GB2592256A

GB2592256A - Vacuum cleaner

Info

Publication number: GB2592256A
Application number: GB2002480.8A
Authority: GB
Inventors: Aston Marcus; Forrest James
Original assignee: Numatic International Ltd
Current assignee: Numatic International Ltd
Priority date: 2020-02-21
Filing date: 2020-02-21
Publication date: 2021-08-25
Also published as: WO2021165687A1; EP4106592A1; GB202002480D0

Abstract

A vacuum cleaner comprises a vacuum chamber 47 that is closable by a pivotable lid (18, fig 2). A pivoted clamp member 20 is provided to lock the lid in a closed position, the arrangement being such that the pivoted clamp member when rotated to the clamped position provides an over-centre clamping action to draw respective latching features 42, 44 into inter-engagement so that the lid is held in its clamped configuration and the clamp member when pivoted away from the closed position disengages the latching features so that the lid can be pivoted to the open orientation. A secondary latch 31 can be provided which acts between a distal end region of the clamp member and the sidewall of the chamber, the secondary latch is configured and arranged to retain the clamp member in its clamped position unless the secondary latch is released, whereupon the clamp member may be pivoted away from its closed position.

Description

Vacuum Cleaner The present invention relates to the field of vacuum cleaners and in particular cleaners which have an openable vacuum chamber for removal of collected detritus, or a filter bag containing detritus. The invention concerns a lid for the chamber with a retaining mechanism for the lid. A particular application is the lid of a vacuum chamber for a handheld stick-type vacuum cleaner, in which the lid serves as a structural support for a stick tube and must therefore be capable of preventing accidental opening during use.

Stick-type vacuum cleaners have become popular in recent years. They are configured to be handheld with a pistol-type hand grip, a suction motor (typically battery-driven) a suction chamber and an elongate detachable barrel or 'stick' portion provided at a distal end thereof with a work head (such as a nozzle or brush bar).

The work head may thus be directed to a floor or other surface area for vacuum cleaning. The stick portion is hollow or tubular and feeds into the suction chamber so that air-entrained matter may be drawn into a generally cylindrical vacuum chamber. The stick portion is usually detachable so that alternative work heads or nozzles may be attached, or to make the cleaner more compact for storage.

The vacuum chamber will be in fluid communication with a suction motor, usually disposed above the hand grip. The suction motor is typically battery powered, and when not in use may be docked with a re-charging station. An example of such a stick vacuum cleaner is disclosed in GB 2569591A (Dyson Technology Ltd.) These machines are lightweight and convenient for wielding when cleaning floors and other objects such as curtains, or furniture such as upholstered chairs or sofas. The stick portion of the machine is usually attached at its base end to one end of the vacuum chamber. Typically this will be by an interference fit of the stick base end region with a collar provided in a front region of the vacuum chamber. Because of the length of the stick portion, and the weight of the work head on the distal end of the stick portion, a high bending stress may be exerted in the region of the base of the stick where it is joined to the vacuum chamber. This applies especially when the device is in use and may be banged against objects, or occasionally dropped. Thus a robust connection between chamber and stick portion must be made.

In a stick type vacuum cleaner developed by the present inventor the vacuum chamber is provided with an openable lid, and the lid itself supports an attached stick portion of the vacuum cleaner. The lid must be securely attached to the chamber in order to prevent it from accidental opening during use.

The present invention seeks more generally to provide an improved lid closure arrangement for a vacuum chamber, which lid arrangement is better capable of resisting unintended opening.

In a particular aspect the present invention provides a handheld vacuum cleaner with a vacuum chamber lid closure arrangement in which the lid not only permits access to the vacuum chamber for emptying thereof, but also carries a stick portion with optional work head. W02019/175561 discloses a handheld vacuum cleaner which has a generally cylindrical configuration, and wherein a vacuum chamber portion is provided with a domed lid portion with a hinge on one side and an over centre latch which permits opening.

