GB2394650A

GB2394650A - Convertible vacuum cleaner

Info

Publication number: GB2394650A
Application number: GB0225479A
Authority: GB
Inventors: Eric Coburn; Barry Pears; Martyn Riley; David Barker
Original assignee: Black and Decker Inc
Current assignee: Black and Decker Inc
Priority date: 2002-11-01
Filing date: 2002-11-01
Publication date: 2004-05-05
Anticipated expiration: 2022-11-01
Also published as: GB2394650B; GB0225479D0

Abstract

The present invention provides a vacuum cleaner convertible between an upright mode of operation and a cylinder mode of operation, which comprises a body (10), a cleaning head (19) and a suction tube (20) for connecting said cleaning head to said body, wherein said body comprises a pair of latches (22) for retaining said suction tube in engagement with said body, each of said latches having an open condition for releasing said suction tube and a closed condition for holding said suction tube, and wherein each of said latches is monostable in the closed condition. Thus, the suction tube may only be released from engagement with the body of the vacuum cleaner by simultaneous operation of both of the latches by a user from the closed into the open condition, and upon release of the latches by the user, both latches will return of their own accord to the closed condition. The latches are therefore inoperable to release the suction tube from engagement with the body of the vacuum cleaner by operation of only one of the latches or by sequential operation of one of the latches and then the other. Since simultaneous operation of both of the latches by accident is extremely unlikely, a convertible vacuum cleaner in accordance with the invention is therefore very much safer than those described in the prior art.

Description

CONVERTIBLE VACUUM CLEANER

The present invention concerns a convertible vacuum cleaner. Vacuum cleaners generally come in two main varieties: upright vacuum cleaners and cylinder vacuum 5 cleaners. Upright vacuum cleaners have a body which is aligned in a generally vertical direction and which rests on a floorcleaning head. The body is pivotable at its lower end about the floorcleaning head. The upper end of the body is normally provided with a handle and the floor-cleaning head has wheels or rollers, whereby the upright vacuum cleaner can be pushed around a surface to be cleaned by a user 10 grasping the handle. Cylinder vacuum cleaners, on the other hand, have a body which is aligned in a generally horizontal direction and which rests directly on the floor.

The body of a cylinder vacuum cleaner is attached to one end of a suction tube, the other end of which is attached to a floor-cleaning head. The body is normally provided with both a set of wheels and a handle, whereby the body can be dragged or 15 pushed around a surface to be cleaned by a user grasping said handle. In addition, the suction tube normally comprises both a rigid portion and a flexible portion or hose.

The rigid portion of the suction tube usually comprises a further handle or gripping portion, whereby the floor-cleaning head of the cylinder vacuum cleaner can be pushed around a surface to be cleaned by a user holding this gripping portion of the 20 suction tube, whilst the body of the cylinder vacuum cleaner remains immobile. The variation in distance between the body and the floor-cleaning head of the cylinder vacuum cleaner created thereby is accommodated by the flexure of the hose portion of the suction tube.

25 Apart from these two main varieties of vacuum cleaner, vacuum cleaners which can be converted between an upright mode of operation and a cylinder mode of operation have also been known for many years. Perhaps the oldest known example is described in US Patent No. 2,898,621 assigned to The Hoover Company, which dates from 1959. A more recent example of a convertible vacuum cleaner is 30 described in US Patent No. 4,393,536 of Tapp. Fig. 1 of Tapp shows the convertible vacuum cleaner thereof in cylinder mode and Fig. 2 of Tapp shows the convertible vacuum cleaner thereof in upright mode. As may be seen in Fig. 1 of Tapp, the body P-UICHW 033 A

10 of the vacuum cleaner is provided with two clamps 22. As shown in Fig. 2 of Tapp, in upright mode, rigid portion 15 of the suction tube of the vacuum cleaner engages with clamps 22 in a releasable manner, as described at column 3, lines 7 to 10 of Tapp. As further described at column 3, lines 32 to 34 of Tapp, the rigid portion 15 5 of the suction tube may also function as a carrying handle for the vacuum cleaner when engaged with clamps 22 in the manner shown in Fig. 2 of Tapp. The entire vacuum cleaner may then be lifted from the floor by a user and carried around using the rigid tube 15 of the suction tube as a handle for the vacuum cleaner, which is clearly desirable and convenient.

