Apparatus For Scrubbing Rugs, Floors And The Like

Abstract

The invention relates to a device for attachment to a domestic vacuum cleaner to clean floor coverings and the like. More particularly, the invention relates to a drive coupling for use in the device. The drive coupling consists essentially of an inner element connected to an outer element by straps and a spring positioned between the elements for biasing the elements apart and extending the straps. The drive coupling is positioned between an output from a turbine and a brush for transmitting torque from the turbine output to the brush. When the brush meets an increased resistance in cleaning the floor covering, the straps move from their normal axial position into an inclined position thereby elevating the brush and reducing the resistance to rotation for limiting the effects of the resistance on the turbine.

Description

This invention relates to a device for cleaning floor coverings and the like and more particularly to a drive coupling for use in the device. The device is preferably powered by air passing to a sub-atmospheric source such as a domestic vacuum cleaner.

In cleaning carpets it is essential that only sufficient cleaning fluid is used to clean the carpet so that the carpet is not subjected to excessive moisture. Applicators for applying the fluid are available and consist essentially of a reservoir containing the fluid and a pad through which the soap solution passes for spreading over the carpet. The user moves the applicator to and fro over the carpet at a substantially constant speed thereby gradually applying the solution to the whole carpet. Although such devices achieve a measure of success, they do not scrub the carpet and consequently are of limited use where the carpet has been marked or has localized dirty areas.

Attempts have been made to produce domestic devices which clean carpets by a scrubbing action and which are powered by a domestic vacuum cleaner. Each of these devices consists essentially of a turbine driven by air which is being sucked into a vacuum cleaner, and a brush driven about a vertical axis by the turbine. A drive coupling is positioned between the brush and the turbine and this coupling includes a means for permitting the brush to move axially. The brush is contained in a downwardly-opening skirt so that when the brush meets a high resistance to turning, the brush moves vertically into the skirt thereby bringing the skirt into contact with the carpet and reducing the resistance to avoid stalling of the turbine.

In prior art devices, the vertical brush movement has been achieved by the use of various mechanical parts which slide one over the other to permit the vertical movement. This mechanical sliding action creates frictional problems and in use, tends to become clogged with soap solution and dirt from the carpet or other floor coverings which have been cleaned. Consequently, the essential vertical movement is hampered and stalling of the turbine tends to result.

In one of its aspects, the present invention provides a drive coupling for use in a floor cleaning device of the type including a drive means, and a brush driven by the drive means and positioned within a skirt such that soap solution can be dispensed from within a reservoir above the skirt for use on the brush to clean a floor covering such as a carpet. The drive coupling comprises: an inner element including means for fixedly connecting the inner element to the drive means; an outer element adapted to be fixedly coupled to the brush with the inner and outer elements disposed about a vertical axis and spaced axially; straps extending generally axially and attached at respective first ends thereof to the inner element and at respective other ends thereof to the outer element; and spring means biasing the outer element axially away from the inner element to cause the brush bristles to project beyond the skirt such that in use when the brush encounters a relatively high resistance to rotation, the straps move towards the horizontal position and the spring is stressed resulting in an upward movement of the brush so that the skirt contacts the floor covering whereby the brush resistance is reduced and brush stalling is substantially obviated.

In another of its aspects the present invention provides a device for washing floor coverings such as carpet and the like. The device includes a housing defining a downwardly-opening skirt and a reservoir above the skirt for containing cleaning fluid such as soap solution. Below the reservoir a brush is mounted within the skirt for rotation about a vertical axis and a turbine is coupled by a drive coupling to the brush so that upon connection of the device to a sub-atmospheric source such as a domestic vacuum cleaner, the turbine rotates thereby driving the brush. The drive coupling includes generally upright straps operably coupled at respective first ends thereof to the turbine and at respective other ends thereof to the brush to provide upward movement of the brush within the skirt when the brush meets an increased resistance to rotation during use in cleaning the floor covering.