According to one aspect of the invention there is provided a vacuum cleaner (preferably handheld) comprising a suction drive, a vacuum chamber in fluid communication with the suction drive, a hand grip and an inlet port for admitting air-entrained detritus sucked into the vacuum chamber, wherein the vacuum chamber comprises a base region, sidewalls and a distal end which together define an interior volume, the distal end being provided with a lid through which is provided an inlet port, the opening of which lid provides access to the interior volume, wherein one side region of the lid is attached to a corresponding side region of the distal end of the vacuum chamber by a joint that permits pivoting of the lid with respect to the distal end so as allow movement of the lid between open and closed positions. A pivoted clamp member may be provided which is configured to act between the lid and the chamber so that when the clamp member pivots to a clamped configuration respective mutually inter-engageable latching features provided on the clamp member and a distal end region of the chamber sidewall become engaged. The arrangement being such that the pivoted clamp member when rotated to the clamped position provides an over-centre clamping action to draw the respective latching features into inter-engagement so that the lid is held in its clamped configuration, and the clamp member when pivoted away from the closed position disengages the latching features so that the lid can be pivoted to the open orientation. The cleaner is preferably configured and arranged as a handheld cleaner, preferably a stick vacuum cleaner.

In another aspect of the invention, a secondary latch is provided which acts between a distal end region of the clamp member and the sidewall of the chamber, which secondary latch is configured and arranged to retain the clamp member in its clamped position unless the secondary latch is released, whereupon the clamp member may be pivoted away from its closed position.

A base region of the clamp member may be pivotally attached to the lid. The secondary latch may be attached to a free end of the clamping member and acts upon a sidewall feature of the chamber, such as a lip or indent thereon.

The secondary latch preferably comprises a rocker member pivotally attached to the distal end region of the clamping member. The rocker member may have a distal end region away from the pivot, which distal end region is provided with a latching feature which is configured to engage with the sidewall feature of the chamber when the rocker member is closed. Biasing means may be provided for urging the rocker member latching feature into engagement with the sidewall feature.

In yet another aspect of the invention a latch release mechanism is provided which comprises a shuttle which can travel in a release direction to approach the distal end of the secondary latch and displace and release the latch. The shuttle preferably has a leading end which is provided with a ramp feature (in profile) which acts on the free end region of the rocker member to rock the rocker member away from latching engagement. Beneficially, there may be a corresponding undercut ramp feature (in profile) which is provided on the distal end region of the latch member to facilitate displacement of the latch member when the shuttle approaches. Thus the shuttle travel lifts a free end of the latch so as to release it.

For ease of operation the shuttle may be provided with a button or plate or fin which may be manipulated to move the shuttle. The shuttle may, after displacement of the latch member, travel further to act on the distal end region of the clamp member to pivot the clamp member away from the closed position to its open orientation so that the lid can swing to its open orientation. This action may be aided by biasing means (such as a spring) which acts to open the lid.

The secondary latch member is preferably configured so as to lie flush with a sidewall outer surface of the chamber when in the latched position. This avoids snagging of the secondary latch and helps prevent accidental opening of the lid.

In yet a further aspect of the invention there is provided a vacuum cleaner (preferably handheld) comprising a suction drive, a vacuum chamber in fluid communication with the suction drive, a hand grip and an inlet port for admitting air-entrained detritus sucked into the vacuum chamber, wherein the vacuum chamber comprises a base region, sidewalls and a distal end which together define an interior volume, the distal end being provided with a lid in which is provided an inlet port, the opening of which provides access to the interior volume, wherein one side region of the lid is attached to a corresponding side region of the distal end of the chamber by a joint that permits pivoting of the lid with respect to the distal end so as allow movement of the lid between open and closed positions, wherein a pivoted clamp member is provided which is configured to act between the lid and the chamber so that when the clamp member pivots to a clamped configuration respective mutually inter-engageable latching features provided on the clamp member and a distal end region of the chamber sidewall become engaged. The arrangement being such that the pivoted clamp member when rotated to the clamped position provides an over-centre clamping action to draw the respective latching features into inter-engagement so that the lid is held in its clamped configuration, and the clamp member when pivoted away from the closed position disengages the latching features so that the lid can be pivoted to the open orientation.

