Abstract:
A domestic appliance, such as a cyclonic vacuum cleaner, includes a component such as a separating apparatus, carried by a chassis. A catch is operable to release the component from the chassis. The component and the chassis can move with respect to each other. When the appliance is lifted there is relative movement, against the force of a resilient member, between the component and the chassis, so that the catch occupies a position that inhibits its release. Previous catches that inhibited from release when the appliance is lifted had a drawback in that slight relative movement between the component and the chassis when the appliance was resting on a surface tended to put the catch into the unreleasable position. The resilient member provides resistance to the catch moving into the locked position, thereby ensuring that the catch is inhibited from release only when the appliance is lifted from a surface.

Description:
REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a national stage application under 35 USC 371 of International Application No. PCT/GB2007/002674, filed Jul. 16, 2007, which claims the priority of United Kingdom Application No. 0615681.4, filed Aug. 8, 2006, the contents of which prior applications are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to a domestic appliance, such as a vacuum cleaner. 
       BACKGROUND OF THE INVENTION 
       [0003]    Vacuum cleaners which separate dirt and dust from an airflow without the use of a filter bag, so-called bagless vacuum cleaners, are becoming increasingly popular. Most bagless cleaners use cyclonic or centrifugal separation to spin dirt and dust from the airflow. By avoiding the use of a filter bag as the primary form of separation, it has been found possible to maintain a consistently high level of suction, even as the collecting chamber fills with dirt and dust. 
         [0004]    In a typical cyclonic vacuum cleaner, an airflow in which dirt and dust is entrained enters a first cyclonic separator via a tangential inlet. The inlet causes the airflow to follow a spiral or helical path within a collection chamber so that dirt and dust is separated from the airflow. Relatively clean air passes out of the chamber whilst the separated dirt and dust is collected therein. In some cyclonic vacuum cleaners, the airflow is then passed to a second cyclone separator which is capable of separating finer dirt and dust than the upstream cyclone. The airflow is thereby cleaned to a greater degree so that, by the time the airflow exits the cyclonic separating apparatus, the airflow is almost completely free of dirt and dust particles. The dirt and dust is left behind inside the collecting chamber. 
         [0005]    When the collecting chamber becomes full, a user typically removes the collecting chamber from the chassis of the machine, carries the chamber to a dust bin or refuse sack and empties the contents of the chamber into the bin or sack. The chamber may be emptied by inverting it. Alternatively, a manually operable catch may release the base portion of the chamber so that the dirt and dust falls out of the chamber into the bin or sack. 
         [0006]    Typically, a handle is provided to enable the user easily to carry the collecting chamber to the bin or sack for emptying. Conveniently, the same handle may be employed by the user for lifting the vacuum cleaner in its entirety when the collecting chamber is attached to the chassis, to facilitate carrying the cleaner between different locations. 
         [0007]    A problem which may be encountered with such appliances is that, when the user is carrying the appliance by means of the handle, he may accidentally release the catch that holds the collecting chamber to the chassis. Thus, the chassis may be released completely from the chamber and fall to the ground. This may cause damage to the chassis as well as being an inconvenience and potential safety hazard to the user. 
       SUMMARY OF THE INVENTION 
       [0008]    The invention provides a domestic appliance comprising a component carried by a chassis and a catch operable to releasably hold the component to the chassis arranged such that there is relative movement, against the force of resilient means, between the component and the chassis when the appliance is lifted, so that the catch occupies a position that inhibits its release. 
         [0009]    The provision of a catch that is not releasable when the appliance is lifted against resilient means prevents the chassis and the component from being released accidentally from each other. Previous proposals for catches inhibited from release when the appliance is lifted had a drawback in that slight relative movement between the component and the chassis when the appliance was resting on a surface tended to put the catch into the unreleasable position. For example, it was found that the action of grabbing the handle on the collecting chamber of a vacuum cleaner was sometimes sufficient to urge the catch accidentally into the locked position. This was inconvenient and confusing to the user, especially when trying to release the collecting chamber for emptying. The provision of resilient means provides some resistance to the catch moving into the locked position, thereby ensuring that the catch is inhibited from release only when the appliance is lifted from a surface. 
