GB2141328A

GB2141328A - Vacuum cleaner

Info

Publication number: GB2141328A
Application number: GB08316643A
Authority: GB
Inventors: Leonard Taylor
Original assignee: LAMSON D D PLC
Current assignee: LAMSON D D PLC
Priority date: 1983-06-18
Filing date: 1983-06-18
Publication date: 1984-12-19
Also published as: GB8316643D0; GB2141328B

Abstract

An industrial vacuum cleaner mounted on wheels has an upright drum detachably mounted in the body of the cleaner with its open top in sealing engagement with a seating 18 around an opening 14 leading to a motor-driven impeller. A U-shaped handle 28 is pivoted to the drum by trunnions 30. To lift the drum of its own wheel 27 and into the body of the cleaner free end portions 31 of the handle 28 engage fulcrum pins 21 on the body and the handle 28 is raised. The trunnions 30 engage guides 22 and lead the mouth of the drum into correct position against the seating 18. The drum is held against the seating by a catch 33 which retains the handle 28 in the raised position. <IMAGE>

Description

SPECIFICATION Vacuum cleaner This invention relates to vacuum cleaners and more particularly to vacuum cleaners of the type, included in the general term industrial vacuum cleaners, in which the cleaner is mounted on wheels to enable it to be moved from place to place and comprises a motor-driven impeller for producing subatmospheric pressure within an upright, usually cylindrical, drum for receiving waste material. The waste material is collected by a nozzle connected directly to the drum or indirectly through a flexible hose. The drum is detachably mounted in the cleaner to enable it to be emptied. An open top of the drum is held in sealing engagement with a seating around an opening into a chamber connected to the impeller. The chamber usually houses filter means through which dust-laden air passes before reaching the impeller.

One way in which the drum has previously been mounted in industrial vacuum cleaners of this type is by toggle clips on opposite sides of the drum which suspend the drum and hold its open top against the seating. The drum, even when empty, can be quite heavy. The drum is usually provided with its own wheels which aid moving it between the cleaner and the emptying point but lifting the drum from the floor and locating its open top against the seating can be awkward. The toggle clips usually have to be done up one at a time and when the first clip is done up the drum is canted to one side and this may result in incorrect engagement of the drum with the seating.

The present invention consists in a vacuum cleaner mounted on wheels to enable it to be moved from place to place and comprising a motor-driven impeller for producing sub-atmospheric pressure within an upright drum for receiving waste material collected through a nozzle open to the interior of the drum, the drum being detachably mounted in the body of the cleaner for emptying and an open top of the drum being held in sealing engagement with a seating around an opening leading to the impeller wherein is provided means having separable but interengageable elements on the drum and the body of the vacuum cleaner for lifting and lowering the drum and guiding it, at least during lifting, Into engagement with the seating.

The lifting and lowering means preferably comprises sets of interengageable elements on opposite sides of the drum and may further comprise arms on opposite sides of the drum and pivoted thereto, an extension of each arm beyond the pivot being provided with a formation engageable with a complementary formation on the body and forming at least a part of a respective one of the sets of interengageable elements, the formations and complementary formations when engaged co-operating to provide a fulcrum for lifting the drum by the arms The arms could be separate and be manually operated simultaneously but are preferably connected together for simultaneous and equal movement about their pivots, for example by being formed by the arms of a U-shaped handle which embrace the drum.

To guide the drum into and out of engagement with the seating upwardly extending guides mounted on the body may be provided to be engaged by lateral projections on the drum.

In vacuum cleaners, especially though not exclusively industrial vacuum cleaners, having an upright drum to receive waste material it is convenient to have a disposable bag, for example one made of polyethylene, for actually receiving the waste material. The bag can be lifted out of the drum for disposal when sufficiently filled. If the bag is put in the drum as a simple linear it is apt to collapse inwards and even to be sucked into the air outlet of the drum as soon as the vacuum cleaner is started.

