U.S. patent number RE33,926 [Application Number 07/679,588] was granted by the patent office on 1992-05-19 for scrubber squeegees for scrubbing forward and backward.
This patent grant is currently assigned to Tennant Company. Invention is credited to Steven J. A. Waldhauser.
United States Patent |
RE33,926 |
Waldhauser |
May 19, 1992 |
Scrubber squeegees for scrubbing forward and backward
Abstract
This is an improvement for a powered floor scrubber which in use
is moved forward and backward across a floor to be scrubbed. A
scrub brush is rotated within a housing which is open at the bottom
and water is supplied within the housing. The improvement consists
of attaching double lipped suction squeegees at both the front and
rear of the housing and connecting them both to a source of vacuum
to suck up soiled water from the floor. The flexible squeegee lips
are mounted in such a way that as the machine is moved forward the
lips of the front squeegee fold together and shut off the airflow
to it while the rear squeegee remains functional. When the machine
is moved backward a reverse action of the squeegees occurs, so that
there is always a functional squeegee sucking up soiled water
behind the scrub brush while airflow to the opposite squeegee is
shut off whether the machine is moving forward or backward.
Inventors: |
Waldhauser; Steven J. A.
(Niagara Falls, NY) |
Assignee: |
Tennant Company (Minneapolis,
MN)
|
Family
ID: |
26880757 |
Appl.
No.: |
07/679,588 |
Filed: |
April 3, 1991 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
185064 |
Apr 22, 1988 |
04817233 |
Apr 4, 1989 |
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Current U.S.
Class: |
15/320; 15/322;
15/364; 15/401 |
Current CPC
Class: |
A47L
11/302 (20130101); A47L 11/4044 (20130101); A47L
11/4041 (20130101) |
Current International
Class: |
A47L
11/30 (20060101); A47L 11/29 (20060101); A47L
011/202 () |
Field of
Search: |
;15/321,322,330,364,401 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Moore; Chris K.
Attorney, Agent or Firm: Kinzer, Plyer, Dorn, McEachran
& Jambor
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. In a scrubber, a mobile frame, at least one scrub brush attached
to the frame to engage and work on a surface to be cleaned, an
enclosure over the brush having a defined periphery approaching and
opposing the surface, means for supplying a cleaning solution to
the brush, squeegees engaging the surface on the front and rear
portions of the periphery of the enclosure, a vacuum chamber
associated with the enclosure in communication with the squeegees
and a source of vacuum, and means for communicating only the rear
squeegee to the vacuum chamber when the scrubber is moving forward
and communicating only the front squeegee to the vacuum chamber
when the scrubber is moving to the rear.
2. The structure of claim 1 further characterized in that the
communicating means automatically responds to the movement of the
machine.
3. The structure of claim 2 further characterized in that the front
and rear squeegees each include outer and inner elongated flexible
spaced apart rubber-like blades, the bottom of the inner blade
closely approaching engagement with the surface during operation,
the outer blade being longer than the inner blade so that when the
inner blade closely approaches engagement with the surface, the
outer blade will be flexed in engagement with the surface, the
differential length of the outer blade being such that it will flex
toward and engage the inner blade to function as a check valve when
the machine is moving in the direction of the outer blade and will
flex away from and be in spaced relation to the inner blade when
the machine is moving toward the inner blade.
4. The structure of claim 3 further characterized in that the
squeegees are generally rectilinear and further including
longitudinally disposed seals along the sides of the
enclosure-engaging the ends of the squeegees and also the surface
to be cleaned.
5. The structure of claim 3 further characterized in that the outer
blade of each squeegee has a corrugated outer surface so that
liquid on the surface will pass under the outer squeegee blade when
it is flexed inwardly.
6. The structure of claim 3 further characterized in that the inner
blade of each squeegee has spaced notches along its lower edge to
provide for liquid flow .[.hen.]. .Iadd.when .Iaddend.its bottom
edge is in contact with the surface.
7. The structure of claim 1 further characterized in that the brush
is a cylindrical brush.
8. The structure of claim 1 further characterized by and including
a seal around the periphery of the enclosure engaging the surface,
the squeegees being a part of the seal. .Iadd.
