end of which is sealingly attached to the upstream mouth of the inlet port 32 and the other end of which is sealingly attached to the periphery of an aperture in the cleaner head 22. When the cleaner head 22 moves upwardly with respect to the chassis 12, the rolling seal 30 distorts or crumples to accommodate the upward movement of the cleaner head 22. When the cleaner head 22 moves downwardly with respect to the chassis 12, the rolling seal 30 unfolds or extends into an extended position to accommodate the downward movement.

In order to assist the cleaner head 22 to move vertically upwards when an obstacle is encountered, forwardly projecting ramps 36 are provided at the front edge of -the cleaner head 22. In the event that an obstacle is encountered, the obstacle will initially abut against the ramps 36 and the inclination of the ramps will then lift the cleaner head 22 over the obstacle in question so as to avoid the cleaner 10 becoming lodged against the obstacle. The cleaner head 22 is shown in an upper position in Figure 2. The castor wheel 16 also includes a ramped portion 17 which provides additional assistance when the cleaner 10 encounters an obstacle and is required to climb over it. In this way, the castor wheel 16 will not become lodged against the obstacle after the cleaner head 22 has climbed over it.

The chassis 12 carries a plurality of sensors 40 which are designed and arranged to detect obstacles in the path of the cleaner 10 and its proximity to, for example, a wall or other boundary such as a piece of furniture. The sensors 40 comprise several ultra-sonic sensors and several infra-red sensors. The array illustrated in Figure I is not intended to be limitative and the arrangement of the sensors 40 does not form part of the present invention. Suffice is to say that the vacuum cleaner 10 carriers sufficient sensors and detectors 40 to enable the cleaner 10 to guide itself or to be guided around a predefined area so that the said area can be cleaned. The various sensors and their control of the cleaner are more particularly described in our co-pending British Patent Application No 98 277758.5 filed on 18 December 1998.

There are various ways in which the cleaner can be programmed to operate but one particularly advantageous way is described in our co-pending British Patent Application No 98 27777.5 filed on 18 December 1998. Control software, comprising navigation 6 controls and steering devices, is housed within a housing 42 located beneath a control panel 44 or elsewhere within the cleaner 10. A light detector 19 detects light received from a plurality of compass points around the vacuum cleaner and its function is more particularly described in our co-pending British Patent Application No 98 27771.8 filed on 18 December 1998.

Battery packs 46 are mounted on the chassis 12 inwardly of the driven wheels 14 to provide power to the motors for driving the wheels 14 and to the control software. The battery packs 46 are removable to allow them to be transferred to a battery charger (not shown). The vacuum cleaner 10 also includes a motor and fan unit 50 supported on the chassis 12 for drawing dirty air into the vacuum cleaner 10 via the suction opening 24 in the cleaner head 22 or via a hose inlet 6 1.

The chassis 12 also carries a cyclonic separator 52 for separating dirt and dust from the air drawn into the cleaner 10. The features of the cyclonic separator 52 are best seen from Figures 2 and 3. The cyclonic separator 52 comprises an outer cyclone 54 and an inner cyclone 56 arranged concentrically therewith, both cyclones 54, 56 having their coaxial axes lying horizontally. The cyclonic separator 52 comprises an end portion 58 which has a first tangential inlet 59 and a second tangential inlet formed by the hose inlet 61. The tangential inlet 59 from the cleaner head has a mouth at the distal end thereof. The mouth is generally circular in shape, but is somewhat flattened along one edge to give the mouth a vaguely D-shaped section. The end portion 58 is otherwise generally cylindrical and has an end wall 60 which is generally helical. The end portion 58 opens directly into a cylindrical bin 62 having an outer wall 64 whose diameter is the same as that of the end portion 58. The end portion 58 and the cylindrical bin 62 are held together by way of a releasable clip which can be of any known design. No specific clip is shown in the drawings. A lip seal is provided between the cylindrical bin 62 and the end portion 52 in order to maintain a good seal between the respective parts. The cylindrical bin 62 is made from a transparent plastics material. The end of the bin 62 remote from the end portion 58 is frusto-conical in shape and closed. A locating ring 66 is formed integrally with the end of the bin at a distance from the outer wall 64 thereof and a dust ring 68 is 7 also formed integrally with the end of the bin 62 inwardly of the locating ring 66. Located on the outer surface of the bin 62 are two opposed grippers 70 which are adapted to assist a user to remove the separator 52 from the chassis 12 for emptying purposes. Specifically, the grippers 70 are moulded integrally with the transparent bin 62 and extend upwardly and outwardly from the outer wall 64 so as to form an undercut profile as shown in Figure 1.