A base end region of the clamp member is typically pivotally attached to the lid. The lid may have a rim which facilitates pivotal attachment by providing a location for a pivot/swivel. The pivot axis may extend in a transverse direction with respect to the sidewalls of the chamber. The chamber is generally cylindrical in configuration and the transverse pivot axis corresponds to the direction of a diameter or tangent of the lid.

In a preferred arrangement a base end region of the clamp member is pivotally attached to the lid. The clamp member pivot axis extends in a transverse direction with respect to the sidewalls of the chamber. The chamber is typically generally cylindrical in configuration. The transverse pivot axis may correspond to the direction of a diameter or tangent of the lid. The transverse pivot axis is preferably generally centrally disposed and extends across the lid. The clamp member may have two spaced apart base regions which span the lid and are attached to the lid via a common transverse pivot axis. The clamp member may have a generally U-form or C-form which provide the two base regions which span the lid, and a free end therebetween which is offset from the common pivot axis, and this acts as a lever around the pivot.

The latching feature(s) of the clamp member are preferably disposed closer to the pivot axis than the free end. This provides a mechanical advantage when the clamp member is rotated to cause engagement, and allows a strong clamping effect to be formed. The latching feature(s) of the clamp member are most preferably disposed in the base regions thereof, offset from the pivot axis.

The respective latching features may comprise one or more nubs and corresponding pockets, which engage with one another when the clamp member is in the clamped position. Said nubs or pockets may be transversely or diametrically opposed with respect to one another. Thus they may be sited on the exterior of the chamber sidewalls, and on an inside region of the lid (or an inside region of a rim of the lid).

The core features of the invention relate to a closure for a container (the vacuum chamber). The invention may thus find application for containers in general, in which case, insofar as the description refers to a vacuum chamber, this could in other embodiments be considered as a container with a lid therefor, and claimed as such.

Following is a description by way of example only and with reference the figures of the drawings of one mode for putting the present invention into effect.

In the drawings:-Figure 1 is a side view of a handheld vacuum cleaner in accordance with the invention.

Figure 2 is a three quarter perspective view of the handheld vacuum cleaner, with a vacuum chamber lid in a closed and locked position.

Figure 3 shows the same cleaner with a locking latch in a release position.

Figure 4 shows the same cleaner with the lid opened and a filter pod removed.

Figure 5 is a partial side view of the front portion of the vacuum cleaner.

Figure 6 is similar to figure 5, but with a locking latch released.

Figure 7 is also similar to figure 5 but with the locking latch released and a clamping member in an open position.

Figure 8 is similar to figure 5 but with the lid fully open (as also shown in figure 4).

Figure 9 is another cross-sectional partial side view of the vacuum cleaner showing the release mechanism of the locking latch in detail.

Figure 10 is similar to figure 9, with the locking latch popped up to a release position.

S

Figure 11 is similar to figure 10 with a clamp member and the associated locking latch rotated.

Figure 12 is a cross sectional view of detail of the clamp member pivot showing the over-centre mechanism.

Figure 13 is a similar view to figure 12 with the over centre mechanism fully engaged.

In figure 1 a handheld vacuum cleaner in accordance with the present invention is shown generally as 10. The cleaner has a generally cylindrical motor housing 11 for an electric motor unit (not visible). The housing is formed with a plurality of cooling perforations 12. An inboard portion of the cylindrical housing has depending therefrom a pistol grip 13. An upper region of the grip is provided with a ridge 14 which serves as rest for the user's index finger. A lower region of the grip 13 extends to a platform 45. The platform projects forward towards an underside region of a cylindrical vacuum chamber sidewall 15, and continues in the form of a ridge 16 along the sidewall underside. A front region of the ridge is provided with a transverse lid hinge 17. The hinge attaches a generally annular lid member 18 (as best shown in figure 4) for the font edge of the vacuum chamber. The lid member is provided with a central stub port 19, with a portion which protrudes forward. A semi-circular clamp member 20 is attached via a pivot A-A' at diametrically opposed transverse edge regions of the lid.

