CA1121116A

CA1121116A - Device for scrubbing carpet

Info

Publication number: CA1121116A
Application number: CA000307147A
Authority: CA
Inventors: Robert C. Fay; Robert S. Brown
Original assignee: Milliken Research Corp
Current assignee: Milliken Research Corp
Priority date: 1977-08-02
Filing date: 1978-07-11
Publication date: 1982-04-06
Also published as: NO782579L; DE2861310D1; NZ188020A; MX146011A; DK340278A; EP0000629B1; EP0000629A1; AU3826678A; JPS5441560A

Abstract

Case 1262/1272 DEVICE FOR SCRUBBING CARPET

Abstract of the Disclosure A device for scrubbing carpet having a brush which rotates about a point which is eccentrically driven in a small circle. The bristled area of the brush has a number of protruding areas around its periphery, When the scrubber is used with powdered cleaning composition, the bristles in these pro-truding areas press the powder down into the pile of the carpet and so tend to minimize redistribution of the powder by the brush as it rotates. A press bar may be located at the front of the machine to press powder down into the pile of the carpet. Means may also be included for dispensing powder in front of the press bar.

Description

Many consider wall-to-wall carpeting to be ' the peak of luxury; housewives love it for the warm atmosphere it hrings, businessmen value it for the air o:E corporate dignity it lends their o~ices; but to those who must clean and maintain it, wall-to-wall ..
carpeting i9 an immense headache. It must be cleaned in place; the cleaning must be accomplished in a relatively short time and if the carpet is not kept ! scrupulously clean, its life may be severly shorten-ed. For these reasons, the carpet cleaning industry is constantly seeking improved methods and machinery for cleaning carpets.

.,, Recently, a radical:ly new approach to c:Lean-ing carpets has been developed whichl uses a powdered cleaning composition con-taining a mixture o~ extreme-ly porous solid part:icles and a solven-t. This new cleaning composition is described in U. S. Patent 4,013,594 and has proved especially effective in re-moving soil from carpets. Further, only a short lnterval is required between application and removal of the powdered cleaning composition. Using this new cleaning composition, it has now become possible to clean wall-to-wall carpets in offices and stores dur-ing working hours with little disruption of normal affairs. However, this progress in cleaning composi-tions has exposed shortcomings in the carpet clean-iny machines known to the prior art.
When the devices which are known to the prior art are used with this new powdexed cleaniny composi-tion, it is Eound that some areas oE the carpet are cleaned much better than other areas and -that a streak-ed appearance results. It is theorized that thls streak-ed appearance is due to the fact that the powder, un-like a liquid, must be physically moved into in-timate contact with the fibers to be cleaned; therefore, to obtain the full benefit of the powdered cleaning com-position, it is thought to be desirable to provide a device which is capable oE transmitting a great deal of eneryy to the carpet in order to bring the powdered cleaning composition into intimate contact with the fiber whi]e distributing -this energy uniformly over the area which is scrubbed. Further, it is desirable

-2~

to provide a device which does not redistribute -the powder which has been applied to the carpet.
It is therefore an object of this invention to provide a device which is capable of transmitting energy to the carpet uniformly while not redistribut-ing the powder which has been applied to the carpet.
It has been found that ~his object can be accomplished by providing a device of the type having a scrubber which rotates about a point which is driven in a circle wherein the scrubber is pivotably mounted on a frame and the weight of the device is supported by the scrubber and two wheels at the rear of the frame.
Means for pressing powdered cleaning compositiGn into the carpet are mounted on the rotating scrubber.
Brief Description of the Drawings Figure 1 is a side elevation of the carpet scrubbing machine.
Figure 2 is a schematic sectional view taken along section line 2-2 in E~igure 1.
~'igure 3 :is a sectional view taken along line

3~3 in Figure Z.
Figure 4 is a partly cutaway top view of the carpet scrubbing machine.
Figure S is an enlarged schematic side eleva-tion of the front of the machine, partly in section, showing the manner in which powder is dispensed, and pressed into the powder if the optional press bar is used.