With the aim at least of contributing to the solution of this problem, according to another aspect the present invention provides, in or for a vacuum cleaner having an upright drum and an inlet for waste material to enter the upper part of the drum and fall into and be collected in the lower part of the drum, a holder for a disposable bag for the waste material comprising a ring to support the mouth of the bag below the waste inlet, means for retaining the bag on the ring with the mouth held open and upwardly directed, and means for sustaining the ring in the drum, the arrangement being such that an air space is maintained between the outside of the bag and the wall of the drum in which air can circulate so as to balance the air pressures inside and outside the bag during use of the vacuum cleaner.

The inlet for waste material may be arranged in the upper part of the wall of the drum or it may be at the end of a conduit inside the drum and leading from an opening through the lower part of the drum, for example as described in Patent Specification 1 524 254.

The support ring may be a strip of flat metal or plastics bent into a hoop with the width of the strip parallel to the axis of the hoop. The means for sustaining the ring in the drum preferably comprises legs secured at their upper ends to the ring, their lower ends being engageable with the base of the drum. Alternatively the support ring could be sustained from the adjacent wall of the drum by brackets on the drum or the ring. The means for retaining the mouth of the bag on the ring may be a retaining ring slightly larger than the support ring and adapted to be passed downwards onto the ring and to surround material of the mouth of the bag folded outwards over the support ring. The retaining ring may be prevented from sliding downwards too far by shoulders provided, for example, by the upper ends of legs of the sustaining means.

A removable collector of rigid or relatively stiff material is preferably provided above the mouth of the bag, the Interior of the collector having a hollow conical base sloping to a bottom opening and an upright wall or walls which conform closely to the upper part of the wall of the drum and extend above the level of the inlet for waste material, means being provided for the passage of air between the air space around the outside of the bag and the interior of the drum above the collector. As the collector, unlike the disposable bag, is not made of flexible material a narrow annular gap between the wall or walls of the collector and the wall of the drum can be maintained in use of the vacuum cleaner and may form the means for such passage of air. The collector avoids the risk of overflow of waste material from the bag into the air space and directs into the bag waste material falling from a filter in the chamber. The collector may be combined with the retaining ring or other retaining means to form a single unit.

Vacuum cleaners with an upright drum for collecting waste material and, particularly though not exclusively industrial vacuum cleaners, are often required for use in wet situations or actually to pick up water or other liquids. A substantial quantity of liquid may have to be collected in the drum and there is a risk, especially in powerful machines, of liquid being drawn into the filter and impeller.

To adapt a vacuum cleaner for use in such circumstances according to a further aspect the present invention provides, in or for a vacuum cleaner having an upright drum, an outlet for air from the upper part of the drum to the impeller, and an inlet for waste material to enter the upper part of the drum, a baffle adapted to be removably disposed in the drum and adapted to separate the inlet from the outlet and cause air drawn into the inlet to follow an indirect path between the inlet and outlet of the drum.

The inlet for waste material may be arranged in the upper part of the wall of the drum or it may be at the end of a conduit inside the drum and leading from an opening through the lower part of the drum, for example as described in Patent Specification 1 524254.

The baffle preferably comprises a first element adapted to divide the upper part of the drum into vertically spaced zones of which the inlet opens into the lower zone and the outlet opens from the higher zone, and a second element depending from the first element between an aperture through the first element and a portion of the first element which in the position of use of the baffle in the drum is adjacent the Inlet.

The aperture in the first element enables air to pass from the inlet to the outlet but the second element forces it to follow an extended path in the lower zone before reaching the aperture. The areas of the aperture and of the cross-section of any passages defining the path are preferably, but not necessarily, greater than that of the Inlet so that the air velocity Is reduced, helping to separate entrained liquid from the air and to avoid the picking up of liquid from Inside the drum.

A float-operated valve may be provided to close the aperture or any equivalent opening in the baffle when liquid accumulated in the drum has reached a predetermined level.

An embodiment of the invention will now be described. by way of example only, with reference to the accompanying drawings in which Figure 1 IS a side elevation, partly broken away to show hidden details. of a vacuurn cleaner according to the invention.

Figure 2 Is a diagrammatic view of a holder for 3 disposable bag for use in the vacuum cleaner of Figure 1, Figure 3 is a diagrammatic view of a baffle to be fitted to the vacuum cleaner of Figure 1 when the cleaner is to be used to pick up wet waste material, and Figure 4 is a sectional view on line IV-IV of Figure 3.