An upper region of the housing is formed as a curved elongate upper ridge 21. An ellipsoidal cut-out slot 22 is formed in a mid region of the upper ridge. The slot accommodates a sliding shuttle member 23 for travel in an axial (fore-aft) direction. The shuttle member is provided with an upstanding, inverted T-profile thumb grip 24, which may be moved in the direction of arrow B in figure 2 to open the lid, as will be described in more detail hereinafter. A rear end region of the upper ridge is provided with a flat circular control pad 26, provided with a power/battery charge LED light and on/off buttons. This arrangement is preferred over a trigger-style actuation lever which can become tiresome for a user over prolonged operation.

A battery pack 25 is removably attached to an underside of the platform 45, as a sliding fit with a retaining latch. The battery pack is ellipsoidal in profile, with several cylindrical cells (not visible) arranged side by side transversely across the pack. The pack is oriented with an upwards incline with respect to a longitudinal axis of the cylindrical vacuum chamber, so that the front end region thereof is above the grip end of the pack, as shown in figure 1. The lower face of the battery pack serves as a support for the vacuum cleaner, upon which it may be rested. The battery may be recharged in situ or remotely after removal.

In use the motor unit drives a coaxial suction fan (not visible) inboard of the motor unit. The fan chamber is in fluid communication with the interior of the vacuum chamber 47. Air is thus drawn into the vacuum chamber through the port 19 (and before that via any work head and stick tube also attached). A cylindrical semi-rigid pod-style collection bag 30 (shown in figure 4) is accommodated in the vacuum chamber and collects air-entrained detritus, whilst the filtered air exhausts from the fan chamber. The bag 30 may be emptied, or may be disposed of as required.

The present invention relates primarily to the locking, opening and closing of the lid and will be explained in more detail below. In figure 9 the release grip 24 is shown in a first position, at the rear end of the upper ridge cut-out slot 22. In this position a latch member 31 lies generally flush with an outer rim 32 of the lid. The latch member has a base end which is attached to an upper portion of the lid rim at a pivot joint 33. A distal end of the latch member is formed as a leaf 34.

As shown in figure 9, the shuttle member includes and elongate traveller 37 which is attached to the thumb grip by a bolt 38. The front, leading end of the traveller is formed as a depending ramp 36. This abuts a correspondingly rising ramp 35 of the underside of leaf 34. A lower end of the rising ramp is formed with a depending lip 39. The lip 39 hooks over an upstanding transverse rib 40 of an upper outside edge of the chamber sidewall, so that the clamp member is retained hard against the sidewall.

This release mechanism operates such that when the grip is used to slide the shuttle member 37 forwards to the position 2 shown in figure 10, the shuttle member ramp 36 impinges upon the leaf rising ramp 35 (see figure 8) and lifts the latch member about its pivot. This releases the lip 39 from the rib 40. Further longitudinal sliding of the shuttle member to the position 3 shown in figure 11 causes the lower blunt edge of the leading end ramp 36 to abut the lip 39. This shifts the clamp member 20 (with latch member 31) away from the edge of the vacuum chamber about the clamp pivot A (see also figure 3).

Figure 12 shows a lower, pivot end of the clamp member 20. Offset to the rear of the pivot A is radiused cam seat 42. A nub 43 is fixed to an outer surface of the vacuum chamber upper sidewall. The nub has a rear semi-circular cam 44. When the clamp member is in the close position (as per figure 12) the cam is engaged with the cam seat. The cam seat moves with the clamp member, and is shaped so as to ride over and grasp the cam surface when being engaged therewith. In this way an over centre clamping action is achieved, with the mechanical advantage provided by the lever length of the clamp member from pivot to upper end being applied to the pivot of the cam seat against the cam and holding the lid tightly against the rim 46 (see figure 4) of the vacuum chamber sidewall. Of course, the clamp member straddles opposite sides of the vacuum chamber and the above arrangement of nub, cam and cam seat is mirrored on the diametrically opposite side of the vacuum chamber. The clamp action is therefore very strong and secure. A lever length of more than a radius of the chamber provides a significant mechanical advantage applied to the cam and cam seat engagement, and a very stable clamp pivot is derived from the diametric spacing of the clamp member arms.

