Note: Descriptions are shown in the official language in which they were submitted.
s
TUMBLING APPARATUS
This application is a division of Canadian
serial number 497,100 filed December 6, 1985.
Backqround of the Invention
Field of the Invention
This invention relates to tumbling apparatus
and, in particular, to improved vibrating tumbling
machines for mixing materials and for cleaning or
shake-ou~ of par~s to be processed, ~uch as castings,
moldings or bulk material with or without a working
media.
, . . .
The Problem and the Prior Art
In many foundry operations, separation of 6and
and ~cale ~rom castinys is required. Typically, the
castings are in~tially tumbled to dislodge foreign matter
adhering to the castings. To assist this dislodging,
6hot may be caused to impinge upon the castings as they
are tumbled. An exemplary structure through which
dislodging of foreign matter according to the above can
be accompli6hed i~ shown ~in U.S~ Patent 3,793,780 to
Mus choot. :
In the Musschoot '780 patent, a tipped/
U~shaped hopper i6 provided ~nd has independently
operable, vibratory imparting mechanisms ~ssociated with
each leg of the hspper. Operati~n of the vibr~tory
lmparting mechanism is coordinated to move *he casting
towards a dead zone for tumbling and sho~ ~xea~ing and
~4
~Z67~ 5
away from the dead zone upon completion of the tumbling
and treating operations to discharge the castings.
The principal difficulty with this type of
equipment is that the vibration is not imparted
continuously during the separating operation. Rather,
the vibration imparting mechanisms are stopped and
started, requiring monitoring and coordination. Aside
from the above, the intermittent operation of the
vibration imparting mechanisms result in possible
excessive wear thereorl.
Another drawback with the e~uipment in the
prior art is that intermixing of the castings with the
shot, the separated sand and the scale occurs. In some
prior art, it is intended that sand and shot remain in
lS the hopper with the castings as the castings are agitated `
and transported for discharge. The discharged castings
therefore can retain some of the shot, sand and scale.
In the event that engine blocks or the like are cast,
complete removal of sand, scale, shot and other foreign
matter is absolutely essential. Thus, with the prior art
structures, a subsequent cleaning operation would have to
be performed in the cast parts.
It was found sometime ag~ that an improved
finish could be obtained on cast or molded parts by
adding a vibratory motion to the tumbling apparatus. In
the early 1960's, I developed and patented under U.S.
Patent No. 3,157,004, an improved burnishing appara~us
using a U-shaped tub mounted on trunnions. Vlbratory
force was applied directly to the U-shaped tub and passed
through the center of gravity of the tub. When the tub
was tilte~ about the trunnions, the vibratory force was
used to discharge the media and parts from the tub.
i26788S Case 59
Although improved burnishing of the parts
resulted from the above use of vibratory mo~ion through
the center of gravity of the tumbling apparatus, problems
continued with the balance of the machine, with the wear
on bearings, and with the time it took to obtain the
finish.
The Invention
The present invention is specifically directed
to overcoming the above-enumerated problems in a novel
and simple manner.
According to the invention, a hopper is
vibrated to advance castings continuously in a path
between inlet and outlet ends. Simultaneously, shot,
sand, scale and other foreign matter are discharged from
the hopper separately from the castings. A preliminary
shake-out of the castings takes place prior to the
introduction of the castings into the hopper and a
subsequent abrasive removal operation takes place
separately upon the castings be$ng discharged from the
hopper. Shot can be propelled at the castings in the
hopper to enhance dislodging o foreign matter therefrom.
Castings leaving the system are effectively cleaned of
all foreign matter, i.e. shot, ~and and/or scale.
According to other disclosed versions of the
invention, a vibrating tumbling apparatus comprises a
container, which may be a cylindrical drum, and a frame
which are resiliently mounted on a foundation. A bracket
on the container supports a vibration generator capable
of producing linear vibratory motion. The arrangement is
such that the container is vibrated along small segments
of æn arcuate or circular path centered at a point offset
from the center of the container. The tumbling apparatus
~L2~;'78~
will have a batch of material (which may be castings with
ox without media) in the container, The apparatus may
also be used to mix materials of different
characteristics in a highly efficient manner. 'rhe
material in the container is moved or conveyed and
tumbled not only due to the coefficient of friction of
the material with the ~urface of the container, but also
due to the angle of attack between the material and the
sur~ace of the container at any given point because of
the segmental circular path. A line from the center of
rotation through the center of gravity of the machine
intersects the linear line of force generated by the
vibration generator at an angle o 90. The angle of
attack between the material and the container can be
varied to vary the rate or character of mixing, to vary
the rate of cleaning, to ~ary the amount of tumbling, to
vary the conveying and tumbling action between the
material and the surface of the container and the like.
