Note: Descriptions are shown in the official language in which they were submitted.
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This is a division of Canadian Patent Application Serial No.
993,116, filed June 15, 1967.
This invention relates to a method and apparatus for the surface
treatment of objects of large dimension and particularly heavy metal objects
such as cast metal cylinder heads and the like, and it relates more parti-
cularly to a continuous operation for the surface treatment of heavy metal
objects by centrifugally blasting the surfaces with particulate material, such
as abrasive, grit, shot and the like, for surface cleaning or for surface
peening and the like.
In the copending application, Ser. No. 989,192, filed April 28, 1967,
and entitled "Method and Means for Continuous Surface Treatment", description
is made of a new process and e~uipment for surface treatment of heavy metal
objects in a continuous cycle, wherein use is made of a plurality of open
cages supported at their ends on ring members to enable the cages continuously
to be rotated. The cages are cycled to a loading station wherein heavy metal
objects are inserted into the cages and the loaded cages are displaced onto
the leading end of a roller conveyor. The roller conveyor is formed of a
pair of laterally spaced apart turning rolls which extend continuously through
an enclosed blast zone having one or more centrifugal throwing wheels for
pro~ecting particulate material at high speed onto the loaded cages as they
are advanced along the roller conveyor from the entrance end through the blast
cabinet to the exit end of the conveyor.
The rolls of the conveyor are turned continuously to cause the load-
ed cages continuously to turn as they are advanced along the conveyor through
the blast cabinet whereby maximum surface exposure is made of the castings
to the particulate material.
In the aforementioned copending application, the loaded cages are
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advanced along the loaded conveyor through the blast cabinet by incremental
displacement of each loaded cage as it is deposited on the leading end of the
conveyor thereby to align the cages in end to end relation for advancement
in a single column ~hrough the blas* cabinet. Beyond the blast cabinet, the
loaded cages are displaced from the roller conYeyor to an unloading station
where the surface treated castings are displaced endwise from wlthin the cage
and the empty cage is returned by another conveyor to the head end of the
machine for use in another cycle of operation.
While the apparatus described is capable of continuous operation
for the treatment of such heavy metal objects at relatively high speed and
with uniform coverage of the surface, thereby to provide increased output per
unit time, it is desirable still further to reduce the number of operating
steps embodied in a complete cycle thereby to reduce the amount of equipment,
space and costs of the entire operation.
Thus it is an object of this invention to produce an apparatus and
method suitable for the treatment of objects of large dimension and/or of
heavy weight with particulate material thrown at high speed onto the surfaces
with maximum coverage of the surfaces of the object, in which such operations
can be carried out with a minimum.number of handling steps in processing the
objects through the equipment, in which the process can be carried out in a
manner to enable automation of the equipment through a full cycle of operation,
and it is a related object to produce a method and apparatus of the type
described which is relatively simple in construction and easy in operation,
which is capable of operation without the need for highly skilled labor or
sensitive controls, and in which the objects are fully exposed to the blast
media for surface treatment, in which the blast media is released from the
objects during rotational movement for more complete delivery of the blast
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media for re-use and for retentlon of less of the blast media in the pockets
or other crevices in the treated objects.
Accordingly, in one broad aspect, the invention resides in a
process for surface treatment of articles by the engagement of the surfaces
with particulate treating material, the ~teps of providing an elongate open
cage having a continuous passage extending therethrough from an entrance at
one end to an exit at the other, continuously turning said cage for rotational
movement about its axis, inserting articles endwise into the passage through
the entrance of the turning cage and whereby the articles become aligned in
end to end relationship within said passage for displacement of the aligned
articles lengthwise through said passage from the entrance end towards the
exit end responsive to said insertion of the article and whereby the articles
turn with the cage during lengthwise displacement therethrough, and throwing
particulate treating material onto an intermediate portion of said cage be-
tween the entrance end and the exit end while the cage is being rotated
thereby uniformly to expose the surfaces of the articles within the cage to
the particulate treating material, each of said articles being brought up to
a speed of rotation corresponding to the speed of rotation of the cage, prior
to insertion therein, by inserting the article into a separate feed cage,
aligning the loaded feed cage with the main cage, and rotating the feed cage
for orientation with the rotating main cage and then displacing the article
from the rotating feed cage into the aligned rotating main cage.