         [0010]    Advantageously, a member is provided that is arranged to push the component away from the chassis when the catch is released, so as to assist the user in releasing the component. Preferably, a user-operable actuator is provided. For the convenience of the user, this may be provided adjacent a handle used to carry the component when it is released. 
         [0011]    Advantageously, the resilient means may also be employed to urge the catch into its latched position and to return the actuator to its original position when released. 
         [0012]    A stop may be provided so that, when the catch is in the unreleasable position, the stop prevents release of the catch if the appliance is subjected to a sudden vertical movement. This feature prevents the catch from returning to a releasable position even if the appliance is shaken. 
         [0013]    The invention is particularly applicable to vacuum cleaners. The invention prevents a user from releasing the separating apparatus comprising a collecting chamber employed for collecting dirt and dust from the chassis when the user is carrying the vacuum cleaner. 
         [0014]    A handle may be provided to enable the user to carry the appliance. When the invention is applied to a vacuum cleaner having separating apparatus, this handle may also be the handle provided for carrying the separating apparatus when it is removed from the chassis. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The invention will now be described, by way of example, with reference to the accompanying drawings, in which: 
           [0016]    FIG. 1 is a side view of a domestic appliance constructed according to the invention in the form of an upright vacuum cleaner; 
           [0017]    FIG. 2 is perspective view of the cleaner of FIG. 2, showing release of the separation apparatus; 
           [0018]    FIG. 3 is a side view of the cleaner of FIGS. 1 and 2 being carried by a user; 
           [0019]    FIG. 4 is a schematic sectional side view of part of a domestic appliance constructed according to the invention in a first position; 
           [0020]    FIG. 5 is a schematic sectional side view of part of the appliance of FIG. 4 in a second position; 
           [0021]    FIG. 6 is a schematic sectional side view of part of the appliance of FIG. 4 in a third position; and 
           [0022]    FIG. 7 is a magnified view of part of FIG. 6. 
       
    
    
       [0023]    Like reference numerals refer to like parts throughout the specification. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0024]    Referring to FIG. 1, an upright vacuum cleaner indicated generally by the reference numeral 1 comprises a main chassis 2 which supports dirt and dust separation apparatus 3 incorporating a collecting chamber 4. The lower part of the vacuum cleaner 1 comprises a cleaner head 5 for engaging with the floor surface. The cleaner head 5 has a downwardly facing suction inlet and a brush bar (not shown), mounted in the mouth of the inlet, for agitating the floor surface. The cleaner head 5 is pivotably mounted to a motor housing 6, which houses the motor and fan of the cleaner 1. Support wheels 7 are mounted to either side of the motor housing 6 for supporting the cleaner 1 and allowing movement across a floor surface. 
         [0025]    A spine 8 of the chassis 2 extends upwardly from the motor housing 6 to provide support for the components of the cleaner 1. A cleaning wand 9 having a second dirty air inlet 10 is connected by way of a hose (not shown) to the chassis 2 at the base of the spine 8. The wand 9 is releasable from the spine 8 so as to allow a user to carry out above-the-floor cleaning and cleaning in places which are inaccessible by the main cleaning head 5. When the wand 9 is fixed to the spine 8, the wand forms the handle of the cleaner 1. A hand grip 9′ at the remote end of the wand 9 allows a user to manoeuvre the cleaner 1. 
         [0026]    In the embodiment shown, the dirt- and dust-separating apparatus 3 comprises a cyclonic arrangement but this could readily be replaced by a filter, a bag or a combination of different known separation devices. 
         [0027]    In normal upright use, the vacuum cleaner 1 is manoeuvred over the floor surface to be cleaned whilst the motor causes dirty air to be sucked into the cleaner 1 via the cleaner head 5. The dirty air is passed to the dirt- and dust-separating apparatus 3 where the dirt and dust is extracted and clean air is expelled to the atmosphere. 