Preferred forms of the invention are shown in the
20 accompanying drawinys and the claims in this divisional
application are particularly directed to the embodiments
of Figures 1 to 3 of the drawings and in one aspect
comprehends a vibratory apparatus for separating foreign
matter fro~ castings comprising a hopper having an inlet
25 for admitting the castings to the hopper, an outlet through
which castings are d.ischarged from the hopper, a
longitudinal axis and a bottom surface for supporting the
castings. The hopper inlet and hopper outlet are being
spaced from each other in a first direction and means
30 support the hopper with the bottom surface inclined a few
degrees downwardly from the inlet toward the outlet.
Vibration imparting mèans comprises at least one motor
having a shaft lying in a plane extending transverse to
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-4A-
the first direction and carrying at least one eccentric
weight -thereon. Resilient means is mounted between the
vibration imparting means and the hopper for resiliently
mounting the vibration imparting means to one quadrant of
the hopper and for directing vibratory forces into one
diametrically opposite quadrant and into one other quadrant
on the same level as the opposite quadrant of the hopper
for conveying castings in the ~irst direction from the
inlet to the outlet of the hopper as the castings are
tumbled in a path transverse to the first direction. Means
on the hopper between the hopper inlet and hopper outlet
directs foreign matter separated from the castings in the
hopper away from the hopper upstream from where the
castings are discharged through the outlet, whereby the
castings can be continuously directed between the hopper
inlet and outlet and foreign matter can be continuously
separated from the castings and directed away fro~ the
hopper.
Description of_the Drawings
Figure 1 is a plan view showing schematically
an overall system ~or separating foreign matter from
casting~ with the present- invention incorporated;
Figure 2 is a side elevation view o~ a
continuous hopper section in the system o Fig. l;
Figure 3 is an enlarged sectional view of the
hopper taken along line 2-2 of Fig. 1
Figure 4 is an end view of one preferred form
of a vibratory tumbling machine with some parts shown in
cross-section and some parts shown in phantom,
~LZ1~788~i
Figure 5 is an elevation view of the machine of
Figure 4 as viewed from the right in Figure 4;
Figure 6 is a view like Fig. 4 but with a
difference in the line of application of the vibratory
force.
Figure 7 is a view of one form of deck for
mounting the vibration generator of Figur~ 4 showing
alternate positions of the deck;
Figure 8 is a view similar to Figure 6 showing
a modified form of the invention;
Figure 9 is a view like Fig. 5 of the modified
form of the invention;
Figure 10 is a copy of a chart of the paths of
movement of material in the machine of Figure 4 in
operation;
Fig~re 11 is a copy of a chart of the paths of
movement of material in the machine of Figure 8 in
operation; and
~ igure 12 is a cross-sectional view of a
cylindrical deflector with openings or ports
therethrough; as shown with E'igure 8.
Detailed Descri~tion of the Dra ~ s
In Fig. 1, a aepiction of an overall system
appears for loading castings into a primary separation
structure 10, in which foreign matter such as scale
and/or sand i~ dislodged from the castings, and unloading
of the castings upon treatment in the primary separation
structure 10 for subsequent cleaning occurs. High
frequency shake-out structur~e is indicated at 12 and is
responsible for initial breakup of mold bound castings.
The castings, after initial breakup of the molds occurs,
are directed to an inlet 14 ~or the separation structure
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10 and are operated upon in a manner that will be
described in detail below. The castings discharge from
the separation structure 10 at an outlet 16 and are
directed to a casting roll-over, abrasive removal station
18 whereat final casting cleaning is carried out.
