Multi-core box apparatus for the manufacture of hollow mineral products, particularly foundry cores

Multi-core box apparatus for producing hollow foundry cores made from sand mixed with a binder that is curable either by gaseous catalytic action or by elevated temperature comprises a plurality of core boxes mounted on a housing that is rotatable in a vertical plane. The core boxes are presented sequentially by an index mechanism at various positions where treatment of material in the core boxes is carried out and at a last position a finished hollow foundry core is removed automatically from a core box. The automatic apparatus for removing the finished core from the core box, and for depositing the finished core on a conveyor comprises an elongated rod that can be inserted into the hollow core and that supports the core when the core box half portions separate. The elongated rod is carried by a spindle on a movable carriage so that the spindle and rod rotate and reciprocate thereby removing the hollow core for further treatment.

BACKGROUND OF THE INVENTION 
The present invention relates to a multi-core box apparatus for making 
hollow mineral products, particularly foundry shell cores, using either 
the novel, heatless process described and claimed in my prior application, 
Ser. No. 939,660 filed Sept. 5, 1978, now abandoned, to which further 
reference may be made, or the well-known thermal or Croning process. 
Since the heatless process, as of the present time, is quite new and, 
therefore, is not implemented in the foundry industry, there are no 
specialized types of equipment known at the present time, except an 
experimental unit, which, in essence, is a modified adaptation of existing 
apparatus, for carrying into practice the Croning process. All of the 
existing apparatus have at least five fundamental disadvantages, namely: 
low productivity rate resulting from performance of all operations in 
sequence within one single core box; the necessity for a turntable cradle 
on which the core box is mounted; the necessity for a sand return system 
from a hopper under the core box to a hopper over the core box, which 
system is particularly bulky and costly; the area around the core box is 
congested and is not readily accessible since all of the machine parts 
participating in the execution of the process directly have to be 
concentrated around that one, single core box; and the new heatless 
process cannot be carried into practice. 
In contrast to the apparatus of the prior art, the apparatus of the present 
invention: is free from these disadvantages; has a significantly higher 
productivity rate; requires no cradle; need no sand return system; has 
easy access to the core boxes with simple, convenient design of tooling; 
and is suitable for both the old thermal Croning process and the new 
heatless process. 
BRIEF SUMMARY OF THE INVENTION 
A vertical frame supports rotatable housing including spaced apart annular 
plates to which are secured a plurality of core boxes; preferably four 
boxes being located at 90.degree. spacings. Centrally located with respect 
to the rotatable annular plates are, among other things: a sand mixture 
supply hopper; a sand blower; and conduit for treating the sand mixture to 
harden and form a hollow core in the core box. 
An automatic hollow core unloading machine is provided to remove from the 
core box the finished hollow core and to transfer it to another location. 
For a further understanding of the invention and for features and 
advantages thereof, reference may be made to the following description and 
the drawings which illustrates one embodiment of apparatus in accordance 
with the present invention.

DETAILED DESCRIPTION 
Referring to FIG. 1, a heavy frame 11 comprises a base portion 13, a 
triangular-shaped vertical portion 15, and a horizontal top portion 17. A 
suitable bracket 19 is secured, as by welding, to the base portion 13 and 
the vertical portion 15. A similar bracket 21 is secured to the top 
portion 17 and the vertical portion 15. 
On the base portion 13 there are located, about where shown, spaced-apart 
pairs of rollers 23, 25 and one pair of such rollers 23 is power driven by 
a conventional motor-speed reducer, or by a hydraulic motor 27. 
The top portion 17 also carries one pair of rollers 29 that are mounted 
thereto by means of conventional resilient devices 31, such as Belleville 
springs, or the like. 
The bottom pairs of rollers 23, 25 and the top pair of rollers 29 carry and 
rotatably support a housing 33 comprising two spaced-apart annular plates 
35, 37, each annular plate having a large central opening 39. 
The annular plates 35, 37 are rigidly inter-connected by means of T-bars 
41, spaced suitably about as shown. 
Internally of the housing 33, there are mounted to the annular plates 35, 
37 four core boxes, each comprised of two half portions 43, 43a; 45, 45a; 
47, 47a; and 49, 49a. The core boxes are arranged 90.degree. apart, as 
shown in FIG. 1. The half core box portions 43, 45, 47, 49 are rigidly 
mounted to the annular plate 35, and the other half core box portions 43a, 
45a, 47a, 49a are slidably mounted on three rods 48 that extend between, 
and are rigidly connected to, the annular plates 35, 37. 
