U.S. patent number RE36,565 [Application Number 09/084,700] was granted by the patent office on 2000-02-15 for mobile surface scrubber solution recovery system.
This patent grant is currently assigned to Alto U. S. Inc.. Invention is credited to Jack L. Burgoon, Donald E. Line.
United States Patent |
RE36,565 |
Burgoon , et al. |
February 15, 2000 |
Mobile surface scrubber solution recovery system
Abstract
A mobile surface scrubber for scrubbing a surface wetted with
cleaning solution. The scrubber comprises a frame, a plurality of
wheels rotatably mounted on the frame, scrub brush means attached
to the frame and positioned to scrub the wetted surface as the
scrubber is transported over the surface, and a recovery system for
recovering cleaning solution from the surface. The recovery system
includes a return tank for retaining recovered cleaning solution, a
rear squeegee pivotally connected to the frame, and left and right
side squeegees mounted on the frame. The rear squeegee is
positionable to contact the surface behind the scrub brush means
when the scrubber is transported in the forward direction. The side
squeegees are unvaryingly oriented with respect to the frame and
positionable to contact the surface on opposite sides of the scrub
brush means. The rear squeegee is so constructed and operable that
when the scrubber is transported in a right turning direction, the
rear squeegee pivots relative to the frame to a position in which
the right end of the rear squeegee overlaps the rearward end of the
right side squeegee, and when the scrubber is transported in a left
turning direction, the rear squeegee pivots relative to the frame
to a position in which the left end of the rear squeegee overlaps
the rearward end of the left side squeegee.
Inventors: |
Burgoon; Jack L. (Toledo,
OH), Line; Donald E. (Arlington, OH) |
Assignee: |
Alto U. S. Inc. (Chesterfield,
MO)
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Family
ID: |
24643706 |
Appl.
No.: |
09/084,700 |
Filed: |
May 26, 1998 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
659019 |
Jun 4, 1996 |
05623743 |
Apr 29, 1997 |
|
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Current U.S.
Class: |
15/320; 15/401;
15/50.1; 15/98 |
Current CPC
Class: |
A47L
11/30 (20130101); A47L 11/4011 (20130101); A47L
11/4016 (20130101); A47L 11/4038 (20130101); A47L
11/4041 (20130101); A47L 11/4044 (20130101); A47L
11/4061 (20130101); A47L 11/4072 (20130101); F02B
2075/027 (20130101) |
Current International
Class: |
A47L
11/30 (20060101); A47L 11/29 (20060101); A47L
011/30 () |
Field of
Search: |
;15/50.1,50.2,50.3,98,245,320,401 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Brochure by Clarke American-Lincoln entitled American-Lincoln 7700
Sweeper Scrubber; dated May 1988; 4 pages..
|
Primary Examiner: Moore; Chris K.
Attorney, Agent or Firm: Senninger, Powers, Leavitt &
Roedel
Claims
What is claimed is:
1. A mobile surface scrubber for scrubbing a surface wetted with
cleaning solution, said scrubber comprising:
a frame having a front, a back, left and right sides as viewed
looking forward from the back of the frame, and a central
longitudinal axis extending in a front-to-back direction relative
to the frame;
a plurality of wheels rotatably mounted on the frame for
transporting said scrubber over the surface in a plurality of
directions including forward, left turning, and right turning
directions;
scrub brush means attached to said frame and positioned to scrub
the wetted surface as said scrubber is transported over the
surface; and
a recovery system for recovering cleaning solution from the
surface, said recovery system including a return tank for retaining
recovered cleaning solution, an elongate rear squeegee pivotally
connected to said frame, and left and right elongate side squeegees
mounted on the frame adjacent the left and right sides of the
frame, respectively, said rear squeegee having opposite left and
right ends, each of said side squeegees having forward and rearward
ends, said rear squeegee being positionable to contact said surface
behind said scrub brush means when said scrubber is transported in
the forward direction, said side squeegees being unvaryingly
oriented with respect to the frame and positionable to contact said
surface on opposite sides of said scrub brush means when said
scrubber is transported in the forward direction, said rear
squeegee being so constructed and operable that when said scrubber
is transported in a right turning direction the rear squeegee
pivots relative to the frame to a position in which the right end
of the rear squeegee overlaps the rearward end of the right side
squeegee, and when said scrubber is transported in a left turning
direction the rear squeegee pivots relative to the frame to a
position in which the left end of the rear squeegee overlaps the
rearward end of the left side squeegee.
