U.S. patent application number 12/939589 was filed with the patent office on 2011-05-05 for dust collection in a rotary floor finishing machine.
Invention is credited to Francis A. Barous.
Application Number | 20110099748 12/939589 |
Document ID | / |
Family ID | 43923822 |
Filed Date | 2011-05-05 |
United States Patent
Application |
20110099748 |
Kind Code |
A1 |
Barous; Francis A. |
May 5, 2011 |
DUST COLLECTION IN A ROTARY FLOOR FINISHING MACHINE
Abstract
In a powered floor finishing machine or surface abrading
machine, a housing encloses an abrading component. Dust is
collected at the edge of the abrading component by an airflow drawn
through the gap between the abrading component and the edge of the
housing, through the housing to a suction port and on to a dust
collection system. Supplemental air at relatively higher pressure
is injected into the housing at a favorable position and angle as
to the interior geometry and normal airflow pattern so as to
inhibit dust collection within the housing and increase average
airflow velocity from the gap to the suction port. Less dust is
precipitated out of the airflow before it gets to the suction port,
thus improving the efficiency and effectiveness of dust collection,
and extending the intervals between which the interior of the
housing need be cleaned.
Inventors: |
Barous; Francis A.; (Dracut,
MA) |
Family ID: |
43923822 |
Appl. No.: |
12/939589 |
Filed: |
November 4, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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61258264 |
Nov 5, 2009 |
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Current U.S.
Class: |
15/347 ;
451/456 |
Current CPC
Class: |
B24B 55/102 20130101;
A47L 9/08 20130101; B24B 7/186 20130101; B24B 55/06 20130101 |
Class at
Publication: |
15/347 ;
451/456 |
International
Class: |
A47L 9/10 20060101
A47L009/10; B24B 55/06 20060101 B24B055/06 |
Claims
1. A powered, motion-based, surface abrading machine comprising: a
housing within which a powered motion mechanism moves an abrasive
element with respect to a target surface whereby dust is emitted at
the periphery of the abrasive element, the housing being configured
with at least one suction port, the suction port communicating with
a dust collection system configured to transport the dust in an
airflow drawn through a periphery gap between the abrasive element
and an edge of the housing, through the housing to the suction
port, and hence to the dust collection system; and a supplemental
air source communicating with an air inlet in the housing through
which supplemental air is injected into the housing between the
periphery gap and the suction port.
2. The powered, motion-based, surface abrading machine of claim 1,
comprising at least one supplemental air nozzle attached to said
air inlet and configured to terminate at a selected position and
angle of orientation within the housing so as to increase airflow
velocity between the periphery gap and the suction port.
3. The powered, motion-based, surface abrading machine of claim 1,
configured to inject supplemental air into the housing at a volume
high enough to increase minimum airflow velocity in the housing
between the periphery gap and the suction port while maintaining
dust supporting airflow in the periphery gap, and at a volume less
than the maximum airflow volume capacity of the dust collection
system.
4. A rotary floor finishing machine comprising: a housing within
which rotates a pad-lock, the housing being configured with at
least one suction port, the suction port communicating with a dust
collection system configured for transporting dust in an airflow
drawn through an annular gap between the pad-lock and a lower edge
of the housing, through the housing to the suction port, and hence
to the dust collection system; and a supplemental air source
communicating with an air inlet in the housing through which
supplemental air is injected into the housing between the annular
gap and the suction port.
5. The rotary floor finishing machine of claim 4, comprising a
least one supplemental air nozzle attached to said air inlet and
configured to terminate at a selected position and angle of
orientation within the housing so as to increase airflow velocity
between the annular gap and the suction port.
6. The rotary floor finishing machine of claim 5, the selected
angle of orientation comprising a bias towards the direction of
rotation of the pad-lock.
7. The rotary floor finishing machine of claim 5, the selected
angle of orientation comprising a bias opposing the direction of
rotation of the pad-lock.
8. The rotary floor finishing machine of claim 5, the inlet being
displaced from the suction port.
9. The rotary floor finishing machine of claim 5, the supplemental
air source configured to provide supplemental air of at least
ambient pressure.