The vacuum cleaner shown in Figure 1 is an industrial vacuum cleaner comprising a body 1 and a detachable, upright cylindrical drum 2. The body 1 has a frame 3, a lower, rear part 4 of which is mounted on wheels 5 to enable the vacuum cleaner to be moved from place to place. An electric motor driven impeller (not shown is mounted on the lower frame part 4. The frame 3 has spaced side members which towards the front of the vacuum cleaner have rising portions 7 connecting rearward portions 6, defining the lower part 4 of the frame, to upper forward portions 9. A forwardly curved crossmember 10 connects the front ends of the forward portions 9 of the frame. A sheet metal casing 11 encloses parts of the vacuum cleaner mounted on the frame and above the upper, forward portions 9 defines a forward component 12 which houses a spring-mounted dome 13 defining a chamber 14 which encloses a filter or filters 15. The dome 13 is open at the bottom where it is formed with an inverted peripheral channel 16 fitted with a seal 17 to form a seating 18 for the drum 2. The upper part of the dome 13 is connected by a duct (not shown) to the motor-driven impeller. When the open top of drum 2 is engaged with the seating 18 the impeller extracts air from the interior of the drum 2 through the filter or filters 15 so that sub-atmospheric pressure is produced within the drum. There is an inlet 8 into the upper part of the drum 2 for waste material. The inlet 8 is connected by a hose (not shown) to a nozzle (not shown) suitable for the cleaning work to be done.

The front of the casing 11 is open below the upper portions 9 and forward of the rising portions 7 of the frame side members, and receives the drum 2 between the frame side members. On confronting faces of the rising portions 7 are mounted fixed elements 19 of drum lifting and lowering means.

Each of the fixed elements 19 comprises a flat plate 20 mounted opposite and parallel to the similar plate 20 on the other rising portion 7. On the face of the plate which Is towards the other fixed element 19 are provided a laterally extending fulcrum pin 21, a vertical guide 22 formed by front and rear flanges 23 and 24 respectively and a buffer 25. The front flange 23 is shorter than the rear flange 24 providing a front entrance 26 to the vertical guide 22.

The drum 2 has castors 27 on which it can be moved between the body of the vacuum cleaner and the emptying point.

Towards its too the drum, Is provided with trunnions 30 extending from the outside of the drum along a prolongation of a diameter of the drum. A U-shaped handle. 28 having arms 29 which embrace the drum Is pivotally connected to the drum by the engagement of the triinnions 30 with holes through flattened portions 31 near the free ends of the arms 29. The flattened portions 31 extend beyond the trunnions 30 and near their free ends are formed with shallow elongated recesses 32 in their lower edges.

When the drum 2 is wheeled into the open front of the body 1 with the central part of the handle 28, as shown in Figure 1, lying against the wall of the drum, the buffers 25 engage the curved walls of the drum 2 and guide the drum 2 into a central position between the plates 20. Projections of the trunnions 30 beyond the flattened portions 31 of the arms 29 pass through the front entrance 26 of the vertical guide 22 and movement of the drum on its castors is arrested when the trunnions 30 meet the rear flanges 24 of the guides. At the same time the fulcrum pins 21 engage the recesses 32. When the handle 28 is then raised, pivoting about the fulcrum pins 21, the drum 2 is lifted off the floor and the trunnions 30 travel up the vertical guides 22 which confine the drum to movement along its vertical axis. The elongation of the recesses 32 allows for changing centres of the trunnions 30 and fulcrum pins 21 during this movement. At the upper limit of its travel the rim of the drum 2 engages the seating 18 forming a seal between the interior of the drum and the chamber 14.

A catch 33 is provided to engage the handle 28 and retain the drum in the raised position. The catch 33 is mounted centrally in the cross-member 10 which is of channel section. The catch 33 comprises a catch member 34 made from strip material and of generally reversed C-shape with a flat, sloping extension 35 inclined rearwards and downwards from the free end of its lower curved portion 36. A slot (not shown) through the upper curved portion 37 of the C-shape extends around the curvature of this portion to receive a pin 38 the ends of which are secured to the flanges of the cross-member 10. A compression spring 39 may be fitted around the pin 38 or simply gravity may be relied upon to urge the catch member in a clockwise direction, as viewed in Figure 1, about the point of contact of the free end of the upper curved portion 37 and the angle between the lower flange and web of the cross-member 10.

