CA 02386342 2002-05-29
"' UNITED STATES
TITLE: ROTARY FLOOR SANDER
INVENTOR: EDWIN C. ERNST
CA 02386342 2002-05-29
""' FIELD OF THE INVENTION
The present invention relates to the field of floor
sanders, and more particularly, relates to a rotary floor sander
for use in sanding or finishing floors.
BACKGROUND OF THE INVENTION
It is desirable in modern construction practice that
wooden floors be finished to a relatively smooth, flat surface.
Moreover, it is known in the prior art to employ sanding devices
to mechanically assist in such efforts. For efficient operation,
such devices typical7_y utilize disposable abrasive media, i.e.
abrasive-coated paper or fabric, in belt, disc or sheet form.
An example of a prior art sanding device of this
general type which utilizes disposable abrasive media in belt
form is shown in United States Patent No. 5,575,710 (Kramer),
issued November 19, 1.996. This type of sanding device is known
to be relatively reliable in operation, and to be relatively
effective in material removal. However, this type of sanding
device suffers in that, in order to avoid undulations in the
floor surface, operators are required to exercise significant
", skill and dexterity. Further, abrasive belts are typically
fairly expensive to purchase. As well, this type of sanding
device is unable to effectively sand close up to walls or other
protrusions.
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-- An example of a prior art sanding device which utilizes
disposable abrasive media i.n disc form is shown in United States
"' Patent No. 5,890,9~~4 (Bayous), issued April 6, 1999. This
general type of sandi.n<~ device is known to be relatively reliable
in operation, and to be effective in material removal. Further,
this type of sanding device is known to overcome the shortcomings
inherent in belt-type sanders, in that sanding can be effected
relatively close to walls or other protrusions, and moreover,
undulations in the floor surface may be avoided by the exercise
'-- 10 of relatively modest amounts of skill, concentration and
dexterity. However, this type of sanding device suffers in that
replacement of the abrasive discs, which are relatively expensive
to purchase, is relatively cumbersome and time-consuming, and
typically requires the operator to physically remove and replace,
through the use of hand tools, a bolt which retains the abrasive
disc in position. As wel_1, this type of sanding device is
... intended for use by an operator in a kneeling or stooped
position, and as such, it i.s unsuited for use in sanding large
"" expanses of floor surface. Additionally, this type of sanding
device is known to release significant quantities of dust into
the surroundings, despite the vacuum system provided therewith.
An example of a pr-for art sanding device which utilizes
disposable abrasive media in sheet form is shown in United States
Patent No. 3,638,362 (Stop), issued February 1, 1972. This type
of sanding device is known to be relatively reliable in
operation, and is known to overcome many of the shortcomings
"'- inherent in disc and belt sanders, in that undulations in the
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floor surface will, for practical purposes, result only from
carelessness in operation, and moreover, replacement of the
"" abrasive sheets, which are relatively inexpensive to purchase,
is relatively quick and simple. As well, sanding may be effected
close to walls and other protrusions. However, this type of
sanding device, which relies upon vibratory or orbital action of
the abrasive surface, is known to be relatively slow and
ineffective in material removal, and as such, unsuited for use
in sanding large expanses of floor surface.
SU1~~IARY OF T8E INVENTION
It is an object of the present invention to overcome,
inter alia, the shortcomings of the prior art by providing a
floor sander that is reliable in operation; that does not demand
,,.
unduly onerous levels of skill, dexterity or concentration from
.., 15 the operafor to achieve a relatively smooth, flat finish; that
utilizes inexpensive sheets of abrasive media; that enables
'"" abrasive exchange to be conveniently accomplished without the use
of hand tools; which has practical utility in applications which
require large expanses of floor surface to be sanded; which
releases relatively modest amounts of dust into its surroundings
in use; and which has practical utility in application wherein
,.~ floor sanding operations must be effected close to walls or other
protrusions.
These and other objects are addressed by the present
"" 25 invention, a rotary floor sander.
