U.S. patent application number 12/090835 was filed with the patent office on 2008-11-13 for floor maintenance machine using a spiral, tufted, cylindrical brush.
This patent application is currently assigned to NILFISK-ADVANCE, INC.. Invention is credited to Nick Graupe, Donald Joseph Legatt, David W. Wood.
Application Number | 20080276414 12/090835 |
Document ID | / |
Family ID | 37697968 |
Filed Date | 2008-11-13 |
United States Patent
Application |
20080276414 |
Kind Code |
A1 |
Wood; David W. ; et
al. |
November 13, 2008 |
Floor Maintenance Machine Using a Spiral, Tufted, Cylindrical
Brush
Abstract
Leading and trailing cylindrical brushes (14) are moved in an
operation direction to sweep and wet scrub a floor In differing
aspects, the trailing cylindrical brush (14) is rotated at a
greater rotational speed than the leading cylindrical brush (14) to
enhance sweeping ability and preferably in the order of 1500 RPMs
to enhance polishing. The brushes (14) include spiraled, equally
circumferentially spaced rows (R) of a multiplicity of equally
spaced tufts (54). The tufts (54) of an adjacent trailing row (R)
are indexed laterally from a leading row (R) by an index distance
(T) less than one half of the distance (I) of the tufts (54) in the
rows (R).
Inventors: |
Wood; David W.; (Maple
Plain, MN) ; Legatt; Donald Joseph; (St. Michael,
MN) ; Graupe; Nick; (White Bear Lake, MN) |
Correspondence
Address: |
KAMRATH & ASSOCIATES P.A.
4825 OLSON MEMORIAL HIGHWAY, SUITE 245
GOLDEN VALLEY
MN
55422
US
|
Assignee: |
NILFISK-ADVANCE, INC.
Plymouth
MN
|
Family ID: |
37697968 |
Appl. No.: |
12/090835 |
Filed: |
October 18, 2006 |
PCT Filed: |
October 18, 2006 |
PCT NO: |
PCT/US2006/040913 |
371 Date: |
April 18, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60727950 |
Oct 18, 2005 |
|
|
|
Current U.S.
Class: |
15/383 ;
15/256.5 |
Current CPC
Class: |
A46B 13/001 20130101;
A47L 11/4069 20130101; A47L 11/19 20130101; A47L 11/4041 20130101;
A46B 9/02 20130101; A47L 11/302 20130101 |
Class at
Publication: |
15/383 ;
15/256.5 |
International
Class: |
A47L 5/30 20060101
A47L005/30; A46B 15/00 20060101 A46B015/00 |
Claims
1. Brush for a floor maintenance machine comprising, in
combination: a cylindrical core having a rotational axis and a
cylindrical outer surface concentric to the rotational axis at a
radial spacing, with the cylindrical core adapted to be mounted to
a floor maintenance machine for rotation about the rotation axis;
and a multiplicity of rows of a multiplicity of tufts of bristles,
with the multiplicity of rows being equally circumferentially
spaced and arranged at an acute angle to the rotational axis to
create a spiral, with the tufts being equally spaced by a tuft
spacing in each of the multiplicity of rows, with the tufts of an
adjacent trailing row being indexed laterally from a leading row by
an index distance less than one half of the tuft spacing.
2. The brush of claim 1 with the multiplicity of rows being equally
spaced by a row spacing generally equal to the tuft spacing.
3. The brush of claim 2 with the multiplicity of rows repeating in
at least two identical row patterns.
4. The brush of claim 3 with each of the multiplicity of tufts
comprising a tuft hole extending radially into the cylindrical
outer surface of the core, with the tuft hole having a hole
diameter; and a plurality of bristles received in the tuft hole,
with the index distance being one half of the hole diameter or
less.
5. The brush of claim 4 with the bristles extending from the core
hole by a length, with a ratio of the length of the bristles to the
hole diameter being in the range of 4.5:1 to 5:1.
6. The brush of claim 5 with the acute angle being between
15.degree. and 25.degree. when the cylindrical outer surface is
unwrapped from the rotational axis and lain flat.