2. A scrubber as set forth in claim 1 wherein said rear squeegee
includes a central portion positioned between and behind its said
opposite ends.
3. A scrubber as set forth in claim 2 wherein said rear squeegee is
arcuate.
4. A scrubber as set forth in claim 1 wherein each side squeegee
has a rear portion and a forward portion positioned inboard from
the rear portion.
5. A scrubber as set forth in claim 4 wherein the rear portion of
each side squeegee extends generally parallel to the central
longitudinal axis of the frame.
6. A scrubber as set forth in claim 5 wherein the forward portion
of each side squeegee extends inwardly and forwardly from said
rearward portion to a position in front of said scrub brush
means.
7. A scrubber as set forth in claim 6 further comprising a liquid
dispensing system attached to said frame for dispensing cleaning
solution onto said surface, each side squeegee extending to a
position in front of said liquid dispensing system.
8. A scrubber as set forth in claim 6 wherein said scrub brush
means comprises a left rotary scrub brush adjacent the left side of
the frame, a right rotary scrub brush adjacent the right side of
the frame, and a central rotary scrub brush between the left and
right scrub brushes, the forward portion of the left side squeegee
angling inwardly and forwardly to a position in front of the left
rotary scrub brush, and the right side squeegee angling inwardly
and forwardly to a position in front of the right rotary scrub
brush, the forward ends of the left and right side squeegees being
laterally spaced from one another on opposite sides of said central
longitudinal axis of the frame.
9. A scrubber as set forth in claim 8 wherein the forward ends of
the left and right side squeegees are spaced apart a distance
greater than the diameter of the central rotary scrub brush.
10. A scrubber as set forth in claim 9 wherein the rearward ends of
the left and right side squeegees are positioned rearward of a line
extending in a side-to-side direction with respect to the frame
through the rotational axes of the left and right rotary scrub
brushes.
11. A scrubber as set forth in claim 1 wherein a respective end of
the rear squeegee overlaps a respective side squeegee outboard of
the side squeegee when said scrubber is transported in either of
the turning directions.
12. A scrubber as set forth in claim 1 wherein said rear squeegee
is selectively moveable between a raised position in which the rear
squeegee is spaced above said surface and a lowered position in
which the rear squeegee contacts said surface.
13. A scrubber as set forth in claim 12 further comprising a
linkage connecting said rear squeegee to said frame, the linkage
maintaining the rear squeegee in a constant attitude relative to
the scrubber as the scrubber is transported over the surface and
permitting the rear squeegee to move up and down relative to the
scrubber to accommodate surface discontinuities.
14. A scrubber as set forth in claim 1 wherein said side squeegees
are selectively moveable between a raised position in which the
side squeegees are spaced above said surface and a lowered position
in which the side squeegees contact said surface.
15. A mobile surface scrubber for scrubbing a surface wetted with
cleaning solution, said scrubber comprising:
a frame having a front, a back, left and right sides as viewed
looking forward from the back of the frame, and a central
longitudinal axis extending in a front-to-back direction relative
to the frame;
a plurality of wheels rotatably mounted on said frame for
transporting said scrubber over the surface in a plurality of
directions including forward, left turning, and right turning
directions;
scrub brush means attached to said frame and positioned to scrub
the wetted surface as said scrubber is transported over the
surface; and
left and right side squeegees mounted on said frame adjacent the
left and right sides of the frame, respectively, said squeegees
being unvaryingly oriented with respect to said frame and having
rearward portions outboard of said scrub brush means and forward
portions extending laterally inwardly and forwardly to positions in
front of said scrub brush means.
16. A scrubber as set forth in claim 15 further comprising a liquid
dispensing system attached to said frame for dispensing cleaning
solution onto said surface, the forward portions of said side
squeegees extending to positions in front of said liquid dispensing
system.
17. A scrubber as set forth in claim 15 wherein the rearward
portion of each side squeegee extends generally parallel to the
central longitudinal axis of the frame.
18. A scrubber as set forth in claim 17 further comprising a
cylindric brush mounted for rotation on the frame about a generally
horizontal axis extending side-to-side with respect to the frame
forward of said scrub brush means and the side squeegees, and a
recovery system for recovering cleaning solution from the surface,
said recovery system including a return tank for retaining
recovered cleaning solution, and an elongate rear squeegee mounted
on the frame behind said scrub brush means and said side squeegees
for directing cleaning solution from the surface for delivery to
said return tank.
