Vacuum cleaner cleaning head

Abstract

A vacuum cleaning head for a vacuum cleaner includes structure for inducing vortices in the incoming air travelling between the sole plate and the surface to be cleaned. The vortices assist in entraining dust and dirt particles raised from the surface to be cleaned by a cleaning implement which may be a brush, beater bar or the like. The axis of the vortices is substantially parallel to the surface to be cleaned and the vortices b ring the rotating air substantially adjacent to and preferably in contact with the surface to be cleaned.

Description

FIELD OF THE INVENTION

[0001] This invention relates to the field of vacuum cleaners. In particular, the invention relates to air flow in the cleaning head portion of a vacuum.

BACKGROUND OF THE INVENTION

[0002] Vacuum cleaners involve a suction fan typically driven by an electric motor. The suction fan creates a negative pressure drawing significant amounts of air at relatively high flow rates through a cleaning head and into a dirt collection chamber. Typically the cleaning head includes a rotating cleaning implement. The rotating cleaning implement typically involves bristles but may also involve beater bars and the like. The purpose of the rotating cleaning element is to impact the surface being cleaned such as floors, carpet, upholstery and the like so as to mechanically agitate the surface and cause dirt particles to be raised up from the surface to be cleaned. Once the particles are lifted from the surface to be cleaned, then the intention is that such dirt particles should become entrained in the air being drawn into the suction fan.

[0003] The cleaning head of a vacuum typically defines a sole plate. The sole plate is arranged generally opposite to and substantially parallel to the surface to be cleaned. The sole plate defines a gap between the leading edge of the sole plate and the surface to be cleaned. Air being drawn in by the suction fan typically passes below the leading edge of the sole plate travelling rearwardly toward the cavity in which the brush is located. Some of the incoming air passes below the axis of the cleaning implement more or less along the surface to be cleaned and then passes upwardly into the vacuum inlet or whatever tubing connects the vacuum inlet to the suction fan. This air flows in a relatively organized fashion. The air travels essentially in a direction parallel to the surface to be cleaned. This air stream entrains the liberated dirt particles and carries those particles into the suction conduit.

[0004] In many vacuum cleaning heads the cavity housing the cleaning implement is relatively large compared to the circumference of the circle defined by the radially outermost rotating cleaning elements. The gap between the cleaning head and the circle defined by the rotating elements thus provides another path for incoming air being drawn into the suction conduit. However, air passing above the axis of the cleaning implement, not passing along or substantially next to the surface to be cleaned is not aiding in entraining particles which have been lifted from the surface to be cleaned. Thus, in large measure this air is not productively assisting the cleaning process.

[0005] The remainder of the incoming cleaning air passes beneath the axis of the rotating brush and above the surface to be cleaned.

[0006] It would be desirable, if steps were taken to modify the flow characteristics of the incoming air to assist in entraining dirt particles which have been lifted from the surface to be cleaned by the cleaning element. In addition, it would be desirable to reduce air flow which does not entrain dust particles which have been raised.

SUMMARY OF THE INVENTION

[0007] In accordance with this invention, a vacuum cleaner includes a cleaning head. The cleaning head has a housing and the housing optionally defines a brush cavity for containing an optional rotating cleaning implement and a vacuum inlet aperture. The housing has a sole plate which, in use, will be adjacent to a surface to be cleaned. The sole plate is adapted to direct air toward the vacuum inlet aperture. The cleaning head includes vortex inducing structure for creating vortical flow in the air being directed toward the vacuum inlet aperture.

[0008] In a preferred embodiment of the invention, the vacuum cleaning head include structure for inducing a plurality of vortices in the air being directed toward the vacuum inlet aperture. Most preferably, the vortices are oriented so that the axis of rotation of each vortex is substantially parallel to the surface to be cleaned so that air moving in the vortices travels closely adjacent the surface to be cleaned.