The details of the primary separation
structure, wherein the present invention resides, are
shown in Figs. 2 and 3. The primary separation structure
has a hopper 20 with a bottom surface 22 for supporting
the castings as they travel between the inlet and outlet
ends. A typical casting 24 is shown in Fig. 3 and may
be, for example, an engine block. The bo~tom surface 22
is supported in an inclined attitude as shown in Fig. 2
and slopes downwardly from the inlet end 14 towards the
outlet end 16. The hopper 20 has attached, reinforced
end walls 26, 28 with bottom surfaces 30 borne upon by
isolation springs 32 interposed between the surfaces 30
and the system support surface 34. Spaced longitudinally
directed tubes 35 are fit between the facing surfaces 37
of the end walls 26,28. Coaxial tie rods 39, internally
of the tubes, draw the end walls 26,28 towards each other
and against the tube ends so that a unitary assembly
results. The hopper 20 is fixed captively between the
end walls 26,~8.
The bottom surf~ce 22 of the hopper has a
substantially V shaped configuration in cross-section, as
seen clearly in Fig. 3, and is skewed with respect to ~he
vertical 50 as to define a substantially hori~ontal leg
36 and a ~ertical leg 38 having an upstanding wall
surface 40. The hopper 20 iæ sealed by a removable hood
42 between the end walls 26,28. The end walls 26,28 have
curved cutouts 44 lone ~hown) definin~ pas~ages for the
castings at the inlet 14 and outlet 16.
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Vibration imparting 6tructure for the hopper 20
comprises motors 46 mounted resiliently, as by coil springs
47, to an inclined exciting wall 48 carried by the hopper 20
midway between the end walls 26, 28. The disclosed
arrangement is a two mass vibratory system. The exciting
mass at 50 comprises the motors 46 and associated mounting
base 52. The second mass comprises the hopper 20, end walls
26, 28, hood 42 and discharge section 54 which diverts
separated foreign matter. Each motor 46 has a shaft 56
offset from the vertical and substantially perpendicular to
the line of movement of the castings between the hopper
outlet and inlet. Each shaft 56 carries a pair of eccentric
weights 58 at its ends. As the shafts 56 rotate, the hopper
20 is caused to move reciprocatively substantially along the
lS line 60 so that conveyance of the castings 24 towards the
right (Fig. 2) occurs.
Lines X and Y in Figure 3 effectively divide the
hopper into quadrants A, B, C and D with quadrants B and D
being diagonally opposite quadrant~ and in a direction similar
to vibratory motion as represented by line 60. Quadrant C is
a quadrant on the same level as "opposite ~uadrant" D.
Resilient means 47 between vibration imparting ~eans 46 and
hopper 20 effectively mounts the vibration impartin~ means
46 in quadrant B for directing vibratory forces into the
diametric opposite quadrant D and into quadrant C whlch i8
on the same level as the opposite quadrant D.
The path of an exemplary casting 24 will now be
described. As the motors 46 are activated, the casting
follows the curvature of the bottom surface 2~ and in e~fect
begins climbing the upstanding wall 38. As the casting 24
moves vertically, gravitational forces on the casting due to
the incline of the bottom surface 22 at the same time cause
the casting 25 to vibrate towards the outlet 16. The
casting 25 climbs until it ultimately tumbles over itself.
As this operation continues, the casting 25 traces a
substantially helical path. As the ca~ting follows the
described path, the foreign matter such as the scale and
mold material tends to progressively dislodge.
The invention also contemplates that the
separation of foreign matter be a~sisted by propelling
~hot towards the castings progressing through the
88~;
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structure 10 at a shot treatment station 61. A
conventional wheel 62 directs shot centrifugally through
an opening 64 in the hood 42. The impinging shot jolts
the castings to effect separation of foreign matter that
might otherwise not occur through tumbling alone.
It is a further aspect of the invention to
provide structure for diverting foreign matter, separated
from the castings in the hopper, away from the hopper.
To accomplish this end, openings 66 are provided in the
wall of the hopper. A shelf 68 resides at the openings
66 and is fed by a ramp 70 inclined downwardly away from
the hopper opening 66. The vibration of the hopper tends
to shift the separated foreign matter towards the shelf.
The ramp and shelf vibrate in conjunction with the hopper
so that the foreign matter tends in the direction of
arrow 72 by the combined effect of gravity and the
vibratory conveying force imparted by motor 46.