19. A mobile surface scrubber for scrubbing a surface wetted with
cleaning solution, said scrubber comprising:
a frame having a front, a back, left and right sides as viewed
looking forward from the back of the frame, and a central
longitudinal axis extending in a front-to-back direction relative
to the frame;
a plurality of wheels rotatably mounted on the frame for
transporting said scrubber over the surface in a plurality of
directions including forward, left turning, and right turning
directions;
scrub brush means attached to said frame and positioned to scrub
the wetted surface as said scrubber is transported over the
surface; and
a recovery system for recovering cleaning solution from the
surface, said recovery system including a return tank for retaining
recovered cleaning solution, an elongate rear squeegee pivotally
connected to said frame, and left and right elongate side squeegees
mounted on said frame adjacent the left and right sides of the
frame, respectively, said rear squeegee having opposite left and
right ends, each of said side squeegees having forward and rearward
ends, said rear squeegee being positionable to contact said surface
behind said scrub brush means when said scrubber is transported in
the forward direction, said side squeegees being unvaryingly
oriented with respect to the frame and positionable to contact said
surface on opposite sides of said scrub brush means when said
scrubber is transported in the forward direction, said rear
squeegee being so constructed and operable that when said scrubber
is transported in a right turning direction the rear squeegee
pivots relative to the frame to a position in which the rear and
right side squeegees form an uninterrupted continuous barrier
extending from the left end of the rear squeegee to the forward end
of the right side squeegee for collecting cleaning solution, and
when said scrubber is transported in a left turning direction the
rear squeegee pivots relative to the frame to a position in which
the rear and left side squeegees form an uninterrupted continuous
barrier extending from the right end of the rear squeegee to the
forward end of the left side squeegee for collecting cleaning
solution.
20. A scrubber as set forth in claim 19 wherein each of said left
and right side squeegees has a rearward portion positioned outboard
of said scrub brush means and a forward portions extending
laterally inwardly and forwardly to positions in front of said
scrub brush means. .Iadd.21. A mobile surface scrubber for
scrubbing a surface wetted with cleaning solution, said scrubber
comprising:
a frame having a front, a back, left and right sides as viewed
looking forward from the back of the frame, and a central
longitudinal axis extending in a front-to-back direction relative
to the frame;
a plurality of wheels rotatably mounted on the frame for
transporting said scrubber over the surface in a plurality of
directions including forward, left turning, and right turning
directions;
scrub brush means attached to said frame and positioned to scrub
the wetted surface as said scrubber is transported over the
surface; and
a recovery system for recovering cleaning solution from the
surface, said recovery system including a return tank for retaining
recovered cleaning solution, an elongate rear squeegee pivotally
connected to said frame, and left and right elongate side squeegees
mounted adjacent to the left and right sides of the frame,
respectively, said rear squeegee having opposite left and right
ends, each of said side squeegees having forward and rearward ends,
said rear squeegee being positionable to contact said surface
behind said scrub brush means when said scrubber is transported in
the forward direction, said side squeegees being unvaryingly
oriented with respect to the frame and positionable to contact said
surface on opposite sides of said scrub brush means when said
scrubber is transported in the forward direction, said rear
squeegee being so constructed and operable that when said scrubber
is transported in a right turning direction the rear squeegee
pivots relative to the frame to a position in which the right end
of the rear squeegee overlaps the rearward end of the right side
squeegee, and when said scrubber is transported in a left turning
direction the rear squeegee pivots relative to the frame to a
position in which the left end of the rear squeegee overlaps the
rearward end of the left side squeegee. .Iaddend..Iadd.22. A mobile
surface scrubber for scrubbing a surface wetted with cleaning
solution, said scrubber comprising:
a frame having a front, a back, left and right sides as viewed
looking forward from the back of the frame, and a central
longitudinal axis extending in a front-to-back direction relative
to the frame;
a plurality of wheels rotatably mounted on the frame for
transporting said scrubber over the surface in a plurality of
directions including forward, left turning, and right turning
directions;
scrub brush means attached to said frame and positioned to scrub
the wetted surface as said scrubber is transported over the
surface; and
a recovery system for recovering cleaning solution from the
surface, said recovery system including a return tank for retaining
recovered cleaning solution, an elongate rear squeegee pivotally
connected to said frame, and left and right elongate side squeegees
mounted adjacent to the left and right sides of the frame,
respectively, said rear squeegee having opposite left and right
ends, each of said side squeegees having forward and rearward ends,
said rear squeegee being positionable to contact said surface
behind said scrub brush means when said scrubber is transported in
the forward direction, said side squeegees being unvaryingly
oriented with respect to at least a portion of said scrub brush
means and positionable to contact said surface on opposite sides of
said scrub brush means when said scrubber is transported in the
forward direction, said rear squeegee being so constructed and
operable that when said scrubber is transported in a right turning
direction the rear squeegee pivots relative to the frame to a
position in which the right end of the rear squeegee overlaps the
rearward end of the right side squeegee, and when said scrubber is
transported in a left turning direction the rear squeegee pivots
relative to the frame to a position in which the left end of the
rear squeegee overlaps the rearward end of the left side squeegee.
