PICK-UP HEADS FOR VACUUM CLEANERS

Abstract: A hand-held pick-up head (10) for connection to the suction hose of a vacuum cleaner for the purpose of picking up small quantities of liquids comprises a collection container (12) with an outlet (17) which is adapted for connection to said suction hose by means of a connector (20) which includes a plug member (41) which is received within the outlet (17) and effectively closes same apart from an air outlet opening (49) formed as a flow-restricting orifice. The plug member (41) further defines a vortex chamber (52) adjacent to the orifice and an expansion chamber (53) downstream of the orifice. The head (10) includes a suction slot (34) at the lower end of a suction duct (35) which terminates in a discharge outlet (36) which is directed towards and spaced from the orifice (49), the plug member (41) carrying an air-flow reversing deflector (46) which cooperates with the discharge outlet (36) so that air-flow from the suction duct (35) undergoes a reversal of direction and enters the collection container (12) flowing in a direction away from the orifice (49) and at a position spaced from the walls of the container.

Description: Title: "Pick-up heads for vacuum cleaners" Description of Invention This invention relates to pick-up heads for vacuum cleaners, i.e. suction operated appliances for use primarily on floors and floor coverings, and usually having attachments available for specific cleaning operations. More particularly , this invention is concerned with a pick-up head to form part of such an attachment for picking up liquid and which comprises a pick-up head with a collection container for liquid and a suction hose for connection to an inlet of the vacuum cleaner which serves as a source of suction for the attachment. One such liquid pick-up head is disclosed in German specification 1503858, in which the suction hose is connected to the in-use upper end of the collection container and the interior of the container communicates with a suction chamber by way of a tube of generally inverted J-shape so arranged that liquid picked up by the application of suction to the suction chamber travels upwardly along the longer limb of the tube and is discharged downwardly from the shorter limb of the tube adjacent to a side wall of the collection container. Such an arrangement does not afford very efficient separation of entrained liquid droplets, and accordingly significant quantities of moisture may be drawn through the suction hose and into the vacuum cleaner, with possible deleterious effect. According to the invention we provide a pick-up head for use with a vacuum cleaner and comprising a hollow body defining a collection container to receive and collect liquid, an outlet leading from said container and having associated therewith a connector for connection to a source of suction, and a pick¬ up inlet for application to a surface from which liquid is to be picked up characterised in that upstream of the outlet the collection container has an air outlet opening which comprises a flow-restricting orifice having a cross-sectional area which is significantly less than that of said outlet. Conveniently, an air expansion chamber is provided between said orifice and said outlet. Preferably, the flow-restricting orifice is disposed adjacent to a side wall of the collection container, at or near the in-use upper end of said container. According to a particularly preferred feature of the invention, adjacent to the flow-restricting orifice there is provided a vortex chamber which includes a curved wall forming a concave air-flow directing surface which extends across the collection container from a position adjacent to a side wall thereof opposite to that at which the flow-restricting orifice is provided to a position adjacent to said orifice and such that air-flow off said concave surface is directed generally away from said orifice and is required to undergo a reversal of direction to enter said orifice. The expansion chamber may be in part defined by said curved wall. A filter element is preferably provided between said orifice and said outlet. The pick-up inlet may be in the form of an elongated slot which extends between lateral side walls of the collection chamber, preferably at a position adjacent to the side wall at which said orifice is provided, and a suction duct may extend from the slot to a discharge outlet which is disposed within the collection container at a position between said slot and said orifice. In accordance with a further preferred feature of the invention, the discharge outlet is arranged adjacent to the side wall of the collection container at which said orifice is provided, and is arranged to face said orifice, an air-flow reversing deflector being disposed between said discharge outlet and said orifice, whereby air-flow from said suction duct undergoes a reversal of direction and enters