Clockwise movement is limited to little beyond the position of the catch member 34 shown in Figure 1 by the engagement of the forward end of the slot in the upper curved portion 36 with the pin 38. As the handle 28 is lifted towards its upper limit It strikes the sloping extension 35 urging the catch member to pivot counter-clockwise against the action of gravity or the spring 39. The handle 28 rides over the free end of the lower curved portion 36 and the spring urges the catch member 34 clockwise again to engage the hollow of the lower curved portion 36 with the handle 28 and retain it.

To release the drum and lower it to the ground the handle 28 is lifted to take the weight of the drum from the catch 33 which is then manually pivoted counter-clockwise to disengage It from the handle 28. The drum can then be lowered to the ground by the reverse of the action described for raising it.

Once the drum is standing on its castors 27 and has been pulled forward to disengage the recesses 32 from the fulcrum pins, the handle 28 can be raised and used to manoeuvre the drum and move it to the emptying point.

Figure 2 illustrates the use inside the drum 2 of a holder 51 to enable an impermeable disposable bag 52, such as a plastics bag, made of polyethylene, for example, to be used to collect waste material. The holder 51 comprises a support ring 53 formed by bending a flat strip of metal or plastics and joining the ends to form a hoop with the width of the strip parallel to the axis of the ring. Three legs 54 secured at their upper ends to the outside of the support ring 53 support the holder in the manner of a tripod, the feet of the legs standing on the bottom of the drum.

In use of the holder the mouth of the bag 52 is folded outwards over the support ring 53 and held in place by a retaining ring 55 slightly larger than the support ring 53 and which clamps the marginal portions of the bag between the rings 55 and 53. The ring 55 is prevented from sliding too far down the ring 53 by its lower edge resting on the top of the legs 54. The diameter of the support ring 53 is such that a substantial annular gap is left between the outside of the bag 52 and the wall of the drum, to enable air to circulate freely and allow air pressures inside and outside the bag 52 to balance when the vacuum cleaner is in use.

The retaining ring 55 is part of a collector 56 which has a shallow conical base 57 sloping down to a central opening 58. Around the periphery of the base 57 the collector has an upwardly extending wall 59 only slightly smaller than the inside diameter of the drum. The top of the wall 59 reaches the level of the top of the drum and above the inlet 8 for waste material but below the bottom of a filter 15 or other equipment housed in the dome 13. An inlet elbow 60 extends inside the drum from the inlet 8. The free end of the elbow Is at the centre of the drum and opens downwards over the aperture 58. The elbow 60 is detachable from the Inlet 8 to enable the holder 51 and collector 56 to be fitted an opening in the wall 59 being provided through which the end of the elbow 60 can pass to re-engage the inlet 8.

The upstanding wall 59 of the collector extends well above the inlet 8 and lies close to the wall of the drum, while still allowing air to pass. Air can thus circulate between the air space surrounding the bag 52 and the interior of the drum above at least the base of the collector 56, for pressure-balancing purposes. Waste is directed by the elbow 60 through the aperture 58 into the bag. These arrangements ensure that waste material is almost entirely contained within the bag 52 and prevented from overflowing into the drum around the bag.

For use in picking up liquids or wet waste, a baffle 71 may be fitted in the drum 2 as shown In Figures 3 and 4. The baffle 71 comprises a first element 72 and a second element 73. The first element is In the form of a shallow bowl with an out-turned lip 74 which is fitted with a seal 75 and rests on the rim of the drum 2. At the centre of the bottom of the bowl is an aperture 76 extended downwards by a short spigot 77.

The second element 73 depends from the bottom of the bowl and is U-shaped In plan section, as shown In Figure 4, with a semi-cylindncal wall portion 78 co-axial with the aperture 76 and extend ing into parallel wall portions 79. The second element 73 extends downwards to the lower part of the drum. The baffle extends down over a major part of the depth of the drum, for example, 7096 to 90% of the depth, typically 412 mm in a drum 530 mm deep, leaving a clearance of about 90 mm between the lower edge of the second element 73 and the bottom of the drum.