On the one hand, clamps 22 should be easily releasable by a user for quick and simple operation thereof. On the other hand, however, if the rigid portion IS of the suction tube is used as a carrying handle when engaged with clamps 22, it can readily be seen that all of the weight of the vacuum cleaner body is borne by the two clamps 15 22. There is therefore a risk that if one of these two clamps is accidentally undone, all of the weight of the vacuum cleaner body will then be borne by the second clamp and it will only require this second clamp to be undone as well for the rigid portion 15 of the suction tube to be released. Moreover, if one of the two clamps is accidentally undone, a twisting force will be applied to the second clamp, making it far more likely 20 to undo as well, thereby allowing the rigid portion 15 of the suction tube to disengage from the body 10 of the vacuum cleaner. The body 10 would then be free to drop to the floor and the user would be left unexpectedly holding only the rigid portion 15 of the suction tube, thereby creating a risk of injury to the user, of damaging the vacuum cleaner upon impact with the floor, or both.

The present invention addresses the above problem. Accordingly, the present invention provides a vacuum cleaner convertible between an upright mode of operation and a cylinder mode of operation, which comprises a body, a cleaning head and a suction tube for connecting said cleaning head to said body, wherein said body 30 comprises a pair of latches for retaining said suction tube in engagement with said body, each of said latches having an open condition for releasing said suction tube P-UK-1033A

and a closed condition for holding said suction tube, and wherein each of said latches is monostable in the closed condition.

In a preferred embodiment of the present invention, each of said latches is 5 resiliently biased towards the closed condition.

Thus, the suction tube may only be released from engagement with the body of the vacuum cleaner by simultaneous operation of both of the latches by a user from the closed into the open condition, and upon release of the latches by the user, both 10 latches will return of their own accord to the closed condition. The latches are therefore inoperable to release the suction tube from engagement with the body of the vacuum cleaner by operation of only one of the latches or by sequential operation of one of the latches and then the other. Since simultaneous operation of both of the latches by accident is extremely unlikely, a convertible vacuum cleaner in accordance 15 with the invention is therefore very much safer than those described in the prior art.

Further features and advantages of the present invention will be better understood from the following detailed description, which is given by way of example

and with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a major portion of a vacuum cleaner according to an embodiment of the invention; Fig 2 is a top plan view of the vacuum cleaner of Fig. 1; Fig. 3 is a side elevational view of the vacuum cleaner of Fig. 1; 25 Fig. 4 is a front elevational view of the vacuum cleaner of Fig. 1; Fig. S is a rear elevational view of the vacuum cleaner of Fig. 1; Fig. 6 is a longitudinal section along the line A-A through the vacuum cleaner of Fig. 2 with a bagged version of the dust collection module inserted therein; Fig. 7 shows the airflow through the vacuum cleaner of Fig. 6 when in 30 operation; Fig. 8 is a longitudinal section along the line A-A through the vacuum cleaner of Fig. 2 with a bagless version of the dust collection module inserted therein; P UK HW1033A

Fig. 9 shows the airflow through the vacuum cleaner of Fig. 8 when in operation; Fig. 10 is a longitudinal section along the line A-A through the vacuum cleaner of Fig. 2 with the dust collection module removed; 5 Fig. 11 is a more detailed view of the bagless version of the dust collection module removed from the vacuum cleaner body; Fig. 12 is a more detailed view of the bagless version of the dust collection module inserted in the vacuum cleaner body; Fig. 13 is a transverse section along the line C-C through the vacuum cleaner of 10 Fig. 3 showing a latch mechanism for engaging the rigid portion of the suction tube with the vacuum cleaner body; Fig. 14 is a more detailed view of the part of the latch mechanism of Fig. 13 belonging to the vacuum cleaner body; Fig. 15 is a more detailed view of the part of the latch mechanism of Fig. 13 15 belonging to the rigid portion of the suction tube; Fig. 16 is a transverse section along the line B-B through the vacuum cleaner of Fig. 2 showing a side elevational view of a latch mechanism for engaging the dust collection module in the vacuum cleaner body; Fig. 17 is a transverse section along the line D-D through the vacuum cleaner of 20 Fig. 2 showing a different side elevational view of the latch mechanism of Fig. 16; and Fig. 18 is a lateral section along the line E-E through the vacuum cleaner of Fig. 3 showing a top plan view of the latch mechanism of Fig. 16.

25 With reference to Figs. 1 to 5, a major portion of a vacuum cleaner according to an embodiment of the invention is shown generally at 100. The vacuum cleaner comprises a body 10 provided with a pair of front wheels 11 on either side of said body and with a third wheel 25 on the underside thereof (see Figs. 3 to 5 for third wheel 25). Third wheel 25 is free to swivel around axis Y of wheel mount 26, 30 allowing body 10 to be steered round corners (see Fig. 6 for axis Y). Body 10 is also provided with a handle 12 permitting the body to be pushed or dragged around a surface to be cleaned when the vacuum cleaner is in cylinder mode or to be carried in P-UK-HWI033A

one hand. Housed in recess 13 of body 10 is a removable dust collection module 14, described in greater detail below.

Apart from dust collection module 14, body 10 houses three main components: 5 a cable rewind and storage mechanism 27, a fan 28 and a motor 29 (see Fig. 6).