         [0028]    Dirt and dust is collected in the collecting chamber 4 of the separating apparatus 3 and needs to be emptied periodically when it is full. Thus, the separating apparatus 3 is releasable from the main chassis 2. A manually releasable catch 11 is provided on the spine 8 of the chassis 2 and is arranged to locate the separating apparatus 3, including the collection chamber 4, on the appliance. The user of the vacuum cleaner 1 releases the catch 11 and removes the separating apparatus 3 by means of a handle 12 provided on the upper portion of the separating apparatus. The user then carries the separating apparatus 3 by means of the handle 12 to a refuse bin or sack for emptying. The collection chamber 4 may be emptied by releasing it from the separating apparatus 3 and inverting it over the bin or sack. Alternatively, the collection chamber 4 may have a moveable base portion that can be released, by means of a further manually releasable catch, to allow dirt and dust to fall from the bottom of the collection chamber. 
         [0029]    The handle 12 on the separating apparatus 3 also serves to allow the user to lift and carry the appliance as a whole, as shown in FIG. 3. When the user does this, his hand is close to the catch 11 for releasing the separating apparatus 3 from the chassis 2. With conventional vacuum cleaners, there has been a risk that the user may accidentally release the catch whilst carrying the appliance 1. 
         [0030]    The catch 11 of the vacuum cleaner constructed according to the invention is shown schematically in FIGS. 4 to 7 inclusive. The catch 11 comprises a main catch member 13 having a pivot 14 on its lower portion to enable it to be pivotably connected to the spine 8. The centre portion 15 of the main catch member projects outwardly away from the spine and has a downwardly depending lip 16 at its free end. The upper portion of the main catch member 13 comprises an actuator for the catch 11 in the form of a user-operable button 17. The button 17 is conveniently located adjacent the carrying handle 12. When the user pushes the button 17, the main catch member 13 pivots away from the user, towards the spine 8, and the projecting portion 15 of the main catch member is elevated. Resilient means in the form of a helical spring 18 is provided between the centre portion 15 of the main catch member and a projecting lip 19 on the spine 8 of the chassis. 
         [0031]    FIG. 4 shows the catch in its closed or latched position, with the separating apparatus 3 being attached to the chassis 2. The lip 16 on the projecting centre portion 15 of the main catch member 13 is arranged to engage with a shoulder 20 on the separating apparatus 3. When the user wishes to release the separating apparatus 3, he pushes against the button 17 against the force of the spring 18. This causes the main catch member 13 to move pivotably towards the spine 8 and the rear surface 23 of the catch member moves into a cavity 21 on the spine. This is shown in FIG. 5. The central projecting portion 15 pivots upwardly until the lip 16 clears the top of the shoulder 20 on the separating apparatus. The spine 8 itself acts as a stop to limit rearward motion of the rear surface 23 of the catch member 13. The lower portion 22 of the main catch member 13 is arranged so that, as the catch member pivots towards the spine 8, the lower portion is urged against the separating apparatus 3, thereby pushing it away from the chassis 2 as the catch 11 is released. This feature assists the user in removing the component. 
         [0032]    When the separating apparatus 3 or other component is released, the actuator 17 remains on the chassis 2. If the actuator were to be located on the component itself, this might be confusing to the user when trying to discern another catch or mechanism on the component for operation, such as an actuator for releasing a catch for emptying the collection chamber. 
         [0033]    When the user wishes to re-attach the separating apparatus 3, he simply pushes the separating apparatus 3 back into position on the chassis 2. As he does so, the pivotable member 13 is pushed backwards until it clears the shoulder 20 on the separating apparatus 3. The spring 18 returns the main catch member 13 to its upright position, with the lip 16 of the projecting portion 15 engaging in the shoulder 20 associated with the separating apparatus 3. Thus, the separating apparatus 3 is secured to the chassis 2. 
         [0034]    The catch is arranged so as to allow relative movement between the separating apparatus 3 and the chassis 2 in such a manner that, when the appliance 1 is lifted by the user by means of the handle 12, the catch 11 occupies a position that inhibits its release. With reference to FIGS. 6 and 7, the separating apparatus 3 and chassis 2 are arranged so as to permit a limited amount of relative movement between them, typically less than 0.5 cm. When the user applies a lifting force to the appliance 1 by lifting the handle 12, the separating apparatus 3 is able to move slightly upwardly with respect to the chassis 2 as the appliance is lifted off the ground. The lower portion 22 of the catch member 13 is arranged to support the separating apparatus 3 in the elevated position. 