7. The brush of claim 6 with each of the plurality of bristles
formed of crimped type nylon having a crimp amplitude around 0.025
inch and a pitch around 0.11 inches.
8. A floor maintenance machine utilizing the brush of claim 1.
9. Method of maintaining a floor comprising: rotating a leading
cylindrical brush about a leading rotational axis parallel to the
floor at a first rotational speed, with the leading cylindrical
brush having tufts of bristles extending radially from the leading
rotational axis; simultaneously counter rotating a trailing
cylindrical brush about a trailing rotational axis parallel to the
floor at a second rotational speed greater than the first
rotational speed, with the trailing cylindrical brush having tufts
of bristles extending radially from the trailing rotational axis,
with the leading and trailing rotational axes being parallel;
providing a hopper intermediate the leading and trailing
cylindrical brushes for receiving debris swept from the floor by
the leading and trailing cylindrical brushes; and simultaneously
moving the leading and trailing cylindrical brushes in an operation
direction parallel to the floor with the leading cylindrical brush
being forward in the operation direction of the trailing
cylindrical brush.
10. The method of claim 9 wherein counter rotating the trailing
cylindrical brush comprises counter rotating the trailing
cylindrical brush of identical construction as the leading
cylindrical brush.
11. The method of claim 10 wherein the tufts of bristles of each of
the trailing and leading cylindrical brushes are spaced and are
arranged in a multiplicity of rows, with the multiplicity of rows
being circumferentially spaced around the rotational axes, with the
multiplicity of rows being arranged at an acute angle to the
rotational axis to create a spiral.
12. The method of claim 11 wherein counter rotating the trailing
cylindrical brush comprises counter rotating the trailing
cylindrical brush at the second rotational speed in the order of
1200 to 1800 RPMs.
13. The method of claim 12 wherein the multiplicity of rows are
equally circumferentially spaced, with the tufts being equally
spaced by a tuft spacing in each of the multiplicity of rows, and
the tufts being equally spaced by a tuft spacing in each of the
multiplicity of rows, with the tufts of an adjacent trailing row
being indexed laterally from a leading row by an index distance
less than one half of the tuft spacing.
14. A floor maintenance machine utilizing the method of claim
9.
15. Method of maintaining a floor comprising: rotating a trailing
cylindrical brush about a trailing rotational axis parallel to the
floor surface at a rotational speed in the order of 1200 to 1800
RPMs, with the trailing cylindrical brush having tufts of bristles
extending radially from the trailing rotational axis; and moving
the trailing cylindrical brush in an operation direction parallel
to the floor.
16. The method of claim 15 wherein the tufts of bristles are spaced
and are arranged in a multiplicity of rows, with the multiplicity
of rows being circumferentially spaced around the rotational axes,
with the multiplicity of rows being arranged at an acute angle to
the rotational axis to create a spiral.
17. The method of claim 16 wherein the multiplicity of rows are
equally circumferentially spaced, with the tufts being equally
spaced by a tuft spacing in each of the multiplicity of rows, and
the tufts being equally spaced by a tuft spacing in each of the
multiplicity of rows, with the tufts of an adjacent trailing row
being indexed laterally from a leading row by an index distance
less than one half of the tuft spacing.
18. The method of claim 17 further comprising: simultaneously
counter rotating a leading cylindrical brush about a leading
rotational axis parallel to the floor surface at a first rotational
speed, with the leading cylindrical brush having tufts of bristles
extending radially from the leading rotational axis, with the
leading and trailing rotational axes being parallel; providing a
hopper intermediate the leading and trailing cylindrical brushes
for receiving debris swept from the floor by the leading and
trailing cylindrical brushes; and moving the leading cylindrical
brush in the operation direction parallel to the floor, with the
leading cylindrical brush being forward in the operation direction
of the trailing cylindrical brush.
19. The method of claim 18 wherein rotating the trailing
cylindrical brush comprises rotating the trailing cylindrical brush
of identical construction as the leading cylindrical brush.