Flgure 6 is a top schematic view o a rider brush a~ttached to the main scrubbing elernent for press-ing powdered cleaning com~osition into the carpet.
E'igure 7 is a view taken along line 7-7 of Figure 6.
Figure 8 is a top schematic view of a flexible wiper attached to the main scrubbing element for press-ing powdered cleaning composition into the carpet.
Figure 9 is a view taken along line 9-9 of Figure 8.
Figure 10 is a partial front elevation, partly cutaway, of the carpet scrubbing machine.
Pigure 11 is a schematic bottom view of the most preferred brush for use with the machine of the present invention.
E'igure 12 is a view taken along line 12-12 of Figure 11 showing the lie of the bristles.
Figures 13 through 17 are schematic views of alternate configurations o~ the brush.
DescriptLon o~ the PreEerred Embodiment In E'igure 1, housiny 20 is pivotably mounted on frame 22. Handle 52 is connected to frame 22 and facil-itates translating the machine across the carpet to be ;~ scrubbed. Vacuum means 54 is mounted on handle 52 and is connected to housing 20 by fle~ible hose 56. A pow-der dispenser of the type described in U. S. Patent

4,019,662 is mounted on frame 22. This powder dispen-ser includes: a powder storage bin 36 supported by frame 22 above housing 20 near the front of the machine;

ro-tat:incJ reticulated foam cylinder 38 rotatably mounted within powder storaye bin 36 which presses against fora-minous discharge area 40 and motor 42 for rotating reti-culated foam cylinder 38. Door 4A is provided for seal-ing foraminous discharge area 40 and for sexving as a ramp to aid in depositing powder in front of the machine as it translates over the carpet.
Wheels 23 are rotatably mounted at the lower rear of the frame 22 and partially support the weight of the machine in operation. The axis about which both wheels 23 rotate is parallel to the axis about which housing 20 is free to pivot. This arrangement prevents the housing from canting and insures that as the machine is translated over the carpet, the right side of -the machine will be at the same height as the left side of the machine, thus promoting easier handling of the ma-chine and uniform cleaniny across the wid-th of the path covered by the machine. However, slnce the weiyht o~
the device i~ supported ~y w~leels 23 and scrubber ele-ment 32 and sinae housing 20 is ree to pivot, carpets having piles of various lengths are automatically accom-modated and housing 20 is free to follow the contour of the carpet. Wheel brushes 62 are mounted on frame 22 adjacent to wheels 23 to prevent accumulation of powder on wheels 23.
As shown in Eigure 2, motor 24 having output shaft 26 is mounted vertically within housiny 22.
Eccentric support plate 27 encircles shaft 26 and also engages the inner race of bearing 28, Advantageously, ~5--as shown :in Figure 3, coun-terweights 25 may be ~ount-ed on eccentric support pla-te 27 to compensate for the unbalanced weight of the scrubber element 32. Slippage between eccentric support plate 27 and shaft 26 may be prevented by the inclusion of key 29 as shown in Figure 2. The outer race of bearing 28 is fixed to scrubber support member 30 upon which scrubber element 32 is mounted. Scrubber elemen.t 32 has tufts 31 of bristles 34 which engage the carpet to be scrubbed and which to-gether with wheels 23 support the weight of the machine.
As best shown in Figures 1 and 5, reticulated foam cylinder 38 is rotatably mounted in powder storage bin 36 and presses against foraminous discharge area 40 located at the lower front of the powder storage bin 36. Auxiliary motor 42 rotates reticulated foam cylin-der 38 within powder storage bin 36. Activation of aux-iliary mo'cor 42 causes powder to be dispensed through Eoraminous discharge area 40. Storage bin door ~4 is pivotably mounted on powder storage bin 36 and in c105-ed position, .it covers foraminous d:ischarge area 40.
Storage bin cover 46 is provided for the top of the storage bin and both powder storage bin door 44 and storage bin cover 46 provide moisture tight seals which retard the drying out of the powder stored within powder : 25 storage bin 36. In the open position, as shown in tdotted lines in Figure 5, storage bin door 44 serves as a ramp and aids in depositing powder i.n front of the machine as it translates over the carpet.