These and other aspects of the invention will be better understood with reference to the drawings, in which:

FIG. 1 is a perspective view of a device according to the invention;

FIG. 2 is a sectional side view on line 2--2 of FIG. 1;

FIG. 3 is a top view of the device with parts broken away to show internal elements of the device;

FIG. 4 is an exploded perspective view of a coupling forming a part of the device;

FIG. 5 is a perspective view of a part of the device showing the coupling in position for driving a brush with the brush in a lowered position; and

FIG. 6 is a view similar to FIG. 5 showing the brush in a raised position.

Reference is first made to FIG. 1 which shows the device indicated generally by the numeral 10. The device consists of a main housing 12 containing a brush 14 driven by a turbine which receives air inspired through directional inlets 16 by a sub-atmospheric source applied through a wand 18. A hand control 20 is connected by a cable 22 to the housing 12 and attached to the wand for controlling the flow of soap solution to the brush 14 as will be explained. An end of the wand 18 is attached to a flexible connection 24 which preferably connects the wand pneumatically to a conventional vacuum cleaner. Access is provided through an opening 26 for pouring soap solution or the like into the device, and a spring-loaded lid 28 is operable to close the opening when the device is in use.

Reference is now made to FIG. 2 to describe the internal construction of the device 10 in more detail. The main housing 12 consists essentially of first and second moldings 30, 32 of a suitable plastic material. The molding 30 begins at its lower end in a generally cylindrical skirt 34, defines an annular shoulder 36 and then continues upwardly to define a further shoulder 38. The top of the molding 30 defines a gear cavity 40 and terminates in a downwardly-extending cylindrical portion 42 which is co-axial with skirt 34. Portion 42 defines at its lower end a downwardly-opening annular recess for receiving an upstanding rib 44 formed on the second molding 32.

Second molding 32 includes a generally cylindrical lower portion 46 adapted to engage snugly within skirt 34 and terminating in a shoulder 48 located against an inner side of the shoulder 36 in molding 30. The molding 32 defines a valve housing 50 in which a valve assembly 52 is contained as will be described, and a central opening 53 in alignment with the bore of cylindrical portion 42.

The first and second moldings 30, 32 are bonded or welded together to define a water-tight reservoir 54 above the second molding 32 for containing soap solution 56 and the like.

Continuing with the description of the structural parts of the device, the top of the first molding 30 carries a turbine support 58 which covers the gear cavity 40 and, as better seen in FIG. 3, defines the air inlets 16 previously mentioned with reference to FIG. 1. The inlets 16 are separated by upright vanes 60 positioned to guide incoming air onto a turbine 62 having complementary blades 64 designed to convert the momentum of air entering inlets 16 into a torque applied at turbine shaft 66.

As seen in FIGS. 2 and 3, a vacuum chamber 68 is positioned over the turbine 62 for co-operating with the vanes of the turbine support 58 to guide air leaving the turbine blades 64 towards wand 18 (FIG. 1). To this end, a shroud 70 contains the vacuum chamber 68 and guides air from the vacuum chamber to an integral coupling element 72 in which the wand 18 is received.

The turbine support 58, is preferably of a suitable material in order to act as a heat sink. The vacuum chamber 68, and shroud 70 are preferably of a suitable plastic material. Shroud 70, and turbine support 58 are located positively by four screws 74 (better seen in FIG. 3) which engage in corresponding bosses 76 (FIG. 2) formed integrally in the underside of the top of the first molding 30.

As previously mentioned with reference to FIG. 1, access for soap solution is provided through an opening 26, and a lid 28 is spring-loaded to cover the opening 26 when the device is in use. As seen in FIG. 2, the lid 28 is connected to a pivot pin 78 which in turning rides on a spring 80 so that the lid is positively located either in a closed position as shown in FIG. 2 or in an open position as shown in FIG. 1. The spring 80 is conveniently held in place by adjacent screws 74.

Lid 28 has a downwardly-extending skirt 82 engaged in a spout 84 defining the opening 26. The spout is preferably of a suitable plastic material and is sealed in place in a mating opening formed in the top of first molding 30. The purpose of the spout is two-fold. Firstly, in the event that the device is turned over accidentally, there will be a minimum of spillage because the soap solution will move to the top of the reservoir and leave the lower end of the spout projecting out of the solution. Secondly, the spout limits the possibility that the soap solution will spash upwardly out of the reservoir when the device is in use.