Referring back to Figs. I to 5, body 10 is further provided with a power cable outlet 16 communicating with cable rewind and storage mechanism 27, a cable release button 17 for operating cable rewind and storage mechanism 27, and a power on/off switch 18. Cable rewind and storage mechanism 27 contains a power cable wound 10 therein, which emerges from body 10 through power cable outlet 16 and which is provided with an electrical plug on the exposed end thereof (not shown in the drawings). Cable rewind and storage mechanism 27 comprises both a spring and a ratchet, and operates in the following manner. Pulling the electrical plug at the exposed end of the power cable unwinds the power cable from storage within the 15 mechanism 27, putting the spring thereof under increasing tension as a greater length of power cable is unwound. However, the ratchet of mechanism 27 prevents the power cable from rewinding back into storage under the tension of the spring. On the other hand, depressing cable release button 17 disengages the ratchet, allowing the unwound length of cable to rewind back into storage under the tension of the spring 20 until such time as depression of the cable release button 17 ceases and the ratchet of mechanism 27 therefore re-engages.

Electrical power travelling down the power cable into the cable rewind and storage mechanism 27 is transmitted to motor 29 via wires contained in one or both of 25 the arms 30 of body 10. Depressing power on/off switch 18 alternately makes and breaks an electrical circuit created by these wires, thereby switching power to motor 29 on and off. When in operation, motor 29 causes fan 28 to rotate at high speed.

In addition to body 10, the vacuum cleaner further comprises a suction tube 20 30 which is connected at one end thereof to a floor-cleaning head 19 and at the other end thereof to air inlet 23 of body 10. Suction tube 20 comprises a rigid portion 15 and a flexible portion or hose (not shown in the drawings). Arrow 21 in Figs. 1 and 3 P-UK-HWI033A

represents a continuation of rigid portion 15 of suction tube 20, as well as said hose.

These portions of suction tube 20 not represented in the drawings are generally the same as the portions represented by reference numerals 42 and 13 in the figures of the Tapp patent and fulfil the same functions, except for the additional feature that in this 5 embodiment of the present invention, the flexible hose has a concertina-like structure which makes it extendible, and behaves as follows. One end of the flexible hose is connected to body 10 at locations 35 represented in Fig. 6. Accordingly, part of the total length of the flexible hose is contained within channel 40 of body 10 and emerges from channel 40 if pulled in the direction indicated by arrow L. On the other 10 hand, the flexible hose may also partially retract into channel 40 when not under tension, whereby the length of exposed hose may be varied as desired.

Rigid portion 15 of suction tube 20 comprises two lengths of tube connected together telescopically one inside the other to allow the overall length of rigid portion 15 15 also to be varied for comfortable operation of the vacuum cleaner by different heights of user in both upright and cylinder mode. The inner length of rigid portion 15 is provided with a row of notches along its outer surface and the outer length of rigid portion 15 is provided with a resiliently depressable protrusion on its inner surface. This protrusion engages with one of the notches on the inner length of rigid 20 portion 15 as the inner length slides within the outer length, whereby moderate force accidentally applied along the length of rigid portion IS is insufficient to adjust its overall length, but a greater force deliberately applied by a user is sufficient. In upright mode, rigid portion IS engages with body 10 and is retained in this condition by latches 22, the operation of which will be described in greater detail below with 25 reference to Figs. 13 to l S. Floor-cleaning head 19 is detachable from suction tube 20 and may be replaced by a crevice tool or by an upholstery tool, so that in cylinder mode, the vacuum cleaner may be used either to clean in crevices or to clean upholstery, respectively.

Turning now to Figs. 6 to 10, there is shown a series of longitudinal sections along line A-A of Fig. 2. Dust collection module 14 comprises a handle 31 allowing P-UK-HW1033A

dust collection module 14 to be lifted out of body 10 in the direction of arrow J represented in Fig. 6, when suction tube 20 is not engaged with body 10. In addition, dust collection module 14 is provided with a further handle on its underside (not shown in the drawings) and may be removed from body 10 in the direction of arrow K 5 also shown in Fig. 6 in a manner to be described in greater detail below with reference toFigs. 16tol8. Dust collection module 14 comes in two varieties: a bagged version and a bagless version. In the bagged version shown in Figs. 6 and 7, dust collection module 10 14 comprises a cavity 32 for receiving a disposable dust collection bag 36 in the manner represented in Fig. 7. The disposable dust collection bag 36 engages with lugs 33 of dust collection module 14 and is protected from fan 28 during operation of the vacuum cleaner by protective wall 34. Lid 37 of dust collection module 14 is removable, allowing bag 36 to be removed and replaced as required. During 15 operation of the vacuum cleaner, airflow proceeds in the direction indicated by the arrows in Fig. 7 from floor-cleaning head 19 along suction tube 20 and into bag 36, before passing through fan 28 and motor 29 and exiting out of exhaust vent 24. Dust entrained with air entering via floor-cleaning head 19 is deposited in dust collection bag 36 and clean air leaving dust collection module 14 serves to cool motor 29 before 20 exiting through exhaust vent 24.