. In another broad aspect, the invention resides ln a machine for the
surface treatment of articles, comprising an elongate open maln cage having a
continuous passage extending therethrough from an entrance at one end to an
exit at the other end, said main cage being formed of elongate bars circum-
ferentially spaced one from the other and being formed with ring members at
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its ends, said bars tapering outwardly to the ring member at the entrance end
to deflne a tapered entrance section for displacement of the articles into
the cage, means mounting the maîn cage for rotational movement of the entire
cage about its axis, feed means adjacent the entrance end of the main cage
for alignment of articles with the passage through the main cage and for
bringing the articles up to the rate of rotation of the maln cage for proper
orientation therewith, ram means for displacement of the article axially from
the feed means into the aligned passage of the rotating maln cage through the
entrance end thereby to effect endwise displacement of the articles aligned
in the passage of the main cage for a distance correspondlng to the length
of the article, an enclosure about a portion of the main cage between the
entrance end and the exit end, means ~ithin the enclosure for throwing par-
ticulate material onto portions of the rotating main cage within the enclosure
for uniform engagement of the surfaces of the articles rotating therewith,
and delivery means at the exit end for receiving the artlcles displaced from
the maln cage.
In a further aspect, the invention resides ln a machine for the
surface treatment of articles comprising an elongate open main cage having a
continuous passage extending therethrough from an entrance at one end to an
exit at the other end, means mounting the main cage for rotational movement
of the entire cage about its axis, feed means adjacent the entrance end of the
main cage for alignment of articles with the passage through the main cage
and for bringing the articles up to the rate of rotation of the main cage for
proper orientation therewith, ram means for displacement of the article axial-
ly from the feed means into the aligned passage of the rotating main cage
through the entrance end thereby to effect endwise dlsplacement of the articles
aligned in the passage of the main cage for a distance correspondlng to the
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length of the article, an enclosure about a portion of the main cage between
the entrance end and the ex~t end, means w~thin the enclosure for throwing
particulate material onto portlons of the rotating main cage within the
enclosure for uniform engagement of the surfaces o the articles rotating :
therewith, and delivery means at the exit end for receiving the articles dis-
placed from the main cage, wherein said feed means comprises a separate feed
cage having spaced ring supports and a passage extending therethrough corres-
ponding to the passage through the main cage, rollers on which the rings rest
for support, means for effecting turning movement of the rollers while the
feed cage is ln endwise alignment with the main cage for rotational movement
therewlth, means for stopping rotational movement of the cage, ram means for
insertion of an article axially into the feed cage while ~n stopped position
and ram means for displacement of the article from the loaded feed cage while
rotating in alignment with the main cage.
The foregoing, and other objects and advantages of this lnvention
will herelnafter appear and for purposes of illustration, but not of limita-
tlon, embodiments of the invention are shown in the accompanylng drawings,
in whlch - t
Figure 1 is a schematic sectlonal elevatlonal view of the device
embodying features of thls lnvention;
Figure 2 ls a schematic elevational view of the roller drlve for
' the main cage;
~igure 3 ls a sectional elevational view of the idler supports for
lntermediate portions of the main cagej
~igure 4 is a schematic sectional elevational Yiew showing a modi-
fication for loading ob~ects into the continuously rotating main cage;
Figure 5 is an elevational view of the loading cage and support
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shown in Figure 4;
Figure 6 is a schematic elevational view of one modification for
driving the main cage;
Figure 7 is a sectional elevational view of a modification for the
idler support of the main cage formed of separate cages;
Figure 8 is a schematic sectional view across the blast section;
Figure 9 is a schematic view of a modification in a means for pre-
loading objects for loading into the main cage;
Figure 10 is a sectional view taken along the line 10-10 of Figure
9; and
Figure 11 is a perspecti~e schematic vie~ of an alternate arrange-
ment of a machine o the type to which this in~ention relates.
The invention will be described with reference to the treatment of
large metal castings, such as cylinder heads, but it will be understood that
the concepts of this invention, and the machine and method described therein,
are applicable equally well to other objects of large dimension or of heavy
weight in which it is desired to effect an overall surface treatment such as
blast cleaning, blast peening and the like.
In accordance with the practice of this invention, use is made of
an open cage of the type described in the aforementioned copending application
except that, instead of making use of a plurality of separate short cages in
which castings are loaded at one station for displacement onto the conveyor
and for incremental displacement of the separate cages along the roller con-
veyor for passage in end to end alignment through the blast cabinet, use is
made of but a single elongate open cage 20 which extends continuously through
the blast zone 22. The castings 24 are advanced in end to end relation from
the entrance end to the exit end of the elongate cage for passage through the
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blast housing 26 as the elongate cage 20 is rotated for maxlmum exposure
of the surfaces of the castings to the blast media 28. ~eans are provided
at the entrance end of the elongate open cage ~or the insertion of castings
individually therein for displacement endwise through the cage and other
means are provided at the outlet end for recei~ing the castings as they issue
from the open cage after having passed through the blast cabinet.
Thus the effect ~ecured is similar to that described in the copend-
ing application but, instead of making use of a plurality of separate cages
which require recycling between the unloading and loading zone and delivery
from the loading zone and to the unloading zone from the roller conveyor,
only a single cage is employed which is adapted to be rotated in a set posi-
tion and through which the castings are advanced for movement endwise through
the cage.