When the clamp member is displaced away by action of the shuttle member (as described above and shown in figure 11), the cam seat rides back over the cam, freeing the lid. A biasing spring (not visible) in the hinge 17 can then drive the lid fully open to the position shown in figure 4. The filter pod may then be removed hands-free by inclining the cleaner downwards so the pod slides out. A new pod may then be inserted for continued surface cleaning.

The latch member 31 provides a lock for the clamp member 20. The clamp member can only be moved once the latch member is released, which prevents accidental opening of the lid.

In summary, the present invention relates to the field of vacuum cleaners and in particular cleaners which have an openable vacuum chamber for removal of collected detritus, or a filter bag or pod containing detritus. There is disclosed a vacuum cleaner (10) comprising a suction drive, a vacuum chamber (47) in fluid communication with the suction drive, a hand grip (13) and an inlet port (19) for admitting air-entrained detritus sucked into the vacuum chamber, wherein the vacuum chamber comprises a base region, sidewalls (15) and a distal end which together define an interior volume, the distal end being provided with a lid (1)8 through which is provided the inlet port, the opening of which lid provides access to the interior volume, wherein one side region of the lid is attached to a corresponding side region of the distal end of the vacuum chamber by a joint (17) that permits pivoting of the lid with respect to the distal end so as to allow movement of the lid between open and closed positions, wherein a pivoted clamp member (20) is provided which is configured to act between the lid and the chamber so that when the clamp member pivots to a clamped configuration respective mutually interengageable latching features (42,43) provided on the clamp member and a distal end region of the chamber sidewall become engaged, the arrangement being such that the pivoted clamp member (20) when rotated to the clamped position provides an over-centre clamping action to draw the respective latching features into inter-engagement so that the lid is held in its clamped configuration, and the clamp member when pivoted away from the closed position disengages the latching features so that the lid can be pivoted to the open orientation. A secondary latch (31) maybe provided which acts between a distal end region of the clamp member and the sidewall of the chamber, which secondary latch is configured and arranged to retain the clamp member in its clamped position unless the secondary latch is released, whereupon the clamp member may be pivoted away from its closed position.

