Note: Descriptions are shown in the official language in which they were submitted.
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APPARATUS FOR CLEANING MOVING ABRASIVE MEMBERS
This invention relates to new and useful improvements
in apparatus for cleaning the surface of a moving abrasive
member such as a sanding belt.
Sanding belts are in common use for finishing the
surface of plywood or other sheet products in the manu-
facture thereof. These belts are rather wide in order to
sand a sheet as the latter is passed thereunder. A problem
exists in this art in that the sanding belt becomes clogged
and rapidly becomes less effective or entirely ineffective.
In an attempt to obviate this problem, cleaning apparatuses
have been employed to blow or wash the dust from the sand-
ing belt. Due to the width of the belt, a large capacity
blowing and cleaning system must be provided because of the
requirements of air or liquid that are being ejected. Thus,
large capacity compressors or holding systems must be provi-
ded and of course such is a definite disadvantage. Some
systems also employ a travelling nozzle for air and/or
solvent, such as shown in U.S. Patent No. 3,812,622. While
- such a system requires a smaller capacity compressor and
holding system, lt has the disadvantage that the mechanism
to provide the reciprocating moyement is complicated and
also easily disabled by dust or liquid. Such mechanism
also can easily be damaged by a broken belt.
According to the present invention and forming a
primary objective thereof, an apparatus is provided for
cleaning the surface of a moving abrasive member which is
efficient in use and at the same time is relatively
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simplified in construction, which requires a minimum
capacity compressor system, and which is relatively in-
capable of damage by dust and broken belts.
A more particular object of the invention is to
provide in combination a moving member having a widened
abrasive surface to be cleaned, an elongated hollow
cylindrical housing arranged to be mounted adjacent to
and substantially parallel with the abrasive surface of
the moving member, the housing having a plurality of
radial ports spaced longitudinally therein establishing
communication between the interior and exterior of the
housing, an elongated cylindrical core member rotatably
supported within the housing in interior sealing surface
engagement with the housing, a spiral groove in the surface
of the core member of a selected width and pitch such that
only a small number of ports are exposed to the groove at
a time, fluid conducting means supplying pressured fluid
to the groGVe to provide an outlet jet of fluid from the
housing the width of the ports which are in communication
with the spiral groove, and power means rotating the core
member in the housing to provide repeating ones of the jets
of fluid to tra~el across the housing upon rotation of the
core member for cleaning the abrasive surface of the moving
member.
In carrying out the above objectives, an elongated
hollow cylindrical housing has a row of ports along its
longitudinal length and is arranged to be mounted substan-
tially parallel with the surface of a moving abrasive member
with the ports directed at the abrasive member. An
elon~ated core member is rotatably
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supported within the housing and has a spiral groove which mete~s
out pressurized fluid in a jet through the ports which travels
across the surface of the abrasive member as the core member
rotates. The jet fluid is the width of only a few of the
ports so as to require a minimum of compressor capacity and
little or no fluid holding system. Means are provided to
reciprocate the housing in its longitudinal dimension through
a distance approximately equal to the spacing of the ports so
- as to clean the abrasive member in the area between the ports.
The invention will be better understood and additional
- objects and advantages will become apparent from the following
description taken in connection with the accompanying drawings.
: Figure 1 is a plan view looking into the outlet portion
of apparatus for cleaning the surface of a moving abrasive
member embodying features of the present invention, this view
being taken on the line 1-1 of Figure 6;
Figure 2 is a vertical side elevational view of the appara-
tus taken on the line 2-2 of Figure l;
Figure 3 is also a vertical side elevational view but taken
from the opposite side from Figure 2, this view being taken
on the line 3-3 of Figure l;
Figures 4A and 4B comprise enlarged sectional views in
; composite form taken on the line 4-4 of Figure l;
Figure 5 is an enlarged fragmentary sectional view taken
on the line 5-5 of Figure 4A; and
Figure 6 is a diagrammatic view of a sanding assembly for
traveling sheet products and including the present cleaning
apparatus associated therewith.
With particular reference first to Figure 6, the numeral
10 designates upright sanding belts which move at high speed
over upper and lower rollers 12, also seen in Figures 1, 2 and 3.
The sanding belts are engageable with the surfaces of sheets
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S to be sanded which are moved by a conveyor and feed rolls,
not shown.
The present apparatus is arranged to be supported adja-
cent to the belts and across the latter by suitable frame
members 14 shown in broken lines and two or more cross frame
members 16, it being preferred that the present apparatus be
located at upper and lower areas of the upper and lower rollers
12, respectively, or in adjacent areas so as to clean the belt
at a point where it extends over a rounded surface of the end
rollers whereby the areas between abrasive particles will be
open. The drawings illustrate in detail the apparatus associated
with the top roller 12, the apparatus associated with the lower
roller 12 being the same except for mounting structure.