Having briefly described the concepts of this invention, detailed
description will now be made of the construction and operation of the machine. `
; The elongate open cage 20 comprises a plurality of circumferential-
; ly spaced apart elongate bars 30 fixed at their ends onto ring members 32 with
the circumferentially spaced apart bars definlng an open space therebetween
dimensioned to correspond to the cross-sectional dimenslon of the casting to
enable the casting to be received in supported relationship between the bars
but in a manner to enable sliding movement of the castings lengthwise through
the open space from one end to the other of the open cage.
The rlng members 32 at the ends are of larger diameter than that of
the circumferentially arranged bars and the leading end portions 34 of the
bars are tapered gradually outwardly to the ring members to deflne a tapered
entrance portion 36 for easier insertion of the castlngs lnto the cage.
~or maximum exposure of the surface to the partlculate blast media,
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it is preferred to form the cage bars 30 of bar stock of tubular or rec-
tangular shape for minimum contact with the supported casting. It is also
preferred to space the bars loosely to receive the casting therebetween so
that, during portions of the rotation movement, the bars will ~ecome spaced
from the casting by an amount sufficient to enable the particulate blast
material to gain entrance therebetween for surface engagement. Use can be
made of a variable number of supporting bars 30, depending somewhat upon the
construction and shape of the castings but, it is undesirable to make use
of less than three essential for a three-point support of the casting and it
is also undesirable to make use of so many bars as ~ill excessively ~ock ex-
posure of the surfaces of the casting. For best practice, it is desirable to
make use of from three to six bars in circumferential arrangement.
While the open cage can be formed into a single length stretching
continuously from the entrance end to the exit end, it is preferred to sub-
divide the open cage into sections of shorter lengths aligned in end to end
relationship and interconnected one to the other for turning movement as a uni-
tary structure.
When formed of a single length, means are provided in longitudinal-
ly spaced apart relation to support the load carried by the cage. As illus-
trated in Figure 2, the single length of cage is provided with ring members 32
at the opposite ends mounted on rollers 40 and 41, both of which are turning
rollers interconnected by gears 42 to a driving motor 44 for rotational move-
ment of the driving rolls to impart corresponding rotational movement to the
rings and the single length cage member. For support of the cage intermediate
the ends, laterally spaced apart ring members 46 and 48 are fixed to the
bars and the ring members 46 and 48 are adapted to ride on idler rollers 50
mounted for free rotational movement in suitable bearing members 52 mounted
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within a frame 54 whereby the rings turn easily on the supporting rollers for
intermediate support through the length of the cage. In this construction,
it is desirable to locate the intermediate supports outwardly of the blast
cabinet to avoid excessive wear on the rollers by the blast material.
W~en~ as in the preferred practice of this invention, the length of
cage is subdivided into separately aligned but interconnected sections A, B
and CJ it is preferred to form each section with its own rings 52 and 54 at
each end for interconnection of the sections one to another in the aligned
relationship. Each section is thus formed with a tapered entrance portion 34
~t the forward end by tapering the bars outwardly to the ring members 52
thereby to enhance the smooth passage of the castings from one section to the
next.
The subdivision of the cage into separate sections is preferred not
only for load distribution, ~ut also to enable replacement of the center
section exposed to greatest wear while located in the blasting zone, without
the need for replacement of the other sections of the cage.
The ring members 52 and 54 at each end of each section are adapted
to ride on supporting rollers 56 and 58 with the end rollers constituting the
driving rolls while the intermediate sets of rollers can be idler rolls which
turn with the cage for support of the cage intermediate its length.
~eans may be provided for driving the cage for turning movement
independent of the supporting rollers. For such purpose, a ring gear 60 can
be employed instead of, or in addition to, the end rings 32 with the teeth
of the gear meshing with teeth of a motor driven gear 62 to effect rotational
movement of the cage. Such positive driving means can be provided at both
ends of the cage or only at one end. In the event that such driving means are
employed, the supporting rolls at the ends of the cage may constitute free
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turning idler rollers on which the end rings rest.
An intermediate portion of the cage is enclosed by a blast cabinet
26 dimensioned to have a length corresponding to a multiple of the castings~
such as a length corresponding to five to eight castings, in the modification
illustrated in the drawings. The cabinet, in the form of a sheet metal
housing, is provided with an entrance opening 64 and an exit opening 66
through which the cage extends.
Mounted on top of the blast cabinet are a plurality of wheeels 70
which are fed particulate treating material from a supply bin 72 which communi-
cates with the wheels through the feed tubes 74 whereby the partîculate
material is thrown outwardly from the periphery of the wheels in the direction
downwardly onto the loaded cage while the latter is being rotated. Centri-
fugal blasting wheels of the type described are of conventional construction,
as represented by the wheels marketed by The Wheelabrator Corporation under
the name "W~eelabrator" and more fully described in United States patent No.
2,819,562.