[0009] In another embodiment of the invention, the invention includes a method of entraining dirt particles in an air stream of a vacuum cleaner. The method includes the step of causing inlet air to be drawn between a sole plate of a vacuum cleaning head and a surface to be cleaned and directing that air toward a vacuum inlet aperture. The method also includes the steps of inducing vortices in the incoming air to assist in entraining dust particles. Preferably, the vortices created, cause the incoming air to rotate about axes which are parallel to the surface to be cleaned and the vortices are closely adjacent to the surface to be cleaned.

[0010] In a preferred aspect of the method, the method further includes the step of inhibiting air flow through a secondary route between a rotating cleaning element and a cavity in the cleaning head housing the rotating element.

DETAILED DESCRIPTION OF THE DRAWINGS

[0011] A better understanding of the invention can be obtained from reference to the following description of a preferred embodiment of the invention, and in which:

[0012] FIG. 1 illustrates the general arrangement of parts in a prior art vacuum cleaner;

[0013] FIG. 2 is a cross-sectional view through the cleaning head of the prior art device illustrated in FIG. 1;

[0014] FIG. 3 is a view similar to FIG. 2 showing a cross-section through a cleaning head in accordance with a first embodiment of this invention;

[0015] FIG. 4 is a bottom view of a portion of the cleaning head of FIG. 3;

[0016] FIG. 5 is a front view of the cleaning head of FIG. 4;

[0017] FIG. 6 is a view of one of the vortex inducing elements of the cleaning head of FIG. 3 showing a first form of vortex produced;

[0018] FIG. 7 is a view similar to FIG. 6 showing an alternate form of vortex to be produced by the vortex inducing element;

[0019] FIG. 8 is a diagrammatic illustration of vortices induced by the structure shown in FIG. 7;

[0020] FIGS. 9a-e are front elevational views of the lower portion of a cleaning head including vortex inducers according to the instant invention;

[0021] FIG. 10 is a front perspective view of a sole plate including vortex inducers according to the instant invention;

[0022] FIG. 11 is a bottom plan view of the sole plate of FIG. 11 showing the vortex inducers; and, FIG. 12 is a perspective view of the bottom of the sole plate of FIG. 11.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0023] The general arrangement for a vacuum cleaner is illustrated in FIG. 1. Generally speaking, a vacuum cleaner 10 comprises a cleaning head 12, a body portion 14 and a handle 16. The body portion 14 may include a motor 18 which drives a vacuum suction fan 20. The cleaning head 12 defines a suction inlet conduit 22. The suction inlet conduit 22 of the cleaning head 12 is joined to a suction tube 24 in the body portion 14. The suction tube 24 of the body portion 14 terminates in an outlet 26. As shown in FIG. 1, the vacuum 10 is placed to begin cleaning of a surface, in this case a carpet 30. Upon operation, the suction fan 20 draws air into the vacuum 10. The air passes beneath a sole plate 32 in a generally rearwardly direction as indicated by arrow 34. The air will be drawn into the inlet conduit 22 and pass into the suction tube 24. Upon exiting the outlet 26, the air, as shown by arrow 50, enters the interior of the housing 14. The interior of the housing 14 may separate the dirt from the air by means of various filter means or by using cyclonic action or the like. Advantageously, the vacuum includes a final filter 52 located just before the suction fan 20. Air, as shown by the arrows 54, enters the final filter 52, passes through the suction fan 20 and then passes over the motor 18 as shown by arrows 56 so that the motor is cooled. Air is then exhausted from the vacuum through an outlet port as shown by arrow 58.

[0024] In FIG. 1, the vacuum illustrated is what is referred to as an upright vacuum. In another arrangement of these basic parts, a vacuum may be referred to as a canister vacuum. A canister vacuum will have a power head similar to the power head 12 illustrated in FIG. 1. However, the motor 18, the fan 20 and the dirt collection means may be located in a separate module referred to as a canister. In a canister vacuum a handle is attached to the cleaning head 12 rather than to the canister and suitable conduit means are supplied to conduct the air from the conduit 22 in the cleaning head to the tube 24 within the canister.