In the bagless version of dust collection module 14 shown in Figs. 8 and 9, dust collection module 14 comprises a two-stage filter 38 for filtering dust entrained with air entering via floor-cleaning head 19 in the manner represented in Fig. 9. Filter 38 25 comprises a coarse filter 39 and a fine filter 41, both of which have a generally cylindrical shape with their longitudinal axes coaxially aligned on central axis Z of dust collection module 14 (see Figs. 9 and 11 for axis Z). Coarse filter 39 is typically made of a stiff wire mesh and fine filter 41 is typically made of matted or tightly woven artificial fibres. During operation of the vacuum cleaner, airflow proceeds in 30 the direction indicated by the arrows in Fig. 9 from floor-cleaning head 19 along suction tube 20 and into dust collection module 14, where the dirty air swirls around coarse filter 39. Large dust particles entrained with the dirty air are filtered out by P UK HW1033A

coarse filter 39 and deposited in container region 42 of dust collection module 14.

The partially filtered air passes inwardly through coarse filter 39, where small dust particles still present in the partially filtered air are filtered out by fine filter 41. The fully filtered air then passes up the centre of fine filter 41 and leaves dust collection 5 module 14 via passageway 43, before passing through fan 28 and motor 29 and exiting out of exhaust vent 24. As with the bagged version described above, clean air leaving dust collection module 14 also serves to cool motor 29 before exiting through exhaust vent 24. Lid 37 of dust collection module 14 is removable, allowing container region 42 of dust collection module 14 to be accessed and emptied. In 10 addition, two-stage filter 38, which in operation of the vacuum cleaner is mounted on lid 37, may be disassembled, allowing access to both coarse filter 39 and fine filter 41 for cleaning purposes. Fine filter 41 is also replaceable when degraded by long-term use. 15 Fig. 10 shows the body 10 of the vacuum cleaner with dust collection module 14 (either bagged or bagless version) removed entirely from recess 13. In both versions, channel 40 comprises an inner rigid tube 44 slidingly engageable within an outer rigid tube 45. Outer rigid tube 45 is integral with body 10. Inner rigid tube 44, however, is removable from outer rigid tube 45 for the purposes of packing and 20 shipping the vacuum cleaner in as compact a form as possible. To permit inner rigid tube 44 to be inserted into and removed from outer rigid tube 45, inner rigid tube 44 is provided with a knurled ring 46 by which it may be grasped. Inner rigid tube 44 engages with outer rigid tube 45 by means of a twist-and-click mechanism similar in operation to that of a bayonet-fitting lightbulb. In particular, inner rigid tube 44 is 25 provided on its exterior surface with a pair of protrusions 47, which engage with a pair of corresponding apertures 48 provided on opposites sides of outer rigid tube 45 (see Fig. 1 for the appearance of one of the protrusions 47 and apertures 48).

Protrusions 47 of inner rigid tube 44 are resilient and spring into place in apertures 48 when aligned therewith. On the other hand, depressing protrusions 47 through 30 apertures 48 between the forefinger and thumb of one hand permits inner rigid tube 44 to be rotated by grasping knurled ring 46 with the other hand until protrusions 47 are out of alignment with apertures 48 and inner rigid tube 44 may be withdrawn from P-UK- HW1033A

outer rigid tube 45 by pulling on knurled ring 46. Throughout these operations, the flexible hose portion of suction tube 20 remains attached at locations 35 of inner rigid tube 44 in the manner already described above in relation to Fig. 6.

5 Figs. 11 and 12 show the bagless version of dust collection module 14 in greater detail. As may be seen in Fig. 11, handle 31 of dust collection module 14 comprises a push button 49, which is mounted in a rotatable manner on pin 50 (seen end-on in Figs. 11 and 12) and which is also integral with a lever 51. Lever 51 fits snugly into a corresponding recess provided in side wall 52 of dust collection module 14, so as to 10 lie flush therewith. Depressing push button 49 in the direction indicated by arrow P in Fig. 11 causes lever 51 to hinge about pin 50 in the direction indicated by arrow Q. whilst also compressing spring 55. The rear surface of lever 51 is provided with a tooth which when positioned as shown in Figs. 11 and 12, engages with a corresponding shoulder of side wall 52. When lever 51 moves in the direction 15 indicated by arrow Q. however, the tooth of lever 51 disengages from this shoulder, allowing lid 37, together with the coarse and fine filters 39, 41, to be lifted off dust collection module 14 in the direction indicated by arrow R. When lid 37 is replaced and push button 49 is released, the compression of spring 55 causes push button 49 and lever 51 to return to the positions shown in Figs. 11 and 12, such that lever 51 lies 20 flush with side wall 52 once more, and dust collection module 14 may be smoothly re inserted into and removed from recess 13 of vacuum cleaner body 10. Accordingly, lid 37 may only be removed from dust collection module 14 if the dust collection module is firstly removed from recess 13, and the dust collection module cannot be opened whilst still housed in recess 13. Lid 37 of the bagged version of dust 25 collection module 14 may be removed in exactly the same way by operation of a similar push button 49, although in this case, coarse and fine filters 39, 41 are absent from lid 37.