By proper location of the wheels 70 within the blast cabinet and by
proper angular arrangement of the wheels, substantially the entire length of
the section of the cage within the blast cabinet can be exposed to the blast
of particulate material for processing the surfaces of the castings displaced
endwise through the cage.
By reason of the ricochet of particulate material, thrown at high
velocity onto the surfaces of the castings, surfaces which might otherwise
be concealed are exposed to the blast whereby substantially uniform coverage
is secured in treatment of the surfaces of the csstings with particulate
materials.
The spent particulate material falls gravitationally into the trough
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74 at the bottom for displacement along the bottom by a conventional screw
76 to a lateral screw whereby the particulate material is deposited in an
elevator 78 and raised to a separator 80 where the dirt or other refuse is re-
moved from the particulate material whereby the latter can be returned to the
hopper 82 for re-use.
T~e castings are exposed to the blast of particulate material for
the period of time corresponding to the time that the castings are within the
portion of the cage enclosed by the cabinet. Rotation of the castings with 3
the cage operates not only to provide maximum exposure of the surfaces of the
castings to the treating material but rotational movement of the castings
operates also to du~p particulate material which might otherwise collect in
the pockets of the castings thereby to keep said pockets free of particulate
material so that further blast will continue to hit the surface of the casting
in the pockets and not be masked from the blast by accumulated particulate
material and thereby to deliver a casting which is clean and relatively free
of particulate material and thereby also to reduce the amount of loss or waste
of particulate material.
Since the portion of the cage located within the cabinet is exposed
to the blast of particulate material, it is preferred to fabricate at least
that portion of the cage of a metal which is characterized by high erosion
resistance. In a typical operation for cleaning cylinder heads, the blast
cabinet 22 is dimensioned to correspond to six lengths of castings and it is
provided wlth four blasting wheels arranged in longitudinally spaced apart
relationship within the housing. The cage is adapted to be rotated at a rate
of about 15 revolutions per minute and the castings are displaced through the
cage at a rate of about 200-1000 castings per hour, depending somewhat upon
the means for introducing the castings into the cage.
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The portions of the cage in advance of and beyond the blast housing
26 are preferably enclosed by vestibules 26' to minimize ricohet of blast
media into the surrounding atmosphere.
Having described the construction of the open cage and the blasting
zone operative over an intermediate length of the cage, description will now
be made of the features for the insertion of ca.stings into the leadîng end of
the cage and for the deliver~ of the castings after they have passed through
the cage.
A number of Yery important ~rohlems arise in the feeding of the
castings into-the cage for passage through the cage from the entrance end to
the exit end. In the feeding of the castings, it is desirable to achieve
proper orientation between the cage and the castings so that the castings will
be in proper position for insertion into the cage. This might be accomplished
quite easily by stopping rotational moYement of the cage in a predetermined
position and for a time sufficient to insert the casting. It is preferred,
however, to be able continuously to rotate the loaded cage for uniform ex-
posure of the surfaces to the particulate material while making use of other
means for proper orientation of the castings and for uniform periodic in-
sertion into the entrance end of the cage.
~ne wa~ in which this can be accomplished, in accordance wlth the
practice of this invention, ~s to make use of a separate feed cage 90 dimen-
sioned to receive a single casting and in which the cage is mounted on rollers
92 and 94 in endwise alignment with the main cage 20 whereby rotational move-
ment of the separate feed cage 90 can be stopped or a time sufficient to
enable a casting to be inserted therein while the main cage continues to be
rotated. The loaded feed cage 90 can then be brought up to a speed of rotation
by the rollers 92 and 94 until the rotational movement of the loaded feed
6~L~
~ cage 90 becomes synchronized with the rotational movement of the main cage
: whereafter the casting can be displaced endwise from the rotating feed cage
90 into the continuously rotating main cage 20.
F~ this purpose, use can be made of a single cage of the type des-
cribed in the aforementioned copending application wherein the cage is formed
of a plurality of circumferentially spaced apart bars 96 joined at their ends
to supporting ring members 98 of larger dimension with the bars 96 at the
entrance portion tapering outwardly, as at 100, to the ring members to provide
a funnel-shaped feed opening 102 which facilitates entrance of the casting
therein. One of the cross connecting bars 96 is provided with an abutment 104
extending outwardly therefrom for a distance less than the periphery of the
supporting rings 98. T~e abutment is employed for engagement with stops to
position the cage member on the supporting rolls, as wlll hereinafter be
described.
Por this purpose, use can be made of a loading station of the type
described in the aforementioned copending application but without the need
of means for displacement of the loaded cages onto and off of the rollers 92
and 94. The loading station, aligned in endwise relationship with the main
cage, comprises a pair of laterally spaced apart spinning rollers 92 and 94.