the collection container flowing in a direction away from said orifice and at a position spaced from the walls of the container. These and other features of the invention will now be described by way of example with reference to the accompanying drawings wherein:- FIGURE 1 shows a longitudinal section through one specific embodiment of pick-up head which is intended for connection to a suction hose; FIGURE 2 shows the pick-up head in the direction of arrow II of Figure 1 partially sectioned and as connected to a suction hose; and FIGURE 3 shows a transverse section on the line III-III of Figure 1. The accompanying drawings illustrate a hand-held suction pick-up head for use as an accessory attachment with a generally conventional vacuum cleaner. The suction head 10 is intended for the purpose of picking up relatively small quantities of cleaning liquid, e.g. typically 200 c.cs or thereabouts, as may be applied to a localised area of caφet or other floor covering for the puφose of removing localised heavy soiling. In the embodiment illustrated, the suction head is not provided with any means for delivering such cleaning liquid, which it is intended would be applied manually by the user. However, it will be appreciated that the cleaning head as illustrated could be modified to include liquid delivery means of any appropriate kind, either from a suitable reservoir container formed or provided on the head itself, or from a separate reservoir by means of an appropriate supply pipe. The head can, of course, also be used for picking up small spillages of liquid. As illustrated, the suction head 10 includes a hollow body 11 which defines a liquid collection container 12 generally bounded by a lower wall 13, front wall 14, rear wall 15 and lateral side walls 16. At its upper end, the hollow body 12 defines a tubular outlet 17, through which liquid collected in the container 12 can be emptied, and through which, in use, suction is applied. For this puφose the tubular outlet 17 receives a connection member 20 which comprises a tubular spigot 21 which is a close friction fit within the outlet 17, and a socket 22 adapted to receive an end fitting 60 of a flexible suction hose. A flexible tongue 26 which is formed or provided on the connection member 20 is arranged to enter an internal longitudinal slot 18 formed on the wall of the tubular outlet 17 of the suction head, and an off-set portion 26a of the tongue is adapted to enter a corresponding aperture 19 formed in the wall of the tubular outlet 17 as illustrated at the innermost end of the slot 18. The socket 22 comprises a cylindrical side wall 27 formed internally with a plurality of longitudinally extending circumferentially spaced ribs 23 which project radially inwardly from the wall sill 27 of the socket 22 and which at the inner end of the socket terminate in further radially projecting inward extensions 24. The diametral spacing between the inwardly presented faces of the ribs 23 is such as to receive the hose end fitting as a tight friction fit, and the extensions 24 serve as end stops whereby an annular gap 25 exists between the hose end fitting and the inner end of the socket 22. This enables air to be drawn in along the axial passageways which are defined between the ribs 23 in order to provide an air-bleed passageway which reduces the suction applied to the suction head 10. As illustrated, the ribs 23 may project outwardly beyond the end of the side wall of the socket 22, and be chamfered as indicated at 23a. whereby a user may grip the assembly of tubular outlet 17 and socket 22 in the palm of the hand and regulate the air-bleed by obstructing the axial passageways to a greater or lesser extent, thereby varying the suction power applied to the suction head. The air-bleed facility helps to reduce the air-flow through the suction head, thereby assisting the prevention of excessive turbulence which might tend to cause the contents of the liquid collection container 12 to be drawn up into the suction hose. The lower wall 13 of the suction head is formed with a liquid pick-up inlet 30, which comprises a transversely extending elongate suction chamber 31 which is bounded by a downwardly projecting peripheral rib 32, and an upper wall 33 which is arranged obliquely relative to the mouth of the suction chamber as defined by the lower edge of the peripheral rib, as best seen in Figure 1. The upper wall 33 is formed with a longitudinally extending slot 34 through which suction is applied to the chamber 31. The suction slot 34 opens into a suction duct 35 which is provided on the inner face of the front wall 14 of the liquid collection container 12. The duct 35 includes an upwardly converging inlet portion leading to a generally parallel-sided portion which terminates in a discharge outlet 36 at a position near to the tubular outlet 17, but spaced therefrom. As can be seen, the discharge outlet 36 is directed