Externally of the housing 33 there are mounted to the annular plate 37, in 
corresponding relation to each one of the half core box portions 43a, 45a, 
47a, 49a, fluid-acting, cylinder-piston assemblies; however, only two such 
cylinder-piston assemblies 51, 53 are shown in FIG. 2. Each 
cylinder-piston assembly 51, 53 has a piston rod, such as rods 55, 57, 
extending through the annular plate 37 and connected to the half core box 
portions 43a, 45a, 47a, 49a. The core boxes mentioned herein are either 
like those shown, described and claimed in my prior application mentioned 
previously herein, or like those commonly used at the present time. 
Between the annular plates 35, 37 there is mounted a blow head 59 having a 
frusto-conical top 61 and a frusto-conical bottom 63. The blow head 59 is 
pivotally mounted, as at 65, to a pair of links 67 pivotally connected to 
brackets 69 secured to the vertical wall portion 15 which has one or more 
access openings 60. The blow head 59 is also provided with an arm 71 that 
connects pivotally to a piston rod 73 of the cylinder-piston assembly 75; 
the cylinder-piston assembly 75 being mounted pivotally to fixed support 
structure 77 connected to the wall 15. The lower end of the frusto-conical 
bottom portion 63 carries a transverse blow-plate 78 in which there are a 
plurality of small holes (not shown) having diameters of about one-half 
inch. 
Above the blow head top portion 61 there is a hopper 79 having a slidable 
gate 81 that controls the flow of sand mixture from the hopper 79 into the 
blow head 59. The gate 81 is actuated by a cylinder-piston assembly 83 
supported by the vertical wall portion 15. 
Associated with the hopper 79 is a chute 85 that is disposed beneath the 
output end 87 of a conventional continuous mixer (not shown). 
FIG. 3 illustrates schematically a pair of cams for covering an aperture in 
the core boxes shown and described in my prior application. One cam 89 is 
called a closing cam and includes a slightly arcuate plate 93 having a 
flange 95. The plate 93 is fixed to the vertical wall portion 15 about 
where shown in FIG. 1. A pin 97, protruding above the top of a slidable 
gate 99, engages the flange 95 and thereby closes the aperture as the 
housing 35 rotates in the direction of the arrow A. As shown in FIG. 1, 
there is another cam 89a which is similar to opposite hand and is an 
opening cam. 
Extending between the annular plates 35, 37, about where shown in FIG. 1, 
are two hollow beams 101, 103 which are the side portions of a U-shaped 
yoke. As shown in FIG. 1, the beam 101 supports a hollow guide 105 in 
which is disposed a slidable plunger 107, resiliently activated by a 
spring 107a. The plunger 107 carries at one end a roller 109 that coacts 
with the gate 99. The hollow beam 103 carries internally fluid conduits 
113 that convey gaseous fuel to conventional shell core box whenever the 
present apparatus is used to carry out the Croning process. 
Associated with the yoke arms 101, 103 is first a hydraulic rotary joint 
104 which connects to conduits 106, 108 carrying hydraulic fluid to the 
cylinder-piston assemblies 51, 53 respectively. 
Whenever the present apparatus is used to carry out the Croning process, 
another rotary joint 110 of conventional design is mounted adjacent the 
rotary joint 104 and a fuel gas conduit 112 connects to the rotary joint 
110, as suggested in FIG. 2. 
As shown in FIG. 1a the core box 45, 45a cooperates with an inlet portion 
115 of conduit 117 carrying a catalytic gas to the core box, as shown and 
described in my prior application. A cylinder-piston assembly 118 is used 
to press the inlet portion 115 sealingly over the aperture in the core 
box. 
The portion 115 is connected through a conventional three-way valve to a 
supply of catalyst gas, to an exhaust system, and to a supply of 
compressed air. 
As is well known by those skilled in the foundry art, the removal of cores 
from a core making machine carrying out the Croning process is a tedious 
task carried out in an uncomfortable environment. The cores are formed by 
heat and, when removed, they are very hot and personnel operating the core 
machines work under difficult conditions. 
Recognizing this disadvantage of existing core making apparatus, the 
present invention includes an automatic apparatus for removing hollow 
shell cores from the apparatus of the invention shown in FIGS. 1-3 
described previously herein. 