.Iaddend.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to a mobile surface scrubber for
scrubbing a surface wetted with cleaning solution, and more
particularly the invention relates to a solution recovery system
for recovering cleaning solution from the wetted surface.
Mobile surface scrubbers typically include a cleaning solution
dispensing system, scrub brushes for scrubbing the wetted surface
and one or more squeegees for removing used cleaning solution from
the surface. The squeegees are frequently connected to a vacuum to
improve the removal of the cleaning solution. In addition,
scrubbers frequently include sweeper brushes to sweep debris from
the surfaces, either concurrently with or independently from the
surface scrubbing operation. The sweeper brushes are usually
adapted to sweep the debris into a recovery bin. A vacuum is also
frequently used to draw debris into the recovery bin.
The scrubbers may be driven over a surface such as the floor of a
factory or warehouse so that the sweeper brushes sweep debris into
the bin and the scrubber brushes scrub the wetted floor. Although
machines of this type work well when traveling forward in a
straight line, cleaning solution may bypass the squeegees, leaving
a trail of solution behind the machine, when the machine turns left
or right.
Several developments have been made to improve the performance of
the squeegees during turns so that less cleaning solution bypasses
the squeegees. For instance, the rear squeegee blade has been
formed in an arc or chevron so that the cleaning solution is
directed away from the ends of the blade and toward its center
where a vacuum is located. Further, some machines have been
equipped with rear swing squeegees which pivot about a vertical
axis during turns to project a longer effective blade length as
compared to rigidly mounted squeegees. Longer effective blade
lengths permit the blade to pass over more wetted surface, thereby
retaining and recovering more of the cleaning solution. However,
these rear squeegee designs have not entirely overcome the problems
associated with recovering cleaning solution during turns, because
conventional rear squeegees do not pass over the entire wetted
surface, even when they are arcuate and pivot.
Some prior scrubbers have rigidly mounted side squeegees which
extend parallel with the sides of the scrubber frame and retain
most of the cleaning solution beneath the machine during turns.
However, because the motion of the machine during turns is not
exactly perpendicular to the side squeegees, some of the cleaning
solution flows parallel to the side squeegees and eventually flows
past the ends of the squeegees so that streaks of cleaning solution
trail behind the machines. The cleaning solution usually flows past
the front end of the inside side squeegee during turns due to the
angle and location of the inside side squeegee relative to the
center of turning.
In order to prevent the cleaning solution from flowing parallel to
the side squeegees and past their forward ends, some scrubbers have
been manufactured so that the side squeegees pivot during turns to
an orientation where the fluid is directed rearward toward the rear
squeegee. The pivoting side squeegees are connected to the rear
squeegees by linkages which drive the side squeegees between a
straight-traveling position in which they are generally parallel
with the side of the scrubber, and the turning positions in which
the inside squeegee angles forward and inward, and the outside
squeegee angles forward and outward. However, these linkages
increase the complexity of the solution recovery system thereby
increasing the cost and risk of failure.
SUMMARY OF THE INVENTION
Among the several objects and features of the present invention may
be noted the provision of a scrubber having squeegees which retain
substantially all cleaning solution and prevent a trail of cleaning
solution when the scrubber turns; and the provision of a mobile
surface scrubber having side squeegees which are unvaryingly
oriented with respect to the scrubber frame to reduce manufacturing
expense and risk maintenance.
