Note: Descriptions are shown in the official language in which they were submitted.
L2
SUCTION HOUSING FOR VACUUM SANDING DEVICES
FIELD OF THE INVENTION
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This invention relates to vacuum sanding
devices and in particular to a housing for use with
such sanding devices.
BACKGROUND OF THE INVENTION
Vacuum sanding devices have been known for
sometime. They are usually rotary grinders or double
action sanders although patents have also issued for
vacuum sanders of a rectangular format. Examples of
such rectangular vacuum sanders are to be found in
U.S. Patent 4,062,152 of December 13th, 1977 Mehrer,
3,123,946 of March 10th, 1964 Hoveland, 2,499,933 of
March 7th, 1950 Smul. In circular vacuum sanding
devices, examples may be found in Applicant's Canadian
Patent 1,080,477 August 1st, 1980, Canadian Patent
931,761 to Olmoen, U.S. Patents 3,785,092 Hutchins,
2,895,266 Statler, U.S. 4,164,101 Robert and 3,862,521
January 28th, 1975.
There are several disadvantages in the construc-
tion of the prior art patented devices. Many of them
are complicated, incorporating too many moving parts
and are therefore expensive to manufacture and maintain.
Others do not provide adequate suction adjacent the
immediate work area and, if they do, they sometimes
have upper housings that are spaced substantially
outwardly of the backup pads or sanding blocks so that
the sanding blocks can never reach deeply into corners
or hard-to-get-at areas.
SUMMAR~ OF THE INVENTION
The present invention is constructed so as to
overcome the many deficiencies of the prior art and to
provide a very efficient, light and easy-to-use vacuum
sander through the incorporation of a housing that
allows a sanding operator to get his sand paper close
to if not right at corner portions and hard to get at
areas. The housing of the present invention is adapted
for use on numerous forms of sanders such as double
action or orbita~ sanders, rotary grinders, rectangular
block sanders and hand block sanders. It is also
usable on rectangular vibratory sanders.
According to a broad aspect, the invention
relates to a housing for a vacuum sander of the type
that includes a backup pad. The housing comprises a
plate having leg members on its lower surface for
spacing the plate above the upper surface of the backup
pad, a lip member on the periphery of the housing
defining a relatively narrow peripheral opening between
the edye of the housing and the backup pad underneath
it, the peripheral edge of the housing being coterminous
or nearly so, with the peripheral edge of the backup
pad.
In the embodiment of the invention used on
circular or rotary sanders, the peripheral portion of
the housing reaches down close to the edge of the
backup pad and therefore very close to the sanding
surface. The housing is therefore instrumental in
sucking up dust all around the rim of the operating
sander. The backup pads used with vacuum sanders
normally have holes in the center part all the way
through to an upper chamber formed by a flexible
collar extending downwardly from the rotating mechanism
to the housing. This combination of the vacuum hole
through the backup pad and the peripheral vacuum
inlet formed by the housing! forces the suction to draw the
dust through the holes and all around the backup pad from the
sanded surface. The edge of the suction housing is preferably
flexible so that if an operator hits an edge, it gives and
flexes back to its original position.
In a rectangular form such as a pole sander or hand
sander, again there is a gap between the peripheral lip of
the housing plate and the upper surface of the backup pad
and this causes the vacuum to suck the dust all around and
through the edge of the sanding block as well as through
apertures in the associated backup pad. The apparatus picks
up dust in the front, sides and rear portions equally.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated in the accompanying
drawings in which:
Figure 1 is a cross sectional view of a vacuum sander
incorporating the present invention;
Figure la is a modifi.ed version of the embodiment of
Figure l;
Figure 2 is a fragmentary, perspective view of a
portion of the housing of the present invention;
Figure 3 is a view similar to Figure 1 but showing
a somewhat different arrangement of the housing;
Figure 4 is a plan view of another embodiment of
the invention;
Figure 5 is a sectional view taken along the line 5-5
of Figure 4;
Figure 6 is a sectional view taken along the line 6-6
of Figure 5;
Figure 7 is a cross sectional view of another embodiment
of the invention;
Figure 8 is a sectional view of another embodiment of
the invention;
Figure 9 is a bottom view, partially cut away, of the
embodiment of Figure 8;
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Figure 10 is a sectional view of a portion of the
Figure 8 embodiment; and
Figure 11 is a top view of Figure 10.
Referring to Figures 1, la and 2, the housing 10
according to the invention is illustrated as being mounted
on the backup pad 12 of a rotary grinder or orbital sander
including a vacuum housing 14. T~e backup pad 12 is connected
by a stud 16 to a motor shaft 18 which rotates the backup pad
12 and an abrasive disc mounted on its lower surface.