Figs. 11 and 12 also show that the inlet to dust collection module 14 for air from 30 suction tube 20 is provided with a rubber O-ring 53 to form an air tight seal with channel 40. The outlet from dust collection module 14 for air leaving passageway 43 is surrounded by a raised lip 54 for the similar reason of forming an air tight seal with P-UK-HWI033A

chamber 60 of body 10 containing fan 28 and motor 29. As may be seen from Fig. 12, channel 40 is supplied with a Nylon_ collar 56, which abuts Oring 53 when dust collection module 14 is inserted in recess 13. Chamber 60 is provided with a further rubber O-ring 57, which forms a friction fit with lip 54 at the same time. Within the 5 aperture enclosed by O- ring 57 is mounted a grille or bars (not shown in the drawings) to prevent users from inserting their fingers into chamber 60 when fan 28 is rotating during operation of the vacuum cleaner. As may be seen, O-ring 57 is mounted on bearings 58 of fan 28.

10 In the embodiment of dust collection module 14 described in relation to Figs. 6 to 12, the bagged and bagless versions of the dust collection module are fully interchangable in vacuum cleaner body lO. However, in an alternative embodiment of the invention not shown in the drawings, the bagged and bagless versions may be given different external shapes, so that only one of them may be inserted into a 15 vacuum cleaner body 10 having a recess 13 correspondingly shaped to receive the appropriate version of the dust collection module.

The engagement of rigid portion 15 of suction tube 20 with vacuum cleaner body lO for use as a carrying handle, for operation of the vacuum cleaner in upright 20 mode or for storage of the vacuum cleaner, as well as the operation of latches 22 will now be described in greater detail with reference to Figs. 13 to 15. Firstly referring back to Fig. 1 however, it may be seen that the outer length of rigid portion 15 of suction tube 20 is provided at two locations along its length with two collars 61 corresponding to the positions of latches 22. These collars 61 may also be seen in 25 profile in Figs. 6 to 10 (see especially Fig. lO, where they are labelled). Fig. 13 is a transverse section through body 10 along the line C-C shown in Fig. 3, therefore also providing a transverse section through one of collars 61 and one of latches 22. As may be seen from Fig. 13, pushing rigid portion 15 of suction tube 20 in the direction indicated by arrow S causes collar 61 to engage with latch 22. More specifically and 30 as may be seen more clearly from Fig. 14, latch 22 is provided with two opposing shoulders 66 and 67 which engage with ridges 69, 70 of collar 61, shown in cross section in Fig. 15. In the position of latch 22 shown in Figs. 13 and 14, the space P-UK-HWI033A

between shoulders 66 and 67 is less than the distance between the outermost extremities of ridges 69 and 70. However, top surface 660 of shoulder 66 provides a camming surface for ridge 69, so that as rigid portion 15 of suction tube 20 is pushed in the direction indicated in Fig. 13 by arrow S. outer plane surface 705 of ridge 70 5 slides against upper surface 670 of shoulder 67 and ridge 69 pushes latch 22 by a small amount in the direction indicated in Fig. 14 by arrow T. thereby increasing the separation between shoulders 66 and 67 by the same amount. In addition, collar 61 and latch 22 are made of a stiff but resilient plastics material, such as Nylon_ or acrylobutyl styrene (ABS), which is elastically deformable by a sufficient amount to 10 allow ridges 69, 70 to pass through the space between shoulders 66, 67, even if the separation of shoulders 66, 67 is still slightly less than the distance between the outermost extremities of ridges 69, 70 when the underside of collar 61 contacts lever 64. In order to aid this elastic deformation, a channel 71 is formed in the middle of ridge 70 and the width of channel 71 in the plane of Fig. 15 is able to vary as ridge 70 15 is deformed, by collar 61 sliding around rigid tube portion 15 in a circumferential direction. Collars 61 are both securely mounted on rigid tube portion 15 however by each being provided with a nose 72, which engages with a corresponding hole made in rigid portion 15.

