Core handling apparatus

A core handling apparatus includes an upright, tubular frame adapted for being suspended from an overhead hoist. A pair of upright air cylinders are fixed to opposite sides of the frame and each includes a reciprocable rod. Upper and lower shafts are respectively rotatably mounted in upper and lower end portions of the frame. A first length of roller chain is engaged with a first sprocket mounted on the upper shaft and has its opposite ends coupled to the respective upper ends of the piston rods of the pair of cylinders while a second length of roller chain is engaged with a second sprocket mounted on the lower shaft and has its opposite ends coupled to the respective lower ends of the piston rods. A mandrel plate is fixed for rotation with the lower shaft and is adapted for having various core handling attachments releasably secured thereto. A stop mechanism stop plate is fixed for rotation with the upper shaft and a stop pin is selectively insertable through upper and lower tubular receptacles provided in the upper end portion of the frame so as to respectively cooperate with first and second pairs of adjustable abutment surfaces of the stop plate so as to limit to amount of rotation of the upper shaft respectively to about 90.degree. and 180.degree. and hence to similarly limit the range of rotation of the lower shaft and mandrel plate, whereby an operator controlling reciprocation of the air cylinders will be aided by the stop structure in effecting precise positioning of a core handling attachment relative to or together with a core to be or being handled.

BACKGROUND OF THE INVENTION 
The present invention relates to apparatus for handling foundry sand cores 
and more particularly relates to hoist-hung devices which can be clamped 
on or otherwise secured to a core requiring handling during the process of 
preparing the core for placement in a mold. 
In order to improve the finish on casting surface, cores are often coated 
or washed with a refractory slurry which is then dried onto the core 
surface. One way of applying the wash to the core is by dipping the core 
in a vat containing the slurry. The afore-mentioned hoist-hung devices are 
used to perform the dipping function and the devices are often provided 
with structure whereby the core may be rotated either manually or 
mechanically after being dipped so that excess wash drains from the upper 
surfaces of the core. 
A known hoist-hung device having provision for manually rotating a core 
includes a pair of limbs which straddle the core and are provided with 
fixtures which engage opposite sides of the core and define a pivot axis 
about which the core may be rotated. Two people, one grasping each limb, 
are required to manually engage and flip or turn over the core between the 
limbs. This can be a difficult and dangerous practice, especially when 
handling cores having a large mass which becomes unbalanced relative to 
the pivot axis when the core is being turned over since the core may slip 
from the control of the workers and cause injury to them as it falls out 
of control. Also, the core can be damaged under these circumstances. 
Another drawback of this known hoist-hung device is that it is more or less 
dedicated to handling a single family of cores because of the spacing of 
the limbs and the need to engage opposite sides of the cores. 
Some of the drawbacks of the above-described devise; i.e, the requirement 
for two people, manual roll over and the danger or possible core damage 
associated with the manual roll over operation, are overcome by known 
devices which include power means for pivoting or rolling over the core. 
One such known device includes a pair of double acting, air-operated vane 
type actuators located on opposite sides of and having respective output 
shafts connected to an arbor structure for swinging the latter through 
90.degree., the arbor structure being engageable with a core so as to 
swing the latter with it. This device has the disadvantages of being 
dedicated to handle only one core and thus not being adaptable for having 
different core-engaging attachments secured thereto and of being swingable 
only up to 90.degree.. 
SUMMARY OF THE INVENTION 
According to the present invention, there is provided an improved 
hoist-hung foundry core handling device including a powered means for 
rotating a core. 
A broad object of the invention is to provide a core handling device which 
overcomes the above-noted drawbacks of known handling devices having 
either manual or power rotated fixtures for swinging the core about a 
pivot axis. 
A more specific object is to provide a core handling device including a 
power-rotatable mandrel adapted for having different core engaging 
attachments or fixtures connected thereto, the fixtures being adaptable 
for engagement with respective cores from one side of the cores. 