10. The rotary floor finishing machine of claim 5, the housing and
the pad-lock incorporating vertical extensions whereby the interior
volume between the housing and the pad-lock is enlarged.
11. The rotary floor finishing machine of claim 5, further
incorporating a brush skirt extending from the edge of the housing
to the floor.
12. The rotary floor finishing machine of claim 6, the nozzle
configured to inject the supplemental air so as to impinge on a
selected surface of the housing.
13. The rotary floor finishing machine of claim 6, the nozzle
configured to inject the supplemental air so as to impinge on a
selected surface of the pad-lock.
14. The rotary floor finishing machine of claim 6, the nozzle
configured whereby injected supplemental air accelerates airflow
within the housing in the direction of rotation of the
pad-lock.
15. The rotary floor finishing machine of claim 5, configured to
inject supplemental air into the housing at a pressure and volume
high enough to increase minimum airflow velocity in the housing
between the annular gap and the suction port while maintaining dust
supporting airflow in the annular gap, and at a volume less than
the maximum airflow volume capacity of the dust collection
system.
16. A method for collecting and containing dust when using a rotary
floor finishing machine comprising: providing a housing within
which a powered motion mechanism moves an abrasive element with
respect to a target surface whereby dust is emitted at the
periphery of the abrasive element, the housing being configured
with at least one suction port, the suction port communicating with
a dust collection system configured to transport the dust in an
airflow drawn through a periphery gap between the abrasive element
and an edge of the housing, through the housing to the suction
port, and hence to the dust collection system; and providing a
supplemental air source communicating with an air inlet in the
housing through which supplemental air is injected into the housing
between the periphery gap and the suction port.
17. The method of claim 16, further comprising: providing at least
one supplemental air nozzle attached to said air inlet and
configured to terminate at a selected position and angle of
orientation within the housing so as to increase airflow velocity
between the periphery gap and the suction port.
18. The method of claim 16, further comprising: injecting
supplemental air into the housing at a volume high enough to
increase minimum airflow velocity in the housing between the
periphery gap and the suction port while maintaining dust
supporting airflow in the periphery gap, and at a volume less than
the maximum airflow volume capacity of the dust collection system.
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/258,264, filed Nov. 5, 2009. This application is
herein incorporated by reference in its entirety for all
purposes.
FIELD OF THE INVENTION
[0002] This invention relates to floor finishing machines, and more
particularly to floor finishing machines equipped with suction
ports in their housings connected to vacuum-type dust collection
systems and further configured with a pressurized airflow source
connected to airflow inlets in the housing.
BACKGROUND OF THE INVENTION
[0003] A rotary floor finishing machine, or floor polisher, has a
motor mounted atop a housing with its drive shaft extending into
the housing, terminated by a triple planetary reduction gear that
reduces a motor speed of about 1725-1750 rpm by 11 to 1 down to
about 160 rpm. The reduction gear accepts the keyed attachment of a
circular "pad-lock", which is a rigid disk with a bristled bottom
that readily grips a circular mat, which in turn readily grips a
circular sheet of screen type abrasive floor finishing material.
This type of rotary floor finisher, which may be variously referred
to as a floor buffer or polisher, configured in this manner with
the abrasive screen material, is used to smooth out or "screen" the
surface of a hardwood floor surface prior to applying a finish. The
machine and screening process creates a significant amount of dust.
Dust collection is more important today than in years gone by, due
to the heightened awareness of its environmental and health
effects, including in particular, potential harm to users'
respiratory systems.
[0004] One common solution, a simple adaptation to a basic rotary
floor machine and to other types of surface contact, materials
abrading machines that create a similar dust problem, is to
configure or install a suction port somewhere on a main housing
that substantially encloses the abrading tool and its motorized
motion mechanism to within a minimal distance of the target
surface.
[0005] The lower edge of the skirt portion of the housing is
supported off the target surface by the pad-lock or other abrading
mechanism sufficiently high to avoid contact of the hard edge of
the housing with the floor or target surface and to permit airflow
into the housing through the periphery gap between them. The motion
mechanism may be rotary, orbital, a belt system or otherwise in
type, configured to scour or scrub the target surface with an
abrasive-faced sheet that renders and removes small particles from
the face of the target surface and throws it off into the air as
dust, proximate the edge of the housing and preferably within the
periphery of the enclosing skirt of the housing.