The rollers are longitudinally spaced apart on shafts 106 and 108 by an amount
corresponding to the spaced relationship between the ring members 98. The
ends of the shafts 106 and 108 are rotatably supported in bearings 110 fixed
to a structurally strong and rigid frame section 112. The shafts are provided
at thelr ends with gear members 114 operatively interconnected to gears 116
on the shaft of a driYing motor 118 to effect rotational movement of the spin-
ning rollers.
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Thus the cage 20, at rest on the spinning rollers 92 and 94, can
be rotated by the rollers until stopped in proper orientation for receiving
the castings. A cage stop 120 and limit switch 122 are provided with the
upper end of the cage stop adapted to be rocked into and out of the path of
the abutment 104 to stop rotational movement of the cage on the spinning
rollers 92 and 94, when t~e cage is in proper alignment for receiving the
casting. T~us the spinner rollers operate to rotate the cage until the cage
is stopped by the arm 120 thereby to block further rotational movement of
the cage from its proper oriented position until the casting has been inserted
therein.
T~e casting mounted on a slat conYeyor in endwise alignment with the
feed cage is adapted to be inserted into the feed cage ~y a pusher means.
The pusher means comprises an elongate ram 124 suspended from the frame 126
on the underside of a carriage 128 supported on rollers 130 for endwise dis-
placement between operated and retracted positions of adjustment with the
piston of a fluid cylinder 132 to which it is interconnected. The frame 148
supports the ram at one end with the ram ln endwise alignment with about the
center of the cage and at a level slightly above the top run of the conveyor
134 and with the end of the ram spaced a short distance rearwardly of the
conveyor when in retracted position. The rollers 130, which support the
carriage, operate in tracks rigid with the frame 112. Limit switches are
provided including a switch 136 positioned to be engaged by a trip 138 on the
carriage to signal displacement of the carriage to its first operated posi-
tion of adjustment. Another switch 140 is located beyond the first to be
engaged by the trip 138 to signal displacement of the carriage to its second
operated position and a third switch 142 is spaced rearwardly of the second
switch 140 by an amount corresponding to the full stroke of the piston to
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signal return of the carriage to its retracted position. The first portion
; of the stroke is dimensioned to have a length calculated to effect displacement
of the ram 124 by an amount corresponding to the distance between the end
portion 125 of the ram and the cage whereby a casting on the conveyor, in end-
wise alignment with the cage and in the path of the ram, will be displaced
by the ram forwardly off of the con~eyor and into the cage in response to
movement of the piston from retracted position to the first operated position.
The second portion of the forward stroke is dimensioned to have a length cal-
culated to displace the casting from the feed cage into the main cage whereby
the casting in the feed cage will be displaced from the feed cage into the
main cage after the loaded feed cage has heen brought up to turning speed and
synchronized with the main cage.
It is preferred to proYide for a stroke which is slightly greater
than the distance between the cage and the ram, when the latter is in retract-
ed position, so that the casting will be ~ntroduced into the cage beyond the
rIng member 98 by an amount to balance the casting for centering the casting
substantially equidistantly between the ring members. It will be understood
that other reciprocal means fo~ llnear displacement of the ram can be employed
insteat of a fluid cylinder such as a screw actuator and the like. Return of
the carrlage to retracted positîon ls signalled by the limit switch 142 adapt-
ed to be engaged by the trip 138.
Orientation at the delivery end of the cage is not necessary. Thus
it will suffice merely to provide a chute or conveyor 144 which will recei~e
the casting as it is displaced from the end of the rotating cage for convey-
ance of the casting from the processing machine.
In operation, the feed cage 90 is allowed freely to be rotated by
the supporting rolls92 and ~4 until stopped in oriented position in response
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to displacement of the stop arm 120 into the path of the offset 104 whereby
the cage is held in oriented positîon on the rollers which continue to rotate.
In sequence, operation of the limit switch 122 in response to stop-
page of the cage 90 will initiate operation of the fluld cylinder for displace-
ment of the carriage from retracted position to the first posltlon of
adjustment whereby the casting on the slat conveyor in endwise alignment with
the cage will be engaged ~y the ram for displacement forwardly from the con-
Yeyor into the cage. When the switch 136 is made to lndicate completion of the
first stroke, the stop pin 120 is withdrawn from the path of the offset 104
thereby to free the loaded cage to rotate with the rollers 92 and 94 to speeds
calculated to correspond with the rotational movements of the main cage for
proper orientation therewith. To achieYe orientation, it is desirable to
proYide for rotational moYement of the cage on the rollers 92 and 94 at a
speed of rotation which dlffers slightly from the speed of rotation of the
main cage and preferably at a slightly higher speed so that, during rotation,
an arm which may be extended lengthwise from one cage for engagement with the
abutment of another will operate to lnter-engage the cages for rotational
movement together. Said ar~ can be retracted responsiYe to the displacement
of the casting rom the feed cage to the main cage to free the feed cage for
its next cycle of operation.