Claims

Claims 1. A vacuum cleaner comprising a suction drive, a vacuum chamber in fluid communication with the suction drive, a hand grip and an inlet port for admitting air-entrained detritus sucked into the vacuum chamber, wherein the vacuum chamber comprises a base region, sidewalls and a distal end which together define an interior volume, the distal end being provided with a lid through which is provided the inlet port, the opening of which lid provides access to the interior volume, wherein one side region of the lid is attached to a corresponding side region of the distal end of the vacuum chamber by a joint that permits pivoting of the lid with respect to the distal end so as to allow movement of the lid between open and closed positions, wherein a pivoted clamp member is provided which is configured to act between the lid and the chamber so that when the clamp member pivots to a clamped configuration respective mutually inter-engageable latching features provided on the clamp member and a distal end region of the chamber sidewall become engaged, the arrangement being such that the pivoted clamp member when rotated to the clamped position provides an over-centre clamping action to draw the respective latching features into inter-engagement so that the lid is held in its clamped configuration, and the clamp member when pivoted away from the closed position disengages the latching features so that the lid can be pivoted to the open orientation, wherein a secondary latch is provided which acts between a distal end region of the clamp member and the sidewall of the chamber, which secondary latch is configured and arranged to retain the clamp member in its clamped position unless the secondary latch is released, whereupon the clamp member may be pivoted away from its closed position.
2. A vacuum cleaner as claimed in claim 1 wherein a base region of the clamp member is pivotally attached to the lid and the secondary latch is attached to a free end of the clamping member and acts upon a sidewall feature of the chamber, such as a lip or indent thereon.
3. A vacuum cleaner as claimed in claim 1 or 2 wherein the secondary latch comprises a rocker member pivotally attached to the distal end region of the clamping member.
4. A vacuum cleaner as claimed in claim 3 wherein the rocker member has a distal end region away from the pivot, which distal end region is provided with a latching feature which is configured to engage with the sidewall feature of the chamber when the rocker member is closed.
5. A vacuum cleaner as claimed in claim 4 wherein biasing means are provided for urging the rocker member latching feature into engagement with the sidewall feature.
6. A vacuum cleaner as claimed in any of the preceding claims wherein a latch release mechanism is provided which comprises a shuttle which can travel in a release direction to approach the distal end of the secondary latch and displace and release the latch.
7. A vacuum cleaner as claimed in claim 6 wherein the shuttle has a leading end which is provided with a ramp feature which acts on the free end region of the rocker member to rock the rocker member away from latching engagement.
8. A vacuum cleaner as claimed in claim 7 wherein a corresponding undercut ramp feature is provided on the distal end region of the latch member to facilitate displacement of the latch member when the shuttle approaches.
9. A vacuum cleaner as claimed in any of claims 6 to 8 wherein the shuttle is provided with a button or plate or fin which may be manipulated to move the shuttle.
10. A vacuum cleaner as claimed in claim 9 wherein the shuttle may, after displacement of the latch member, travel further to act on the distal end region of the clamp member to pivot the clamp member away from the closed position to its open orientation so that the lid can swing to its open orientation.
11. A vacuum cleaner as claimed in any of the claims 4 to 10 wherein the secondary latch member is configured so as to lie flush with a sidewall outer surface of the chamber when in the latched position.
12. A vacuum cleaner as claimed in any preceding claim wherein a base end region of the clamp member is pivotally attached to the lid.
13. A vacuum cleaner as claimed in claim any preceding claim wherein the clamp member pivot axis extends in a transverse direction with respect to the sidewalls of the chamber.
14. A vacuum cleaner as claimed in claim 13 wherein chamber is generally cylindrical in configuration and the transverse pivot axis corresponds to the direction of a diameter or tangent of the lid.
15. A vacuum cleaner as claimed in claim 14 wherein the transverse pivot axis is generally centrally disposed and extends across the lid.
16. A vacuum cleaner as claimed in any of claims 12 to 15 wherein the clamp member has two spaced apart base regions which span the lid and are attached to the lid via a common transverse pivot axis.
17. A vacuum cleaner as claimed in claim 16 wherein the clamp member has a generally U-form or C-form which provides the two base regions which span the lid, and a free end therebetween which is offset from the common pivot axis.
18. A vacuum cleaner as claimed in any of claims 12 to 17 wherein latching feature(s) of the clamp member are disposed closer to the pivot axis than the free end.
19. A vacuum cleaner as claimed in claim 18 wherein the latching feature(s) of the clamp member are disposed in the base regions thereof, offset from the pivot axis.
20. A vacuum cleaner as claimed in claim 18 or 19 wherein the respective latching features comprise one or more nubs and corresponding pockets, which engage with one another when the clamp member is in the clamped position.
21. A vacuum cleaner as claimed in claim 20 wherein said nubs or pockets are transversely or diametrically opposed with respect to one another in the sidewalls or lid.