towards the tubular outlet 17. To ensure that liquid picked up through the pick-up inlet 30 is separated from the air-flow which is induced by means of a suction applied through the suction hose, and collected in the container 12, in accordance with the invention an air/liquid separating fitting 40 is provided. The fitting 40 comprises a hollow plug 41 which is received within the tubular spigot 21 of the connection member 20, the plug having a cylindrical wall 42 which is closed at the innermost end by means of an end wall 43, and at its outer end receives a filter element 44. A pair of arms 45 extend away from the end wall 43 at one side of the fitting, and at their free ends carry a deflector 46 which comprises a semi- cylindrical wall 47 with corresponding semi-circular end walls 48. The axial length of the deflector 46 corresponds to the width of the discharge outlet 36 and effectively defines an end portion of the suction duct 35 in which the direction of air-flow is reversed so that the stream of air and liquid entrained therein from the suction chamber 30 is delivered into the collection container 12 at a generally central position spaced from the side walls 14,15,16. This shaφ reversal of air-flow ensures that most of the liquid entrained in the air-flow is separated out. A further reversal in the direction of the air-flow is required to enable the air stream to flow towards the tubular outlet 17. However, in accordance with the invention, communication between the interior of the collection container 12 and the hose attached to the connection member 20 is by way of a flow-restricting orifice 49 formed in the end wall 43 of the plug at a position adjacent to the cylindrical wall 42 and between the arms 45. The orifice 49 significantly restricts the air-flow through the suction head, and its small dimensions, as well as the shielding afforded by the arms 45 and deflector 46, create a significant obstacle to droplets of liquid still entrained in the air-flow, the majority of which will be efficiently removed by contact with the various surfaces which effectively define a tortuous air passageway. In accordance with a further feature of the invention, this effect is enhanced by the provision of a vortex chamber 50 immediately adjacent to the orifice 49. The vortex chamber 50 is defined within the plug 41 by a curved wall 51, which affords a concave surface directed towards the interior of the collection container 12, and by side walls 52 in alignment with the arms 45 and extending from the end wall 43 into the interior of the plug. The curved wall 51 extends from a position immediately adjacent to the orifice 49, inwardly of the hollow plug 41, and terminates at the cylindrical wall 42 of the plug on the side thereof opposite that at which the orifice 49 is provided. The vortex chamber 50, thus defined, provides for a third reversal of the direction of air-flow towards the orifice 49 and sets up a vortex which further assists in the separation of any entrained droplets of liquid. Since the air-flow from the concave face of the curved wall 51 is then directed away from the orifice 49, a fourth reversal of direction is required before the air-flow exits from the collection container 12, again assisting separation of any remaining entrained droplets of liquid. The interior of the hollow plug 41, bounded in part by the cylindrical wall 42 and the curved wall 51 serves as an expansion chamber 53 which gives rise to a substantial reduction in the velocity of air-flow at this point and this provides a still further separation of entrained droplets, and the filter element 44 may serve to retain any remaining droplets before the air-flow passes out of the suction head and into the suction hose. The filter element is preferably in the form of a mesh of filament of material which provides a mechanical barrier to water droplets whilst allowing collected water to drip back from the element when air-flow ceases. The front wall 14 of the collection container 12 may be formed with a central thumb recess as illustrated at 14a. to facilitate gripping of the suction head by the user, and a movable thumb-piece may be provided within the recess for longitudinal sliding movement towards and away from the orifice 49, the thumb piece having a downward extension adapted to close the orifice 49 when the thumb piece is not moved away from the orifice against a spring-bias, so that when the user releases the suction head the orifice 49 is automatically closed in order to prevent liquid leaking out of the collection container and into the suction hose. To empty the collection container after use, it is merely necessary to remove the connection member 20, together with the fitting 40, and to tip away the contents of the container through the outlet 17. The fitting 40 can be removed from the connection member 20 to enable the filter element 44 to be cleaned or replaced.