The inner cyclone 56 is formed by a partially-cylindrical, partiallyfrusto-conical cyclone body 72 which is rigidly attached to the end face of the end portion 58. The cyclone body 72 lies along the longitudinal axis X-X of the transparent bin 62 and extends almost to the end face thereof so that the distal end 72a of the cyclone body 72 is surrounded by the dust ring 68. The gap between the cone opening at the distal end 72a of the cyclone body 72 and the end face of the bin 62 is preferably less than 8mm.

A fine dust collector 74 is located in the bin 62 and is supported by the locating ring 66 at one end thereof. The fine dust collector 74 is supported at the other end thereof by the cyclone body 72. Seals 76 are provided between the fine dust collector 74 and the respective support at either end. The fine dust collector 74 has a first cylindrical portion 74a adapted to be received within the locating ring 66, and a second cylindrical portion 74b having a smaller diameter than the first cylindrical portion 74a. The cylindrical portions 74a, 74b are joined by a frusto-conical portion 74c which is integrally moulded therewith. A single fin or baffle 78 is also moulded integrally with the fine dust collector 74 and extends radially outwardly from the second cylindrical portion 74b and from the frusto-conical portion 74c. The fin 78 extends vertically upwardly from the fine dust collector 74 and has the shape shown in Figure 2.

A shroud 80 is located between the first and second cyclones 54, 56. The shroud 80 is cylindrical in shape and is supported at one end by the end portion 58 and by the cyclone body 72 of the inner cyclone 56 at the other end. As is shown, the shroud 80 has perforations 82 extending therethrough and a lip 83 projecting from the end of the shroud 80 remote from the end portion 58. A channel 84 is formed between the shroud 80 and 8 the outer surface of the cyclone body 72, which channel 84 communicates with an entry port 86 leading to the interior of the inner cyclone 56 in a manner which encourages the incoming airflow to adopt a swirling, helical path. This is achieved by means of a tangential or scroll entry into the inner cyclone 56. A vortex finder 87 is mounted on the housing of the motor and fan unit 50 and extends into the second cyclone 56 through an aperture in the end wall 60 of the end portion 58. In Fig 2 and Fig 3 the fan itself is designated 50a. The vortex finder 87 is located centrally of the larger end of the inner cyclone 56 to conduct air out of the cyclonic separator 52 after separation has taken place. It also helps to secure the cyclonic separator 52 in position on the chassis 12. The exiting air is conducted past the motor and fan unit 50 so that the motor can be cooled befoie the air is expelled to atmosphere. Additionally, a post-motor filter (not shown) can be provided downstream of the motor and fan unit 50 in order to further minimise the risk of emissions into the atmosphere from the vacuum cleaner 10.

The entire cyclonic separator 52 is releasable from the chassis 12. Inlet port 32 is carried on an arm (not shown) which is biased into an upward position by means of a spring (not shown) acting between the arm and the chassis 12. When the cyclonic separator 52 is located in position on the cleaner the inlet port 32 is pressed against the mouth of the tangential inlet 59 of the end portion 58 to form a seal therewith so that in use air flows from the cleaner head 22 directly into the outer cyclone 54. Releasable catches (not shown) are provided to hold the inlet port 32 in place, and the cyclonic separator 52 too. When the catches are released the separator 52 can be lifted away from the chassis by the gripper portions 70. The bin 62 can then be released from the end portion 58 (which carries with it the shroud 80 and the inner cyclone body 72) to facilitate the emptying thereof.

As shown in the Figures, the robotic cleaner has a second tangential inlet 61 on end portion 58 for connecting a hose 90 to the cleaner. Inlet 61 is normally closed by a cover 63 which is pivotally mounted on inlet 61 by a combined pivot and electric switch 65. The inlet 61 is shown closed in Figure 1 and shown open in Figure 2 with the hose 90 connected to the inlet 61.

9 During autonomous operation of the cleaner under control of the guidance and navigation system 34 the floor will be cleaned by the rotating brush bar 26 and air will be drawn through the dirty air suction opening 24 in cleaner head 22 and will enter the cyclonic separator 52 through the first tangential inlet 59. The second inlet 61 is closed at this time by cover 61 as shown in Figure 1.