FIG. 4 is an elevational view of one embodiment of such a core removal 
apparatus. It comprises: spaced-apart, vertically arranged, pairs of 
elongate rails 119, 121 supported in a conventional manner (not shown); a 
carriage 123 having pairs of rollers 125, 127 that coact with the lower 
rails 119; a pair of stationary sheaves 129, 131 that coact with a wire 
rope or chain 133 anchored, as at 135, to the left hand end of the 
carriage 123, and, as at 137, to the right-hand end of the carriage 134. 
One of the sheaves 131 say, is powered preferably by a hydraulic motor 
(not shown) of conventional kind, but any other suitable power source may 
be used if preferred. Near sheave 131 is a guidance sheave 139 that coacts 
with the wire rope 133. 
As shown in FIG. 4, the carriage 134 supports in a boss 141 a rotatable and 
reciprocable sleeve 143 surrounding an axle 183. In the outer surface of 
the axle 183 is a helical cam groove 145 that receives a cam follower 147. 
Mounted to the side of the boss 141, about where shown, is an L-shaped 
stop 151 that coacts with a groove 153 in the outer surface of the sleeve 
143. 
The lower end portion of the axle 183 supports a roller 155 contacting a 
cam groove 157 in a base member 159. 
The upper end of the sleeve 143 carries a bracket 161 to which is secured, 
about as shown, an elongate rod 163, that may, in some cases, be straight, 
or it may be an L-shaped rod. 
Referring to FIGS. 5 and 6, the straight or L-shaped rod 163 has a circular 
cross-section, and the outer end portion is grooved, as at 165, to 
accommodate an elongate bar 167 having a rectangular cross-section. The 
elongate bar 67 is pivotally mounted, as at 169, to the bar 163 and is 
also pivotally connected, as at 171, to an actuator rod 173. The actuator 
rod 173 is an extension of a piston encased in a fluid-actuated cylinder 
175 of conventional form. Instead of the fluid-actuated cylinder 175, an 
electrical solenoid actuator may be used if preferred. 
At the outer end of the elongate rod 163 is a triangular rest or stop 177 
for the elongate bar 167 when in the inoperative position. The position of 
the rod 167, shown in FIGS. 4 and 5, is the operative position. 
When the housing 33 has rotated through 270.degree., to bring the core box 
43 from position I to position IV, the core box half-portion 49a, which is 
slidable on the rods 48, under the influence of the hydraulic 
cylinder-piston assembly 51, starts to move away from the fixed core box 
half-portion 49. At this instant, ejection pins in the half-portion 49, 
acting under the effect of springs compressed by the movable core box 
half-portion 49a, urge the core out of the fixed half-portion 49. At 
first, the half-portion 49a moves a distance of one-half its stroke, at 
which time the rod 163 is inserted into the investment hole in the shell 
core. Thereafter, the movable core box half-portion 49a starts to move to 
the end of its stroke, and the core ejection pins of this core box 
half-portion urge the core out it. Simultaneously, the fluid actuated 
cylinder-piston assembly 175 is activated to move the actuator rod 173 
toward the right, as viewed in FIG. 5, and the bar 167 pivots to the 
angular position shown in FIG. 5. The bar 167 contacts the inner surface 
of the hollow core and it is supported thereby as the core box moves away 
from it. 
After the hollow shell core is removed from the core box, the movable 
half-portion 49a of the core box again mates with the fixed half-portion 
49, as the housing rotates 90.degree. and presents the core box again at 
position I, the initial position, to commence another cycle. 
The carriage 123, under the influence of the powered sheave 131 and the 
wire rope 133, travels any convenient distance toward the right, as viewed 
in FIG. 4. When the carriage reaches a point 181 where the contour of the 
cam groove 157 turns downward, the sleeve 143 both reciprocates down and 
rotates through 90.degree. under the influence of the cam groove 157 and 
the cam cam-follower 145, 147 respectively. The rotary and downward motion 
of the sleeve and the rod 163 carrying the shell core 179 present the 
shell core at a location, suggested by the dotted outline in FIG. 4, where 
it is deposited onto a conveyor belt 184 which carries the core 179 away 
from the rod 163. 
After the shell core has been removed from the rod 163, the carriage 
returns to its initial position at which it commences another cycle. 
In use, the blow head 59 receives from the hopper 79 a supply of sand 
coated with a liquid binder that is hardenable either by a catalytic gas 
or by heat. 
Let us first consider only the new heatless process wherein the hardening 
of the sand mixture is accomplished by a catalist gas. 
The core box at position I, is ready to receive the granular mixture, and 
so, the blow head is lowered under the influence of the cylinder-piston 75 
until it contacts and seats sealingly with the aperture in the core box. 