With reference to Figures 2, 3, 4A and 4B, a pair of angle
frame members 18 are secured in spaced relation between cross
frame members 16. The two frame members 18 support an elongated
tubular cylindrical housing 20 by means of opposite end closures
22 and 24 having threaded connections 26 with the housing.
- O-ring seals 28 are included in these connections. Portions
18a of frame members 18 are curved outwardly to receive the
housing 20 with clearance.
End closure 22 has an end extension 30 slidably extending
through an aperture 32 in a frame member 18. The end closure
24 has a pair of supporting projections 34 which project
slidably through apertures 36 in the opposite frame member 18.
The apertures 32 and 36 provide suitable support for the housing
20 but allow a slidable movement therein for a purpose to be
described, suitable spacing 38 being provided between the inner
surface ends of the end closures and the frame members 18 to
allow for such slidable movement.
The wall of housing 20 has a row of closely spaced ports
40 through which a pressured fluid, such as air, liquid, or a
combination of the two, is to be ejected. This row of holes is
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of a length to extend at least the width of the sander belt
10 .
- Rotatably supported within the housing 20 in surface
sealing engagement is a cylindrical core member 42 having an
axial bore or passageway 44 one end of which communicates with
a source of compressed fluid through the medium of suitable
conduit means 46 shown in full lines in Figure 1 and in broken
lines in Figure 4B. This conduit is connected into a tapped
: bore 48 in the-thrust bearing assembly 24.
The opposite end of core member 42 from the fluid inlet
end has an integral shaft extension 50 which seals this end of
the bore 44 and which passes rotatably through the end closure
22. This shaft extension projects beyond the end of the end
closure 22 and has a sprocket wheel 52 secured thereon driven
. ~ by a sprocket chain 54 from a sprocket wheel 56 secured on the
output shaft of suitable drive mechanism such as an electric
motor 58, Figure 3. Motor 58 has suitable gear reduction means
- 60 as well as speed control means 62. Upon operation of motor
58, core member 42 is rotated within the housing 20, the housing
. 20 being held against rotation by projections 34.
The outer surface of the core member 42 has a longitudinal
-` spiral groove 66, also seen in Figure 5, which is of a length
approximately the length of the row of ports 40. Several ports
68 establish communication between the bore 44 and at spaced
points along the spiral groove 66 to provide an adequate and even
distribution of fluid pressure in the groove 66. Upon rotation
of the core member 42 by the drive mechanism 58, the spiral
groove 66 serves as a valve to cause a narrow jet of fluid to be
ejected through the ports 40 in traveling movement across the
housing to clean the sanding belt. The width of the jet depends
upon the width and pitch of the groove 66, and of course the
frequency of movement of the jet across the housing will depend
upon the pitch of such groove and the speed of rotation of the
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core member 42. One or more of the grooves may be provided
if desired.
Although the ports 40 are spaced relatively close together,
the fluid jets therefrom may leave an unclean area on the belt
between such ports, and to provide a complete cleaning path,
means are provided to reciprocate the housing 20 as the core
member 42 is being rotated. Such means comprises a cam 70,
Figures 1, 3 and 4A, secuxed to the shaft extension 50 for
rotation therewith and having a cam groove 72 in its peripheral
surface concentric with the axis. A cam follower 74 projects
into the groove 72 and has a stationary screw connection 76 on
a frame member 78 secured to frame members 16. Frame member
78 has an offset portion 78a for clearance with the cam. The
ends of core member 42 abut against thrust bearings 79 and 80
whereby upon rotation of the core member, the cam 70 will cause
the entire housing assembly 20 and core member to reciprocate.
The reciprocating movement caused by the cam will be at least
equal to the spacing between ports 40 so that the area on the
sanding belt will be fully engaged by the fluid jet. Clearance
areas 38 between the end closures 22 and 24 and their respective
frame members 18 allow for reciprocation of the housing.
According to the present invention, apparatus for cleaning
sanding belts and the like is provided which accomplishes effi-
cient removal of dust and other foreign particles and which at
the same time is relatively simple in construction and inexpen-
sive to manufacture. Furthermore, the apparatus is substan-
tially maintenance free in operation and will not be damaged
by a broken belt.
It is to be understood that the form of my invention
herein shown and described is to be taken as a preferred example
of the same and that various changes in the shape, size and
arrangement of parts may be resorted to without departing from
the spirit of my invention, or the scope of the subjoined clalms.
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Although the present invention is illustrated for use with
sanding belts, it can as well be used with any type of moving
member, whether or not an abrasive member.