20. A floor maintenance machine utilizing the method of claim 15.
Description
BACKGROUND
[0001] The present invention generally relates to floor
maintenance, particularly to both sweeping and wet scrubbing floors
while removing only a negligible amount of floor finish, and
specifically to novel cylindrical brushes which sweep and wet scrub
without noticeably scratching or dulling the floor and to floor
maintenance machines utilizing such novel brushes.
[0002] Floor maintenance on finished floors typically involves
several separate operations. On floors such as resilient tile,
polished concrete or colored epoxy, a floor finish is applied to
the floor. The floor finish protects the floor surface and provides
a glossy, clean appearance. Often, several coats of finish are
applied to provide additional protection and longer wear.
[0003] Daily maintenance is performed by first pre-cleaning such as
pre-sweeping or dust-mopping to remove debris from the floor. This
is followed by scrubbing with an automatic scrubber. Automatic
scrubbers dispense cleaning solution onto rotating agitator disc
pads or brushes. The spent cleaning solution is then recovered with
a vacuumized squeegee. Operation of automatic scrubbers is well
known.
[0004] The scrubbing operations also remove a small amount of floor
finish. This is due to the abrasive composition of the scrub
pads/brushes. The rotation of the pads/brushes creates very small
scratches in the finish which dull the appearance of the floor. In
order to restore the floor finish back to a glossy appearance, the
scrubbing operation is followed by high speed burnishing.
Burnishing also removes a small amount of finish from the floor.
Burnishing is a dry polishing process, and some of the dry,
powdered floor finish becomes airborne and settles back onto the
floor and surrounding surfaces. This often necessitates yet another
operation to dust-mop the floor.
[0005] Restoration of finish requires periodic stripping and
recoating of finish.
[0006] The majority of the cost of floor maintenance is not the
equipment or the cleaning chemicals, but the labor to perform the
above steps. If one or more steps in the process can be completely
eliminated, the overall cleaning cost can be reduced
significantly.
[0007] One conventional solution was to combine the pre-cleaning
and scrubbing operations into one machine such as by using
cylindrical scrub brushes instead of the more common disc style
pads/brushes. The cylinder brushes sweep debris into a hopper while
simultaneously performing the task of scrubbing. These cylinder
brushes typically rotate at around 900 RPMs or less. The bristles
on these cylinder brushes tend to be relatively stiff so that they
can both sweep and scrub. Like disc brushes, the cylindrical
scrubbers currently on the market remove a small amount of finish
and create small scratches in the floor finish. As a result, they
dull the appearance of the floor. So while cylindrical brush
scrubbers currently available eliminate the need to pre-clean, they
do not reduce or eliminate the need to burnish the floor to restore
an acceptable level of gloss.
[0008] Attempts have been made to combine the scrubbing and
burnishing operations into one machine so that they can be
performed simultaneously such as disclosed in U.S. Pat. No.
6,023,813. Such machines still require pre-cleaning, do not address
the removal of finish by the abrasive scrub pads, and may still
require post-mopping to remove powdered floor finish residue.
Further, such dual function machines are expensive and cumbersome
to operate.
[0009] Thus, the present invention addresses a need in floor
maintenance to reduce or eliminate steps in the daily cleaning of
finished floors.
SUMMARY
[0010] The present invention solves several of the problems
involved in daily floor maintenance by providing a machine that
sweeps and wet scrubs while removing only a negligible amount of
floor finish, and which does not noticeably scratch or dull the
floor. This invention thus eliminates the need for pre-sweeping,
frequent burnishing, and post-mopping. Additionally, because far
less finish is removed, the frequency of stripping and recoating
the floor is greatly reduced.
[0011] In a first aspect, the present invention relates to a brush
and a floor maintenance machine utilizing such a brush. A
multiplicity of rows of a multiplicity of tufts of bristles are
equally circumferentially spaced on the cylindrical outer surface
of a cylindrical core, are arranged at an acute angle to the
rotational axis to create a spiral, and repeat in at least one
identical row pattern upon the cylindrical outer surface. Tufts of
an adjacent trailing row are indexed laterally from a leading row
by an index distance less than one half of the equal spacing of the
tufts in each of the multiplicity of rows.