On many carpets, there is a tendency for brushes to redis-tribu-te the powder on the carpet.
This effect is especially pronounced on low level loop carpets. It is thought that this redistribution of cleaning powder leads to uneven cleaning of the carpet and that a streaked appearance results there-from. It i5 possible to reduce this redistribution by attaching pressing means to scrubber element 32 around its periphery. Such pressing means can in-clude pressing members such as rider brushes 37a as shown in Figures 6 and 7 or flexible wipers 37b as shown in Figures 8 and 9.
In the more preferred embodiments, as shown in Figures 10 through 16, tufts 31 of bristles 34 loca-ted in protruding areas 33 at the outer periphery of scrubber element 32 will function to press the powder-ed cleaning composition into the pile of the carpet and to minimize redistribution of powdered cleaning composition by scrubber element 32.
As shown in Figure 11~ the region of the lower face of the preferred brush 32 to which bristles 34 are applied has several protruding areas 33 around its periphery. Following the periphery of the bristl-ed area from each protrusion 33 in the direction of rotation indicated by the arrow, it can be seen that the distance from the center of the brush to the outer edge of the bristled area decreases steadily until the next protrusion 33 i5 encountered. As best shown in Fi~ure 12, the bristles are slanted at an angle of ~bout 25 from -the ver~ical but as can be seen in Fiyure 2 are substantially perpendicular to the radi a] lines extending from the center of the brush. By applying bristles 34 to the lower face of brush 3Z
as described, it is possible to minimize the tenden-cy of the brush to redistribute the powder which has previously been laid down on the carpet.
In operation as brush 3Z orbits and rotates, tufts 31 in protrudin~ area 33 will encounter parti-cles which have been laid down on the carpet. Since the veIocity of tufts 31 in each of protrudin~ areas 33 which first encounter the particles of cleaning powder is approximately perpendicular to the edge of each bristled area, the tendency of tufts 31 to ride up over the particles and to press them down into the pile of the carpet is enhanced. In contrast when a circular brush is used/ the velocity of the tuEts which first encounter the particles of cleaning pow-der is substantially parallel to the ed~e oE the 2Q bristled area. It is thought that this increases the tendency O:e the bristles to redistribute the powder.
Bristles 34 are inclined for two reasons.
First, they facilitate the rotation of scrubber eLe-ment 32 and the proper inclination makes it easier ~or protruding sections 33 to ride up over the pow-der and work them into the carpet. I motor 24 drives shaft 26 in the clockwise direction when viewed from the top, then bristles 34 should lean to the left when viewed from -the front of the machine. However, if th~ opposite inclincltion i5 used, satisfactory results can be obtained but the device will be more dificul-t to control.
While the shape shown in Figure 11 is the most s preferred shape for the bristled area, other shapes such as those shown in Figures 13 through 17 are also quite suitable. Flgure 13 shows the shape of the - bristled region on a brush having a gear shaped bris-tled region. Figure 14 shows the shape of the bris-tled region on a brush having a cross shaped bristled region. Figure 15 shows the shape of the bristled region on a brush having a fan blade shaped bristled region. Figure 16 shows the shape of the bristled region on a brush having a saw blade shaped bristled region. Figure 17 shows the shape of the bristled region on a brush having an obl,ong shaped bristled region. Figure 16 differs from Figure 11 principally in that there are five protrusions in Figure 11 and six protrusions in Figure 16. I'he shapes shown in Figures 11 and 16 are preEerred because the presence of a plurality unobstructed tufts 35 located along a radial line at the edges of protrusions 33. Each unobstructed tuft is located so that an imaginary tangential line segment can be constructed which pass-es through the center of the tuft and meets the fol-lowing conditions: the line segment is perpendicular to an imaginary radial line drawn through the c~nter of the scrubber element to the center of the tu~t, it extends in the direction of rotation of th~e scrubber _g_.