[0025] FIG. 2 is an enlarged view of a portion of the cleaning head 12 of the prior art device of FIG. 1. The cleaning head 12 defines a cavity 60 for containing a rotating cleaning implement. As shown in FIG. 2, the rotating cleaning implement is a brush 62 having a plurality of radially outwardly extending bristles 64. The bristles 64 may be arrayed about the surface of the brush 62 in any convenient fashion. Typically these bristles are arranged in two rows which extend in spiral fashion along the surface of the brush 62. The brush 62 rotates about an axis 66. As shown in FIG. 2 the brush is rotating counterclockwise as indicated by arrow 68.

[0026] As the brush rotates about the axis 66, the radially outwardly limit of the bristles 64 describe a circle concentric on axis 66. This circle is illustrated by dotted line 70 in FIG. 2. It will be observed that there is substantial clearance between the circle 70 and the surface of the brush cavity 60. This, in turn, means that as the air flows rearwardly as indicated by arrow 34, the air stream splits into two streams, one indicated by arrow 36 and one indicated by arrow 38. The air indicated by arrow 38 travels in the annular gap between the circle 70 and the surface of the cavity 60 above the axis 66. The air indicated by arrow 36 passes substantially along the carpet 30 beneath the axis 66 of the rotating brush. The two air streams converge as indicated by the arrows 38b and 36b where the air then enters an inlet aperture 80. The two air streams merge as indicated by the arrow 82 and pass along the suction inlet conduit 22.

[0027] Air indicated by the arrows 38 and 38b does not pass along carpet 30 and thus does not materially assist in entraining particles which have been raised from the carpet 30. The second component of the air indicated by the arrows 36 and 36b passes in a direction which is generally parallel to the carpet 30 and serves to entrain particles raised up from the carpet 30 by the action of the rotating brush 62.

[0028] FIG. 3 is a view similar to FIG. 2 and like parts have been given similar numbers but with the prescript 1. Thus, the cleaning head 112 of the vacuum cleaner 110 in accordance with this preferred embodiment is positioned adjacent a surface to be cleaned, a carpet 130. The cleaning head 112 comprises a cavity 160. The cavity 160 accommodates a rotating brush 162 having a plurality of bristles 164. The radially outwardly limit of the bristles 164 when rotating, define a circle 170. The brush 162 rotates about an axis 166. The brush rotates counterclockwise as indicated by arrow 168. The cleaning head 112 includes a sole plate 132 which is generally adjacent to the carpet 130. The cleaning head 112 also has a suction inlet conduit 122 having a vacuum inlet aperture 180.

[0029] From review of FIG. 3, it will be noted, that the circle 170 described by the tips of the bristles 164 is located substantially adjacent the surface of the cavity 160. The clearance between the circle 170 and the cavity 160 is reduced to a convenient minimum. The clearance must be such that the tips of the bristles when the brush is installed, in its new condition, do not strike the surface of the cavity 160 as the brush rotates. However, it is desirable to reduce the clearance to an acceptable minimum so as to inhibit any flow in the secondary flow route as indicated in the prior art in connection with arrows 38 and 38b. Thus, in the embodiment illustrated in FIG. 4, for a given in-flow rate as shown at 134, more of the air is caused to pass adjacent to the carpet 130 by the virtual elimination of the secondary air flow route through the clearance gap between the surface of the cavity 160 and the brush 162. Because there is substantially no flow adjacent the surface of the cavity 160, virtually all of the air passes in the general direction indicated by arrow 137, below the axis of rotation 166 of the brush 162 and adjacent the carpet 130. The air then passes, as indicated by arrow 183, into the inlet aperture 180.

[0030] The cleaning head 112 further includes structure 190 for inducing at least one vortex in the incoming air stream. The vortex inducing structure 190 may be located on the sole plate 132 and is intended to induce at least one vortex in the air being directed toward the vacuum inlet aperture 180 such that the airflow passing over the surface to be cleaned is substantially vortical. The ratio of the width Wo of slots 200 to the width Ws of the vortex inducer 190 preferably varies from 4:1 to 1:4, preferably from 3:1 to 1:3 more preferably from 1:2 to 2:1 and most preferably, is about 1:1. Similarly, the ratio of the height Ho of slots 200 to the height Hs of the vortex inducer 190 preferably varies from 4:1 to 1:4, preferably from 3:1 to 1:3 more preferably from 2:1 to 1:2 and most preferably, is about 1:1.