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-- In accordance with a first aspect of the invention, the
rotary floor sander is for use with one or more sheets of
flexible sanding media each having a first portion, a second
portion, a smooth side and an abrasive side, and comprises a
platform. The platform has a rearward end and a forward end and
defines a longitudinal axis extending between the rearward end
and the forward end. Two or more wheels are mounted on the
platform adjacent to the rearward end for rotation about a
lateral axis extending substantially normal to said longitudinal
'"' 10 axis. The wheels are operatively positioned upon the floor
surface so as to support the rearward end of the platform for
rolling movement substantially parallel to the longitudinal axis.
A sanding head member :is also provided. The sanding head member
defines a substantially planar sanding face, and is mounted on
the platform for rotation about a substantially vertical axis
with the sanding face being oriented substantially normal to the
substantially vertical axis and substantially parallel to the
floor surface. A drive means is mounted on the platform for
driving said rotation of the sanding head member about the
substantially vertical axis. Additionally, an attachment means
is provided for selectively, releasably attaching one or more
sheets of said flexible sanding media to the sanding head member
for rotation therewith, with the smooth side of each of said
sheets in contactable relation to said sanding face and with the
abrasive side of each of said sheets in contactable relation to
said floor surface. A handle means is also provided, rigidly
mounted to the platform, adjacent to the rearward end thereof,
.,.,
and oriented substantially upwardly and rearwardly.
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~ According t.o another aspect of the invention, the
rotary floor sander preferably comprises a positioning means for
selective movement of each of the wheels between a fully raised
position, whereat the rearward end of the platform is relatively
proximal to the floor surface, and a fully lowered position,
substantially downwardly disposed from the fully raised position,
whereat the rearward end of the platform is relatively distal to
..,. the floor surface. The positioning means further provides for
selective movement of each of said wheels between a rearward
"' 10 position, whereat said each wheel is relatively proximal to the
rearward end of the platform, and a forward position,
substantially longitudinally forwardly disposed from the rearward
position, whereat said each wheel is relatively distal to the
rearward end of the platform.
According to another aspect of the invention, the
attachment means preferably comprises one or more elongate slots
defined in the sanding face, each of the elongate slots being
shaped and dimension~ad for releasable extension therethrough of
the first portion of a respective one of the sheets of flexible
sanding media.
According to another aspect of the invention, each
".. elongate slot is preferably aligned substantially tangentially
to an arc of rotation defined by the substantially vertical axis.
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~-- According to other aspects of the invention, the rotary
floor sander preferably further comprises a downwardly-depending
housing member mounted on the platform and defining a downwardly-
opening chamber, and a skirt member mounted on the housing member
and defining a chamber extension contiguous with said chamber,
said skirt member being mounted for movement substantially
parallel to the substantially vertical axis between a lowered
"", position, whereat the chamber and chamber extension collectively
operatively enclose said sanding head member. and said one or more
sheets of flexible sanding media, and a raised position,
substantially vertically upwardly disposed from the lowered
position. A vacuum means is additionally provided, in operative
fluid communication with said chamber.
According to one further aspect of an alternative
embodiment of the present invention, the rotary floor sander is
-- for use with one or more sheets of sanding media, each of said
sheets having a smooth side and an abrasive side, and comprises
"""' a platform. The platform has a rearward end and a forward end and
defines a longitudinal axis extending between the rearward end
and the forward end. Two or more wheels are mounted on the
platform adjacent to the rearward end for rotation about a
lateral axis extending substantially normal to said longitudinal
axis. The wheels area operatively positioned upon the floor
surface so as to support the rearward end of the platform for
rolling movement substantially parallel to the longitudinal axis.
A sanding head member is also provided. The sanding head member
defines a substantially planar sanding face, and is mounted on
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-. the platform for rotation about a substantially vertical axis
with the sanding face being oriented substantially normal to the
'~' substantially vertical axis and substantially parallel to the
floor surface. A drive means is mounted on the platform for
driving said rotation of the sanding head member about the
substantially vertical axis. Additionally, an attachment means
is provided for selectively, releasably attaching one or more
sheets of sanding media to the sanding head member for rotation
therewith, with the' smooth side of each of said sheets in
contactable relation to said sanding face and with the abrasive
side of each of said sheets in contactable relation to said floor
surface. A handle means is also provided, rigidly mounted to the
platform, adjacent to the rearward end thereof, and oriented
t
substantially upwardly and rearwardly.