Briefly, apparatus of this invention is a mobile surface scrubber
for scrubbing a surface wetted with cleaning solution. The scrubber
comprises a frame, a plurality of wheels rotatably mounted on the
frame, scrub brush means attached to the frame and positioned to
scrub the wetted surface as the scrubber is transported over the
surface, and a recovery system for recovering cleaning solution
from the surface. The recovery system includes a return tank for
retaining recovered cleaning solution, a rear squeegee pivotally
connected to the frame, and left and right side squeegees mounted
on the frame. The rear squeegee is positionable to contact the
surface behind the scrub brush means when the scrubber is
transported in the forward direction. The side squeegees are
unvaryingly oriented with respect to the frame and positionable to
contact the surface on opposite sides of the scrub brush means. The
rear squeegee is so constructed and operable that when the scrubber
is transported in a right turning direction, the rear squeegee
pivots relative to the frame to a position in which the right end
of the rear squeegee overlaps the rearward end of the right side
squeegee, and when the scrubber is transported in a left turning
direction, the rear squeegee pivots relative to the frame to a
position in which the left end of the rear squeegee overlaps the
rearward end of the left side squeegee.
In another aspect of the invention, the surface scrubber comprises
a frame, a plurality of wheels rotatably mounted on the frame,
scrub brush means attached to the frame and positioned to scrub the
wetted surface, and left and right side squeegees mounted on the
frame. The squeegees are unvaryingly oriented with respect to said
frame and have rearward portions outboard of the scrub brush means
and forward portions extending laterally inwardly and forwardly to
positions in front of the scrub brush means.
In still another aspect of the invention, when the surface scrubber
is transported in a right turning direction, the rear squeegee
pivots relative to the frame to a position in which the rear and
right side squeegees form an uninterrupted continuous barrier
extending from the left end of the rear squeegee to the forward end
of the right side squeegee for collecting cleaning solution.
Similarly, when the scrubber is transported in a left turning
direction, the rear squeegee pivots to a position in which the rear
and left side squeegees form an uninterrupted continuous barrier
extending from the right end of the rear squeegee to the forward
end of the left side squeegee.
Other objects and features of the invention will be in part
apparent and in part pointed out hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a mobile surface scrubber and
solution recovery system of the present invention;
FIG. 2 is a top plan of the solution recovery system;
FIG. 3 is a side elevation of the solution recovery system;
FIG. 4 is a rear elevation of the system;
FIG. 5 is a top plan of the system shown during a 90.degree.
right-hand turn;
FIG. 5A is a top plan of the system shown during a 90.degree.
left-hand turn;
FIG. 6 is a side elevation of the system with the squeegees
raised;
FIG. 7 is a vertical cross section of the rear squeegee taken in
the plane of line 7--7 of FIG. 2;
FIG. 8 is a vertical cross section of the right side squeegee taken
in the plane of line 8--8 of FIG. 2;
FIG. 9 is a fragmentary elevation of the rear and right side
squeegees taken from line 9--9 of FIG. 5; and
FIG. 10 is a schematic showing the scrubber wheel and squeegee
orientations during a typical right-hand turn.
Corresponding reference characters indicate corresponding parts
throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and in particular to FIG. 1, a mobile
surface scrubber indicated generally at 20 is of the type used to
sweep and scrub a surface such as a warehouse or factory floor or a
parking lot. The surface scrubber 20 has a frame 22 supporting a
body 24 which houses the various sweeper and scrubber components. A
seat 26 mounted on the body 24 permits an operator to ride on the
scrubber 20. Hand operated controls, generally designated as 28,
are positioned in front of the seat 24 so that the operator may
access them when seated to control the scrubber 20 operation. Foot
operated controls (not shown) are positioned on the floor in front
of the seat 24. Two front wheels 30 and one rear wheel 32 are
mounted on the frame 22. The rear wheel 32 is driven by an engine
(not shown) such as a 2 liter, 45 hp. 4 cycle. Toyota gasoline
powered engine, a 63 hp, gasoline or LP powered Ford engine, or a
46 hp, 4 cycle, Perkins diesel powered engine to propel the
scrubber over the surface. The rear wheel 32 is also pivotable
about a vertical axis so that the scrubber 20 may be turned to
travel to the left or right.
The scrubber 20 is equipped with a sweeper system, generally
indicated at 40 in FIG. 2, which includes sweeper brushes or brooms
42, 44 and a vacuum (not shown) for removing loose debris. Broom 42
is a rotary disc curb broom which is rotatably mounted on the frame
22 at its front right corner. The curb broom 42 rotates
counterclockwise (as viewed from the top) about a vertical axis to
sweep debris toward the central longitudinal axis or centerline 46
(FIG. 2) of the scrubber 20. As its name implies, the curb broom 42
is particularly useful in sweeping debris away from curbs, walls
and other fixed obstructions. Broom 44 is a rotary cylindrical,
main broom positioned behind the front wheels 30. The broom 44
rotates clockwise (as viewed in FIG. 1) about an horizontal axis to
sweep debris forward and upward into a collection bin (not shown)
mounted on the frame 22 above and forward of the front wheels 30. A
vacuum filtration system (not shown) retains the debris in the bin
and prevents dust from escaping into the surrounding environment.