When the time lapse is sufficient to achieYe proper orientation, the
fluid cylinder passes through its second stage of operation whereby the carri-
age is ad~anced to its second moYement to effect displacement of the casting
from the rotating feed cage into the main cage. This then frees the feed cage ;
for another cycle while the displacement of the casting into the main cage
will operate to effect displacement of all of the castings aligned in end to
end relationship in the rotating main cage for one increment corresponding to
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the length of the casting. The endmost casting aligned in the main cage will
be displaced from the cage and onto the conveyor or chute 144 for transporta-
tion from the machine.
Thus the castings are adapted to be displaced forwardly through the
rotating main cage and through the blast cabinet. During passage through the
blast cabinet, the castings will be rotated with the cage to effect maximum
exposure of all of the surfaces of the castings to the particulate material
thrown from the wheels. In addition, the constant turning movement of the
castings will operate effecti~ely to dump the particulate material for more
complete remoYal from the castin~s and for more complete recovery of parti-
culate material for re-use and thereby also to keep pockets free of particulate
material which might otherwise mask the surface from the blast.
In the preferred practice of this invention, it is desirable to re-
tract the ram a short distance after displacement of the casting from the
conveyor into the feed cage so as not to interfere with the rotational mo~e-
ment of the casting with the feed cage. This can be accomplished by a short
reverse stroke after the first stroke, in response to the making of the first
switch 136.
When the forward stroke has been completed and switch 140 has been
made, the carriage and ram are returned automatically to retracted position
in response to p~eparation of the next cycle of operation. T~is is signalled
by the making of switch 142 whereby the signal is transmitted to the stop arm
120 for rocking movement into position to block the continued rotational
movement of the feed cage on the feed rollers in oriented position.
As previously pointed out, the feed operation of the castings into
the main cage can be effected by stopping rotational movement of the main cage
for a time sufficient to displace the casting into the entrance end portion of
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the main cage. For this purpose, the casting 24 would be brought into position
in endwise alignment with the main cage 20 on the slat conveyor 134 for dis-
placement endwise in~o the main cage when the latter has been stopped in pro-
perly oriented position. T~e construction and operation of elements for
carrying out the described steps would be the same as that pre~iously described
for feeding the castings into the feed cage except that the feed cage would be
replaced by the main cage for a single step displacement by the ram for move-
ment of the casting from the conveyor into the main cage. Thus the fluid
cylinder would operate to its first stop and back to bring the end of the ram
124 into engagement with the rear portion of the casting 24 on the con~eyor
134 for displacement of the casting from the conveyor directly into the
aligned main cage as the fluid cylinder operates to advance the carriage 126
through its first stroke to engage the stop switch 136. This signals the
completion of the feed cycle whereby the stop 120 is withdrawn from engagement
with the cage to permit renewal of its rotational movements on the rollers 32.
This technique of stopping the cage in its rotational movement will
operate to slow the output of the machine by ~eason of the time lost in stop-
ping and starting the rotational movement of the loaded cage and it will
operate to expose the surfaces of the castings unevenly to the blast material
since the portion facing the blast during the feeding operation will be ex-
posed to more blasts than the remainder. However, the foregoing does provide
a workable system for advancing the castings into and through the cage for
surface treatment.
T~USJ instead of ad~ancing the castings rom the stopped feed cage
for subsequent transmission from the rotating feed cage to the rotating main
cage, the castings are rammed directly into the stopped main cage, using
about one-half o the feed cycle previously described but in which the opera-
- 18 -
- . .. .
. ' `. ; - ' '' : ;~, ' ' : '
. ~ : : . - . . : .
~ ~i4~
tion is otherwise substantially the same, with substantially the same means,
but substituting the main cage for the feed cage.
Another technique which is effective further to increase the feed
rate for higher production and output of the machine is illustrated in Figures
9 and 10. Instead of making use of a single feed cage which passes through
the cycle of stopping rotation, insertion of a casting into the stopped cage,
bringing the loaded cage up to the desired rotational speed, and then dis-
placing the casting from the rotating feed cage into the aligned rotating main
cage, the present concept makes use of a plurality of feed cages 96 mounted
for rotational movement in a turret or ferris wheel 150 which in turn is
mounted for rotational movement about its central axis 152. In the illus-
trated modification, use is made of four feed cages 96 mounted 90 apart in
the turret but more than four and as few as two such cages may be employed.
The turret is aligned with the end of the main cage to provide two stations
about 180 apart with one station (called the ~eed station) aligned endwise
with the rotating main cage, while the other station (called the loading
station) is aligned endwise with a conveyor 134 on which the castings 24 are
brought to the machine.