The shelf 68 resides in a chamber 71 abo~e a
floor 74 at the bottom of the chamber and has openings 76
to permit passage of a first size material which drops to
the floor 74 and moves in the direction of arrow 78 to a
point of collection. Material unable to pass through the
shelf discharges from the upper portion of the chamber
separately fxom the smaller size particles. By
separating the foreign ma~ter as the castings move along
the length of the separating structure, the foreign
matter does not find its way back into chambers and/or
crevices defined by the castings or reattach to the
castings. Upon exiting the separation structure, the
castings are rolled over and any remaining foreign matter
separated at station 18.
In one preferred form of the invention shown in
Figs. 4-6, a tumbling apparatus for mixing, cleaning,
~2~i7~385
and/or shake out of parts is designated by the numeral
110 and comprises a container 112 which in the
illustrated form is a cylindrical drum and a vlbration
generator 114. The container 112 could be an open top
member, an oval member or any desired shaped member as
long as it has a horizontal axis. ~he container 112 is
attached at each end to end plates 116 of a frame 118.
In addition to the end plates 116, the frame has a bottom
plate 120 connected to the end plates with corner
reinforcing gussets 122 extending between the container,
an end plate and the bottom plate ~or supporting the
container 112. Gussets 124 extend ~etween a flange 126
and the end plates in the vicinity of the corners of the
machine to provide reinforced pads at the corners. The
machine is resiliently supported on a foundation or base
128 by means of springs 130 attached to the pads on the
flanges 126 and to the foundation. The springs 130 may
be coil springs, as shown, or may be air ~prings or the
like.
The containex 112 has an inlet port 132 near
the high point o the container at one end portion and is
comprised of a flanged opening 134 having a funnel shaped
hopper 136. The inlet port 132 could be through the hiqh
part of the end plate 116 just as well. An outlet port
138 is formed through the.side wall o the containex
upward of the low point of the container and at the
opposite end of the container from the inlet port. The
outlet port 138 can be opened or closed, but when opened,
has a platform 140 over which the discharged parts and/or
media flows. A conveyor 142 communicates with the outlet
port for conveying discharged parts andjor media away
from the machine. The discharge or outlet port 138 could
be through the low point of the cylinder of the container
~78~3S
--10--
for certain applications. It will be noted in Figure 5
that the horizontal axis 139 of the container angles a
few degrees from the horizontal so that the outlet end of
the container is lower than the inlet end. This
S accommodates flow of the material through the container
as the tumbling, mixing, polishing and/or shake-out is
taking place.
A bracket 144 includes a pair of spaced apart
mounting supports 146 is affixed to the container on one
side of the vertical axis of the container. The ends of
the supports 146 spaced from the container have a
substantially horizontal edge 148 with an aperture 150
through an end portion of each support in horizontal
alignment with each other. A horizontal axis 152
connecting the centers of the two apertures 150 is
parallel to the horizontal axis 139 of the container. As
shown in Figur~ 4, a line 154 drawn through the center
(at the horizontal axis 139) of the container 112 and the
centex (horizontal axis 152) of the apertures 150 of the
bracket 144 forms an angle A to the vertical axis 156 of
the machine. As shown, the angle A between line 154 and
vertical axis 156 o the container is approximately 45.
The bracket 144 also has a mountinq deck 158 between the
supports 146 and, as shown, the deck is pivotally rnounted
to the supports 146 by pi~ot pins 160 passing through
apertures 162 in depending flanges 164 on the deck and
through the apertures 150 in the supports 146. The deck
158 is locked in position relative to supports 146 by
means of a pair of ~olts 166 passing through ~rcuate
slots 168 in the supports 146. When the bolts 166 are
ti~htened down, the deck 158 is locked in place on the
supports on the container. For the purposes of Figure 4,
the surface of the deck 158 lies in a plane perpendicular
~IL2678~
to the vertical axis 1S6 and parallel to the horiz~ntal
axis 152 of the pivot pins 160.
The vibration generator 114 comprises a support
plate 169 resiliently mounted on the deck 158 of the
bracket 144 by a plurality of springs 170. A motor 172
is mounted on the support plate 169 with the axis of the
double ended drive shaft 174 lying substantially parallel
to the longitudinal axis 139 of the container. Eccentric
weights 176 are mounted on each end of the double ended
shaft and are encased in covers 178. Variable ~orce
vibration generators such as the types shown in my U.S.