The housing 10 comprises an upper plate portion 20
of circular configuration having a central, upstanding flange
22 and a peripheral lip member 24 depending therefrom and
extending outwardly and downwardly from the plate member. The
lower surface of the plate member is provided with a plurality
of legs 26 which serve to space the housing plate 20 upwardly
from the backup pad 12 as shown in Figure 1. This spacing
can be varied in accordance with the length of the legs 26
used in the particular requirements of the operation. In any
case, the spacing of the vacuum housing plate 20 above the
upper surface of the backup pad 12 defines a vacuum chamber
which is in communication with a large vacuum exit or opening
30 defined by the flange 22. In the embodiment of Figure 1,
a resilient seal ring 32 mounted on the body of the vacuum
housing 14 extends downwardly and rests on the upper surface
of the housing plate 20. This serves to seal the vacuum
chamber so that any air drawn into the chamber must come in
either through apertures 34 in the hottom of the backup pad
12 or in through the peripheral opening 36 defined between
the lip member 24 and the sloped surface 38 of the backup pad.
The flexible sealing ring 32 may include a conduit 40
for detachable ~onnection to suitable vacuum means, not shown.
The embodiment of the invention shown in Figure la is
basically the same as that in Figure 1 but the conduit 40
is taken off the side of the housing 14 and not the seal
ring 32.
The embodiment of the invention illustrated in
Figure 3 is similar to that shown in Figure 1 but the
backup pad 12 is of somewhat different configuration and
the legs 27 spacing the plate 21 above the backup pad are
longer than the legs 26 in the embodiment of Figure 1.
Moreover, instead of having a circular opening as defined
by the flange 22 in Figure 1, the plate 21 has a series of
apertures 23 which allow passage of air upwardly through the
apertures 34 in the backup pad and through the peripheral
opening 36 into the chamber defined by the ring 32 and
outwardly through the vacuum conduit 40.
It will be appreaciated that in either the Figure 1
or Figure 3 embodiment, the peripheral edge 25 of the lip 24
and the peripheral edge 13 of the backup pad are cot~rminous
or nearly so with one another so that an operator can move
the sanding device right into hard-to-get-at areas such as
corners, valleys, etc. The housing 10 can be manufactured
from a flexible plastic material so that if the lip 24
contacts any part of the working surface, it will give
and then return to its original location.
Turning now to the embodiment of the invention in
Figures 4-6, the housing of the embodiment in Figure 4
consists of an elongated rectangular plate 42 having a
series of depending legs 44 which serve to space the plate
42 above a base member 46 and to which is attached a sanding
block or backup pad 48. As with the embodiment of
Figures 1-3, the spacing of the plate 42 above the hase
member 46 defines a v~cuum chamber 50 which is in communica-
tion with external vacuum means through a circular upstanding
flange 52 to which one end of a flexible tube 54 is connected.
This embodiment of Figures 4-6 is provided with a
universal joint indicated generally at 56 and includes a
pair of upright plate members 58 integral with or otherwise
secured to the base member 46 and extending upwardly through
the opening defined by the flange 52. Plates 58 support a
roll pin 60 to which is attached a T-shape member 62 allowing
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horizontal movement in one direction of that T-shaped
member. The upper part of member 62 is provided with
another roll pin 64 at right angles to pin 60 and it
provides horizontal movement to a connector 66 attached
to it. The connector in turn is adapted for detachable
securement to the terminal end of a vacuum pipe 68 which
may also serve the function of an elongated handle for
actuating the sander.
Looking at Figures 5 and 6, it will be seen that
the base member 46 is provided with a chamfered edge portion
70 and the housing plate 42 is, as in Figure 1, provided
with a peripheral lip 72 extending outwardly and downwardly
from the plate 42 so that the converging edges of the lip 72
and the chamfered edge of the base plate 46 define a
peripheral opening 74. It will also be noted that the edge
of the base member 46 and the terminal edge of the lip
members 72 are coterminous with one another so that an
operator can move the sanding device into corners and other
hard-to-get-at locations during the sanding operation.
Turning now to Figure 7, the vacuum sander 76 has
the same basic configuration as the sander in Figures 4 and
5 but instead of the plate 42 having a central opening for
attachment to vacuum means, the housing plate 78 has an
integrally formed handle member 80 and as the handle member
80 is of tubular construction, it provides communication
between the chamber 82 defined between the plate 78 and
the base 84 and external vacuum means, not shown, whlch is
attached to the handle at a suitable outlet 86. As in
the embodiment of Figure 5, the housing plate 78 is attached
to the base 84 by suitable screws 86 extending through legs
90, the backup pad or sanding block 92 being attached to
the lower end of the base. The peripheral lip 94 of the
plate 78 is spaced somewhat from the chamfered edge 96
of the base 84 so that peripheral opening 98 is provided.
Turning now to Figures 8 and 9 a housing 9 has
secured thereto a backup pad 11 that is pro~ided with at
least one circular suction channel 15, two such channels
being illustrated. Depending on work requirements, diameter
of the pad, etc. several concentric or one single channel
would be used. As seen in Figure 8, the channels are
preferably the same or somewhat greater in width than the
diameter of the apertures 17 which are provided in the base
of the pad 11. As shown in the bottom view of the pad in
Figure 9, circular channel 15 interconnects apertures 17
while channel 15a interconnects apertures 17a.