[0031] In the preferred embodiment shown in FIGS. 9b and 10-12, the ratio of the width Wo of slots 200 to the width Ws of the vortex inducer 190 is 1:1 and the ratio of the height Ho of slots 200 to the height Hs of the vortex inducer 190 is 1:1. Alternate workable profiles are shown in FIGS. 9a-9e. In the preferred embodiment shown in FIG. 9a, the ratio of the width Wo of slots 200 to the width Ws of the vortex inducer 190 is 1:2 and the ratio of the height Ho of slots 200 to the height Hs of the vortex inducer 190 is 1:1. In the preferred embodiment shown in FIG. 9c, the ratio of the width Wo of slots 200 to the width Ws of the vortex inducer 190 is 2:1 and the ratio of the height Ho of slots 200 to the height Hs of the vortex inducer 190 is 1:1. In the preferred embodiment shown in FIG. 9d, the ratio of the width Wo of slots 200 to the width Ws of the vortex inducer 190 is 1:1 and the ratio of the height Ho of slots 200 to the height Hs of the vortex inducer 190 is 3:2. In the preferred embodiment shown in FIG. 9e, the ratio of the width Wo of slots 200 to the width Ws of the vortex inducer 190 is 1:1 and the ratio of the height Ho of slots 200 to the height Hs of the vortex inducer 190 is 3:1.

[0032] As shown from the forgoing examples, when vortex inducers 190 are narrower than the slot 200 between them, effective vortices can also be created (see FIG. 9c). Alternately, when the vortex inducers may be wider (e.g. twice as wide) than the slot between them, effective vortices can also be created (see FIG. 9a).

[0033] Preferably, a plurality of vortices are induced along essentially the entire length of the front of the vacuum cleaner. Thus, the air drawn in by the suction fan passes between the sole plate 132 and the carpet 130, as indicated by arrow 134. The air passes through the vortex inducing structure 190 under the rotating brush 162 and into the aperture 180.

[0034] FIG. 4 illustrates a portion of the sole plate 132 of the cleaning head 112 illustrated in FIG. 3. From reference to FIG. 4, it will be noted that the vortex inducing structure 190 comprises a plurality of blade members 190a. There are 12 such blade members 190a shown in FIG. 4 which are aligned to interact with the incoming air flow as indicated by the arrows 134. Most of the air being drawn into the vacuum inlet port 182 will enter the cleaning head 112 adjacent the leading edge 113. Wheels or other structure in the cleaning head 112 may inhibit air flowing in from the sides of the cleaning head 112. As shown in FIG. 4, the air stream indicated by arrows 134 is flowing substantially rearwardly from the leading edge 113 toward the inlet aperture 182. Each of the individual blade members 190a creates a vortex downstream of the blade member 190a. This is indicated generally by the lines 194.

[0035] FIG. 5 illustrates the cleaning head 112 from the front, located adjacent the carpet 130.

[0036] FIGS. 6 and 7 illustrate two slightly differently shaped blade members 190a and 190b. The shape of the blade members can be any shape which creates a downstream vortex in the air stream passing by the blade member 190a or 190b respectively.

[0037] As shown in FIG. 6, the blade member 190a creates a single downstream vortex which may be substantially aligned with the general axis of symmetry 191 of the blade member 190a. In this case, the air streams passing along either side face of the blade member 190a meet to form the vortex 194. The vortex 194 spins about an axis 195 which is aligned with axis 191. The precise shape, location and configuration of the vortex 194 will dependent on the particular shape and configuration of the blade member 190a. A single vortex 194 for each such blade member 190a has been illustrated in FIG. 4.