Other advantages, features and characteristics of the
,., present invention, a:> well as methods of operation and functions
of the related elements of the structure, and the combination of
"" parts and economies of manufacture, will become more apparent
upon consideration of the following detailed description and the
appended claims with reference to the accompanying drawings, the
latter of which is briefly described hereinbelow.
CA 02386342 2002-05-29
.~- BRIEF DESCRIPTION OF THE DRAWINGS
""'' The novel features which are believed to be
characteristic of the rotary floor sander according to the
present invention, as to its structure, organization, use and
method of operation, together with further objectives and
advantages thereof, will become more apparent upon consideration
of the following detailed description and the appended claims
,_,.
with reference to the accompanying drawings, the latter of which
is briefly described hereinbelow. It should be expressly
understood, however, that the drawings are for the purpose of
illustration and de;~c:ription only, and are not intended as a
definition of the l.irnits of the invention. In the accompanying
drawings:
Figure 1 i.s a perspective view of a preferred
,.- 15 embodiment of the rotary floor sander according to the present
invention;
Figure 2 is a side elevational view of the rotary floor
...
sander of Figure 1, with a portion of the housing cut away, for
clarity;
Figure 3 is a partial bottom perspective view of the
rotary floor sander of Figure 1, with each of the wheels shown
"' at their respective forward positions;
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Figure 4 is view similar to Figure 3, with each of the
wheels shown at their respective rearward positions;
Figure 5 ins an enlarged view of a portion of the rotary
sander taken from the circumscribed area "F" of Figure 2, the
right wheel thereof being shown at its fully raised position,
with a portion of such wheel being shown in phantom outline;
Figure 6 is a view similar to Figure 5, with the right
wheel thereof being shown at its fully lowered position;
Figure 7 i.s a partial front elevational view of the
rotary floor sander of Figure 1, with the left wheel thereof
(appearing in the right side of the figure) at its fully raised
position, with the right wheel thereof (appearing in the left
side of the figure) at its fully lowered position, and the cover
"" removed for clarity;
Figure 8 is a front elevational view of a portion of
the rotary floor sander of Figure 1 taken from the circumscribed
area "G" of Figure 2 showing, inter alia, the winch, the carriage
..., and the rail means;
°"' Figure 9 is a view similar to Figure 8, showing the
winch and the carriage means translated toward the left of the
figure along the adjustment axis relative to their respective
positions shown in Figure 8;
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-- Figure 10 is a rear elevati.onal view of the winch of
Figure 8;
Figure 11 i:~ a view similar to Figure 10, with the
blocks of the winch drawn together relative to their positions
shown in Figure 10;
Figure 12 is an exploded bottom partial perspective
view of the rotary floor sander of Figure 1;
Figure 13 is a top plan view of the sanding head member
of the rotary floor sander of Figure 1, with sheets of sanding
media respectively operatively positioned in each elongate slot;
'-- Figure 14 is a .sectional view of the sanding head
member of Figure 13, t=aken along sight line 14-14 of Figure 13,
illustrating a respecr_ive sheet of sanding media operatively
positioned in a respective elongate slot;
Figure 15 is a sectional view of the rotary floor
sander of Figure 1, taken along sight-line 15-15 of Figure 7;
Figure 16 i.s a sectional view of the rotary floor
sander of Figure 1, taken along sight-line 16-16 of Figure 6;
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... Figure 17 is a partial bottom perspective view of a
rotary floor sander according to an alternative embodiment of the
"" present invention;
Figure 18 is an exploded bottom perspective view of the
rotary floor sander of Figure i8;
,.. Figure 19 is a bottom plan view of the rotary floor
sander of Figure 1, with the sanding head member removed for
"" clarity;
Figure 20 is a partially exploded perspective view
similar to Figure 3, with the sanding head member removed for
~.
clarity;
Figure 21 i~, a partial sectional view of the rotary
"' floor sander of Figure 1, along sight-line 21-21 of Figure 19,
showing the skirt member at, its raised position; and
Figure 22 is a view similar to Figure 21, showing the
...
skirt member at its lowered position.
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,.... DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
""" With general. reference to Figures 1 through 16 and 19
through 22, a preferred embodiment of the present invention is
illustrated and is designated by general reference numeral 20.