Valve assembly 52 is sealed in the valve housing 50 for releasing the soap solution from the reservoir 54. The valve assembly consists essentially of a generally cylindrical main portion 86 which is sealed in corresponding openings formed in the first and second moldings 30, 32 such that an inner end of the portion 86 projects into reservoir 54. The inner end of the portion 86 is sealed by a conical valve head 88 attached to an inner end of the core 90 of cable 22. A collar 92 is also attached to the core 90 and spaced from the valve 88 with a coil spring 94 positioned between the collar 92 and an inwardly projecting annular flange 96 formed on the main portion 86. The spring is in compression so that the valve head 88 is biased into sealing engagement with the inner end of the main portion 86.

Reference is next made to FIGS. 1 and 2. The manual control 20 includes a trigger 98 operable to compress the spring 94 by moving the core 90 further into the reservoir 54 and thereby moving the valve head 88 off the main portion 86 to permit soap solution 56 to enter into the main portion 86. A downwardly opening port 100 in the main portion 86 permits the soap solution to flow downwardly for co-operating with the brush 14 to wash a carpet or the like.

The valve assembly 52 is fused, or welded in place in the first and second moldings 30 and 32 when a collar 104 at the outward extremity of the main portion 86 is in engagement with the outer surface of the first molding 30 and the inner end of portion 86 is located in a hole in the valve housing 50 and projects into the reservoir 54.

The valve assembly 52 is completed by a suitable ring 102 which serves to engage a collar 106 which is fastened to the cable sheath 22. The ring 102 has a spring action which firmly holds the collar 106 and attached cable assembly in place and allows for the removal of the cable assembly.

Reference is now made to FIG. 2 to describe the drive between the turbine 62 and the brush 14. Beginning at the turbine, the turbine shaft 66 passes through journal bearings 108 positioned in the turbine support 58 in alignment with a vertical axis of the brush 14. Driving torque passes from the turbine shaft 66 by way of pairs of reduction gears 110, 112 and 114, 116. The gears 112 and 114 are formed from a common gear blank and attached to a spindle 118 rotatably mounted in journal bearings 120 set in the turbine support 58. The spindle 118 includes a thrust collar 122 at its upper end to positively locate the gears 112, 114 vertically. Bearings 108, 120 are preferably of a sintered metal capable of absorbing oil. These bearings are commonly referred to as "self-lubricating" bearings.

Gear 116 includes a boss 124 engaged in a tubular output shaft 126 and is locked in place by a pin 128. Output shaft 126 rotates in journal bearings 130 set in the cylindrical portion 42 of the first molding 30 and in the aligned opening 53 in the second molding 32. The shaft 126 is located against a downward movement by the gear 116 and against upward movement by a thrust collar 132 attached by a pin 134 to the output shaft 126.

The parts thus far described with reference to driving the brush are not normally removable from the device unless a major repair is to be made. However, it will be appreciated that the brush is preferably removable for replacement by a different type or by a new brush when an old brush is worn.

The arrangement of the brush and the drive from the drive shaft 126 to the brush will now be described with reference primarily to FIGS. 2 and 4. Collar 132 includes four radial ribs 136 which engage in radial slots 138 formed in an inner element or central boss 140 of a drive coupling 142. This coupling transmits torque from the drive shaft 126 to the brush 14 as will be described. The arrangement of ribs 136 on collar 132 and slots 138 in central boss 140 is such that drive is transmitted from shaft 126 by way of collar 132 to the drive coupling 142.

As best seen in FIG. 4, drive coupling 142 consists of the boss 140 and an outer element or ring 144 which include four pairs of respective radial inner and outer fingers 146, 148, and four integral straps 150 each of which interconnects a corresponding pair of inner and outer fingers. The drive coupling 142 is preferably molded from a suitable plastic material which is both flexible and sufficiently strong to transmit the required torque to the brush. A coil spring 152 is positioned under radial fingers 146 and above radial fingers 148 so that the spring biases the fingers apart and extends the straps 150 into generally upright positions. The fingers 148 project inwardly beyond straps 150 and terminate in upwardly extending lips 154 for locating a lower end of the spring 152.