[0012] In a further aspect of the present invention, counter
rotating leading and trailing cylindrical brushes move in an
operation direction with their rotational axes being spaced and
parallel to each other and to the floor. The rotational speed of
the trailing cylindrical brush is greater than that of the leading
brush to enhance sweeping performance. In most preferred forms, the
leading and trailing cylindrical brushes are of identical
construction and include tufts of bristles arranged in a
multiplicity of rows arranged at an acute angle to the rotational
axis of the brush.
[0013] In still a further aspect of the present invention, a
cylindrical brush moving in an operation direction parallel to the
floor is rotated about a rotational axis at a rotational speed in
the order of 1200 to 1800 RPMs to enhance polishing benefit. In
most preferred forms, the brush includes tufts of bristles arranged
in a multiplicity of rows arranged at an acute angle to the
rotational axis of the brush.
[0014] The present invention will become clearer in light of the
following detailed description of an illustrative embodiment of
this invention described in connection with the drawings.
DESCRIPTION OF THE DRAWINGS
[0015] The illustrative embodiment may best be described by
reference to the accompanying drawings where:
[0016] FIG. 1 shows a perspective view of a floor maintenance
machine according to the preferred teachings of the present
invention.
[0017] FIG. 2 shows an exploded perspective view of portions of a
floor maintenance machine of FIG. 1.
[0018] FIG. 3 shows a perspective view of a cylindrical brush
utilized in the floor maintenance machine of FIG. 1.
[0019] FIG. 4 shows a front elevation view of the cylindrical brush
of FIG. 3.
[0020] FIG. 5 shows an end elevation view of the cylindrical brush
of FIG. 3.
[0021] FIG. 6 shows a diagrammatic view of the outer surface of the
cylindrical brush core of FIG. 3 with the tufts of bristles removed
and with the outer surface unwrapped.
[0022] All figures are drawn for ease of explanation of the basic
teachings of the present invention only; the extensions of the
figures with respect to number, position, relationship, and
dimensions of the parts to form the preferred embodiment will be
explained or will be within the skill of the art after the
following description has been read and understood. Further, the
exact dimensions and dimensional proportions to conform to specific
force, weight, strength, and similar requirements will likewise be
within the skill of the art after the following description has
been read and understood.
[0023] Where used in the various figures of the drawings, the same
numerals designate the same or similar parts. Furthermore, when the
terms "top", "bottom", "first", "second", "front", "back",
"height", "width", "length", "end", "side", "trailing", "leading",
"horizontal", "vertical", "axial", "radial", "longitudinal",
"lateral", and similar terms are used herein, it should be
understood that these terms have reference only to the structure
shown in the drawings as it would appear to a person viewing the
drawings and are utilized only to facilitate describing the
illustrative embodiment.
DESCRIPTION
[0024] A floor surface maintenance machine such as a floor surface
sweeping and wet scrubbing machine according to the preferred
teachings of the present invention is diagrammatically shown in
FIG. 1 and generally designated 10. In the preferred form shown,
machine 10 is movably supported by three or more wheels, casters or
the like 12 upon the surface to be cleaned, with one or more of the
wheels, casters or the like 12 being driven if desired. The
operator can either walk behind or ride upon machine 10 as desired.
Machine 10 includes suitable elements for maintaining the floor
surface such as first and second rotatable cylindrical brushes 14
mounted to machine 10 for rotation about spaced parallel rotational
axes 42 parallel to the floor as diagrammatically shown. In the
most preferred form shown, brushes 14 are of identical
construction. A cleaning solution such as but not limited to water
and water-based solutions (which can be premixed or which could be
separately provided and mixed within the machine 10 where desired)
is delivered via line 15 from a source of cleaning solution in the
form of a solution tank 16 adjacent to brushes 14 such as by a
solution pump 18 in fluid communication with tank 16. In the
preferred form, machine 10 includes a recovery tank 26 and a
suitable vacuum system including a solution pickup element 28 such
as squeegee as diagrammatically shown for collecting solution from
the surface to be cleaned and delivering such collected solution to
recovery tank 26.