The precise manner of construction and operation of the preferred
embodiment will be fully described in the following paragraphs.
However, for greater clarity, the main components and general
manner of operation of the preferred embodiment, and the
-- cooperating environment within which it is intended to be used,
will be firstly described.
In this regard, and as best illustrated in Figures 1
through 3, the machine comprises a platform 22, said platform 22
having a rearward end 24 and a forward end 26 and defining a
longitudinal axis "A" extending between said rearward end 24 and
a.. 15 said forward end 26. A cover 70 is usefully provided to, inter
alia, shield interior components of the machine 20 from dust.
A pair of wheels 28 are mounted on the platform 22 adjacent to
the rearward end 24 for rotation about a lateral axis "B"
extending substantially normal to said longitudinal axis "A". In
use, the wheels 28 are operatively positioned upon a floor
surface 30 to be finished and support the rearward end 24 of the
platform 22 for rolling movement substantially parallel to the
longitudinal axis "A" . A sanding head member 32 , defining a
-- substantially planar sanding face 34, is also provided. The
sanding head member 32 is mounted on the platform 22 for rotation
"'" about a substantially vertical axis "C" with the sanding face 34
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thereof being orier~ted substantially normal to the substantially
vertical axis "C" and substantially parallel to the floor surface
M"' 30. Additionally, an attachment means is provided, which is
designated by general reference numeral 36 in Figures 3 and 4.
The attachment means 36 selectively, releasably attaches one or
more sheets of flexible sanding media 38, of the type having a
smooth side 40 (shown and indicated in Figures 12 and 14) and an
abrasive side 42, to the sanding head member 32, with the smooth
side 40 of each of said sheets 38 in contactable relation to the
.... 10 sanding face 34 and with the abrasive side 42 of each of said
sheets 38 in contactable relation to the floor surface 30, as
best indicated in Figures 3 through 7 and 14. It will be evident
to persons skilled in the art that, when the foregoing structure
is operatively positioned, rotation of the sanding head member
32 about the substantially vertical axis "C" effects concurrent
rotation of the sheets of sanding media 38 and consequent
"""" abrasion of the floor surface 30 by the abrasive sides 42
thereof, which rotation in the present invention is provided by
a drive means, designated in Figures 1 and 15 by general
reference numeral 44, which rotates said sanding head member 32
at relatively high speeds, preferably in or about 3000 rpm. The
drive means 44 is discussed more fully below. As illustrated in
Figures J_ and 2, a handle means 46, extending upwardly and
rear<aardly from the rearward end 24 of the platform, is also
provided, for guidance of the machine 20 in operation, and also
for transport of the machine 20 when not in operation.
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,~- Turning now to the precise manner of construction and
operation of the preferred embodiment, it will firstly be
appreciated that as a first feature of the preferred embodiment,
as best indicated ir.W~igures 12 through 15, the sanding head
member 32 comprises a substantially planar plate portion 48 of
circular plan outline, a fE~lt disc portion 51 of circular plan
outline and a first driven shaft portion 50, said first driven
shaft portion 50 being substantially centred about the
substantially vertical axis "C", rigidly attached to an upper
-- 10 face 54 of the plate portion 48, as best seen in Figure 14, and
operatively received by a thrust bearing 56 mounted on the
platform 22, as best seen in Figure 15. The felt disc portion
51 is affixed to a lower face 52 of the planar plate portion 48
with a lower face 53 of the felt disc portion 51 defining the
sanding face 34.
.- As best seen in Figures 1, 15 and 16 , in a further
feature of the preferred embodiment, the drive means 44 comprises
" a first pulley 58 operatively connected to said first driven
shaft portion 50; a motor 60 rigidly mounted on the platform 22
and having a drive shaft 62; a second pulley 64 operatively
connected to said drive shaft 62; and a drive belt 66 extending
between and in operative receipt of the first pulley 58 and the
second pulley 64.
-- As yet a further feature of the preferred embodiment,
as best indicated in Figures 3, 4 and 12 through 14, the
attachment means 36 comprises three elongate slots 68 passing
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~- substantially vertically through the plate portion 48 and the
felt disc portion 51, each slot 68 being aligned substantially
tangentially to an arc of rotation "E" defined by the
substantially vert:.ical axis "C", as illustrated in Figure 13.