In the preferred embodiment, the curb broom 42 is 24 inches in
diameter, and the main broom 44 is fifty inches long; however,
because the curb broom only partially overlaps the main broom, the
area swept by the scrubber 20 is approximately sixty inches wide.
The previously described general surface scrubber 20 configuration
and the sweeper system 40 configuration are conventional and will
not be described in further detail.
As illustrated in FIGS. 2 through 4, the scrubber system, indicated
generally at 50, comprises a cleaning solution dispensing system 51
(FIG. 2). scrub brush means (generally designated 52), and a
solution recovery system (generally designated 54). As is
conventional in the art, the solution dispensing system 51 includes
a solution storage tank (not shown) and nozzles (not shown) which
are connected to the tank for dispensing cleaning fluid from the
tank to the surface in the vicinity of the scrub brush means
52.
The scrub brush means 52 includes a chevron-shaped plate 60 secured
to the frame 22, and three rotary disk scrub brushes 62 rotatably
mounted on the plate. Each of the brushes 62 bears down on the
surface and is powered to rotate about a vertical axis to scrub the
surface. Although each of the brushes 62 is approximately seventeen
inches in diameter, the central brush is positioned somewhat
forward of the left and right brushes so they are laterally
overlapped and the area scrubbed during each pass is fifty inches
wide in the preferred embodiment. The plate 60 is connected to the
frame 22 by two links 64 which are pivotally connected to both the
frame and the plate. An hydraulic actuator 66 connected between the
frame 22 and plate 60 permits the plate to be raised (FIG. 6) and
lowered (FIG. 3). Although the scrub brush means 52 of the
preferred embodiment includes a plate and three rotary disk scrub
brushes, it should be understood that the term is used herein to
mean any scrubbing apparatus known in the art, including any number
of brushes or the like, and other similar apparatus.
The solution recovery system 54 includes right and left side
squeegees 70R, 70L, respectively, and a pivotally-mounted, arcuate,
rear squeegee 72. The side squeegees 70R, 70L are mounted outboard
from the scrub brush means 52. As shown in FIG. 8, each of the side
squeegees 70R, 70L includes a blade 74 which wipes the surface
ideally to retain the dispensed cleaning solution inboard from the
side squeegee. The blades 74 have rearward portions which extend
parallel to the longitudinal centerline 46 of the scrubber 20 and
forward portions which extend inwardly and forwardly from the
respective rearward portions to forward ends positioned in front of
the left and right scrub brushes 62 of the scrub brush means 52.
The forward ends of the side squeegee blades 74 are spaced from one
another on opposite sides of the centerline 46 by a distance which
is greater than the diameter of the central scrub brush 62. The
rearward portions of the side squeegee blades 74 extend to rearward
ends which are positioned behind the rotational axes of the left
and right scrub brushes 62. The side squeegees 70R, 70L are mounted
on the frame 22 so that they do not pivot substantially as the
scrubber 20 turns left or right. In other words, the side squeegees
70R, 70L are unvaryingly oriented relative to the frame 22.
However, each of the side squeegees 70R, 70L includes an horizontal
axle 80 connected to the frame 22 so that the squeegee can pivot
upward away from the surface to ride over obstacles and follow the
contour of the surface being scrubbed. Each side squeegee 70R, 70L
also includes an arm 82 (FIG. 2) which engages a bar 84 extending
from the corresponding link 64 supporting the scrub brush means 52
so that the squeegees are raised when the scrub brush means is
raised by the hydraulic cylinder 66, as shown in FIG. 6.
Referring to FIGS. 2, 3 and 7, the rear squeegee 72 includes two
blades 90 which define a channel 92. A vacuum hose 94 is connected
to an orifice 96 midway along the rear squeegee 72 so that solution
trapped within the channel 92 is sucked into a recovery tank 98
(FIG. 3) to leave the surface virtually dry behind the rear
squeegee 72. Three casters 100 mounted on the rear squeegee 72
support the squeegee so that the blades wipe against the surface
being cleaned. A wheel 102 is mounted on each end of the rearward
squeegee 72 so that the wheel rotates about a vertical axis for
fending the squeegee off walls and other obstructions to prevent
damage to the squeegee and the obstructions.