[0006] The suction port is connected directly or by a suitable
length of flexible hose or other type conduit to a dust collection
system, in the case of some rotary floor sanding machines a
separate, portable industrial dust collection system. In other
embodiments, the dust collection system may be integral to the
surface-contact materials abrading machine. The dust collection
system typically includes a vacuum source in the form of a powered
blower connected to a container or dust repository configured with
a dust filtration system upstream of an exhaust port or vent, which
acts as a trap for the airborn dust materials. The blower may be
upstream of the dust filter in the dust ladened airflow, or more
commonly downstream of the dust filter, in the filtered airflow.
The blower may be driven by its own motor such as if the dust
collection is a separate device, or in some cases by the same motor
that drives the abrading motion system.
[0007] The suction action of the dust collection system is applied
through the hose and port to the housing so that air is drawn into
the housing around its periphery, carrying the dust created by the
abrading motion into and through the housing into the dust
collection system. In this respect, the housing can be considered
an extension of the dust collection system On the backend of the
dust collection system, the airflow from which most of the dust has
been removed and deposited in a dust repository, is ejected by
blower pressure to atmosphere. The dust container or repository is
emptied from time to time as required. The dust filtration
mechanism may be changed or cleaned or otherwise renewed from time
to time as required, by any common means including but not limited
to simple brushing or shaking, changing of the filtering element,
or airstream backflow.
[0008] In the specific case of a rotary floor finishing machine
with a separate dust collection system connected in the manner
described, air is drawn into the housing at floor level through the
annular gap around the perimeter of the rotating pad-lock, through
the plenum formed by the housing and the pad-lock, into the suction
port, and through the hose to the dust collection system.
[0009] However, the floor finishing machine used in the screening
mode where some abrading of floor surface material is intended and
dust is created, with a vacuum system attached and operating, is
commonly known to be susceptible of dust accumulation or dust build
up on the top of the pad-lock and elsewhere on the interior wall of
the housing. This accumulation eventually impedes or clogs the
airflow pathway, and requires disassembly and removal of the dust
build up.
[0010] What is needed, therefore, are techniques for more efficient
and effective dust collection in a floor finishing machine.
SUMMARY OF THE INVENTION
[0011] Applicant has determined that the rotary floor sander and
dust collection system in the commonly used configuration described
above may provide adequate air velocity at floor level at the
periphery of the pad-lock, beneath the skirt or edge of the
housing, to pick up much of the abraded dust material emitted at
the edge of the screen and draw it into the plenum created by the
housing. But the larger central volume of the plenum or interior
space within the housing and above the pad-lock creates a change in
airflow velocity. The airflow velocity drops between the edge of
the pad-lock and the suction port due to the enlarged cross section
area through which it is drawn, and increases again in the reduced
cross section area of airflow at or nearer the suction port.
[0012] In the slow airflow zone between the high velocity pickup
zone and the high velocity suction zone, some of the dust, the
heavier particles in particular, precipitates or falls out of the
airflow, and does not make it to the suction port. This "dust
precipitate" is a major source of the clogging accumulation of dust
that builds up within the housing. The buildup creates a growing
resistance to airflow and rapidly reduces the effectiveness of the
dust collection system.
[0013] One embodiment of the present invention provides for
injecting supplemental or makeup air into the housing, downstream
of the floor level opening and upstream of the suction port, within
the airflow volume limits of the dust collection system, which may
contribute to stimulating a higher average airflow velocity through
the housing above the pad-lock to the suction port than would
otherwise be present. The higher velocity airflow through the
housing keeps more of the collected dust airborne until it is drawn
to and into the suction port. The supplemental air source may be
injected with one or more nozzles in such a manner as to impinge on
selected surfaces, inhibiting the settling of any dust there and
carrying it back into the primary airflow path where it is disposed
of as intended. The supplemental air may be delivered from an
independent airflow source such as a separate fan or blower.