The elongate slots 68 are equally circumferentially spaced from
one another, and are each :shaped and dimensioned for releasable
extension therethrough of a first portion 72 of a respective one
_, of said sheets of flexible sanding media 38, such that, when
operatively positioned, the smooth side 40 of a second portion
74 of said sheet 38 is positioned in underlying contactable
relation to the sanding face 38, the abrasive side 42 of the
second portion 74 is positioned in overlying contactable relation
to the floor surface 30 and the first portion 72 of said sheet
38 is positioned ira inserted relation to the elongate slot 68.
To assist in retention of said sheets 38 during
..- rotation as aforedescribed, the attachment means 36 further
comprises a pair of spacer bars 76 and a rectangular cap plate
'"" 78 for each elongate slot 68, the spacer bars 76 being rigidly
attached to the upper face 54 of the plate portion 48, adjacent
respective ends of said elongate slot 68 and aligned in
transverse relation thereto, and the cap plate 78 rigidly
extending between each pair of spacer bars 76 in spaced relation
"" to the plate portion 48 and in aligned, overlying relation to the
elongate slot 68. The spacer bars 76 and cap plates 78 are
shaped and dimensioned such that, when said sheets of sanding
media 38 are operativE~ly positioned, the abrasive side 42 of each
bears in frictionally retained relation against a respective cap
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..-.. plate 78, as seen in Figure 14. A reinforcement plate 83 is
advantageously positioned in surrounding relation to each
""" elongate slot 68.
It will be evident that the foregoing provides for
relatively convenient abrasive exchange in that, when a sheet of
abrasive media 38 has become worn, it need simply be removed, and
a fresh sheet inserted. Although sheets of sanding media 38 of
square plan outline may be utilized (not shown), it is
advantageous that each sheet 38 have at least one arcuate edge
80 that roughly corresponds to the circular outline of the plate
portion 48 when operai~ively inserted, to maximize the working
abrasive area. Indeed, preferably, the sheets 38 are provided
with opposed arcuate edges 80, as shown, inter alia, in Figure
3, 12 and 13, such that, when worn, the sheets 38 may be removed,
reversed and reinserted.
Also provided in the preferred embodiment is a
positioning means, designated by general reference numeral 82 in
Figure 2, for selective movement of each of said wheels 28
between a fully raised position, best illustrated in Figure 5,
whereat the rearward end 24 of_ the platform 22 is relatively
proximal to the floor surface 30, and a fully lowered position,
e,_, substantially downwardly disposed from the fully raised position
and best illustrated in Figure 6, whereat the rearward end 24 of
the platform is relatively distal to the floor surface 30. The
positioning means 82 also provides for selective movement of each
of said wheels 28 between a rearward position, illustrated in
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Figure 4, whereat said each wheel 28 is relatively proximal to
the rearward end 24 of the platform 22, and a forward position,
substantially longitudinally forwardly disposed from the rearward
position and illustrated in Figure 3, whereat said each wheel 28
is relatively distal to the rearward end 24 of the platform 22.
It will be evident to persons skilled in the art that
the adjustment of the positioning means 82 as aforedescribed
enables an operator of the sanding machine 20 of the present
.._ inventlOll to select: an orientation of the plate portion 48
thereof, which ability has been found to have significant
""' utility. For example, movement of the wheel members 28 to their
respective lowered positions causes the plate portion 48 to tilt
forwardly, as illu~>trated in Figure &, in which configuration,
the machine 20 is we7..l-suited for floor sanding operations while
travelling longitudinally rearwardly and longitudinally
frontwardly. Alternatively, movement of the left wheel member
28 towards its fully raised position and movement of the right
wheel member 28 towards its fully lowered position causes the
plate portion 48 to tilt downwardly to the left, as illustrated
in Figure 7, in which configuration, the machine 20 is well-
suited for floor sanding operations while following an
obstruction, such as a wall, located to its left (not shown)-
It will be appreciated that under both of the above-described
operating conditions, the sheets of flexible abrasive media 38
are only in periodic contact with the floor surface 30, and as
such, are provided an opportunity to cool during use. This is
particularly advantageous in refinishing applications, i.e.