9. In a scrubber, a mobile frame, at least one scrub brush attached
to the frame to engage and work on a surface to be cleaned, an
enclosure over the brush having a defined periphery approaching and
opposing the surface to be cleaned, means for supplying a cleaning
solution to the brush, front and rear squeegees engaging the
surface on the front and rear portions of the periphery of the
enclosure, a vacuum chamber associated with the enclosure in
communication with the squeegees and a source of vacuum, the front
and rear squeegees each including paired outer and inner elongated
flexible generally parallel spaced part rubber-like blades, the
blades being generally rectilinear and further including a
corrugated outer surface on at least the outer blade of each pair
so that liquid on the surface will pass under the outer squeegee
blade when it is flexed inwardly, and means sealing the ends of the
outer and inner squeegee blades .Iadd.in both the front and rear
squeegees .Iaddend.to provide an enclosed compartment between
.Iadd.each pair of .Iaddend.blades. .Iadd.10. The structure of
claim 9 further characterized by and including means for
communicating only the rear squeegee to the vacuum chamber when the
scrubber is moving forward and communicating only the front
squeegee to the vacuum chamber when the scrubber is moving to the
rear. .Iaddend. .Iadd.11. The structure of claim 10 further
characterized in that the communicating means automatically
responds to the movement of the machine. .Iaddend. .Iadd.12. The
structure of claim 9 further characterized in that the bottom of
the inner blade of each pair closely approaches engagement with the
surface during operation, the outer blade being longer than the
inner blade so that when the inner blade closely approaches
engagement with the surface, the outer blade will be flexed in
engagement with the surface, the differential length of the outer
blade being such that it will flex toward and engage the inner
blade to function as a check valve when the machine is moving in a
direction in which the outer blade leads the inner blade and will
flex away from and be in spaced relation to the inner blade when
the machine is moving in an opposite direction in which the outer
blade trails the inner blade. .Iaddend. .Iadd.13. The structure of
claim 9 further characterized in that the inner blade of each
squeegee has spaced notches along its lower edge to provide for
liquid flow through the blade when its bottom edge is in contact
with the surface. .Iaddend. .Iadd.14. The structure of claim 9
further characterized in that the brush is a cylindrical brush.
.Iaddend.
Description
.Iadd.This is a reissue of U.S. Pat. No. 4,817,233 issued Apr. 4,
1989.
BACKGROUND OF THE INVENTION
Floor scrubbers are sometimes used on floors which are so badly
soiled that one pass with the scrubber is not enough to get the
floor clean, and several passes are needed to do a good job. In
restricted areas the most convenient way to do this would often be
to move the scrubber forward and backward over the coiled floor.
However, this has not been feasible with a conventional scrubber
because the suction squeegee which is mounted behind the scrub
brush to suck up dirty water in normal forward moving operation is
on the wrong side of the brush to work when the machine is moved
backward. Dirty water would flow out in front of the brush housing
and made a mess on the floor. In addition, the rear squeegee could
be damaged by being dragged backward.
Scrubbing only in forward movement is not always the best way. In
smaller establishments, for example fast food outlets and small
retail shops, space is often so constricted that it is awkward to
turn a scrubber around. Also, the scrubber can not scrub completely
into the corners of a room, and they must be scrubbed manually or
not at all. In such places it would often be more effective and
convenient to move a scrubber back and forth, and not have to turn
it around. This would simplify scrubbing in spaces such as narrow
aisles and passageways. It would also make it possible to scrub
completely into a corner and then back out while scrubbing in both
directions, thus doing a better job than could be done with a
scrubber that only works while moving in a forward direction.
Suction squeegees are commonly used on scrubbers to remove dirty
water from the floor. They commonly are comprised of two flexible
rubber strips or lips dragging on the floor, one ahead of the
other, with the space between them connected by a flexible tube to
a vacuumized tank which collects the dirty water. The tank is
vacuumized by a suction blower driven by a motor and exhausting air
to the atmosphere. Air is pulled under the front squeegee lip into
the space between the lips, where it entrains dirty water and
carries it up the tube into the tank. The water drops into the tank
and the air is exhausted by the suction blower to atmosphere.
Substantial power is required to run the blower, so much that it is
a major concern in designing a scrubber. The system is designed to
minimize air requirements, and certainly it would be intolerable to
have more than one squeegee pulling air.
SUMMARY OF THE INVENTION
The present invention overcomes the shortcomings of previous
scrubbers and makes it possible to build a scrubber that can be
operated forward and backward. It does this by providing a suction
squeegee behind the scrub brush and another one in front of the
brush, with both squeegees being connected to a vacuumized
collection tank. These are double lipped squeegees that suck up
dirty water in the conventional way, but they have an additional
capability not found in conventional squeegees. When the machine is
moved forward the front squeegee acts like an air valve and shuts
off the airflow to that squeegee, so that all the available airflow
is directed to the rear squeegee, which is picking up dirty water
behind the scrub brush. When the machine is moved backward the rear
squeegee valves shut and shuts off airflow there, while the front
squeegee returns to an open condition. The entire available airflow
then moves through the front squeegee, and it operates to pick up
the dirty water which is now being left in front of the brush as
the machine is moved backward. This configuration of squeegees
permits scrubbing while the scrubber is moving forward or backward,
which is a significant improvement in the field of powered floor
scrubbers.