Thereupon, the granular mixture is blown by air into the core box, and the 
pattern therein fills with the mixture. 
As soon as the pattern is filled the air pressure in the blow head is 
reduced to atmospheric pressure and the housing rotates in the direction 
of arrow A. As the housing rotates, the pin 97 on the slidable gate 99 
engages the flange of the closing cam 89 and the slidable gate 99 closes 
the aperture in the core box. 
When the core box reaches position II, the roller 109 contacts the slidable 
gate 99 and, under the urging of the resilient member 107a contacting the 
plunger 107, the slidable gate sealingly closes the aperture. At this 
time, the catalytic gas, described in my prior application, enters the 
core box through the conduit 117 and reacts to harden the outer layer of 
the mixture within the porous pattern inside the core box, thus forming a 
hollow shell core with a quantity of mixture inside of it that was not 
hardened. 
The housing, acting under the influence of conventional indexing apparatus, 
not shown, advances the formed shell core from position II to position 
III. Just prior to reaching position III however, the pin 97 of the 
slidable gate 99 engages the opening cam 89a, and the slidable gate 99 
opens. The loose, unhardened granular mixture inside the pattern now 
gravitates therefrom into the hopper 79 from which it flows into the blow 
head for use again. Those skilled in the art will recognize that in some 
instances, a vibrator or the like may be used to loosen the granular 
unhardened mixture so that it can flow freely from the pattern at position 
III. 
After a predetermined number of seconds of time, the housing indexes 
another 90.degree. rotation and advances the core box from position III to 
position IV. At position IV the finished hollow core is removed from the 
core box as described previously herein, or it may be removed manually. 
When the present apparatus of the invention is used for performing the 
thermal or Croning process to produce shell cores, then on both sides of 
each core box half-portions are placed conventional gas burners in the 
manner described and shown in the prior art. Fuel gas to these burners is 
supplied through inlet 112 and conventional rotary joint 110. The burners 
keep the core box half portions at approximately 450.degree. F., which is 
sufficient to harden the binder in the outer layer of sand inside the core 
box. 
The productivity rate of the apparatus of the invention is determined by 
the ratio, P=60/C, where P is productivity in the number of products made 
in one hour and C is the duration of the production cycle in minutes. 
C=T+t, where T is the dwelling time of the housing 33 and is equal to the 
duration of the longest operation performed at any one position during the 
cycle; and t is the indexing time of the housing 33 and is equal to the 
time required to turn the housing 33 through an angle 360.degree./n, where 
n is the number of positions or core boxes on the housing 33. 
When the apparatus of the invention is used to perform the heatless 
process, T, on the average, is 6 seconds; t is 2 seconds; and therefore C 
is 8 seconds. 
Apparatus known from the prior art, when used to perform the Croning or 
heat process, consumes, on the average, 3 minutes or 180 seconds to 
complete a cycle. Thus, for prior art apparatus the productivity rate, 
C.sub.1, is 180 seconds. Hence, the productivity rate of the apparatus of 
the invention is C.sub.1 /C or 180/8=22.5 times the productivity rate of 
apparatus known from the prior art. 
From the foregoing description of one embodiment of the invention, those 
skilled in the art will recognize many important features and advantages 
of it, among which the following are particularly significant: 
That the apparatus of the present invention is used to produce hollow 
mineral products by either the heatless forming process of my prior 
invention or by conventional thermal-forming or Croning process; 
That the apparatus produces hollow mineral products at a much higher 
productivity rate of speed than conventional apparatus using the 
conventional thermal process; 
That a conventional sand recirculating system, used by conventional 
apparatus, is not required for the apparatus of the present invention; 
That conventional core box cradles, required by conventional apparatus, are 
not needed in the apparatus of the present invention; 
That the hollow product removal and transferring apparatus of the present 
invention eliminates the need for intensive manual labor during operation 
of conventional shell core forming apparatus, and makes full automation of 
the heatless process possible; 
That the present apparatus includes a plurality of core boxes in which 
hollow mineral products are formed in a sequence of steps, and the core 
boxes rotate in a vertical plane about a horizontal axis; and 
That the apparatus includes an automatic device that supports and removes 
the finished hollow mineral products from an open core box and transports 
such product to another location, using no manual assistance. 
While the invention has been described herein with a certain degree of 
particularity it is to be understood that the present disclosure is made 
only as an example of the invention and that the scope of the invention is 
defined by what is hereafter claimed.