         [0035]    In accordance with the invention, when the appliance 1 is elevated, the separating apparatus 3 moves with respect to the chassis 2, and the entire catch 11 moves with the separating apparatus against the force of the helical spring 18. In this embodiment, both the separating apparatus 3 and the catch 11 move upwardly with respect to the spine 8 of the chassis 2. The main catch member 13 occupies a position where at least part of its rear surface 23 is adjacent the spine 8 and is clear of the cavity 21 in the spine. Thus, if the user accidentally pushes the button 17, the main catch member 13 cannot pivot rearwardly, because its rear surface 23 abuts the spine 8 of the chassis. The prevention of movement of the main catch member 13, and hence the button 17 provides an indication to the user that the catch 11 is inoperable while the appliance 1 is lifted. 
         [0036]    FIG. 7 shows the catch in more detail. A catch stop in the form of a lip 24 is provided on the chassis 2 to prevent the catch member 13 from moving into a position where the catch 11 can released while the appliance 1 is lifted, even if the appliance is shaken or receives some other sudden force. The lip 24 engages with a ledge or notch in the rear surface 23 of the catch member 13. If the user attempts to release the catch 11 whilst shaking the appliance 1, the catch member 13 may move vertically against the spine 8, but the lip 24 prevents the catch member from moving vertically downwardly into a position adjacent the cavity 21, where it may pivot into the released position. 
         [0037]    The spring 18 in FIGS. 6 and 7 is compressed and is biased so as to urge the catch member 13 and the separating apparatus 3, in the absence of external forces, downwardly into the position where the catch 11 may be released. However, the spring force is not sufficient to do so while the appliance 1 is lifted because of the weight of the chassis 2 reacting against the spring 18. The provision of a spring 18 or other resilient means provides a reaction force that prevents the separating apparatus 3 from being inadvertently lifted into a position that inhibits release of the catch 11. For example, if the user grabs the handle 12 and attempts to lift the separating apparatus 3 away from the chassis 2 whilst trying to activate the catch 11, the user may inadvertently apply a vertically upwardly-directed force. In the absence of the resilient spring 18 pushing the catch member 13, and hence the separating apparatus 3, downwards, the lifting force may be sufficient to urge the catch 11 from the configuration shown in FIG. 4 to that shown in FIG. 6, thereby accidentally preventing release. 
         [0038]    The spring 18 or other resilient means is multi-functional: it returns the actuator 17 to its original position after it is pressed, it returns the catch member 13 to a latched position, so that the separating apparatus is secured to the chassis 2 and, as described above, it prevents the catch 11 from being moved accidentally into a position that inhibits release. By using one spring 18 to perform a plurality of functions, the number of components employed in manufacturing the catch 11 can be reduced. 
         [0039]    When the user puts the appliance 1 back down on a floor surface, the catch member 13 and separating apparatus move back downwardly with respect to the chassis 2 and occupy their normal positions as shown in FIG. 4, so that the separating apparatus is once again releasable from the chassis. 
         [0040]    Of course, variations may be made without departing from the scope of the invention. For example, the resilient means may be provided between the component and the spine. Separate resilient means may be provided to return the catch member into the latched position and to return the actuator to its original position when the catch has been released. 
         [0041]    The handle for lifting the appliance need not be the same as that provided for carrying the separating apparatus. A separate handle or hand-grip may be provided. The handle for lifting the appliance may be provided on the chassis, in which case the catch would need to be reconfigured so that relative downward movement of the catch and component with respect to the chassis causes the catch to occupy a position where its release is inhibited. 
         [0042]    The catch of the invention may be provided to locate other components on the chassis, so that those components are not releasable whilst the appliance is being carried. 
         [0043]    Although the invention has been described with reference to an upright vacuum cleaner, it is equally applicable to cylinder cleaners and other appliances that may be carried by a user. For example, a lawn mower may be provided with a chassis and a chamber for collecting grass clippings produced by the mower. The invention may be employed to prevent the collecting chamber from being released when the user is carrying the lawn mower. The invention may also be applied to, for example, other surface-treating appliances, such as those that apply polish or paint to a surface.