Brackets 106 extend down from the frame 22, and compound hinge
assemblies 108 pivotally connect two pairs of parallel links 110 to
the brackets so that the links are pivotable about vertical and
horizontal axes with respect to the brackets. The links 110 extend
from the brackets 106 to a connector plate 114 which extends upward
from the rear squeegee 72. Compound hinge assemblies 112 connect
the links 110 to the connector plate 114 so that the links are
pivotable about vertical and horizontal axes with respect to the
plate. The link 110 and compound hinge assemblies 108. 112 form
parallelogram linkages (as viewed from the side). which allow the
rear squeegee 72 to rise and fall to ride over obstructions, but
which keep the rear squeegee generally parallel with the frame 22
as it rises and falls so that the squeegee blades 90 ideally
contact the surface over their entire lengths. Limited play in the
compound hinge assemblies 108. 112 prevents the squeegee 72 from
rotating significantly about the longitudinal centerline 46 of the
scrubber 20. However, a small amount of play in the hinge
assemblies 108. 112 permits the rear squeegee 72 to rotate slightly
about the lateral and longitudinal axes of the scrubber 20 to
follow minor discontinuities in the surface being scrubbed.
Further, the links 110 and compound hinges 108. 112 form a four-bar
linkage (as viewed from the top) which permits the rear squeegee 72
to move from side to side with respect to the frame 22. However,
because the rearward compound hinges 112 are more closely spaced
than the forward hinges 108, the linkage forces the rear squeegee
72 to turn as it moves from side to side so the concave side of the
squeegee is always directed toward the scrub brush means 52.
Large nuts 116 (FIG. 3) fasten the connector plate 114 to the rear
squeegee 72. The nuts 116 have heads 117 which may be manually
gripped and turned to loosen the nuts so that the squeegee 72 may
be removed and replaced without tools when the blades 90 are worn
or the squeegee needs other maintenance. A cable 118 connects the
rear squeegee 72 to a pivotable lever 120 mounted on the frame 22.
An actuator 122 (FIG. 3) is mounted on the frame 22 for pivoting
the lever 120 to raise and lower the rear squeegee 72 as needed.
The flexibility of the cable 118 also permits the rear squeegee 72
to rise and fall to pass over obstructions and to swing from side
to side during turns.
The overall operation of the surface scrubber 20 is conventional.
An operator operates the scrubber 20 by sitting in the seat 24 and
operating the controls 28. The operator may engage the sweeper
system 40 or the scrubber system 50 or both to sweep and/or scrub a
surface as he or she drives over it in the scrubber 20. During a
sweeper pass, the curb broom 42 rotates to sweep debris toward the
longitudinal centerline 46. As the machine progresses in a forward
direction, the main broom 44 sweeps the debris forward into the
collection bin where it is held until the machine is emptied. The
single, steered rear wheel 32 enables a tight minimum turning
radius so that the machine may be turned at the end of each pass
and directed along an adjacent return path. During a scrubber pass,
the solution dispensing system 51 dispenses cleaning solution onto
the surface either in front of or through the scrub brushes 62. The
scrub brushes 62 bear down on the surface and rotate to scrub the
surface thereby cleaning it. The side and rear squeegees 70L, 70R,
72 funnel the used solution toward the center of the arcuate rear
squeegee where the vacuum sucks the solution through the hose 94
into the recovery tank 98. The recovery tank 98 may be emptied when
it becomes full of dirty cleaning solution. In other preferred
embodiments, the recovery tank 98 may be outfitted with separators
and extra filtration systems so that the filtered cleaning solution
may be re-dispensed to extend the time and distance between
recovery tank emptying and solution dispensing system
replenishment.
Because the scrubber 20 has rear wheel steering, the scrubber turns
right when the rear wheel 32 is turned left, and vice versa, as
shown in FIG. 10. Further, due to the rear wheel steering, the
rearward portion of the scrubber 20 always moves away from the
direction of the turn. For example, in the lowermost view of FIG.
10, the rear wheel 32 is aligned with the longitudinal centerline
46 and the scrubber 20 is travelling in a straight line (toward the
top of the view). When the rear wheel 32 is turned to the left as
shown in the middle view of FIG. 10, the rearward portion of the
scrubber 20 moves to the left which directs the scrubber forward
and to the right. If the rear wheel 32 is turned perpendicular to
the scrubber 20 centerline 46 as shown in the uppermost view of
FIG. 10, the rearward portion also moves to the left and the
scrubber is directed to the right: however, because there is no
forward motion, the scrubber 20 will spin about a center of turning
130 positioned midway between the front wheels 30. The uppermost
view of FIG. 10 shows a minimum radius turn.