The outer ring 144 of the drive coupling 142 defines an outwardly-projecting radial flange 156 below which a generally cylindrical wall 158 projects. As seen in FIG. 2, the wall 158 and flange 156 combine to locate a mating part of brush 14. Screws 159 pass through the flange 156 and are threadably engaged in the brush to retain the brush in place on the outer ring 144. As a result the brush moves with the ring.

Referring again to FIGS. 2 and 4, the drive coupling 142 is adapted to slidably engage on the output shaft 126 and locate on the collar 132 for transmitting drive from the shaft 126 as previously described. On engaging the coupling over the shaft 126, the boss 140 deflects rounded ends of a retaining spring 160 radially inwards until a major part of the boss has passed over the spring and the spring is then free to move outwardly into a suitable recess 161 formed in the boss for receiving the spring ends. The spring is held in place in the shaft 126 by the pin 134 and is located in the shaft in two axial slots 162 extending outwardly from a lower end of the shaft. The spring is sufficiently strong to retain the coupling and brush in place when the device is lifted from a supporting surface, but is sufficiently resilient to permit the coupling to be removed by pulling it off the shaft 126. The operation of the drive coupling will be described after further description of the brush.

As seen in FIGS. 2 and 5, the brush 14 includes a radial upper portion 163 and an upwardly curved portion 165 which terminates at the inner extremity of the portion 163. The portion 165 includes generally radial raised ribs 166 for dispersing soap solution falling from valve assembly port 100 (FIG. 2). The soap solution moves upwardly under the influence of centrifugal force and is frothed to some extent by its movement over the ribs 166. The soap solution then moves outwardly over the upper portion 163 under the influence of centrifugal force before landing on an inner surface of the second molding 32 at the lower portion 46. This inner surface is formed with circumferentially extending tapers and steps as shown in FIG. 2. The steps are indicated by numeral 168 and the tapers extend between these steps such that sponges 170 attached to the upper portion 163 are compressed gradually as they pass over the tapered portions and then allowed to expand once they pass each step. Consequently, in proceeding through one revolution, each of the sponges is alternately compressed and expanded in passing over the tapered portions and steps 168.

Because the soap solution is thrown outwardly onto the tapered portions, the sponges contact the soap solution as it falls downwardly under gravitational influences, and because of the continuous compression and decompression of the sponges, there is a tendency for the sponges to alternately pick up soap solution and squeeze it out causing the soap solution to froth and foam. This is a desirable requirement in a device of this type in order to disperse the soap solution and also to create a foam which the user can see in applying soap solution to a floor covering such a carpet.

As the soap solution leaves the sponges and falls downwardly, it is picked up by bristles 172 set conventionally in the underside of the upper portion 163 of the brush.

In use, it will be evident that the brush should be in contact with the surface being cleaned. However, in the event that the friction between the brush and the surface reaches a point at which the turbine would stall, it is necessary that the brush move upwardly out of engagement with surface sufficient to free the brush and ensure continuous rotation of the brush. This is achieved by the drive coupling 142 in combination with the lower extremity of skirt 34. The bottom of skirt 34 is shaped as shown in FIG. 2 so that with the axis of drive shaft 126 vertical, and the device on a horizontal surface, the skirt is in contact with the surface only at two points diametrically opposite and at the centre of FIG. 2. The bottom of the skirt tapers away from these points to define a small angle indicated at 174 to both sides of the skirt. Accordingly, the device can be rocked on the supporting surface through an angle of twice the angle indicated at 174. This rocking action combined with the action of the drive coupling (to be described) limits the possibility of the device becoming lodged against projections on floor coverings and the like and also aids in preventing stalling of the turbine.