22. A vacuum cleaner comprising a suction drive, a vacuum chamber in fluid communication with the suction drive, a hand grip and an inlet port for admitting air-entrained detritus sucked into the vacuum chamber, wherein the vacuum chamber comprises a base region, sidewalls and a distal end which together define an interior volume, the distal end being provided with a lid in which is provided an inlet port, the opening of which provides access to the interior volume, wherein one side region of the lid is attached to a corresponding side region of the distal end of the chamber by a joint that permits pivoting of the lid with respect to the distal end so as to allow movement of the lid between open and closed positions, wherein a pivoted clamp member is provided which is configured to act between the lid and the chamber so that when the clamp member pivots to a clamped configuration respective mutually inter-engageable latching features provided on the clamp member and a distal end region of the chamber sidewall become engaged, the arrangement being such that the pivoted clamp member when rotated to the clamped position provides an over-centre clamping action to draw the respective latching features into inter-engagement so that the lid is held in its clamped configuration, and the clamp member when pivoted away from the closed position disengages the latching features so that the lid can be pivoted to the open orientation.
23. A vacuum cleaner as claimed in claim 22 wherein a base end region of the clamp member is pivotally attached to the lid.
24. A vacuum cleaner as claimed in claim 22 or 24 wherein the pivot axis extends in a transverse direction with respect to the sidewalls of the chamber.
25. A vacuum cleaner as claimed in claim 24 wherein chamber is generally cylindrical in configuration and the transverse pivot axis corresponds to the direction of a diameter or tangent of the lid.
26. A vacuum cleaner as claimed in claim 25 wherein the transverse pivot axis is generally centrally disposed and extends across the lid.
27. A vacuum cleaner as claimed in any of claims 22 to 26 wherein the clamp member has two spaced apart base regions which span the lid and are attached to the lid via a common transverse pivot axis.
28. A vacuum cleaner as claimed in claim 27 wherein the clamp member has a generally U-form or C-form which provide the two base regions which span the lid, and a free end therebetween which is offset from the common pivot axis.
29. A vacuum cleaner as claimed in any of claims 22 to 28 wherein latching feature(s) of the clamp member are disposed closer to the pivot axis than the free end.
30. A vacuum cleaner as claimed in claim 29 wherein the latching feature(s) of the clamp member are disposed in the base regions thereof, offset from the pivot axis.
31. A vacuum cleaner as claimed in any of claims 22 to 30 wherein the respective latching features comprise one or more nubs and corresponding pockets, which engage with one another when the clamp member is in the clamped position.
32. A vacuum cleaner as claimed in claim 31 wherein said nubs or pockets are transversely or diametrically opposed with respect to one another.
33. A vacuum cleaner as claimed in any of claims 22 to 32 wherein a secondary latch is provided which acts between a free end region of the clamp member and the sidewall of the chamber, which secondary latch is configured and arranged to retain the clamp member in its clamped position unless the secondary latch is released, whereupon the clamp member may be pivoted away from its closed position.
34. A vacuum cleaner as claimed in claim 33 wherein a base region of the clamp member is pivotally attached to the lid and the secondary latch is attached to a free end of the clamping member and acts upon a sidewall feature of the chamber, such as a lip or indent thereon.
35. A vacuum cleaner as claimed in claim 33 or 34 wherein the secondary latch comprises a rocker member pivotally attached to the distal end region of the clamping member.
36. A vacuum cleaner as claimed in claim 35 wherein the rocker member has a distal end region away from the pivot, which distal end region is provided with a latching feature which is configured to engage with the sidewall feature of the chamber when the rocker member is closed.
37. A vacuum cleaner as claimed in claim 36 wherein biasing means are provided for urging the rocker member latching feature into engagement with the sidewall feature.
38. A vacuum cleaner as claimed in any of the preceding claims wherein a latch release mechanism is provided which comprises a shuttle which can travel in a release direction to approach the distal end of the secondary latch and displace and release the latch.
39. A vacuum cleaner as claimed in claim 38 wherein the shuttle has a leading end which is provided with a ramp feature which acts on the free end region of the rocker member to rock the rocker member away from latching engagement.
40. A vacuum cleaner as claimed in claim 39 wherein a corresponding undercut ramp feature is provided on the distal end region of the latch member to facilitate displacement of the latch member when the shuttle approaches.
41. A vacuum cleaner as claimed in any of claims 38 to 40 wherein the shuttle is provided with a button or plate or fin which may be manipulated to move the shuttle.
42. A vacuum cleaner as claimed in any of claims 38 to 41 wherein the shuttle may, after displacement of the latch member, travel further to act on the distal end region of the clamp member to pivot the clamp member away from the closed position to its open orientation so that the lid can swing to its open orientation.
43. A vacuum cleaner as claimed in any of the claims 33 to 42 wherein the secondary latch member is configured so as to lie flush with a sidewall outer surface of the chamber when in the latched position.
44. A vacuum cleaner as claimed in any of the preceding claims wherein biasing means are provided for urging the lid towards its open position.
45. A vacuum cleaner as claimed in any of the preceding claims wherein the cleaner is configured and arranged as a handheld cleaner, preferably a stick vacuum cleaner in which a stick tube extends co-axially from the vacuum chamber lid.