[0038] FIG. 7 illustrates an alternately shaped blade member 190b. Blade member 190b produces a pair of vortices on either side of the general axis of symmetry 193 of the blade member 190b. These vortices are shown as 196a and 196b. The vortices 196a and 196b are caused to spin about axes 198a and 198b respectively. For reasons which will be discussed below, advantageously, the direction of spin in vortex 196a is opposite to the direction of spin in the vortex 196b.

[0039] The vortex 194 is spinning about the axis 195 while the vortices 196a and 196b are spinning about their respective axes 198a and 198b. All three of the axes 195, 198a and 198b, lie substantially parallel to the carpet 130. Thus, the axes of spin of the vortices may be said to coincide with the arrow 137 showing the general direction of air flow in FIG. 3. Each vortex is therefore spinning about an axis which is substantially parallel to the carpet 130. The axis 137, 198a and 198b are adjacent the carpet 130. As the air spins about its respective axis, in the vortices as discussed above, the air impacts the floor with relatively high velocity. Because of the spinning of the air in the vortices, there is highly turbulent flow of the air adjacent to the carpet 130. Thus, there is substantially increased turbulence at the flow indicated by arrow 137 in FIG. 3 as opposed to the flow as indicated at arrow 36 in prior art devices. The air flow has a rearward component generated by the suction fan. In addition, the air has a spiralling component generated by the vortex inducing structure 190. This increased turbulence in the air assists in entraining dirt particles which have been liberated from the carpet 130 by the brush 164.

[0040] Conveniently, the brush 164 may be formed similar to brushes commonly used in the vacuum art. Such brushes contain a plurality of bristles arranged in two rows. The rows are arranged in spiral fashion along the length of the brush 162. Thus, each vortex 194, 196a or 196b respectively is not effected by the bristles 164 of the brush 162 except on those occasions when a bristle is directly aligned with the particular member 190a or 190b, respectively. If there are two rows of bristles on the brush 162, then this interruption of the vortex will occur only momentarily, twice during each revolution of the brush 162. The vortex, however, will remain in place during the remainder of a rotation of the brush 162.

[0041] Preferably, as shown in FIG. 7, the vortex inducing structure 190 includes blade members 190b which produce a pair of counter rotating vortices 196a and 196b. These are shown in the front view in FIG. 5. One vortex 196a and one vortex 196b is induced by each individual blade member 190b. However, adjacent vortices 196a and 196b between adjacent blade members 196b are rotating in complimentary directions. This is illustrated in FIG. 8. In FIG. 8, the vortices 196a and 196b for each of two blade members 190b are illustrated. The outer elements of the adjacent vortices are moving in the same direction. Thus, the turbulence of each vortex does not dissipate but rather supplements the next adjacent vortex.

[0042] The plurality of vortices formed by the vortex inducing structure 190 serves to assist in entraining dirt particles which are raised from the carpet 130 by the brush 162. The vortex may break up before the air stream enters the vacuum inlet port 182. However, once dirt is entrained in the air flow, the dirt tends to stay entrained. By utilizing the vortices as explained herein, enhanced entrainment of the dirt raised by the cleaning implement is achieved.

[0043] The vortex inducing structure 190 has been explained in association with a plurality of individual members which are essentially tear dropped shaped. Many other forms of vortex inducing structure may be utilized.

[0044] The purpose of the vortex is to assist in entraining dirt raised by the rotating cleaning element. Thus, the vortex inducing structure can be located anywhere as convenient provided it produces vortices which are effective to entrain dirt. As shown in FIG. 3, the vortex inducing structure can be attached to the sole plate 132 just forward of the cavity 160 for containing the brush. However, the vortex inducing structure can be mounted anywhere as desired.

[0045] In order to assist in maintaining the front of sole plate 132 at the desired distance above the surface to be cleaned, wheels, glides or the like may be provided, preferably proximate leading edge 113, as is known in the art. In the preferred embodiment of FIGS. 10-12, wheel wells 202 are provided adjacent opposed lateral sides of sole plate 132.

[0046] While the invention has been discussed in the context of certain preferred embodiments, these embodiment are illustrative only. For the full scope of the invention, reference should be made to the following claims. It will be appreciated that cleaning head 112 may be utilized without the operation of brush 162. Further, in some embodiments, cleaning head need not include brush 162 or other like cleaning implement.