[0014] Supplemental air nozzles may be directed perpendicular to
the plane of rotation of the rotating abrading component, or biased
at an angle supporting a circular airflow corresponding to the
direction of rotation of the rotating component, or conversely, in
a direction opposing the direction of rotation so as to optimize
the scouring effect of injected airflow on the rotating component,
or on the housing wall. The supplemental air may come from several
sources. For example, it may be scavenged off the filtered air
exhaust outlet of the dust collection system itself. Any convenient
source of air may be used, and pressure alone is not critical, so
long as the supplemental airflow volume delivered to the housing is
controlled so as not to exceed the airflow rate capacity of the
collection system and not to negatively impact the dust collection
airflow path from floor to suction port or the dust pickup suction
power and airflow velocity at floor level.
[0015] A suitable pressure and volume of supplemental airflow may
be admitted and directed into the housing at a favorable position
and angle with respect to the geometry of the interior space
available for airflow, so that the airflow from floor to suction
port is not subject to a seriously reduced velocity midway in
between. By this means, the tendency for dust to accumulate in the
housing is reduced, thus improving the efficiency and effectiveness
of the dust collection system, and extending the intervals between
which the interior of the housing need be cleaned.
[0016] In another embodiment of the present invention a suction
port may be configured as an annular opening about the central
drive shaft or be located outboard of the central driveshaft
elsewhere on the housing. Supplemental air inlets and/or their
nozzles may be displaced or directed so as to create turbulence
and/or enhance airflow velocity in areas of otherwise lower airflow
velocity than at the point of initial dust pickup.
[0017] The invention, in another embodiment, may be extended to
rotary, vibratory, and belt type floor finishers and abrading
machinery of all types, where the disk, plate, or belt mechanism is
enclosed by a housing and skirt that extends to or nearly to the
floor or other target surface being abraded, creating in effect a
plenum within the housing around the motion mechanism, where floor
or surface covering material is abraded by the rotating, vibrating
or rolling motion of the selected abrasive or polishing material to
the extent that dust is created.
[0018] The dust created may be collected at floor or surface level
or around the periphery of the disk or belt contact surface within
the skirt of the housing, and drawn up and through the periphery of
the open housing, and through the housing interior, to a suction
port higher in the housing. The suction port or ports may be piped,
plumbed or otherwise in communication with a dust collection system
which may be mounted on the machine or be remote to the
machine.
[0019] The supplemental air source and nozzle of the invention is
applicable to any such device or machine where dust collection
airflow velocity is subject to significant reduction as it flows
from the restricted entry gap at floor or abrading surface level
through the relatively larger interior volume of the housing
enclosing the abrading mechanism, to the suction port leading to
the dust collection system, as a means of improving and extending
the dust collection capability of the machine's overall
functionality.
[0020] The features and advantages described herein are not
all-inclusive and, in particular, many additional features and
advantages will be apparent to one of ordinary skill in the art in
view of the drawings, specification, and claims. Moreover, it
should be noted that the language used in the specification has
been principally selected for readability and instructional
purposes, and not to limit the scope of the inventive subject
matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a diagrammatic view of a floor finishing machine
configured with a supplemental air injection system and connected
to a separate dust collection system.
[0022] FIG. 2 is a diagrammatic top view of another floor finishing
machine depicting a drive motor and gearbox centrally mounted on a
circular housing, a pair of inlets 180 degrees apart on the top of
the housing outboard of the motor for makeup air, and a pair of
suction ports on top of the housing outboard of the motor,
rotationally displaced 90 degrees from the makeup air inlets.
[0023] FIG. 3 is a diagrammatic top view of another floor finishing
machine depicting a drive motor and gearbox centrally mounted on a
circular housing, with a singular makeup air inlet on the top of
the housing outboard of the motor, displaced from a singular
suction port on the top of the housing outboard of the motor.
[0024] FIGS. 4A, 4B and 4C depict three embodiments of a makeup air
inlet nozzle configuration as mounted in the top of a housing, with
respect to an enclosed rotating abrading component including its
plane and direction of rotation; the nozzle of FIG. 4A being
directed perpendicular to the plane of rotation, the nozzle of FIG.
4B being configured at an angle biased against the direction of
rotation, and the nozzle of FIG. 4C being configured at an angle
biased towards the direction of rotation of the abrading unit.