~eans are provided for stopping rotational movements of the cages
while in the loading station so that the ram 124 can be operated by the hy-
draulic cylinder 132 to effect displacement of the ram from the retracted
position to the first operated position whereby the casting on the slat
conveyor is rammed into the stopped feed cage 96. For this purpose, use can
be made of a stop arm of the type illustrated by the arm 120 and switch 122
to effect orientation of the cage with the casting in the loading position,
and use can be made of a hydraulic cylinder and ram arrangement, as represent-
ed by the numerals 124 to 136, for actuation of the ram between operated and
.' - 19 --
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.,, . ~ : ~: -, -.: -: , , , ~
-
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retracted positions through a distance corresponding to the first stage of
movement in the loading cycle for the feed cage, as previously described.
When the loading cycle has been completed, as indicated by the mak-
ing of the switch 142, and the stop arm 120 has been retracted, as indicated
by the making of switch 122, the turret wheel is turned through 9oD to bring
another empty cage into the loading position while the loaded cage comes into
engagement with an endless belt or chain 154 operating about driven rollers
156 and bearing against the periphery of the cage rings 98 to bring ab~ut
rotational movement of the loaded cage. For this purpose, the cages are mount-
ed for free rotational movement within the turret as by means of rollers ex-
tending crosswise between the opposite side ~alls 158 and 160 of the turret
with the axis of the rollers 162 being mounted in suitable bearings fixed in
the side walls of the turret.
By the time that the turret is turned through its next cycle of
operation to bring the loaded cage to the feed station iD endwise alignment
with the rotating main cage, the loaded cage is up to speed and oriented with
the main cage. A second hydraulic cylinder and piston arrangement, similar
to that employed at the feed station, is provided with the ram in endwise
alignment with the casting in the rotating feed cage. Thus responsive to move- r
ment of the carriage from retracted to operated positions, the ram comes into
engagement with the casting in the rotating feed cage to effect displacement
of the casting endwise from the feed cage into the end of the aligned loaded
main cage. When limit swith 136 is madeJ the piston and its supporting carri-
age returns to retracted position thereby to free the turret for turning move-
ment to bring the next loaded cage into alignment.
This arrangement is faster than the concepts previously described
since loading of the feed cages at one station and unloading of the feed cages
- 20 -
... .
- ..
at another station can be carried out simultaneously~ as distinguished from
sequentially, as ln the system previously described.
The fluid displacement means can be the same as ln the loading
station, including an elongate ram suspended from a carriage by rollers operat-
ing in tracks with a switch operating member on the carriage to engage a
limit switch when the piston is displaced to operated position and another
limit switch when the piston is returned to retracted posltion.
While it is possible merely to let the casting issue from the exit
end of the cage, it is often desirable to receive the casting in a cage syn-
chronized with the rotational movement of the main cage to overcome the centri-
fugal orce of the casting.
For this purpose, use can be made of a turret similar to that des-
cribed for the feed section with two stations located 180 apart including a
receiving station in endwise alignment with the end of the main cageJ and an
unloading station which is, in effect, the reverse of the operation and ele-
ments employed in the loading station. While in the receiving station, with
a cage in endwise alignment with the main cage, the cage is rotated in syn-
chronous movement with the main cage by the chain or belt 154 for receipt of
the endmost casting displaced from the main cage.
At the unloading station, the chain no longer engages the cage so
that its rotational movement can be stopped by means of a suitable block, such
as the stop 120 of the type previously described. A hydraulic operating ram
is employed at the unloading station with the ram in endwise alignment with the
center of the stopped cage. The ram construction and operation is similar to
that previously described in that the horizontally disposed elongate ram is
supported from a carriage by rollers operating in a track to support the carri-
age which is movable with the piston reciprocably mounted within a fluid
- 21 -
.- ., . .-.. , : , ,
operated cylinder. A switch pin is provided on the carriage for engagement
with a limit switch 136, when in operated position, and for engagement with
a limit switch 142, when returned to retracted position. The stroke of the
ram is sufficient to effect displacement of the casting from the stopped cage.
To position the turret for free rotational movement free of the
main cage, it is often desirable to effect endwise displacement of the turret
for a short distance longitudlnally away from the end of the cage. This can
be accomplished by mounting the turret for lengthwise sliding movement along
the shaft on which the turret is rotatably supported. l~e turret is displaced
outwardly away from the cage by means of an air cylinder and it is returned
to a position adjacent the cage by the return movement of the cylinder. In-
stead, the entire turret and its supporting structure is mounted on tracks
for movement in the direction toward and away from the cage responsive to
operation of a fluid cylinder as previously described. Switch means are ~.
provided in the path of the casting to signal receipt of a casting within the
rotating turret. Responsive to the signal, the turret is displaced by the
cylinder in one direction. Other switch means responsive to movement of the
turret is provided to signal the completion of rotational movement of the
turret from one station to the next for operation of the cylinder in its return
stroke. Such switch may be made by pawls extending outwardly from the turret
corresponding in nunlber to the number of unloading cages rotatably mounted in
the turret.