Yet another specific object is to provide a core handling device including 
a power-rotatable mandrel and means associated with the drive for the 
mandrel for delimiting the range of its movement such that the mandrel may 
be precisely positioned for engaging a given fixture with a core to be 
handled without relying on the skill or attention of an operator. 
These and other objects of the invention will become more apparent upon 
reading the ensuing description together with the appended drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The terms front, rear, left, etc. used herein are from the perspective of 
an operator facing controls carried at one side of the core handling 
apparatus with the one side being considered the rear of the apparatus. 
Referring to FIGS. 1-4 of the drawing, there is shown a core handling 
apparatus 10 of a type adapted to be hung from a hoist. Specifically, the 
apparatus 10 includes a main frame 12 defined by a vertical tubular 
section 14 and a horizontal tubular section 16 having its rear end fixed, 
as by welding, to a forward side location of the section 14 just below a 
removable top portion 18 of the latter, whereby the section 16 is 
cantilevered from the section 14. Extending centrally along the top of and 
being welded to the horizontal tubular section 16 is a hoist eyelet plate 
20 provided with a series of apertures 22 spaced lengthwise therealong and 
providing alternate connection points for a clevis 24 adapted for having 
an overhead hoist hook engaged therewith. 
The top portion 18 of the vertical frame section 14 is provided with a 
horizontal rectangular mounting plate 26 at its lower end which is bolted 
to a similar plate 28 provided at the top of the remainder of the section 
14. Upper and lower stop pin receptacles 30 and 31 are respectively 
defined by parallel upper and lower fore-and-aft disposed tubes extending 
horizontally through the top portion 18 of the frame section 14 at a zone 
just above the mounting plate 26. The rear end portion of the tubes are 
welded to the, backside of the frame portion 18 while an upper set of 
gusset plates is welded opposite sides of the upper tube and to the frame 
portion 18 and a lower set of gusset plates is welded to opposite sides of 
the lower tube and to the frame portion 18. A stop pin 34 is selectively 
insertable through the receptacles 30 or 31 for a purpose explained below. 
An upper sprocket shaft 36 is rotatably supported in fore-and-aft spaced 
bearings 38 having respective mounting flanges 40 bolted to respective 
bearing mounting plates 42 welded to opposite front and rear faces of the 
frame top portion 18 and to which a top end cap 44 is welded. An upper 
sprocket 46 is mounted on the upper shaft 36 with opposite peripheral 
portions of the sprocket extending through respective cut-out areas 48 
provided in opposite side faces of the top frame portion. A lower sprocket 
support shaft 50 is similarly rotatably supported in fore-and-aft spaced 
bearings 52 having respective flanges 54 bolted to respective bearing 
mounting plates 56, welded to opposite front and rear faces of a lower end 
of the vertical frame section 14, and to which a bottom end cap 58 is 
welded. A lower sprocket 60 is mounted on the lower shaft 50 with opposite 
peripheral portions of the sprocket extending through respective cut-out 
areas 62 provided in opposite side faces of the frame section 14. 