Another object or feature is a scrubber that will squeegee up
existing liquid on the surface, such as in a liquid spill or a
double scrub operation, when the scrubber is traveling either
forward or backward. In the present arrangement this is
accomplished by allowing the liquid to pass under the leading
squeegee so that the trailing squeegee may pick up. This is
accomplished by using on both squeegees a corrugated blade as the
outer squeegee blade which allows liquid to pass under it in one
direction but acts as a squeegee in the other.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view looking at the front of a power
scrubber equipped with the present invention;
FIG. 2 is a rear view of the scrub head of the scrubber of FIG. 1,
as seen from view line 2--2 in FIG. 1 on an enlarged scale, with a
portion of the exterior surface broken away to show the interior of
the air plenum chamber;
FIG. 3 is a cross section through the scrub head, taken along
section line 3--3 in FIG. 2;
FIG. 4 is a cross section through the scrub head, taken along
section line 4--4 in FIG. 2,
FIG. 5 is a view of the left end of the scrub head, taken along
view line 5--5 in FIG. 2,
FIG. 6 is an enlarged cross section of a squeegee of the invention
in an inoperative position,
FIG. 7 is like FIG. 6 but in an operative position,
FIG. 8 is like FIG. 6 but in a different operative position,
FIG. 9 is a partial edge view of the outer lip of FIGS. 6-8 taken
from view line 9--9 in FIG. 6,
FIG. 10 is a partial plan view of the inner lip of FIGS. 6-8 taken
from view line 10--10 in FIG. 6,
FIG. 11 is a view along line 11--11 of FIG. 7, and
FIG. 12 is a view along line 12--12 of FIG. 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a power scrubber which is equipped with the present
invention. It is shown as a relatively small scrubber, adapted for
scrubbing small commercial establishments such as, for example,
fast food outlets and small retail shops. It has a body 10 which is
preferably made of molded plastic, but could be otherwise, such as
for example, welded stainless steel. It is supported by a pair of
free rolling wheels 12, and is moved by an operator who grasps
handlebar 14, there being no powered propulsion drive. There is a
scrub head 16 attached to the body by a mounting bracket 18. This
bracket is shown in FIGS. 1, 2 and 5, but for clarity is omitted
from FIGS. 3 and 4. The scrub head has a housing 20. On both ends
of the housing there are skids 21 made of a low friction rigid
plastic material, which slide on the floor and support the weight
of the forward part of the machine. They also serve as skirts to
close in the ends of the scrub head and contain water within it.
Mounted within the housing there is a cylindrical scrub brush 22,
shown in FIGS. 3 and 4. In use this brush is caused to rotate by an
electric motor, not shown but located behind the mounting bracket
18 in FIG. 1, and a drive belt at one end of the housing. These
features are entirely conventional, according to the usual practice
in manufacturing power floor scrubbers, so will not be described
here.
The brush drive motor and suction air blower 24 in FIG. 1 may be
powered either by batteries carried on body 10 or by a power cord
plugged into a wall outlet. Suitable control switches, although not
shown, are located below handlebar 14, within convenient reach of
an operator walking behind the machine.
Within body 10 there is also a supply tank for storing clean water
or cleaning solution. Flow out of this tank is controlled by valve
which can be set by the operator. From the valve two flexible
tubes, one of which is shown at 26 in FIG. 1, lead down to the
scrub head, where they connect to stub tubes 28. These feed into
two manifolds 30, each of which has several holes 32 opening into
the interior of the brush housing, so that cleaning solution can
flow onto the brush and thence down to the floor.
Body 10 also houses a tank for recovering and storing dirty scrub
water. Suction air blower 24 is mounted on top of and operatively
connected to this tank so that it evacuates air from the tank and
exhausts it to the atmosphere. The tank is connected by a flexible
tube to the squeegees on the floor, and the vacuum in the tank
creates a suction through the tube to the squeegees which pick up
dirty water from the floor and deposits it in the recovery tank.
Everything thus far described is quite conventional except for the
presence of two squeegees.
There is a front squeegee 34 which has an outer lip 36 and an inner
lip 38, and there is a rear squeegee 40 which has an outer lip 42
and an inner lip 44. These lips are made of a flexible rubber-like
material, which may be similar to that used in other squeegees, and
they extend along the length of the housing 20 and are attached to
it. The inner lips 38 and 44 are attached to the housing in such a
way that they extend down almost to the floor, possibly touching it
at times. The outer lips 36 and 42 are wider that the inner lips,
so that they extend down to the floor and their lower edges are
caused to flex somewhat by the floor, as shown in FIGS. 3 and 4.
The unflexed widths of these lips are shown in dotted outline in
FIG. 3, but the flexed or curved profile is the normal condition
when in contact with a floor. The width of these outer lips is made
such that when they flex inwardly toward the inner lips, the outer
lips will just touch the inner lips. If they are made wider than
that the outer lip will get squeezed under the inner lip, which
increases the friction of that outer lip with the floor and makes
the machine harder to push. A good air seal can be obtained if the
outer lips just touch the inner lips, and more width on the outer
lips is not needed.