20 Once both collars 61 are engaged with both latches 22 in the manner shown in Fig. 13, rigid portion 15 of suction tube 20 is therefore unable to rotate about its longitudinal axis. Moreover, although a small lateral movement of rigid portion 15 may be possible, since the separation of shoulders 66, 67 is less than the distance between the outermost extremities of ridges 69, 70, rigid portion 15 is unable to 25 escape from latches 22 in a direction opposite to that indicated by arrow S. Referring back to Fig. 10, it may also be seen that rigid portion 15 is unable to slide in a longitudinal direction either because latches 22 are slightly recessed into the body 10 of the vacuum cleaner, thereby creating shoulders 73 on body 10 which collars 61 are unable to pass. Finally, since rigid portion 15 also rests on surfaces 74 of body 10, 30 even if one of latches 22 is released, rigid portion 15 is prevented from twisting in either of the directions indicated by arrows M and N in Fig. 10 (see also the top plan view of Fig. 2 for surfaces 74). Thus, rigid portion 15 of suction tube 20 is held Pa HW033A

securely in engagement with the body 10 of the vacuum cleaner for use as a carrying handle, for operation of the vacuum cleaner in upright mode or for storage of the vacuum cleaner.

S Returning to Fig. 14, operation of latches 22 by a user to release rigid tube 15 from engagement therewith will now be described. As may be seen from Fig. 14, latch 22 comprises a press switch 62, which is mounted in a rotatable manner on pin 63 (seen end-on in Figs. 13 and 14) and which is also integral with a lever 64.

Pushing press switch 62 in the direction indicated by arrow T in Fig. 14 increases the 10 separation between shoulders 66, 67 of latch 22 until it is greater than the distance between the outermost extremities of ridges 69, 70 of collar 61. Pushing press switch 62 in the direction indicated by arrow T also causes lever 64 to hinge about pin 63 in the direction indicated by arrow U. thereby lifting rigid portion 15 of suction tube 20 out of engagement with latch 22. Finally, pushing press switch 62 in the direction 15 indicated by arrow T also compresses spring 65, so that when press switch 62 is released, switch 62 and lever 64 return to the positions shown in Figs. 13 and 14, at which time the separation of shoulders 66 and 67 is less than the distance between the outermost extremities of ridges 69, 70 once again and the undersides of ridges 69, 70 rest on top of shoulders 66, 67, so that suction tube 20 is free to be picked up by a 20 user, whilst leaving body 10 immobile. Throughout these operations, arm 68 of switch 62 prevents spring 65 from escaping.

Since each of latches 22 individually constrains rigid portion 15 of suction tube 20 from moving laterally and longitudinally, as well as from rotating and twisting, 25 rigid portion 15 may only be released from engagement with body 10 when both of latches 22 are operated simultaneously. The simultaneous operation of both of latches 22 is very easily achieved, however, by a user pushing both of press switches 62 at the same time with the thumb of each hand, whereupon rigid tube portion 15 springs out of latches 22 under the action of levers 64.

The insertion of dust collection module 14 into recess 13 of body 10 and its removal therefrom will now be described in greater detail with reference to Figs. 16 to P-UK-HWI033A 18. As already mentioned above, lid 37 of dust collection module 14 is

provided with a handle 31 allowing dust collection module 14 to be lifted out of body 10 in the direction indicated by arrow J when suction tube 20 is not engaged with body 10.

Dust collection module 14 is also provided with a further handle on its underside (not 5 shown in the drawings), allowing it to be removed from body 10 in the direction indicated by arrow K as well. Fig. 16 is a transverse section along the line B-B shown in Fig. 2, therefore also providing a transverse section through a latch mechanism 76 which retains dust collection module 14 in recess 13. As may be seen from Fig. 16, latch mechanism 76 comprises a tooth 77, a spring 78 and a push button 79. Inserting 10 dust collection module 14 into recess 13 from the underside of body 10 in the direction indicated by arrow J causes shoulder 80 of dust collection module 14 to be guided into recess 13 by chamfer 81 of body 10. Shoulder 80 then pushes tooth 77 in the direction indicated in Fig. 16 by arrow V, compressing spring 78, until the tip of tooth 77 lies flush with wall 85 of body 10. This leaves dust collection module 14 15 free to continue sliding in the direction of arrow J until tooth 77 is aligned with a recess formed in the side wall of dust collection module 14, whereupon the compression of spring 78 urges tooth 77 in a direction opposite to that indicated by arrow V and tooth 77 engages with the recess formed in the side wall of dust collection module 14 in the manner shown in Fig. 16. Friction between the end face 20 of tooth 77 on the one hand and chamfer 84 of the recess on the other prevents further movement of the dust collection module in the direction of arrow J. whilst end stop 83 prevents the dust collection module from being removed in the direction of arrow K, thereby latching dust collection module 14 in place in recess 13 of body 10.