Supported at a midsection of vertical frame section 14 are right and left 
air cylinders 64 and 66, respectively. Specifically, a rear set of upper 
and lower cylinder mounting blocks 68 and 70 are welded to the rear side 
of the vertical frame section 14 and a front set of upper and lower 
cylinder mounting blocks 72 and 74 are welded to the front side of the 
frame section at respective positions directly opposite from the blocks 68 
and 70. The upper blocks 68 and 72 are each provided with a horizontal 
transverse bore and the upper ends of the cylinders 64 and 66 are 
respectively defined by end caps 75 and 76 each having a pair of apertured 
mounting ears 78 and 80 with the ears 78 engaging opposite sides of and 
being clamped to the upper rear mounting block 68 by a bolt and nut 
assembly 82 and with the ears 80 engaging opposite sides of and being 
clamped to the upper front mounting block 72 by a bolt and nut assembly 
84. Similarly, the lower blocks 70 and 74 are each provided with a 
horizontal transverse bore and the lower ends of the cylinders 64 and 66 
are respectively defined by end caps with only the end cap 88 of the right 
cylinder 66 being shown, and each end cap having a pair of apertured 
mounting ears 90 and 92 with the ears 90 engaging opposite sides of and 
being clamped to the lower rear mounting block 70 by a bolt and nut 
assembly 94 and with the ears 92 engaging opposite sides of and being 
clamped to the lower front mounting block 72 by a bolt and nut assembly 
96. The cylinders 64 and 66 respectively include piston rods 98 and 100 
having respective pistons 102 and 104 (FIG. 8) located centrally along the 
length of the rods. An upper length of roller chain 106 is engaged with 
the upper sprocket 46 and has its opposite ends respectively pinned to 
clevises 108 and 110 respectively carried by upper ends of the rods 98 and 
100. Similarly, a lower length of roller chain 112 is engaged with the 
lower sprocket 60 and has its opposite ends respectively pinned to 
clevises 114 and 116 respectively carried by lower ends of the rods 98 and 
100. As can best be seen in FIG. 1, the rod 98 of the right cylinder 64 is 
shown in its full up position while the rod 100 of the left cylinder 66 is 
shown in its full down position. Thus, it will be appreciated that by 
simultaneously connecting air pressure to the top of the piston 102 
carried by the rod 98 and to the bottom of the piston 104 carried by the 
rod 100 while simultaneously venting the spaces below and above the 
pistons 102 and 104, respectively, the rod 98 will move downwardly while 
the rod 101 moves upwardly thus effecting clockwise rotation of the upper 
and lower sprockets 46 and 60 and hence of the upper and lower shafts 36 
and 50. 
A mandrel 118, in the form of a square plate, has a centrally located hole 
passing therethrough and is welded to a forward end of the lower shaft 50 
which is received in the hole whereby the mandrel rotates with the shaft. 
A plurality of the threaded holes 120 are provided in the mandrel 118 and 
are arranged in a square pattern having the shaft 50 at its center. 
Interchangeable core handling attachments, examples of which are described 
below, are adapted to be bolted to the mandrel. 
The rotation imparted to the mandrel 118 by actuation of the cylinders 64 
and 66 is precisely controlled by a stop mechanism (FIG. 4) including a 
rotation limiting plate 122 mounted to a forward end of the upper shaft 36 
for rotation therewith. Specifically, the plate 122 is substantially 
hemispherical in shape and includes a hub 124 received on and fixed to the 
shaft by a keyway and set screws (not shown) received in threaded holes 
offset 90.degree. from each other in the hub 124. The plate 122, as viewed 
in FIG. 4, has a central peripheral surface 128 curved arcuately about the 
shaft 36 through an angle somewhat more than 180.degree. and having 
opposite ends respectively terminating at upper and lower vertically and 
oppositely extending tab-like projections 130 and 132, respectively. The 
radial distance of the surface 128 from the axis of the shaft 36 is such 
that when the pin 34 is received in the receptacle 31 a forward-end 
portion of the pin will extend past the plate 122 adjacent the surface 128 
and will be disposed in the path of movement of the projections 130 and 
132 so as to limit the rotation of the plate 122 and, hence the mandrel 
118 to about 180.degree.. Precise adjustment of the amount of allowable 
rotation is provided by an upper stop screw 134 adjustably, threadedly 
received in an upper block 136 welded to a forward surface of the upper 
projection 130 and located such that an end of the screw 134 will engage 
the pin 34 to limit clockwise rotation of the plate 122, as viewed in FIG. 
1. Counterclockwise rotation of the plate 122 is similarly limited by a 
lower stop screw 138 adjustably threadedly received in a lower block 140 
welded to a forward surface of the lower projection 132. 