element; it lies within the face of the scrubber elernen-t and it does not pass throug~ any portion of any o-ther tuft or between any two other tuf-ts which are adjacent to each other. Since the brushes shown in Fiyures 11 and 16 have a plurality of unobstructed bristles lying on a radial line, they are the most preferred embodiment of the invention, but other embodiments in which there are a plurality of un-obstructed bristles which do not lie on the same radial line are acceptable.
By shaping the bristled region such that there are a number of unobstructed bristles, it is possible to reduce the tendency of the brush to redistribute powder. In the most preferred configuration, the un-obstructed bristles will lie on a substantially radial line. By this combination of scrubber shape and bris-tle orientation, it i5 possible to minimize the ten-dency of the brush to redistribute the powder which has been laid down on the carpet.
In order to further minimize redistribution of powder, press bar 48 may be plvotably mounted on frame 22 by means of rods 50. As best shown in Figures 4,

5 and lO,,each rod 50 terminates in a flattened por-tion 51 and tabs 49 are attached to each end of press bar 48. Each flattned portion 51 is pivotably con-nected to the corresponding tab portion 49 and each rod 50 is pivotably connected to frame 22 so that press bar 48 is free to follow the contour of the carpet. If press bar 48 is included, storage'bin door 44 should be of sufficient lenyth to insure that the powder will be deposited :in t.ront o pre~s bar 48. In!operation, as the scrubber i5 advanced over the carpet, powder will be dispensed in front of press bar 48 which minimizes redis-tribution of powder by pressing the powder into the pile of the carpet.
Press bar 48 thus tends -to immobilize the powder and may advantageously be included when use of the irregularly shaped brush is insufficient to reduce streaking to acceptable levels.
OPEP~ION
Upon activation of motor 24, shaft 26 is rota-ted. Since shaft 26 is fixed to eccentric support plate 27, the center of scrubber element 32 is driven in a circle. Since scrubber element 32 is free to rotate about its center it does no-t rotate at the same speed as shaft 26 but rather ro-ta-tes more slowly.
For example, in the most preferred embodimen-t, motor 24 will drive shaft 26 at 3400 rpm, scrubber element 32 will usually rotate at between 50 and 100 xpm de--pending upon the type of bristles used and on the type of carpet being scrubbed.
Upon activation of auxiliary motor 42, reti-culated foam cylinder 38 is rotated. Particles of cleaning powder enter the pores of reticulated foam cylinder 38, are transported into contact with fora-minous discharge area 40 where they are discharged onto storage bin door 44 which serves as a ramp and causes them to be deposited in Eront of housing 20.

:r~ pre~s; bar 48 is i.rlcludecl, the part:ia:le~ of cleaninc~ powder are pushed .into the pile of the ruy by press bar 48 as the machine is translated over the carpet.
Whether or not press bar 48 ls used, tuf-ts 31 in the protrudincJ areas 33 of scrubber element 32 encounter the particles of cleanin~ powder heore the other tufts on scrubber element 32 and aid in press-ing the powder down into the carpet. The remaining tufts 31 scrub the powder into the carpet. Vacuum means 54 prevents excessive dust from escaping from under housing 20.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A device for cleaning carpets, comprising:
a frame;
a housing mounted on said frame;
a substantially vertical shaft rotatably supported by said housing;
means for rotating said shaft;
an orbiting scrubber element rotatably mounted on said shaft, said scrubber element being rotatable about an axis which is substantially parallel to, but offset from the axis of rotation of said vertical shaft, said scrubber element having:
a body member;
a plurality of tufts fixed to said body member, each said tuft in-cluding a plurality of bristle members; and, means mounted on said scrubber ele-ment and engaging said carpet for pressing powdered cleaning composition into the pile of said carpet and for minimizing re-distribution of said powdered cleaning composition, said means being mounted closely adjacent to the outer periphery of the scrubber element .