When the scrubber 20 is in a right-hand turn, the friction between
the rear squeegee blades 90 and the surface causes the rear
squeegee 72 to move to the right of the scrubber centerline 46. The
tighter the turn, the farther the rear squeegee 72 moves to the
right of the longitudinal centerline 46, as shown by a comparison
of the middle and uppermost views of FIG. 10.
FIG. 5 illustrates the position of the solution recovery system 54
during a minimum radius, right-hand turn. (The position of the
recovery system during left-hand turn is generally opposite the
position shown in FIG. 5.) During a minimum radius, right-hand
turn, the caster 100 adjacent the right end of the rear squeegee 72
contacts the right side squeegee 70R to prevent further movement.
Thus, the rear squeegee 72 cannot swing beyond the position shown
in FIG. 5. The flexibility of the vacuum hose 94 and cable 118
connected to the rear squeegee 72 permit the squeegee to move to
the position shown. In this position, the front blade 90 of the
rear squeegee 72 contacts the rearward end of the right side
squeegee blade 74 so that the right side and rear squeegees form an
uninterrupted continuous barrier extending from the left end of the
rear squeegee to the forward end of the right side squeegee 70R as
shown in FIG. 9 to retain cleaning solution beneath the machine.
The left side squeegee 70L travels away from the wetted floor area
so that it has no effect on the cleaning solution. Because the
forward portion of the right side squeegee 70R is obliquely angled
rearward and laterally outward from its forward end, solution
travels rearward and laterally outward along the squeegee and no
solution flows past the forward end of the right side squeegee 70R.
Further, the solution travelling rearward is trapped along the
rearward portion of the right side squeegee 70R. When the turn is
completed and the scrubber 20 is driven forward in a straight line,
the trapped solution flows to the center of the rear squeegee 72
and is sucked through the vacuum hose 94 into the recovery tank
98.
The solution recovery system 54 behaves similarly in a minimum
radius, left-hand turn as shown in FIG. 5A. For brevity, the
left-hand turn behavior will not be explained in detail. In larger
radius turns, the system 54 also operates in a similar fashion.
However, when the rear squeegee blade 90 does not contact one of
the side squeegee blades 74, the side squeegee blades immediately
direct the solution toward the rear squeegee blade, rather than
trap the solution along the rearward portion of the side squeegee
blade until the scrubber travels in a straight line. Therefore, the
solution recovery system 54, and in particular the rear and side
squeegee apparatus of the present invention assures complete
cleaning solution removal during forward travel regardless of
whether the travel is in a straight line or turning.
FIG. 6 illustrates the solution recovery system 54 in the raised
position wherein the side squeegees 70L, 70R, the rear squeegee 72
and the scrub brush means 52 are raised substantially off the
surface. The controls 28 allow the operator to raise the system to
the raised position when not in use, e.g., when the scrubber 20 is
only being used to sweep the surface or when the scrubber is being
transported to a particular work site. Thus, the squeegee blades
74, 90 need not be abraded by the surface when they are not being
used to remove cleaning solution. The controls 28 may also include
a logic circuit which raises the solution recovery system 54 when
the scrubber 20 travels in a rearward direction to avoid damage to
the system.
Thus, the surface scrubber 20 of the preferred embodiment overcomes
each of the problems associated with prior art surface scrubbers
identified above. Further, because the side squeegees are
unvaryingly oriented with respect to the scrubber frame, the
complicated linkages connecting the side squeegees to the rear
squeegee to control movement of the side squeegee during turns are
eliminated. This reduces the manufacturing and maintenance costs
and increases the reliability of the apparatus of the present
invention as compared to the prior art devices having rotating side
squeegees.
In view of the above, it will be seen that the several objects of
the invention are achieved and other advantageous results
attained.
The surface scrubber shown in FIG. 1 is an American-Lincoln 7700
Sweeper Scrubber manufactured by Clarke Industries. Inc. of St.
Louis. Mo.; however, it should be understood that the present
invention is equally applicable to other surface scrubbers
including push models. As various changes could be made in the
above constructions without departing from the scope of the
invention, it is intended that all matter contained in the above
description or shown in the accompanying drawings shall be
interpreted as illustrative and not in a limiting sense.
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