[0025] In a most preferred form where machine 10 sweeps as well as
wet scrubs the floor surface, a hopper 33 is positioned above and
intermediate the first and second brushes 14 for receiving debris
swept from the floor as brushes 14 are simultaneously moved in an
operation direction parallel to the floor. It should be appreciated
that hopper 33 allows solution and small particles to flow
therethrough to the floor but retains debris and large particles
which can be manually removed such as by sliding hopper 33 from
machine 10 and emptying. However, hopper 33 can take other forms
and/or could be eliminated in certain embodiments according to the
preferred teachings of the present invention.
[0026] Machine 10 as previously described can be of a variety of
types and forms, and the present invention is not intended to be
limited to any particular type or form including but not limited to
the type or form shown and/or described.
[0027] According to the teachings of the present invention, each
brush 14 generally includes a cylindrical core 40 mounted for
rotation about rotational axis 42. In the most preferred form
shown, cylindrical core 40 is in the form of a tube which is
slideably received on spindles 44. At least one of such spindles 44
of each brush 14 is rotated by a motor 46 through a suitable drive
such as sheaves and a V-belt 48. It should be appreciated that core
40 can have other forms as is known in the art. Similarly, core 40
can be driven by different manners as is known in the art according
to the teachings of the present invention such as, but not limited
to, by a single motor 46 while having drives resulting in the
desired speed relationship, or the like. In any case, each
cylindrical core 40 includes a cylindrical outer surface 50 having
a core diameter D3 and concentric to rotational axis 42 at a radial
spacing equal to one half of core diameter D3.
[0028] In the most preferred form, core 40 includes a multiplicty
of drilled tuft holes 52 extending radially into cylindrical outer
surface 50. Each of the tuft holes 52 has a diameter 52a. Each of
tuft holes 52 receives a multiplicity of individual bristles B to
define an individual tuft 54 extending radially from rotation axis
42. According to the teachings of the present invention, tuft holes
52 and thus tufts 54 are arranged as a multiplicity of rows R.
Specifically, in the form shown, rows R are spaced by a row spacing
S circumferentially around cylindrical outer surface 50, and in the
most preferred form, row spacing S is equally spaced between each
of rows R around the entire cylindrical outer surface 50. Likewise,
each of the rows R includes a multiplicity of tuft holes 52 and
tufts 54 which are spaced by a tuft spacing I. In the most
preferred form, tuft spacing I is equally spaced in each and every
row R, and row spacing S is generally equal to tuft spacing I.
[0029] According to the teachings of the present invention,
cylindrical brush 14 includes several features which cooperate
together to produce synergistic results. One such feature is that
rows R of spaced tufts 54 of bristles B are arranged in a spiral at
an acute angle A1 to the rotational axis of between 15 and
25.degree. and preferably in the order of 20.degree. when measured
at surface 50 unrolled and lain flat. Spiraling tufts 54 minimize
imprints of tufts 54 on the floor finish as occurs when tufts are
arranged in straight rows across the brush.
[0030] Further, in the preferred form where each tuft 54 in brush
14 is formed by a multiplicity of individual bristles B received in
drilled tuft hole 52 in core 40, the diameter D3 of core 40 of
brush 14 is in the range of 2 to 5 inches and in the most preferred
form in the order of 2.9 inches. The diameter 52a of drilled tuft
hole 52 in core 40 is in the range of 0.25 to 0.375 inches and in
the most preferred form in the order of 0.31 inches. The length of
bristles B extending from tuft hole 52 is in the range of 1.25 to
1.75 inches and in the most preferred form in the order of 1.5
inches. The ratio of length of bristles B to the diameter of tuft
drill hole 52 is in the range of 4.5:1 to 5:1 and in the preferred
form in the order of 4.8:1. Each bristle B in the preferred form is
formed from 0.008 inch crimped type 6.12 nylon in the preferred
form. The crimp amplitude is around 0.025 inch and the pitch is
around 0.11 inch. Bristles B could also be formed by polypropylene
having a similar flex modulus or other water resistant bristle
material according to the teachings of the present invention.