DETAILED DESCRIPTION
[0025] The invention is capable of various embodiments, which may
encompass three major components: an abrading machine, a dust
collection system, and a supplemental airflow (or air injection)
system. What is illustrated and described is intended to be
instructive but not limiting of the scope of the invention.
[0026] The abrading machine may be a surface contacting,
motion-based abrading machine, in this case a rotary type floor
finishing machine. The abrading machine may be connected to or
configured to be connected to a dust collection system, in this
case a separate, free standing dust collection system. The dust
collection system generates a suction force within the machine's
housing, creating an airflow path from floor or work surface level
around the periphery of the abrading component, in this case a
rotating pad-lock, between the pad-lock and the lower edge or skirt
of the housing in which it is enclosed, through the interior of the
housing, into one or more suction ports in the housing wall, and
hence to the dust collection system.
[0027] The supplemental air source and system for supplying
supplemental air to the housing, is in this case a fan or blower
device mounted on the floor finishing machine and connected by an
air line to an inlet on the housing, although in other embodiments
it may be separate from the abrading machine, and integral or
separate from the dust collection system, being connected to the
abrading machine only by the air line.
[0028] The first abrading machine and dust collection system
typically require a power source, which may be separate or shared.
The dust collection system will generate negative pressure within
the housing, with respect to ambient pressure. The supplemental air
system may or may not be powered for pressurization above
atmosphere, depending on the amount of pressure differential
desired between plenum pressure and supplemental air pressure or
injection pressure. The scouring effect of injection air on
surfaces is enhanced by higher excess pressure, while the
enhancement of airflow velocity is less dependent on excess
pressure and more on the added volume of supplemental air. Other
and numerous variations in the configuration of these three major
components and their respective details of construction and design
are within the scope of the invention.
[0029] Referring now to the embodiment of FIG. 1, floor finishing
machine 1 is connected to dust collection 2, and is configured with
a supplemental air injection system 3. In more detail, the floor
finishing machine 1 has a housing 10, upon which is centrally
mounted a motor 12. The motor shaft extends to and rotates pad-lock
14 within housing 10. Rotation of the pad-lock and selected pads
that may be applied or attached to it causes an abrading action on
the floor surface to which it is applied. The rotating action
causes the abraded material to be thrown off as dust at the edge of
the pad-lock. Dust collection system 2, powered by blower 28,
creates an airflow that draws air ladened with at least some of the
emitted dust through gap 20 between pad-lock 14 and the lower edge
of housing 10, through plenum 22 defined by housing 10 and the
enclosed rotary components, into suction port 24, through conduit
26, and into dust collection receptacle 27 where it is filtered
from the air and collected. The filtered air is exhausted to
atmosphere.
[0030] Supplemental air injection system 3 includes a motorized fan
38, mounted in this embodiment on the side of motor 12, which
provides a calibrated or metered amount of supplemental air through
air line 36, through inlet 34, to be injected by nozzle 32 into
plenum 22.
[0031] It will be apparent that the volume of airflow through
suction port 24 is the sum of the periphery airflow through gap 20
and the supplemental airflow injected at nozzle 32. The volume
supplemental airflow delivered to the plenum must always be less
than the volume of airflow drawn through section port 24, or
airflow through gap 20 is negative and no dust will be
collected.
[0032] Referring now to FIGS. 2 and 3, the air inlets and suction
ports may be variously configured on a housing. In FIGS. 2 and 3,
housing 10 of a rotary type floor finishing machine is equipped
with one or more suction ports 24 connectable by a conduit to a
dust collection system. A supplemental or makeup air source, which
may be in the form of a fan or blower mounted on or near the floor
finishing machine and connected by an airline to housing 10 as in
the embodiment of FIG. 1, has one or more nozzles 32 installed at
respective inlets 34.
[0033] The two inlets 34 of FIG. 2 are installed in the top of
housing 10, displaced radially 180 degrees from each other,
although in other embodiments there may be more or fewer inlets,
configured uniformly or otherwise with respect to one another. The
two suction ports 24 in the deck or top of housing 10 are similarly
180 degrees radially displaced from each other, and 90 degrees
displaced from inlets 34. The embodiment of FIG. 3 illustrates one
suction port 24 and one air inlet 34 mounted atop housing 10,
outboard of motor 12, and displaced from each other radially.