Claims

1. A cleaning head having a front end comprising a sole plate, a vacuum inlet aperture, and vortex inducing structure for inducing vortical flow in air travelling toward said vacuum inlet aperture.

2. The cleaning head of

claim 1 wherein said vortex inducing structure includes a plurality of vortex inducing members for inducing a plurality of vortices across essentially all of the front of the cleaning head.

3. The cleaning head of

claim 2 wherein said vortices produced by said plurality of vortex inducing members rotate about a respective vortex axis and the axes of said plurality of vortices extend substantially parallel to said surface to be cleaned.

4. The cleaning head of

claim 3 wherein said plurality of vortex inducing members are blade members and each of said blade members creates at least one vortex.

5. The cleaning head of

claim 4 wherein each of said blade members creates a plurality of vortices.

6. The cleaning head of

claim 5 in which each blade member produces two vortices and the air in the two vortices rotates in opposite directions.

7. The cleaning head of

claim 1 further comprising a cleaning element.

8. The cleaning head of

claim 7 wherein the cleaning element comprises a rotating cleaning implement and said cleaning implement rotates about an axis and said cleaning head comprises means for inhibiting flow of air between said rotating cleaning implement and a surface of said cavity for housing said cleaning implement.

9. The cleaning head of

claim 1 wherein said vortex inducing structure includes a plurality of vortex inducing members for inducing a plurality of vortices spaced along at least a portion of the front of the vacuum cleaner head and defining slots openings between adjacent vortex inducing members and the ratio of the width of the openings to the width of the vortex inducing members varies from 4:1 to 1:4 and the ratio of the height of the openings to the height of the vortex induceing members varies from 4:1 to 1:4.

10. The cleaning head of

claim 1 wherein said vortex inducing structure includes a plurality of vortex inducing members for inducing a plurality of vortices spaced along at least a portion of the front of the vacuum cleaner head and defining slots openings between adjacent vortex inducing members and the ratio of the width of the openings to the width of the vortex inducing members varies from 3:1 to 1:3 and the ratio of the height of the openings to the height of the vortex induceing members varies from 3:1 to 1:3.

11. The cleaning head of

claim 1 wherein said vortex inducing structure includes a plurality of vortex inducing members for inducing a plurality of vortices spaced along at least a portion of the front of the vacuum cleaner head and defining slots openings between adjacent vortex inducing members and the ratio of the width of the openings to the width of the vortex inducing members varies from 2:1 to 1:2 and the ratio of the height of the openings to the height of the vortex induceing members varies from 2:1 to 1:2.

12. The cleaning head of

claim 1 wherein said vortex inducing structure includes a plurality of vortex inducing members for inducing a plurality of vortices spaced along at least a portion of the front of the vacuum cleaner head and defining slots openings between adjacent vortex inducing members and the ratio of the width of the openings to the width of the vortex inducing members is substantially 1:1 and the ratio of the height of the openings to the height of the vortex induceing members is substantially 1:1.

13. A method of entraining dirt for use in a vacuum cleaner having a vacuum cleaning head, said vacuum cleaning head having a sole plate and a vacuum inlet aperture causing air to pass in an air stream between said cleaning head and a surface to be cleaned, and inducing vortical flow in said air stream as said air travels toward said vacuum inlet aperture.

14. The method of

claim 13 wherein said cleaning head includes a cavity for containing a cleaning implement and a cleaning implement in the cavity and the method further comprises the step of inhibiting the flow of air between said cleaning implement and said cavity.

15. The method of

claim 13 further comprising the step of inducing a plurality of vortices in said air stream.

16. The method of

claim 15 in which said vortices are arranged to spin about respective axes and said axes extend generally parallel to said surface to be cleaned.

17. The method of

claim 16 in which said vortices are arranged such that the axes of rotation of said vortices lie substantially adjacent to said surface to be cleaned so that the air rotating in said vortices is substantially adjacent to the surface to be cleaned.