In some situations, it may be desirable to limit the rotation of the 
mandrel 118 to about 90.degree.. This is accomplished by an arcuate slot 
142 of slightly more than 90.degree. in length provided in the plate 122 
in parallel relationship to a portion of the arcuate surface 128 extending 
from the upper projection 130. The radial distance of the slot 142 from 
the axis of the shaft 36 is chosen such that the forward end portion of 
the pin 34 will project through the slot in the vicinity of the right end 
thereof, as viewed in FIG. 1, when the pin is inserted through the upper 
receptacle 30, such insertion being possible when the piston rods 98 and 
100 are respectively centered within the cylinders 64 and 66. Precise 
adjustment of the amount of allowable rotation is provided by a stop screw 
144 adjustably threadedly received in a block 146 welded to the forward 
face of the plate 122 in alignment with that end of the slot 142 which is 
remote from the projection 130 and by a stop screw 148 adjustably 
threadedly received in a block 150 welded to the forward face of the plate 
122 in alignment with that end of the slot 142 which is adjacent to the 
projection 130. 
Referring now to FIG. 6, there is shown one type of core handling 
attachment or fixture 152 formed by an elongate tapered spud 154 
preferably of rectangular of square cross section and having its longer 
end welded to a central location of one side of a square mounting plate 
156 having mounting holes 158 arranged in a pattern to match up with some 
of the holes 120 provided in the mandrel plate 118 whereby the attachment 
152 may be releasably bolted to the mandrel plate. The spud 154, when 
mounted to the mandrel plate 118 as viewed in FIG. 1, would extend 
horizontally and be adapted for insertion into a complimentary shaped, 
horizontal receptacle provided in one side of a sand core to be handled by 
the core handling apparatus 10. 
Referring now to FIG. 7, there is shown another core handling attachment 
160 of a type utilizing air arbors for releasably engaging sand cores. 
Specifically, the attachment 160 includes an arbor support beam 162 formed 
from an angle iron having an end welded to a central location of a forward 
face of a mounting plate 164 provided with four mounting holes 166 
arranged for matching up with four of the holes 120 provided in the 
mandrel plate 118 whereby the beam 162 may be releasably bolted to the 
plate 118. The beam 162 has a vertical flange 168 in which front and rear 
horizontal elongate slots 170 and 172, respectively, are located. An air 
arbor assembly 174 includes an L-shaped mounting bracket 176 having a 
horizontal leg 177 located beneath a cylinder 180 and a vertical leg 181 
mounted to the beam 162 by a pair of bolts 182 extending through the front 
slot 170. A piston (not shown) is located in the cylinder 180 with air 
fittings and 180, respectively, being located above and below the piston. 
A piston rod 186 has its upper end fixed to the cylinder and has an 
elastomeric sleeve 188 received thereon and held in place by a washer 190 
held against the bottom thereof by a nut 192. By routing air into the 
fitting 184 while coupling the fitting 182 to exhaust, the rod 186 will be 
retracted to thus cause the sleeve 188 to be squeezed resulting in the 
latter bulging outwardly. A second air arbor assembly 194, constructed 
identically to the assembly 174, includes an L-shaped mounting bracket 196 
mounted to the beam 162 by a pair of bolts 198 inserted through the rear 
slot 172 and vertical leg 200 of the bracket. A cylinder 202 is supported 
by a horizontal leg 204 of the bracket and located in the cylinder is a 
piston (not shown) to which a vertically extending piston rod 206 is 
fixed. The cylinder contains upper and lower air passage respectively 
coupled to upper and lower air fittings 208 and 210 and opening into the 
cylinder above and below the piston. An elastomeric sleeve 212 is received 
on the rod 206 and a washer 214 is held against the bottom of the sleeve 
by a nut 216 screwed onto a threaded lower end of the rod 206. 
Located below the arbor assemblies 174 and 194 and containing respective 
vertical holes 218 and 220 for receiving the sleeves 188 and 212 of the 
arbor assemblies is a sand core 222 the holes 218 and 220 being sized just 
slightly larger than the unexpanded diameter of the sleeves. 
Thus, once inserted into the holes 218 and 220 and expanded, the sleeves 
188 and 212 will grip the sand core to permit the latter to be handled by 
the apparatus 10. 