Patent No. 4,495,826 and 3,358,81S may be substituted for
the eccentric weights 176 on each end of the shaft 174.
As illustrated in Figures 4-6, the linear vibratory
lS forces are generated by a two mass system, the motor 172,
plate 169 and weights 176 beinq one mass, and the
container 112, bracket 144 and frame 118 being the second
mass. The vibration generator 114 as shown in ~igure 4
has an axis 180 which is vertical and intersects the axis
154 of the pivot pins 160 and is perpendicular to the
support surface or foundation 128.
Operation of the vibration generator 114 will
produce vibratory forces 182 (illustrated generally by
the double ended arro~) along a linear path axis 180. As
shown, the path 180 and t-he linear forces 182 pass
exteriorly o the container 112. The path 180 may
intersect the container, but it should not go throuqh the
center of gravity of the container.
When the apparatus shown in ~igs. 4 and 5 is
operating and the vibration generator is producing linear
vibratory forces along the axis 180, the container 112
will move in an arcuate pathl basically segments of a
circle, having a center of rotation offset from the
~267~385;
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. .
center of the container and located at point R. The
material within the container in contact with or close to
the inside surface will be moved along an angle of attack
with respect to the inside surface of the container. The
angle of attack is arcuate, basically a segment of a
circle centered at R.
The center of rotation R is either a point or a
small closed figure such as a small circle or ellip~e
which for all practical purposes may be considered to be
a point. The point R will lie along a line passing
through the center of gravity CG of the container and
intersecting the linear line of force 182 at an angle of
90. That intersection is on one side of the center of
gravity CG and the point R will be on the other side of
the center of gravity.
The center of rotation R should be offset from
the center of the cylindrical container. If the contain~
er is not cylindrical but has a concave material support-
ing surface, the center of rotation R should be offset
from the centers of circles osculating said concave
surface.
To illustrate the concept, see Fig. 10, a sheet
of paper was affixed to one end of the container 112 and
the vibration generator 114 was energized and tuned to
resonance, thereby producin~ a linear force 182 along the
axis 180. A stylus carried by an immovably fixed support
OD the foundation or stationary surface 128 was engaged
.
Webster's New Collegiate Dictionary 1975 defines an
oscu ating clrcle as a c whose center lies on
the concave side of a curve on the normal to a given
point of the curve and whose radius is equal to the
radius of curvature at that point~.
lZ~;7~38~;
with the paper at various points on the end plate in
alignment with the surface of the container. A tracing
of the movement of the container, indicated at 184, was
subscribed on the paper by the stylus. The stylus was
spotted against the paper and container, a multiplicity
of times in the vicinity of the center of rotation until
the point R was located; that is, the point about which
the container rotated. By drawing radii 186 from point R
to the tracings, it was found that the tracing segments
of a circle are centered at R.
The movements 184 along the bottom (or low
point) of the container are directed inward into the mass
with an angle of attack to produce conveying action of
the media and parts. The moYements 184 acting on the
working media 188 and/or parts 190 in the container
provide a vigorous and effective counter-clockwise path
of motion to the media and parts in the container. The
parts and media are conveyed up the inner surface of the
container adjacent the vibration generator before falling
back into the container. The vigorous circulatory motion
provides improved tu~bling o~ the parts in the media to
increase the speed and effectiveness of the mixing in the
container and of the burnishing and polishing of the
parts. Due to the slight tilt to the axis 139 of the
container 112 to the hori~ontal, the parts, as they are
tumbled, will migrate from the inlet end to the discharge
end of the container. In the alternative, with the axis
139 of the container horizontal, the amount of material
added at the inlet 136 will determine the amount of
material discharged at the outlet port 138. The outlet
port 138 can be open or closed (shown open in Figure 4).
When outlet port 138 is open, the media and parts will
exit the container on the ramp I40 at the upper portion
~885
of the circulatory path. The ramp 140 can be foraminous
to permit the media to fall down into a collection
receptical prior to being returned to the container or,
as shown, the paxts and media are delivered onto the
conveyor 142 and will be conveyed to the next processing
station. The inner surface of the container may be
coated or lined 183 with a material having a particular
coefficient of friction to aid in the conveying action
and to improve the tumbling of the parts. The lining
acts as a wear surface and can be replaced when worn.