Likewise, although crimping adds fullness to tufts 54, bristles B
could be flagged to add fullness according to the teachings of the
present invention. In addition to diameter, material and type,
performance of tuft 54 is affected by length of bristles B and the
number of tufts 54 per area. Specifically, the distance I between
adjacent tufts 54 within the same row R is in the range of 0.50
inch to 0.75 inch and in the most preferred form is in the order of
0.59 inch. The exact distance I between tufts 54 is determined by
the length of rows R along the working length D1 of brush 14. The
length of rows R is divided by the preferred distance and rounded
to the nearest whole number.
[0031] In the preferred form, the spacing S between rows R of
spaced tufts 54 of bristles B is generally the same as the distance
I between adjacent tufts 54 in rows R in the preferred form. The
number of rows R should result in row patterns repeating itself at
least once for each full rotation of brush 14. In the preferred
form, the number of rows R of tufts 54 is in the range of 14 to 18
rows R and in the most preferred form in the order of 16 rows R. As
an example, a 16-row brush 14 could have either two or four
identical groups of eight rows or four rows R, respectively. A
15-row brush 14 could have three identical pattern groups of five
rows R each. An 18-row brush 14 could have either two or three
identical groups of nine rows R or six rows R, respectively.
[0032] Additionally, tufts 54 are indexed such that tufts 54 in
trailing rows R are indexed laterally by a distance T from tufts 54
in the preceding or leading row R. Distance T depends upon the
number of rows R and the number of repeat patterns formed by the
rows R. Particularly, distance T is equal to the distance I between
tufts 54 in the same row R divided by the product of the number of
rows R in turn divided by the number of repeat patterns. In the
preferred form, distance T is of an amount no greater than in the
order of one half of diameter 52a of tuft holes 52 in cylindrical
outer surface 50 of brush 14 for receiving tufts 54 and not less
than one ninth of diameter 52a of tuft holes 52 in cylindrical
surface 50 of brush 14 for receiving the tufts 54. In the most
preferred form, distance T is in the order of one quarter of
diameter 52a of tuft holes 52 in cylindrical outer surface 50 of
brush 14 for receiving tufts 54.
[0033] Furthermore in the most preferred form, at least one of
brushes 14 is rotated by floor maintenance machine 10 faster than
cylindrical brushes of conventional automatic scrubbers such that
the tip speed of bristles B is faster in the present invention than
in conventional automatic scrubbers. Specifically, cylindrical
brushes of convention automatic scrubbers were typically rotated at
900 RPMs and resulted in individual tuft imprints on the floor
finish. In the preferred form for brush 14 having a diameter D2 in
the order of 5.9 inches, the trailing brush 14 in the direction of
travel is counter rotated at a speed in the range of 1200 to 1800
RPMs and preferably in the order of 1500 RPMs, and with the
preferred bristle length resulting in a tip speed in the range of
1850 to 2750 feet per minute and preferably in the order of 2300
feet per minute. Such speeds according to the preferred form of the
present invention synergistically resulted in polishing benefits
which were not obtained at conventional speeds. However, it should
be appreciated that in the preferred form, the angle A1 and speed
are related. For any given RPM, if angle A1 is too shallow or too
great, row effect or tuft imprints as experienced with conventional
automatic scrubbers may result.
[0034] Further in the preferred form, the rotational speed of
leading and trailing brushes 14 are different, with trailing brush
14 in the direction of travel rotating faster than the leading
brush 14. In the most preferred form, where trailing brush 14
rotates in the order of 1500 RPMs, the leading brush 14 is rotated
in the order of 900 RPMs. It was surprisingly discovered that
sweeping performance of machine 10 was better when brushes 14 were
rotated at differing speeds, and the polishing benefit was still
obtained if trailing brush 14 was rotated faster than conventional
speeds.
[0035] Thus since the invention disclosed herein may be embodied in
other specific forms without departing from the spirit or general
characteristics thereof, some of which forms have been indicated,
the embodiments described herein are to be considered in all
respects illustrative and not restrictive.
* * * * *