Claims: CLAIMS 1. A pick-up head (10) for use with a vacuum cleaner and comprising a hollow body (11) defining a collection container (12) to receive and collect liquid, an outlet (17) leading from said container and having associated therewith a connector (20) for connection to a source of suction, and a pick-up inlet (30) for application to a surface from which liquid is to be picked up, characterised in that upstream of the outlet (17) the collection container (12) has an air outlet opening which comprises a flow-restricting orifice (49) having a cross-sectional area which is significantly less than that of said outlet (17). 2. A pick-up head according to Claim 1 wherein an air expansion chamber (53) is provided between said orifice (49) and said outlet (17). 3. A pick-up head according to Claim 2 wherein the flow-restricting orifice (49) is disposed adjacent to a side wall (14) of the container (12), at or near the in-use upper end of said container. 4. A pick-up head according to Claim 3 wherein adjacent to the flow- restricting orifice (49) there is provided a vortex chamber (52) which includes a curved wall (51) forming a concave air-flow directing surface which extends across the container from a position adjacent to the side wall (15) thereof opposite to that (14) at which the flow-restricting orifice (49) is provided to a position adjacent to said orifice, and such that air-flow off said concave surface is directed generally away from said orifice (49) and is required to undergo a reversal of direction to enter said orifice. 5. A pick-up head according to Claim 4 wherein said air expansion chamber (53) is in part defined by said curved wall (51). 6. A pick-up head according to Claim 4 wherein the connector (20) includes a plug member (41) which fits within the outlet (17), the flow-restricting orifice (49), vortex chamber (52) and expansion chamber (53) being formed in said plug member (41). 7. A pick-up head according to Claim 1 wherein a filter element (44) is provided between said orifice (49) and said outlet (17). 8. A pick-up head according to any one of Claims 3 to 6 wherein said pick-up inlet (30) is disposed at a position adjacent to the side wall (14) at which said orifice (49) is provided. 9. A pick-up head according to Claim 8 wherein a suction duct (35) extends from the pick-up inlet (30) to a discharge outlet (36) which is disposed within the collection container (12) at a position between said slot (34) and said orifice (49). 10. A pick-up head according to Claim 9 wherein said discharge outlet (36) is arranged adjacent the side wall (14) of the collection container (12) at which said orifice (49) is provided, and is arranged to face said orifice, an air-flow reversing deflector (46) being disposed between said discharge outlet (36) and said orifice (49), whereby air-flow from said suction duct (35) undergoes a reversal of direction and enters the collection container (12) flowing in a direction away from said orifice (49) and at a position spaced from the walls (14, 15, 16) of the container. 11. A pick-up head according to Claim 6 and Claim 10 wherein the air¬ flow reversing deflector (46) is also carried by said plug member (41). 12. A pick-up head according to any one of the preceding claims wherein the pick-up inlet (30) is in the form of an elongated slot (34) which extends between lateral side walls (16) of the collection chamber (12). 13. A pick-up head according to Claim 1 wherein said connector (20) comprises a socket (22) to receive an end fitting (60) of a suction hose and is formed to afford an air gap (25) providing an air-bleed passageway to the interior thereof. 14. A pick-up head according to Claim 13 wherein said socket (22) is formed with a plurality of longitudinally extending circumferentially spaced internal ribs (23) which collectively are adapted to receive and locate said suction hose end fitting (60), the air gap (25) comprising an annular gap around said end fitting (60). 15. A pick-up head according to Claim 14 wherein said ribs (23) are formed with inwardly projecting extensions (24) serving as end stops for said hose card fitting (60). 16. A pick-up head according to Claim 14 wherein said ribs (23) extend axially beyond said socket (22) and are formed with chamfered ends (23a) whereby a user may regulate the air-bleed by gripping the socket in such a way as to abstract the air-bleed passageway to a greater or lesser extent. 17. A pick-up head substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

Inventors: MCCAFFREY ANDREW FRANCIS, RICKETT PETER DAVID, MCCAFFREY, ANDREW, FRANCIS, RICKETT, PETER, DAVID
Applicants: MCCAFFREY ANDREW FRANCIS, RICKETT PETER DAVID, VAX LTD, VAX LIMITED
Application year: 1993
Main classification: A47L7
IPC codes: A47L7