It will be appreciated that with the provision of the
suction channels 15, 15a it is unnecessary for an operator
to line up suction holes in a sanding disc with the apertures
17 in the pad and, further, it is unnecessary to use a loading
device with a centering pin for that purpose. h~ith the
circular suction channels the operator just sticks the
paper to the backup pad using the outside diameter of the
paper and backup pad as a guide and, while the holes in the
paper may not align vertically with the apertures 17 in the
pad 11, the holes in the paper will overlie an associated
channel 15 or 15a so that, in operation, dust is sucked
up through the channel 15, then through the aperture 17
and into the housing above. At the same time dust is also
being drawn into the peripheral opening 23 between the
housing lip and the edge 35 of the pad 11.
It will be understood that sanding discs having one
or two concentric rings of holes can be used on a pad
according to Figures 8 and 9.
Lookiny to Figures 10 and 11, the inside surface 25
of the frusto~conical skirt 27 of the housing may be provided
with a series of shallow ribs 29, shown in phantom line in
Figure 11. These ribs prevent the closing off of the
space 31 between the inside of the suction skirt and the
edge of the backup pad when the operator applies downward
pressure on the edge of the pad against a work surface 33
as shown in Figure 10.
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It will be appreciated in all embodiments of
the present invention that the peripheral opening allows
efficient vacuuming of dust that accumulates anywhere
around the periphery of the sanding device whether it
is circular or horizontal. The dust can be drawn in
through the back, sides or front of the device to provide
a much more efficient unit than is available in the prior
art. The arrangement of the present invention can be used
on all rectangular vibrators, hand sanders, pole sanders
and disc sanders or long body files. The housing can be
made out of various materials such as nylon, fiberglass or
various alloys.
The invention is effective either using the peripheral
suction alone or in combination with suction apertures such
as 34 in Figures 1 and 3 or 45 in Figures 5 and 7 which extend
through the backup pad and or base from the work surface to
the vacuum chamber.
While the present invention has been described in
connection with specific embodiment thereof and specific
uses, various modifications will occur to those skilled in
the art without departing from the spirit and scope of the
invention as set forth in the appended claims.
The terms and expressions which have been employed
in this specification are used as terms of description
and not of limitation and there is no intention in the use
of such terms and expressions to exclude any equivalence
of the features shown and described or portions thereof.
It is recogni~ed that various modifications are possible
within the scope of the invention claimed.
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A further embodiment of the in~ention is illustrated
in Fiqure 12. A backup pad 100 is provided ~ith a suction
plate 102 secured thereto by screws 104. The plate 102,
like that shown in Figure 8, has a depending rim 106 spaced
outwardly from the adjacent, sloped edge 108 of the backup
pad 100 to provide the peripheral channel 110. While not
essential to the operation of the device, the spacing means
112 between the plate rim 106 and the backup pad eage 108
ensure constant spacing between the two surfaces when the
working edge of the backup pad 100 flexes upwards and outwards
as in Figure 10. It will be understood that the spacing
means can be in the form of ribs integrally formed with the -
rim 106 of the plate 102 as shown in Figures 10, 11 or 12 or
they can be formed on the sloped edge of the backup pad 100.
Moreover, the spacing means need not be in the form of a
rib but would be also effective in the form of projections
such as beads or knobs.
In compliance with the embodiment of Figure 8, the
plate 102 has a central opening 11~ t~ allow air and dust to
be drawn upwardly through the peripheral channel 110 between
the rim 106 and the adjacent backup pad surface 108 and into
a vacuum housing 116 and conduit 122. The backup pad and its
associated abrasive disc 115 may have apertures therethrough
as in the Figure 8 embodiment or such apertures can be omitted,
as in Figure 12, particularly if the sanding device is of the
double-action or orbital type.
To enhance the gathering of dust at the periphery of
the sandingdevice I have provided an outerl flexible skirt 118,
perferably o rubber, ha~ing a walst band 120 to secure the
skirt to the vacuum housinq 116 as shown~ Skirt 118 has inwardly
directed dimple-like pro~ections 124 to sPace the skirt 118 from
the outer surface of the rim 106. As illustrated, the
flexible skirt 118 extends down to, or close to, the work
surface 126, depending on the amount of suction being applied.
The provision of the adjustable waistband 120 allows room for
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setting the skirt 118 up or down on the housin~ 116. It will
be understood that if the backup pad 100 is used as a rotary
grinder or sander it, together with its suction plate iO2
will rotate at high speed under the skirt 118 or, in an
orbital mode, backup pad 100 and plate 102 will move in an
orbitai path under the skirt. In either case, the flexibility
of the skirt, which is stationary due to its connection to the
housing 116, is prevented from surface wearing contact with
the rim 106 by means of the projections 124 and a smooth
plastic finish of the rim 106. This allows the backup pad
100 to vibrate and turn under the skirt 106 without wearing
away the components. Moreover, an additional peripheral
vacuum channel 128 is provided which substantially increases
the removal of dust from the work surface.
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