2. The device of Claim 1 wherein the means for pressing powdered cleaning composition into the pile of said carpet and for minimizing redistribution of powdered cleaning composition comprises:
a plurality of unobstructed inclined tufts fixed to said body member, each said unobstructed inclined tuft including a plurality of bristle members, each said un-obstructed inclined tuft being inclined in the direction of rotation of said scrubber member, each unobstructed inclined tuft being located so that an imaginary tangential line segment beginning at the center of said unobstructed inclined tuft, perpendicular to an imaginary radial line drawn from the center of said scrubber element to the center of said tuft, extending in the direction of rotation of said scrubber element and lying within the face of said scrubber element, does not pass through any portion of any other tuft or between any two other tufts which are adjacent to each other.

3. The device of Claim 2 wherein the tufts form a bristled region on the lower face of said brush which region is saw-blade shaped.

4. The device of Claim 2 wherein the tufts form a bristled region on the lower face of said brush which region is gear shaped.

5. The device of Claim 2 wherein the tufts form a bristled region on the lower face of said brush which region is fan-blade shaped.

6. The device of Claim 2 wherein the tufts form a bristled region on the lower face of said brush which region is cross shaped.

7. The device of Claim 2 wherein the tufts form a bristled region on the lower face of said brush which region is oblong shaped.

8. The device of Claim 2 wherein each of said unobstructed tufts is located on substantially the same radial line as at least one other of said un-obstructed tufts.

9. The device of Claim 2, further comprising two wheels rotatably mounted on said frame and partially supporting said device, said wheels being rotatable about the same axis of rotation;

and wherein said housing is pivotably mounted on said frame and wherein said housing is free to pivot about an axis which is substantially parallel to said carpet and substantially parallel to the axis of rotation of said wheels.

10. The device of Claim 9 further comprising means for spreading coherent powder, said means including:
a powder storage bin having foraminous discharge area;
a cylinder of pore bearing resilient reticulated foam rotatably mounted within said bin and disposed such that on a rotating it presses against the wall discharge area forcing said powder through said perforations;
and means for rotating said cylinder.

11. The device of Claim 10, further compris-ing means for pressing powdered cleaning composition into said carpet as said machine is translated over said carpet, said means including a horizontal press-ing member and means for holding said pressing mem-ber in contact with said carpet.

12. The device of Claim 10 wherein the tufts form a bristled region on the lower face of said brush which region is saw-blade shaped.

13. The device of Claim 10 wherein the tufts form a bristled region on the lower face of said brush which region is gear shaped.

14. The device of Claim 10 wherein the tufts form a bristled region on the lower face of said brush which region is fan-blade shaped.

15. The device of Claim 10 wherein the tufts form a bristled region on the lower face of said brush which region is cross shaped.

16. The device of Claim 10 wherein the tufts form a bristled region on the lower face of said brush which region is oblong shaped.

17. The device of Claim 2 wherein said tufts are inclined in the direction which facilitates rota-tion of said scrubber element in the direction of rotation of said shaft.

18. The device of Claim 1, further comprising two wheels rotatably mounted on said frame and par-tially supporting said device, said wheels being rotatable about the same axis of rotation;

and wherein said housing is pivotably mounted on said frame, said housing being free to pivot about an axis which is substantially parallel to said carpet, and substantially parallel to the axis for rotation of said wheels.

19. The device of Claim 1, further comprising means for pressing powder cleaning composition into said carpet as machine is translated over said car-pet, said means including a horizontal pressing member and means for holding said pressing member in contact with said carpet.

20. The device of Claim 1 further comprising means for spreading coherent powder, said means in-cluding:
a powder storage bin having foraminous wall discharge area;
a cylinder of pore bearing resilient reticulated foam rotatably mounted within said bin and disposed such that on rotating, it presses against the wall discharge area forcing said powder through said perforations;
and means for rotating said cylinder.

21. The device of Claim 1, further comprising means mounted on said frame for pressing powdered cleaning composition into said carpet as said machine is translated over said carpet, said means including a horizontal pressing member and means for holding said pressing member in contact with said carpet.

22. The device of claim 1, wherein said tufts are inclined in a direction which facilitates rotation of said scrubber member in the direction of rotation of said shaft.