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,.,.. wherein an existing coating is required to be removed from the
floor surface 30, since the resultant reduction in temperature
'"" of the abrasive media 38 renders the coating less prone to
melting, which tends to quickly gum the abrasive and render it
unusable. In conditions wherein the existing coating is
particularly heavy, the wheel members 28 may be moved to their
respective rearward positions, as illustrated in Figure 4, in
,_", which configuration, the machine is balanced such that less
pressure is exerted by the sheets of abrasive media 38 upon the
-- 10 floor surface 30, thereby to further reduce the working
temperature thereof.
As a yet further feature of the preferred embodiment,
and as best illustrated in Figures 5, 6, and 20 through 22, a
downwardly-depending housing member 84 is advantageously
provided, mounted on the platform 22 so as to define a
,.... substantially downwardly-opening chamber 86, as is a skirt member
85, mounted on the housing member 84 and defining a chamber
"" extension 87 contiguous with said chamber 86, said skirt member
85 being mounted f:or movement substantially parallel to the
substantially vertical axis "C" between a lowered position,
illustrated in Figure 22, whereat the chamber 86 and chamber
extension 87 collectively enclose the sanding head member 32 and
said one or more sheets of sanding media 38, and a raised
position, illustrated in Figure 21, substantially vertically
upwardly disposed from the lowered position. This, coupled with
a vacuum means, designated in Figure 2 with general reference
""" numeral 88 and seen in Figure 15 to comprise a vacuum impeller
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.., 90 in operative fluid communication with the chamber 86, effects
the evacuation of dust and other particulate matter generated
'" through abrasion, for the safety and comfort of operators and
bystanders. As best illustrated in Figures 15, 16 and 20, the
vacuum impeller 90 has an inlet 154 operatively opening into the
chamber 86 and a se>.cond driven shaft 156, said second driven
shaft 156 having a third pulley 158 operatively connected
thereto, said third pulley 158 being disposed between the first
pulley 58 and the second pulley 64 and operatively, drivingly
-- 10 engaged by the drive belt 66.
""' To achieve the aforedescribed functionality of the
skirt member 85, which works to maintain suitable sealing of the
skirt member 85 as against the floor surface 30 irrespective of
the relative orientation of the platform 22 (resultant from
adjustment of the positioning means 82 as aforedescribed), the
housing member 84 and skirt member 85 are each substantially
cylindrical in shape, the skirt member 85 being fitted in
p"' concentric snug-fit relation around the housing member 84. To
prevent separation of the skirt member 85 from the housing member
84, an inwardly projecting flange 162 is formed on the skirt
member 85 and radially projecting stop pin members 164 are
provided adjacent a lower edge 166 of the housing member 84,
which flange 162 bears against said stop pin members 164 when
said skirt member 85 is at its lowered position, thereby to
prevent further downward movement. Respective apertures 168, 170
are additionally formed in the skirt member 85 and the housing
°" member 84, to ensure vacuum draw.
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".... To achieve the contemplated functionality of the
positioning means 82, the positioning means 82 of the preferred
""" embodiment, as best seen in Figures 1 through 6, generally
comprises a pair of subframe members 92, a pair of support arms
94, a cable means 96 having two free ends 98, each operatively
pivotally attached to the support arms 94, a differential
winching means 100 and a guide means, designated by general
reference numeral 102 in Figures 1 and 2 and seen to comprise
several pulleys 104 operatively mounted to the handle means 46,
said pulleys 104 being shaped and dimensioned for, and in guiding
receipt of, said cable means 96. The subframe members 92 are
r' laterally spaced from one another, and mounted to the platform
22 by means of bolts 106 which ride in elongate channels 108
formed in said sub.frame members 92, thereby to facilitate
relative selective sliding substantially longitudinal movement
of said subframe members 92. The bolts 106, of course, may be
tightened to fix the relative position of said subframe members
92. The support arms 94, as best illustrated in Figures 3-6,
°""' each rigidly extend bE~tween a first pivoting portion 110 thereof,
which is operatively pivotally attached to a respective one of
the subframe members 92, and a second pivoting portion 112
thereof, which is operatively pivotally attached to a respective
one of the wheels 28. The differential winching means 100 is
operatively attached to t;he cable means 96 for selective
independent withdrawal of the free ends 98 towards said
differential winching means 100 and for selective independent
extension of the free ends 98 away from said differential
"" winching means 100, with the guide means 102 directing and
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",., guiding the cablE:~ means 96 such that, upon said selective
withdrawal and said selective extension of the free ends 98, each
of said wheels 28 i=s caused to travel between the fully raised
position and the fully lowered position thereof.