Functionally, it performs similarly to the embodiment of FIG.
2.
[0034] In both embodiments, supplemental air injected at inlets 34
adds volume and velocity to the airflow in the central portion of
the plenum defined by the housing and the rotating components
within, between the point of dust intake at floor level and the
suction port in the top of the housing. This offsets the normal
drop in velocity that occurs in that region, and promotes carriage
of more of the dust in the airflow to the suction port and hence to
the collection system. In other words, the force and volume of the
injected air, in addition to the air and dust drawn in at floor
level, promotes turbulence and higher average velocity of airflow
in the plenum, tending to keep the collected dust airborne until it
reaches the suction port where the cross section of the airflow
path is reduced and airflow velocity is greatest.
[0035] The supplemental air volume added to the housing for
maintaining airflow velocity through the housing is one aspect of
the invention. Referring now to FIGS. 4A, 4B, and 4C, the makeup
air nozzle configuration and inlet pressure can be in the form of a
relatively open nozzle of relatively lower air pressure or more of
a smaller diameter, higher pressure air jet. The makeup air nozzle
can be arranged to have injected airflow impinge on the wall of the
housing, or as illustrated in FIG. 4A, perpendicular to the plane
of the pad-lock so as to have airflow impinge on the top of the
pad-lock, inhibiting the settling of dust at that location.
[0036] Referring to FIGS. 4B and 4C, the nozzle can alternatively
be oriented at any angle off the perpendicular towards or opposite
the direction of rotation or radially inboard or outboard from the
axis of rotation of pad-lock 14 up to parallel with the plane of
rotation. The direction of rotation of the pad-lock is indicated by
the solid arrow as one example for illustrative purposes.
Supplemental air injected at an angle biased against or opposing
the direction of rotation as in FIG. 4B impinges on the pad-lock
with a scouring, uplifting action so as to inhibit the settling of
dust thereon. Supplemental air injected at an angle biased towards
the direction of rotation as in FIG. 4C can both impinge on the
pad-lock so as to inhibit the settling of dust thereon, while also
enforcing the circular airflow within the housing consistent with
the direction of rotation of the pad-lock 14, enhancing airflow
velocity within the housing and sustaining the suspension dust in
the airstream. There may be more than one nozzle at a respective
inlet. Different nozzles may have the same or different angular
orientations. The pad-lock may rotate in either direction.
[0037] In other embodiments, the housing may be terminated at the
lower edge with a perimeter brush extending to floor level. The
brush helps contain dust emissions to within the annular region or
gap 20, and increase airflow velocity at floor level due to the
restriction of the opening between the housing and the floor, for
optimal lifting of the emitted dust without harming the floor.
[0038] Details among embodiments can vary considerably. For
example, injection of supplemental air may be limited to the
controlled admission of outside air at atmospheric pressure, no
further pressurization needed, through the one or more air inlets
into the housing where the dust collection system maintains a
lower-than-atmosphere pressure for suction. Nozzles may be limited
to mere openings at appropriate locations in the housing, or they
may extend as one or more tubes from the housing wall or other
manifold into the interior of the housing, to positions where the
injection of supplemental air is most beneficial to maintaining
airflow velocity through the housing, thus keeping the dust
suspended and moving.
[0039] In all cases, make up air must not be injected into the
housing at a rate so high that it will exceed the suction power and
airflow capacity of the suction port and dust collection system, or
even so much as to reduce the suction power or airflow volume and
velocity at the floor level around the pad-lock below that amount
required to effectively pick up the dust initially and draw it into
the housing.
[0040] With respect to new machine design or retrofitting existing
machines already equipped with suction based dust collection
systems, the optimal range of makeup air pressure, volume, and
nozzle configuration may be determined empirically for particular
models and combinations of abrading machinery and dust collection
systems. In new or retrofit systems, the source of supplemental air
may be independent, or be directly or indirectly provided by the
abrading machine itself from its own motor and air cooling system
or by the dust collection system, such as by its motor and air
cooling system or by scavenging filtered exhaust air.
[0041] The invention is capable of other and various embodiments.