In an alternative arrangement shown in Figure 11, illustration is
made of a conveyor 200, in the form of a pair of longitudinally traveling,
laterally spaced apart endless belts 202 and 204 operating about rollers 206
and 208 supported on shafts 210 and 212, one of which is a driven shaft opera-
tively connected through gears 214 to a driving motor 216.
-- 22--
.. . .
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. ,, ; ~
:.. - , . .. . . :, ,-
.. . . . . .
., :: ....... . : . . - -, - ,. .. ~ , . -
.. . . . . . . .
-
The belts are provided with cleats 218 which are longitudinally
spaced apart by a distance proportional to the rotational movement of the
cage 20 whereby the belt will be longitudinallr displaced by an amount corres-
ponding to the spaced relationship between the cleats during each rotation of
the cage, or a predetermined multiple thereof.
It will be understood that the castings 24 will be placed across
the upper run of the belt whereby the load on the ~elts will be great such
that additional roller supports or table (not shown) will underlie the upper
run of the belt for support thereof.
Rotatable with the cage and attached to the end thereof and in
crosswise alignment therewith is a loading cage 220 having an opening 224 ex-
tending lengthwise therethrough in lengthwise alignment with the openings
through the main cage 20. A clearance or passage 226 through one side of the
loading cage 220 is dimensioned to enable a casting 24 to be disposed radially
therethrough into the loading cage. In the illustrated modification, the
loading cage 220 is in the fo~m of a U-shaped or rectilinearly shaped trough
which is open at the ends and along one wall to define a three-sided recept-
acle formed of the walls 228, 230 and 232. The loading cage 220 is dimension-
ed to have a length greater than the laterally spaced apart relation between
the belts 202 and 204 of the conveyor in crosswise alignment therewith.
The loading cage 220 is formed with a pair of arms 234 which extend
; outwardly from the cage with the upper surface of each of the arms substantial-
ly flush wlth the inner face of the wall 232 defining the trailing edge of the
open side 226. The arms are laterally spaced one from the other by an amount
slightly greater than the spaced relationship between the pair of conveyor
' belts 202 and 204 so as to pass alongside the belts during rotational movement
of the cage. The arms are dimensioned to extend outwardly beyond the cage by
- 23 -
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,:~: . : : ,: ,.: , :: ' " : : - : .:
:~ . . .. : . ., -
~146~
.
an amount greater than the width of the castings so that, when the belts
displace a casting onto the end portion thereof, the casting will be in
position to be engaged by the arms to lift the casting from the belt in res-
ponse to rotational movement of the cage, as in the clockwise direction shown
in the drawings.
As the loading cage continues to rotate, the arms 234 lift the
casting until the slope of the arms i5 such as will cause the casting gravita-
tionally to slide over the arms and through the slot 226 into the basket or
opening of the rotating loading cage in endwise alignment with the continuous-
ly rotating main cage 20 and in proper orientation therewith.
rn endwise alignment with the open end of the loading cage, in thedirection away from the main cage, a ram 236 is mounted adapted to be operated
mechanically or by 1uid in a piston-crlinder assembly. When the casting 24
has become settled within the loading cage, the ram 236 is operated for dis-
placement forwardly by an amount to engage the casting and to displace the
casting from the loading cage 220 into the main cage 20. The operation of
the ram is signaled in response to the seating of the casting in the loading
cage but it is preferred to signal operation of the ram in timed sequence with
', the rotational movement of the loading cage and main cage to initiate the
il 20 forward stroke when the loading cage has been rotated through an angle of
about 90 from the loading position and to complete the stroke for reverse
movement of the ram or withdrawal from the cage by the time that the cage
turns through a further angle of 90. As a result, the casting will be dis-
placed from the loading cage before the side opening 226 faces in a downward
direction whereby the casting might otherwise fall from the cage or from the
desired oriented position.
An unloading cage 240, similar to the loading cage, is positioned
- 24 -
, . . , , . . , ,. . ............................. . ~ ~
.
~4~
in end~ise ali.gn~ent with th.e main cage 2Q adjacent the apposite end of the main
cage ~hereby t~e treated castings w~ll be displaced from the main cage into the
unloading cage 240, w~ile in an oriented position~ Rotat~onal movement of the
unloading cage w~t~ the main cage will cause the casting gravitationally to
slide through.the opening onto a receiving conveyor of similarly spaced belts.
In a system of the type described, with the cages rotating at a rate
of 15 revolutions per minute, the assembly can be employed for the displacment
and treatment of 900 castings per hour.
It will be apparent from the foregoing that a new and efficient means
for the continuous s.urface treatment of castings of large dimension and weight
has been provided whereby such treatments can be effected with a minimum amount
of equipment, time, materials and labor, while achieving substantially complete
coverage of the surfaces.
It will be understood that changes may be made in the details of
construction, arrangement and operation without departing from the spirit of
tho invontlon, espccially as defined in the followlng clai=s.
;
.
_ 25 -