As illustrated in Figures 5, 6, 8 and 9, in the
preferred embodiment shown, the cable means 96 comprises two
cables 114, each of said cables 114 having a first end 116 and
a captive end 118, the first end 116 defining a respective one
..,.. of the free ends 98 of the cable means 96, and the captive end
118 being operatively rigidly attached to the differential
""' winching means 100. However, it should be appreciated that the
cable means 96 could take other forms with equal utility, such
as, for example, a single cable (not shown).
Similarly, in the preferred embodiment illustrated,
",. 15 lever arms 120 are also provided, each rigidly extending from the
second pivoting portion 1.12 of a respective support arm 94, in
~~ angular relation thereto, t:o a respective terminus 122 to which
is pivotally attached the free end 98 of a respective cable 114.,
as seen in Figures 5 and 6. The provision of lever arms 120
greatly reduces the complexity that would otherwise be required
of the guide means 10?., but it will be evident that same are not
necessary for utility.
As best illustrated in Figures 8 and 9, the
differential winching means 100 of the preferred embodiment
comprises a rail member 124 rigidly connected to the handle means
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,.,. 46 and defining an adjustment axis "D", with a carriage member
126 mounted for selective translational movement upon said rail
"' member 124 parallel to said adjustment axis "D", and a winch 128
rigidly mounted to said carriage member 126 and operatively
connected to the captive end 118 of each cable 114. Wheel
members 129 are provided on said carriage member 126 to
facilitate said translational movement, as is a set screw member
127, which selectively locks said carriage member 126 as against
relative translational movement.
It will be evident that a conventional drum-style winch
(not shown) could be employed for the purpose of extending and
retracting the cables 114. However, in the preferred embodiment
illustrated in Figures 10 and 11, t;he winch 128 is seen to
comprise a double-ended bolt 130, a pair of threaded shuttle
members 132, respectively positioned adjacent the ends of the
"", double-ended bolt 130 and in operative threaded engagement
thereof and two linkage assemblies 134 positioned one each on
~~ respective sides of the double ended bolt 130. Each of the
linkage assemblies 134 comprises a block 136, rigidly attached
to the captive end 118 of a respective one of the cables 114, and
a pair of links 138, each of said links 138 being pivotally
attached to said block 136 and to a respective one of said
threaded shuttle members 132. It will be evident upon rotation
of said double-ended bolt 130, the shuttle members 132 will be
caused to traverse said bolt 130, whereupon the links 138 will
cause the blocks 136 to be drawn together, or distanced from one
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r~~
CA 02386342 2002-05-29
another, as the case may be, and a handle 140 is accordingly
provided, for turning the double-ended bolt 130.
As previously outlined, in the preferred embodiment of
the present invention, the attachment means 36 comprises, inter
alia, elongate slots 68 adapted to receive flexible sheets of
sanding media 38. However, it will be appreciated that the
teachings of the present invention may be applied in an
alternative embodiment of the rotary floor sander, shown in
.-r 10 Figures 1.7 and 18, for use with sheets of rigid sanding media in
disc form 142. In this embodiment, the sanding face 34 is
-"' operatively positioned in abutting contacting relation against
a smooth side 144 of the abrasive disc 142, and the attachment
means 36 comprises a retaining plate 146 in abutting relation
against an abrasive side 148 of the disc 142, which retaining
plate 146 is secured in position by means of a bolt 150
operatively threadi.ngly engaged in a threaded bore 152 provided
in the plate portion 48.
While but a single preferred embodiment and a single
alternative embodiment of the present invention is herein shown
and described, it will be evident to persons skilled in the art
that other modifications and alterations may be used in the
design and manufacture of the rotary floor sander according to
the present invention without departing from the spirit and scope
,... 25 of the invention, which is limited only by the accompanying
claims.
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