For example, there is within the scope of the invention, a powered,
motion-based, surface abrading machine comprising a housing within
which a powered motion mechanism moves an abrasive element with
respect to a target surface whereby dust is emitted at the
periphery of the abrasive element, the housing being configured
with at least one suction port, the suction port communicating with
a dust collection system configured to transport the dust in an
airflow drawn through a periphery gap between the abrasive element
and an edge of the housing, through the housing to the suction
port, and hence to the dust collection system, and a supplemental
air source communicating with an air inlet in the housing through
which supplemental air is injected into the housing between the
periphery gap and the suction port. There may be at least one or
more supplemental air nozzles attached to the air inlet and
configured to terminate at a selected position and angle of
orientation within the housing so as to increase airflow velocity
between the periphery gap and the suction port. The machine may be
configured to inject supplemental air into the housing at a
pressure and volume high enough to increase minimum airflow
velocity in the housing between the periphery gap and the suction
port while maintaining dust supporting airflow in the periphery
gap, and at a volume less than the maximum airflow volume capacity
of the dust collection system.
[0042] Another embodiment of the invention is in the form of a
rotary floor finishing machine comprising a housing within which
rotates a pad-lock, the housing being configured with at least one
suction port, the suction port communicating with a dust collection
system configured for transporting dust in an airflow drawn through
an annular gap between the pad-lock and a lower edge of the
housing, through the housing to the suction port, and hence to the
dust collection system, and a supplemental air source communicating
with an air inlet in the housing through which supplemental air is
injected into the housing between the annular gap and the suction
port. There may be at least one or more supplemental air nozzles
attached to each air inlet and configured to terminate at a
selected position and angle of orientation within the housing so as
to increase airflow velocity between the annular gap and the
suction port. The selected angle of orientation may have a bias
towards or away from the direction of rotation of the pad-lock. The
inlet may be displaced from the suction port. The supplemental air
source may be configured to provide supplemental air of at least
ambient pressure.
[0043] The housing and/or the pad-lock may incorporate vertical
extensions and/or interior spacers or filler components whereby the
interior volume between the housing and the pad-lock is selectively
enlarged or reduced so that the airflow path between the gap and
the suction port is otherwise improved and the airflow velocity
better maintained. The machine in these or other embodiments may
incorporate a brush skirt extending from the edge of the housing to
the floor.
[0044] In yet other embodiments, the nozzles may be configured to
inject the supplemental air so as to impinge on a selected surface
of the housing or the pad-lock. The machine may be configured to
inject supplemental air into the housing at a pressure and volume
high enough to increase minimum airflow velocity in the housing
between the annular gap and the suction port while maintaining dust
supporting airflow in the annular gap, and at a volume less than
the maximum airflow volume capacity of the dust collection
system.
[0045] The invention is also susceptible to methods for collecting
and containing dust when using a rotary floor finishing machine.
For example, a first mode is providing a housing within which a
powered motion mechanism moves an abrasive element with respect to
a target surface whereby dust is emitted at the periphery of the
abrasive element, the housing being configured with at least one
suction port, the suction port communicating with a dust collection
system configured to transport the dust in an airflow drawn through
a periphery gap between the abrasive element and an edge of the
housing, through the housing to the suction port, and hence to the
dust collection system. A second mode is providing a supplemental
air source communicating with an air inlet in the housing through
which supplemental air is injected into the housing between the
periphery gap and the suction port. There may be provided at least
one or more supplemental air nozzles attached to the air inlet and
configured to terminate at a selected position and angle of
orientation within the housing so as to increase airflow velocity
between the periphery gap and the suction port. Supplemental air
may be injected into the housing at a pressure and volume high
enough to increase minimum airflow velocity in the housing between
the periphery gap and the suction port while maintaining dust
supporting airflow in the periphery gap, and at a volume less than
the maximum airflow volume capacity of the dust collection
system.
[0046] The foregoing description of the embodiments of the
invention has been presented for the purposes of illustration and
description. It is not intended to be exhaustive or to limit the
invention to the precise form disclosed. Many modifications and
variations are possible in light of this disclosure. It is intended
that the scope of the invention be limited not by this detailed
description, but rather by the claims appended hereto.
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