There is a plenum chamber 46 which connects the spaces between the
inner and outer lips of both squeegees with a stub tube 48 to which
is attached the flexible tube leading to the recovery tank in body
10. Thus the vacuum created in the recovery tank by vacuum blower
24 is conveyed to the spaces between the inner and outer lips of
both the front and rear squeegees.
The rigid plastic skids 21 on the ends of the housing act to close
off the ends of the squeegees against airflow so air will be pulled
in under the inner lips. Other methods of closing off the squeegee
ends could be used, as anyone familiar with scrubbers will
recognize.
The use, operation and function of the invention are as follows. To
use the scrubber, the operator will turn on the scrub brush and the
suction blower and open the water supply valve as needed. He or she
will then start pushing and pulling the scrubber forward and
backward across the floor to be scrubbed.
When the motion is forward as indicated by arrow 50 in FIG. 3 the
squeegees will assume the positions shown in FIG. 3. The outer lip
36 of the front squeegee will be bent back by its contact with the
floor until it touches inner lip 38. This will shut off airflow
through this squeegee. At the same time the outer lip 42 of the
rear squeegee will also be bent back because of contact with the
floor. This will open the space between it and inner lip 44. Air
will be pulled under inner lip 44, where it will entrain dirty
scrub water and carry it into the space between the lips, up
through the plenum chamber 46, and out through connection 48 to the
recovery tank. This flow path of air and entrained water is shown
by arrows in FIGS. 2 and 3.
When the scrubber motion is backward as indicated by arrow 52 in
FIG. 4, the squeegees will assume the positions shown in FIG. 4.
The outer lip 42 of the rear squeegee, due to its contact with the
floor, will be bent toward the inner lip 44 until they touch, which
will shut off airflow through the rear squeegee. The outer lip 36
of the front squeegee will be bent away from the inner lip 38, thus
opening the front squeegee for airflow. Air will enter under lip
38, entraining dirty water with it, and carrying it into the space
between the lips, then up through the plenum chamber 46, and out
through connection 48 to the recovery tank. This flow path is shown
by arrows in FIG. 4.
Plenum chamber 46 extends above brush housing 20 in the center of
the housing, but tapers down to the squeegees so that it is below
the top of the housing for most of the housing length. The water
manifolds 30 are also below the top of the brush housing, and the
housing itself is fitted as closely as practicable around the scrub
brush. Thus the scrub head has minimum height near its ends which
facilitates scrubbing under overhanging toe spaces of store
counters, restaurant tables and the like.
In FIGS. 6 through 12, variant forms have been shown in which the
outer squeegee blade 54 has corrugations or channels 56, as in FIG.
9, on its outer surface so that when it is flexed inwardly as shown
in FIGS. 7 and 11, spaced openings or passages are provided along
the bottom edge, as at 58 in FIGS. 7 and 11. These allow some
liquid to pass under the blade when moving in the direction of
arrow 59 in FIG. 7 but the blade acts as a squeegee when moving in
the other direction as shown by arrow 57 in FIG. 8. Thus the
device, in addition to squeegeeing up the liquid that the machine
applies, may also be used to squeegee up existing liquid on the
floor as, for example, after a double scrub operation or to pick up
accidentally spilled liquids. If desired, the inner squeegee blade
38, if it is long enough to contact the floor may be provided with
notches 60, such as shown in FIG. 10 to allow some water and air
flow. As shown in FIGS. 7 and 8 the inner blade does not contact
the floor surface. In such an arrangement the notches 60 would not
be necessary, so in that sense FIG. 10 is an alternate form of what
is shown in FIGS. 6 through 8.
The total effect of the invention, therefore, is to provide a
functional suction squeegee behind the scrub brush in the direction
of travel, whether the scrubber is moving forward or backward, and
to direct the entire available airflow to that squeegee. The
operation is entirely automatic requiring no attention from the
operator. Also, the valving of air from one squeegee to the other
is accomplished entirely by the squeegees themselves. No additional
valves or auxiliary parts are required.
The invention has been described in connection with a relatively
small scrubber, but it is not limited to small scrubbers. It can as
well be applied to a large industrial scrubber, as for example a
machine required to scrub long aisles too narrow to turn around in,
thus necessitating backing out. Also, the scrubber which has been
described has a single cylindrical scrub brush. It is common
practice to build scrubbers with two cylindrical brushes. The
number and type of brushes used are immaterial to the invention.
The squeegee arrangement which has been described would be
applicable to any scrubber, regardless of its brush
configuration.
While the preferred form and several variations of the invention
have been shown, described and suggested it should be understood
that the invention should not be restricted thereto, but that
suitable additional modifications, substitutions, alterations and
variations may be used.
* * * * *