The first tangential inlet 59 is controlled by a valve flap 67 which is pivotally mounted at 69 on the inside wall of the inlet 59. The position of the valve flap 67 is normally open as shown in Figure 3 during autonomous use of the cleaner.

The position of the valve flap 67 is controlled electromagnetically by a motor 71 through a link bar 73 connected at one end to a control arm 75 of the motor and at the other end to a pivot 77 on the flap 67. Alternatively, an electromagnetic solenoid could be used to operate the valve flap 67.

The cleaner has a user interface 35 comprising control buttons 96, 97 and 98 and indicator lights 99. These buttons 96, 97, 98 control the operation of the cleaner 10 and the lights 99 indicate the mode of operation and also provide warnings to the user, such as "hose connected", "battery low", "bin full". These control buttons and lights are coupled to the battery management system 18 via the user interface 35 and will be discussed more fully below.

Referring to Figure 4 the battery and motor management system 18 comprises a central processor 33 which receives data from batter monitors (not shown) in the rechargeable battery packs 46. The processor 33 calculates the remaining charge in the battery packs and passes this information on to the processing circuitry 23 of the navigation system 34.

The central processor 33, typically a Hitachi H8/3334 microprocessor, is connected to the user interface board 35 and supplies power to the navigation system 34 which includes the processing circuitry 23 and sensors 40. It also supplies power to the motor and fan unit 50, drive motors 15, brush bar motor 28, and valve flap motor 71.

The button 96 is a global ON/OFF switch and is located on the user interface 35. The switch 96 interacts directly with the processor 33. Setting the switch 96 to OFF initiates a power down sequence which ultimately sets the processor 33 into an inactive state, Setting the switch 96 to ON activates the processor 33 which then executes a power up sequence. Buttons 97 select slow or fast forward operation in autonomous mode of the cleaner, and button 98 is a go/pause button.

Communication lines 37 between the processor 33 and the navigation system 34 carry data relating to the battery packs 46 and the motor 50 in one direction, and a drive command for the motor 50, drive motors 15, brush bar motor 28 and valve flap motor 71 in the other direction.

The battery and motor management system 18 includes a power supply unit 47 for providing a regulated supply to the navigation system 34. The power supply unit 47 and the motors 15,28,50,71 have current sensors (not shown) and these allow the processor 33 to monitor the current taken by the power supply unit 47 and the aforementioned motors.

The traction and brush bar motors 15,28 require pulse width modulation (PWM) speed control. The PWM control of the motors 15,28 is carried out in the navigation system 34.

The provision of two separate processing systems 23 and 33 allows each system to carry out an integrity check on the other system and to shut down the vacuum cleaner 10 if a fault is detected.

The user interface 35 controls the cleaner 10 through user interaction with the control buttons 96, 97 and 98 and the hose connection 61. The switch 65 and the valve flap motor 71 are connected through the navigation system 34.

When it is desired to use the cleaner in a manual mode using a hose 90, the cover 63 is first manually pivoted away from the inlet. This operates the switch 65 which in turn operates the motor 71 so that the valve flap 67 is moved so as to close off the inlet 59. The valve flap 67 then occupies the position shown in broken lines in Figure 3.

The hose 90 has a spigot 92 which fits into the forward-facing opening 61a of the hose inlet 61 and is retained in place by a catch 63a on the cover 63 which locks over an annular flange 94 on the hose 90 to retain the hose in a connected position.

When the hose 90 is connected, the navigation system 34 detects this through activation of the switch 65. The user interface 35 will light the appropriate indicator iamp 99 and will instruct the power control system 18. The global ON/OFF button 96 when operated executes a power up sequence. The control processor 33 will be sent a signal informing it that the hose 90 is connected. Button 98 is a "GO/PAUSE" button and when pressed will operate only the fan unit 50 to enable manual cleaning with the hose 90. The brush bar motor 28 will not be operated by the processor, being inhibited because the hose 90 is connected. The navigation system 34 is also inhibited at this time, so long as the hose 90 is connected.

The cover 63 is spring-loaded. When the hose 90 is disconnected, the cover 63 therefore returns to its closed position as shown in Figure I to close off the second inlet 61 to the separator 52 and reactivate the switch 65. This in turn operates the motor 71 through the user navigation system 34 so that the valve flap 67 returns to its open position as shown in solid lines in Figure 3. The cleaner 10 will now operate in autonomous mode on instruction by the user through the user interface 35.