25 Alternatively, inserting dust collection module 14 into recess 13 from above body 10 in the direction indicated by arrow K allows the dust collection module to slide in recess 13 in the direction of arrow K until chamfer 82 formed on the underside of the dust collection module encounters tooth 77. Chamfer 82 then pushes tooth 77 in the direction indicated by arrow V, compressing spring 78, until the tip of 30 tooth 77 lies flush with wall 85. This leaves the dust collection module free to continue sliding in the direction of arrow K until tooth 77 is aligned with chamfer 84, whereupon the compression of spring 78 urges tooth 77 in a direction opposite to that P-13K-HW1033A

indicated by arrow V and tooth 77 engages with the recess formed in the side wall of the dust collection module in the manner shown in Fig. 16. Once again, dust collection module 14 is latched in place in recess 13 of vacuum cleaner body 10 for the same reasons as already explained above.

s In order to remove dust collection module 14 from recess 13 in the direction of arrow J. a user merely applies a pulling force to handle 31 of lid 37 sufficient to overcome the friction between the end face of tooth 77 on the one hand and chamfer 84 of the recess formed in the side wall of the dust collection module on the other. At 10 this point, chamfer 84 then pushes tooth 77 in the direction of arrow V, compressing spring 78 until the tip of tooth 77 lies flush with wall 85 of body 10, leaving dust collection module 14 free to continue sliding in the direction of arrow J until fully withdrawn from recess 13.

15 On the other hand, in order to remove dust collection module 14 from recess 13 in the direction of arrow K, a user depresses push button 79 in the direction indicated by arrow W in Fig. 17 and applies a pulling force to the handle provided on the underside of dust collection module 14. Fig. 17 is a transverse section along the line D-D shown in Fig. 2, therefore providing a side elevational view of latch mechanism 20 76. As may be seen from Fig. 17, push button 79 is mounted on one end of a movable block 86 having an angled face 87. Angled face 87 of block 86 contacts a corresponding angled face forming part of tooth 77, so that when push button 79 is depressed, angled face 87 pushes tooth 77 in the direction indicated by arrow V, compressing spring 78, until the tip of tooth 77 lies flush with wall 85. This leaves 25 dust collection module 14 free to slide in the direction of arrow K for as long as push button 79 remains depressed, so that when a user simultaneously applies a pulling force to the handle provided on the underside of dust collection module 14, the dust collection module may be withdrawn from recess 13 in the direction of arrow K. 30 Removal of dust collection module 14 from recess 13 in either of the directions indicated by arrows J and K is therefore straightforward, and is easily achieved by a user with only two-handed operation in both cases, with one hand being used to grasp

one of the two handles provided on the top and bottom of dust collection module 14 as desired and the other hand being used either to provide a counterforce pushing on body 10 (in the case of removal in the direction of arrow J) or to depress push button 79 (in the case of removal in the direction of arrow K). Thus dust collection module 5 14 may be both inserted into and removed from either the top or the bottom of vacuum cleaner body 10, as desired.

When push button 79 has been depressed and is released, it returns to the position shown in Figs. 16 and 17 in the following manner. Compression of spring 78 10 urges tooth 77 in a direction opposite to that indicated by arrow V, and tooth 77, by contact with angled face 87 of block 86, pushes block 86 in a direction opposite to that indicated by arrow W until push button 79 lies flush with the underside of vacuum cleaner body 10. Block 86 is also provided on either side with a pair of wings 88 (one of which may be seen end-on in Fig. 17) which come into contact with 15 an end stop 89 when push button 79 lies flush with the underside of body 10, thereby arresting the travel of block 86 in the direction opposite to arrow W and preventing block 86 from sliding any further in that direction. Wings 88 of block 86 may be seen more clearly in Fig. 18, which is a lateral section along line E-E in Fig. 3 and which therefore also provides a top plan view of latch mechanism 76. As may also be seen 20 from Fig. 18, the end of block 86 opposite to push button 79 emerges through a rectangular hole formed in tooth 77, and both tooth 77 and block 86 slide in channels defined by retaining walls 90, two of which may be seen in side elevation in Fig. 17.

Although in the illustrated embodiment, tooth 77 is withdrawn from 25 engagement with dust collection module 14 by operation of push button 79 as described above, in an alternative embodiment not illustrated in the drawings, push button 79 may be replaced by a pivoting lever or other means also appropriate for fulfilling the same function as push button 79.

30 Also visible in Fig. 18 is part of cable rewind and storage mechanism 27, including the ratchet 91 thereof and guides 92 for a power cable.