The bottom of the bowl is just above the level of the top of the drum inlet 8 which is provided with a short, detachable elbow 80 which can be turned about the axis of the inlet 8 so that its mouth can be directed downwards as shown in Figure 3 or in another direction, for example tangentially of the drum. It is important that the baffle 71 be correctly located in relation to the inlet 8 so that the semicylindrical wall portion 78 is towards the inlet 8. To ensure correct location the baffle is provided with an annular, depending flange 81 which has in the appropriate position a recess complementary to the inlet elbow 80. The flange 81 prevents the baffle lip from seating on the rim of the drum unless the recess engages elbow 80.

The first element 72 divides the upper part of the drum into vertically spaced zones of which the inlet 8 opens into the lower zone. The higher zone opens to an outlet from the drum through filter 15. Communication between the two zones is confined to the aperture 76 which air from the inlet 8 can reach only by following a longer, indirect path around the back of the semi-cylindrical wall portion 78 and the free edges of the parallel wall portions 79. The path to be followed by the air entering the drum through the inlet 8 is defined by a passage formed by the inner wall of the drum, the second element 73, the underside of the first element 72 and the surface of liquid in the drum. Even at the highest liquid level allowed in the drum the cross-section of this passage is several times larger than the area of the inlet 8 and of the aperture 76 so that the air velocity along the passage and particularly the velocity of air near the surface of the liquid is very much less than that through the inlet 8 and aperture 76. This induces the deposition in the drum of liquid entrained in the air and helps to avoid picking-up by the air flow of liquid from the drum.

To prevent the level of liquid from rising too high in the drum a float-operated valve 82 Is provided to close the aperture when the liquid accumulated in the drum reaches a pre-determined level. The valve 82 comprises a float 83 confined by a cage 84 to guide Its vertical movement towards and away from engagement of a sealing face 85 of the float with the lower edge of the spigot 77. In the present example the float 83 Is an upright cylinder but the float could be of spherical or other convenient shape suitable for closing the spigot 77 and thus, in effect, the aperture 76 when the liquid has reached the predetermined level. With the aperture 76 closed, suction is cut off from the inlet 8 and the drawing in of further waste material is prevented. The cage Is made of open mesh material, for example, wire mesh or expanded metal or a skeletal frame with a plastic mesh sleeve, to reduce the risk of debris jamming the movement of the float.

Claims

1. A vacuum cleaner mounted on wheels to enable it to be moved from place to place and comprising a motor-driven impeller for producing sub-atmospheric pressure within an upright drum for receiving waste material collected through a nozzle open to the interior of the drum, the drum being detachably mounted in the body of the cleaner for emptying and an open top of the drum being held in sealing engagement with a seating around an opening leading to the impeller wherein is provided means having separable but interengageable elements on the drum and the body of the vacuum cleaner for lifting and lowering the drum guiding it, at least during lifting, into engagement with the seating.

2. A vacuum cleaner according to claim 1 wherein the lifting and lowering means comprises sets of interengageable elements on opposite sides of the drum.

3. A vacuum cleaner according to claim 2 wherein the lifting and lowering means comprises arms on opposite sides of the drum and may further comprise arms on opposite sides of the drum and pivoted thereto, an extension of each arm beyond the pivot being provided with a formation engageable with a complementary formation on the body and forming at least a part of a respective one of the sets of interengageable elements, the formations and complementary formations when engaged cooperating to provide a fulcrum for lifting the drum by the arms.

4. A vacuum cleaner according to claim 2 or claim 3 wherein the arms are connected together for simultaneous and equal movement about their pivots.

5. A vacuum cleaner according to claim 4 wherein the lifting and lowering means comprises a U-shaped handle, the arms being formed by the arms of the U-shaped handle which embrace the drum.

6. A vacuum cleaner according to any one of claims 3 to 5 wherein the formations on the arms include recesses, one In the lower edge of each extension, and the complementary formations on the body are laterally extending fulcrum pins.

7 A vacuum cleaner according to any preceding claim wherein on the body of the cleaner upwardly extending guides are mounted which are engageable by lateral prolections on the drum.