The character of movement of the container and
handling of the material within the container may be
altered or modified by moving the location of the center
of rotation R. The position of R will change if the
direction of the linear vibratory forces change. Simi-
larly, the position of R will change if the center of
gravity CG is changed such as, for example, by adding
weights to the container. Incidentally, when the center
of gravity of the container is referred to, it includes
not only the container 112 but all parts attached to the
container between the springs 130 and the springs 170.
The effects of changing the direction B2 of the
vibratory forces is illustrated in Fig. 7. In this case
the bolts 166 were loosened and the vibration generator
114 was tilted to incline the line o vibratory forces
182 some 5 from vertical and the line of vibratory
forces angled toward the container. Inasmuch as the
center of rotation R lies on a line normal to the line of
force and passing through the center of gra~ity CG, R
will assume a new position as shown in Fig. 7. With R in
a new position, points on the inner surface of the
container will move in a arcuate path or segments of a
circle centered at the new location of R. This imparts a
781~
vibratory conveying movement to the material adjacent or
in contact with such point to move along such paths
thereby providing a different character of movement of
the mass o material inside the container. The effect
that will be first noted with the relocation of R is the
change in the slope of the material within the container.
A valuable and perhaps surprising characteris-
tic in the operation of the apparatus shown when use~ as
a vibrating tumbling apparatus where parts and a media
are placed within the container is that the parts them-
selves will remain immersed in the media. This is of
importance not only in enhancing the cleaning and bur-
nishing effect of the operation but also prevents damage
to the parts being treated which would occur if the parts
surfaced and vibrated directly against the interior
surfaces of the container and against each other.
Figs. 8 and 9 show the machine 110 with the
axis of the vibration generator 114 tilted to a 95~ anqle
as in ~ig. 7. A baffle or deflector 192 is selectively
located in the container with Fig. 11 showing the flow
pattern and forces acting on the material when the
deflector 192 is added to the systern. A11 of the
structural elements of Fig~ 8 that are the same as the
structural elements of Figure 4 will bear the same
reference numerals. The line of vibrational force 182 is
external of the containex. The instantaneous center of
rotation R will be located at point R so that the
movements 184 acting on the material in the drum will
subscribe the appropriate angle of attack with the
surface of the container.
The baffle 192, which in Figs. 8 and 9 is
cylindrical but which could be square, rectangular, tear
drop shape or the like in cros.s section, extends from end
7885i
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to end of the container 112 between the end walls 116 and
can be adjusted to any desired position using appropriate
means. The baffle or deflector 192 deflects a portion of
the media over the outside of the deflector changing the
pattern of flow of media and parts 190 in the container.
The baffle can be set so that only media goes over the
deflector so that the parts remain submerged in the
media. The tumbling and mixing of the media was more
pronounced and the media and parts climbed higher in the
container before the media cascaded back down over the
deflector. With the deflector 192 adjusted so that it
was closer to the container walls, the parts were
sometimes exposed on the surface of the media but once
the parts 190 tumbled over the deflector, they
re-immersed in the media thereby minimizing scratching
and bumping between the parts.
The deflector 192 may be provided with
openings, or ports 193, see Figure 12, through which hot
air for heating the media or cold air for cooling the
media can be piped. Burner jets could be provided in the
deflector with the nozzles pointing into the media. When
ignited, the jets would burn off carbonaceous particles
on sand being processed and cleaned.
The line of force 182 along the axis 180 of the
vibration generator passes e~terior of the container or
intersects the container, but does not pass through the
center of gravity of the container.
Although I have described the improved tumbling
apparatus as employing a two mass system, such as shown
at 114 in Figure 4, the apparatus does operate
effectively with any lînear vibratory force system
mounted directly on the container and producing a linear
line of force. The vibration generator 114 is shown
12~;713~5
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upward and to the right of the container 112. It is to
be understood that the vibration generator may be located
at other positions as long as the line of force 182 is
suhstantially offset from the center of gravity of the
apparatus and so long as the center of rotation is not on
the vertical centerline of the container 112. Thus, as
all points on the material supporting surface of the
container are moved in segments or paths of different
circles having a common center at R, such segments or
paths are not parallel.