P-UK-HW1033A

In an alternative embodiment of the invention not represented in the drawings, wheels l l of body 10 are adapted to support the vacuum cleaner in upright mode as well as in cylinder mode. In this alternative embodiment, the parts of body 10 in the region of exhaust vent 24 are shaped to provide a recess for receiving floor-cleaning head 19, 5 such that when rigid portion 15 of suction tube 20 is engaged with latches 22, the underside of floor-cleaning head l 9 is coplanar with the outer circumferential surfaces of wheels l 1. In this condition, wheels l l rest on a surface to be cleaned at the same time as floor-cleaning head. 19, thereby permitting the weight of body 10 to be supported by the wheels l l as floor-cleaning head 19 travels over the surface to be 1 0 cleaned.

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Claims

1. A vacuum cleaner convertible between an upright mode of operation and a cylinder mode of operation, comprising: 5 a body (10); a cleaning head; and a suction tube (20) for connecting said cleaning head to said body; wherein said body comprises a pair of latches (22) for retaining said suction tube in engagement with said body, where each of said latches (22) has an open 10 condition for releasing said suction tube and a closed condition for holding said suction tube; characterized in that: each of said latches (22) is monostable in the closed condition.

15 2. A vacuum cleaner according to claim 1, wherein suction tube (20) has a rigid portion (15) comprising at locations along its length corresponding to the positions on said body (10) of said latches (22), means (61) for engagement with said latches, said means being wider in a direction normal to the longitudinal axis of said rigid portion (15) than a mouth of each of said latches for receiving said rigid portion in the closed 20 condition of said latches, but narrower than said mouths in the open condition of said latches. 3. A vacuum cleaner according to claim 2, wherein said means (61) for engagement with said latches are asymmetric about the longitudinal axis of said rigid 25 portion (15) and said latches (22) are correspondingly asymmetric about said longitudinal axis when said rigid portion is engaged with said latches, whereby rotation of said rigid portion about said longitudinal axis is prevented.

4. A vacuum cleaner according to claim 2 or claim 3, wherein said latches (22) 30 are recessed into said body (10) and said means (61) for engagement therewith are wider in the direction of said body than the rigid portion (15) of said suction tube (20) P-UK-HW1033A

when said rigid portion is engaged with said latches, whereby movement of said rigid portion in a direction parallel to said longitudinal axis is prevented.

5. A vacuum cleaner according to any one claims 2 to 4, wherein said body (10) 5 comprises at least one surface (74) located to abut the rigid portion (15) of said suction tube (20) when said rigid portion is engaged with said latches (22), whereby twisting of said rigid portion in a direction (M, N) away from said surface (74) upon operation of just one of said latches into the open condition thereof is prevented.

10 6. A vacuum cleaner according to any one of the preceding claims, wherein said latches (22) comprise means (64) for ejecting the rigid portion (15) of said suction tube (20) from engagement with said latches when said latches are operated from the closed into the open condition.

15 7. A vacuum cleaner according to any one of the preceding claims, wherein each of said latches (22) is resiliently biased towards the closed condition.

8. A vacuum cleaner according to any one of the preceding claims, wherein said body (10) comprises a recess (13) for receiving a removable dust collection module 20 (14) and said vacuum cleaner further comprises a dust collection module adapted to fit in said recess.

9. A vacuum cleaner according to claim 8, wherein said recess (13) is provided with a first access point allowing said dust collection module (14) to be removed from 25 said recess in a first direction (J) and a second access point allowing said dust collection module (14) to be removed from said recess in a second direction (K) opposite to said first direction.

l O. A vacuum cleaner according to any one of the preceding claims, wherein said 30 cleaning head is detachable from said suction tube (20) and comprises at least one of a crevice tool, an upholstery tool and a floor-cleaning head (19).

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11. A vacuum cleaner according to any one of claims 2 to 10, wherein the rigid portion (15) of said suction tube (20) comprises two lengths of tube connected together telescopically one inside the other, and wherein said means (61) for engagement with said latches (22) are located on the outer one of said lengths of rigid 5 portion (15).

12. A vacuum cleaner according to claim 11, wherein the inner length of rigid portion (15) is provided with a row of notches along its outer surface and the outer length of rigid portion (15) is provided with a resiliently depressable protrusion on its inner surface, for engagement with one of the notches on the inner length of rigid portion (15) as said inner length slides within said outer length.

13. A vacuum cleaner according to any one of the preceding claims, wherein said suction tube (20) comprises a flexible hose portion resiliently extendible in a 15 lengthwise direction, and wherein a part of said flexible hose portion is contained within a channel (40) of said body (lo), whereby the length of said flexible hose portion outside said channel (40) may be varied by pulling said flexible hose portion in a lengthwise direction away from said body (10).

20 14. A vacuum cleaner substantially as hereinbefore described with reference to the accompanying drawings.

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