8. A vacuum cleaner according to claim 7 wherein the body of the cleaner Is open at the front to receive the drum and the guides are channels with their open sides confronting, a rearward flange of the channels extending below a forward flange and below the level of the lateral projections on the drum when the drum is resting on the floor. the arrangement being such that engagement of the lateral projections with the rearward flange serves to arrest rearward movement of the drum relative to the body of the cleaner when the drum Is brought into the body of the cleanser.

9. A vacuum cleaner according to claim 7 or8 as appendant to claim 3 wherein the lateral projections are formed by trunnions on the drum which also serve to pivot the arms on the drum.

10. A vacuum cleaner according to claim 7 or 8 as appendant to claim 3 or according to claim 9 wherein the formation and complementary formation of each set of interengageable elements is engageable simultaneously with the engagement of the lateral projection with the guide of the associated set of interengageable elements.

11. A vacuum cleaner according to any preceding claim wherein buffers are provided on the body to engage opposite sides of the upright wall of the drum during mounting of the drum in the body.

12. A vacuum cleaner according to any preceding claim and having an inlet for waste material to enter the upper part of the drum and fall into and be collected in the lower part of the drum, wherein is provided a holder for a disposable bag for the waste material comprising a ring to support the mouth of the bag below the waste inlet, means for retaining the bag on the ring with the mouth held open and upwardly directed, and means for sustaining the ring in the drum, the arrangement being such that an air space is maintained between the outside of the bag and the wall of the drum in which air can circulate so as to balance the air pressures inside and outside the bag during use of the vacuum cleaner.

13. A vacuum cleaner according to claim 12 wherein the means for sustaining the ring in the drum comprises legs secured at their upper ends to the ring, the lower ends of the legs being engageable with the base of the drum.

14. A vacuum cleaner according to claim 12 or claim 13 wherein the means for retaining the mouth of the bag on the ring is a retaining ring slightly larger than the support ring and adapted to be passed downwards onto the ring and to surround material of the mouth of the bag folded outwards over the support ring.

15. A vacuum cleaner according to any one of preceding claims 12 to 14 which further comprises, above the mouth of the bag, a removable collector of rigid or relatively stiff material, the interior of the collector having a hollow conical base sloping to a bottom opening and an upstanding wall or walls which conform closely to the upper part of the wall of the drum and extending above the level of the inlet for waste material, means being provided for the passage of air between the air space around the outside of the bag and the interior of the drum above the collector.

16. A vacuum cleaner according to claim 15 wherein the collector and retaining means are combined to form a single unit.

17. A vacuum cleaner according to any one of preceding claims 1 to 11 and having an outlet for air from the upper part of the drum to the impeller and an Inlet for waste material to enter the upper part of the drum, wherein is provided for use in picking up liquids or wet waste, a baffle adapted to be removably disposed in the drum and adapted to separate the inlet from the outlet and cause air drawn into the inlet to follow an indirect path between the Inlet and outlet of the drum.

18. A vacuum cleaner according to claim 17 wherein the baffle comprises a first element adapted to divide the upper part of the drum into vertically spaced zones of which the inlet opens into the lower zone and the outlet opens from the higher zone, and a second element depending from the first element between an aperture through the first element and a portion of the first element which in the position of use of the baffle in the drum is adjacent the inlet.

19. A vacuum cleaner according to claim 18 wherein the area of the aperture and of the crosssection of any passages defining the path are preferably greater than that of the inlet so that the air velocity is reduced, helping to separate entrained liquid from the air and to avoid the picking up of liquid from inside the drum.

20. A vacuum cleaner according to any one of preceding claims 17 to 19 wherein a float-operated valve is provided to close the aperture or any equivalent opening in the baffle when liquid accumulated in the drum has reached a pre-determined level.

21. A vacuum cleaner substantially as described herein with reference to and as illustrated by Figure 1 of the accompanying drawings.

22. A vacuum cleaner according to any one of preceding claims 1 to 11 and having a holder for a disposable bag substantially as described herein with reference to, and as illustrated by, Figure 2 of the accompanying drawings.

23. A vacuum cleaner according to any one of preceding claims 1 to 11 and having a baffle for use in picking up liquids or wet waste substantially as described herein with reference to and as illustrated by Figures 3 and 4 of the accompanying drawings.