The action of the drive turbine 142 is illustrated in FIGS. 5 and 6. In FIG. 5 the brush is at its lowest extremity in which position the straps 150 are fully extended in a generally axial or upright position. As previously described, spring 152 causes this downward displacement and upward alignment of the straps. Upon standing the device on a supporting surface, the weight of the device is transmitted to the spring 152 by the bristles 170 and associated parts of the brush 14. Consequently, the spring is compressed to some extent and the straps move towards an inclined position shown in FIG. 6. As the straps become inclined, there is a relative rotational movement between the brush and the output shaft 126.

Once the device is started, the bristles 172 will pass over the surface being cleaned driven by the straps 150. In the event that the bristles engage an obstacle which tends to stop rotation of the brush, there is an increased tension in the straps 150 resulting in the straps tending to become horizontal. As a result, the brush is moved upwardly sufficient to either disengage itself from the projection or to bring the skirt 30 into solid engagement with the supporting surface. The brush is then no longer supporting the device so that friction between the brush and the projection is reduced and the brush then frees itself of the projection and continues to rotate. Once the device has passed over the projection, the spring 152 will force the brush downwardly so that the brush is again substantially supporting the device on the surface.

It has been found that the following materials are suitable for making the major components. The turbine and gears are of DELRIN a trade mark of a polyoxymethylene and the parts forming the main housing 12 are of acrylonitrite butadiene stynene although, as previously described, the turbine support is of a suitable metal. The brush and drive coupling of polypyropylene and the bristles are of 0.009 inches diameter nylon.

Claims

WHAT WE CLAIM FOR OUR INVENTION IS:

1. A device for washing floor coverings such as carpets and the like, the device comprising:

a housing defining a generally cylindrical skirt disposed about an upright axis, and a reservoir above the skirt for storing soap solution and the like;

a valve assembly coupled to the housing and operable to permit soap solution to flow from the reservoir to within the skirt;

a brush mounted within the skirt for rotation about said upright axis and having bristles extending downwardly for engagement with the floor covering;

drive means coupled to the housing and operably coupled to the brush for rotating the brush to create relative movement between the bristles and the floor covering; and

a drive coupling connecting the drive means to the brush, the drive coupling comprising: an inner element coupled to the drive means; an outer element coupled to the brush and spaced axially below the inner element; generally upright straps connected at upper ends thereof to the inner element and at lower ends thereof to the outer element; spring means biasing the outer element axially downwards so that the bristles project downwardly beyond the skirt such that in use when the brush encounters a relatively high resistance to rotation, the straps move towards horizontal positions, the spring means is further stressed, and the brush moves upwards so that the skirt contacts the floor covering whereby the brush resistance is reduced and brush stalling is substantially obviated.

2. A device as claimed in claim 1 in which the brush further comprises sponges at the periphery of the brush, and in which circumferentially extending tapers and steps are provided inside the skirt for alternately compressing the sponges as the sponges pass over the tapers and relaxing the sponges as the sponges pass over the steps whereby as soap solution from the reservoir meets the sponges the soap solution is made to froth and foam before reaching the floor covering.

3. A device as claimed in claim 2 in which the housing comprises first and second moldings, the first molding defining the skirt and the second molding positioned inside the first molding, the moldings combining to define the reservoir and the second molding defining the tapers and steps.

4. A device as claimed in claim 3 and further comprising a valve assembly mounted in the housing and operable manually to permit soap solution to flow from the reservoir to within the skirt.

5. A device as claimed in claim 1 in which the drive means comprises a turbine and reduction gearing operably connecting the turbine to the drive coupling, the turbine being adapted to be driven by air drawn through the turbine by a sub-atmospheric source such as a domestic vacuum cleaner and the like.

6. A device as claimed in claim 1 in which the drive coupling inner and outer elements include respective inner and outer fingers, the inner fingers extending radially outwards and the outer fingers extending radially inwards and in which each of the straps is integrally connected at respective said upper and lower ends to corresponding inner and outer fingers, and in which the spring means comprises a coil spring in compression and located between the inner and outer fingers.

7. A device as claimed in claim 1 in which the drive means includes a shaft on which the drive coupling is releasably engaged, and the device further comprising a spring coupled to the shaft for retaining the drive coupling on the shaft and for permitting removal of the drive coupling by applying an axial downward forc to the drive coupling.