As an alternative to the manually operated spring-loaded valve flap cover 63 illustrated in Figure 3, it would be possible to have instead an automatic motorised valve flap inside the hose inlet 61, similar to the motorised valve flap 67. One example is illustrated schematically in Figures 5A and 5B. Figure 5A shows the hose inlet 61 with the valve 12 in its normally closed position and Figure 5B shows the hose inlet 61 with the hose 90 inserted and the valve 100 opened.

Referring to Figure 5A, the hose inlet 61 is modified to have inside it a valve flap 100 pivotally mounted at 102 on the wall of the hose inlet 61. A motor 104 has a control arm 106 coupled by a link beam 108 to the valve flap 100. At the opening 61a a micro switch 110 is mounted having an operating member 112 projecting through an aperture 114 into the inlet opening 61 a. When the hose spigot 92 is inserted into the inlet opening 61 a, the operating member 112 is pressed upwardly and this operates the switch 110 thus detecting the presence of the hose 90. This alerts the navigation system 34 that manual operation with the hose 90 is required by the user and the motorised valve 100 is opened to the position shown in Figure 5B. Simultaneously, the normally open valve 67 is closed so that it assumes the dotted-line position shown in Figure 3. The appropriate "hose connected" warning light 99 lights on the user interface 35 and manual operation of the cleaner 10 can be initiated by operation of the user button 96 (power up) and 98 (go/pause). The speed selection buttons (fast/slow) 97 will not be operative when the hose 90 is connected as they select the forward speed of the cleaner 10 in autonomous mode.

Removal of the hose 90 releases the operating member 112 and the navigation system 34 returns the motorised valves 67 and 100 to their normal positions for autonomous operation of the cleaner 10, i.e. normally closed at hose inlet 61 and normally open at inlet 59. In this embodiment, the microswitch 110 and the motor 104 are coupled with the navigation system 34 in place of the switch 65.

Instead of a micro-switch, the hose inlet 61 could alternatively make use of an optical device having an optical beam at hose opening 61a. One such embodiment is illustrated schematically in Figure 5C. An infra-red transmitter T is mounted on the hose inlet 61 at the opening 61a. An infra-red beam 113 travels through the aperture 114, across the opening 61a and through a second aperture 116 to an infra-red receiver R. Insertion of the hose spigot 92 into the opening 61a will break the beam 113, thereby triggering 13 operation of the two motorised valves 67,100 to open the hose inlet 61 and close the inlet 59. Removal of the hose spigot 92 from the aperture 61a will restore the beam 113 and thus return the motorised valves 67,100 to their normally closed and normally open positions in inlets 61 and 59, respectively.

The transmitter T and receiver R are coupled to the navigation system 34 in place of the microswitch 110. In the modifications of Figure 5, the hose can be held in place by any suitable clips (not shown) in the absence of the cover 63.

14

Claims (10)

1. A vacuum cleaner having a normally open dirty air floor inlet and a normally closed dirty air hose inlet, and a sensor for sensing the presence of the hose at the hose inlet and for automatically closing the floor inlet when the hose is present at the hose inlet.

2. A vacuum cleaner as claimed in claim 1, wherein the hose inlet is opened manually when the hose is connected to the hose inlet.

3. A vacuum cleaner as claimed in claim 1, wherein the hose inlet is opened automatically when the sensor senses that the hose is present at the hose inlet.

4. A vacuum cleaner as claimed in any one of claims I to 3, wherein the sensor comprises a switch which is operated on connection of the hose to the hose inlet.

5. A vacuum cleaner as claimed in claim 4, wherein the switch is operated in response to a cover of the hose inlet being removed.

6. A vacuum cleaner as claimed in claim 4, wherein the switch is operated in response to the hose being inserted into the hose inlet.

7. A vacuum cleaner as claimed in any one of claims 1 to 3, wherein the sensor comprises an optical device.

8. A vacuum cleaner as claimed in claim 7, wherein the optical device includes a beam having a path which is interrupted by a portion of the hose on connection of the hose to the hose inlet.

9. A vacuum cleaner as claimed in any one of the preceding claims, wherein the floor inlet has an associated valve flap for closing the floor inlet, which valve flap is operated by the sensor.

10. A vacuum cleaner substantially as hereinbefore described with reference to Figures I to 4 of the accompanying drawings, or as modified with reference to Figure 5A and 5B, or as modified with reference to Figures 5C of the accompanying drawings.