While the air arbor assemblies 174 and 194 are here illustrated as being 
identical, it is to be understood that the respective piston rods could be 
of different lengths for insertion into core holes of different depth as 
may be the case with irregular sized cores. Also, the assemblies 174 and 
194 are shown engaging only a single core 222, however, by using longer 
rods, at least two cores 222 may be stacked one on the other with the 
pistons extending through the upper most core or cores and with the 
expandable sleeves being positioned for engaging the lower most core 
whereby multiple cores may be handled at the same time. 
Referring now back to FIGS. 1-3 and also to FIG. 7, the means for 
controlling the core handling apparatus 10 will be described. 
Specifically, a control panel 226 which is rectangular in top view (FIG. 
3) is mounted to the back side of the vertical frame section 14 by a pair 
of parallel gusset plates 228 welded to a central front underside location 
of the panel and to the frame section 14. Right and left hand grips 230 
and 232 are respectively fixed to right and left sides of and project 
rearwardly from the panel 226. A central, inverted U-shaped hand grip 234 
has its opposite ends respectively welded to the top of the panel at rear 
corners of the latter. 
An air arbor control valve 236 has a housing mounted to a right hand 
underside location of the panel 226 by a pair of screw fasteners 238. The 
valve 236 is oriented such that a valve element 239 thereof will be 
shifted fore-and-aft by fore-and-aft movement of a control lever 240 which 
is coupled to the element 239 and projects upwardly through an opening 242 
provided in the panel. 
A mandrel rotation control valve 244 has a housing mounted to a left rear 
underside location of the panel 226 by a pair of screw fasteners 246. The 
valve is oriented such that a valve element 248 thereof will be shifted 
sideways or left and right by left and right movement of a control lever 
250 which is coupled to the element 248 and projects upwardly through an 
opening 252 provided in the panel. 
The valves 236 and 244 are each 4-way, five port, two position control 
valves and are coupled in parallel with each other to a main source of 
shop air 254 by a supply line 256. The line 256 includes a nipple 258 
disposed vertically and mounted to the backside of the vertical frame 
section 14. A flexible air supply hose 260 having a length sufficient to 
permit unrestrained movement of the apparatus 10 is connected to the top 
of the nipple 258 while a length of hose 262 is coupled to the bottom of 
the nipple 258 and to appropriate plumbing (not shown) coupled to 
respective inlets of the valves 236 and 334. 
First and second supply-return hoses 264 and 266 are respectively coupled 
to first and second supply-return ports of the arbor control valve 236, 
extend upwardly through an opening 267 provided in a central front 
location of the panel and terminate in first and second quick-connect 
couplings 268 and 270. A first pair of restricted bleed lines 272 and 274 
are respectively coupled to a first pair of exhaust ports located on 
opposite sides of the valve inlet. The upper fittings of the arbor 
assemblies 174 and 194 are plumbed in parallel to a first air hose 276 
having a quick-connect coupling 278 releasably coupled to the 
quick-connect coupling 268. Similarly, the lower fittings of the arbor 
assemblies 174 and 194 are plumbed in parallel to a second air hose 280 
having a quick-connect coupling 282 releasably coupled to the 
quick-connect coupling 270. The hoses 276 and 280 are each of a length 
permitting free movement of the core handling attachment 160 during 
oscillation of the mandrel 118 through operation of the cylinders 64 and 
66. 
Third and fourth supply-return hoses 284 and 286 are respectively coupled 
to third and fourth supply-return ports of the mandrel control valve 244 
and extend upwardly through the opening 287, the hose 284 being plumbed to 
the top of the right hand cylinder 64 and to the bottom of the left hand 
cylinder 66 and the hose 286 being plumbed to the bottom of the right hand 
cylinder 64 and to the top of the left hand cylinder 66. A second pair of 
restricted bleed lines 288 and 290 are respectively coupled to a second 
pair of exhaust ports located at opposite sides of the inlet of the valve 
244. 
The operation of the core handling apparatus 10 is briefly as follows: 
Assuming that it is desired to dip in a core wash or dressing or otherwise 
handle a sand core provided at one of its sides with a horizontal hole 
shaped complimentary to the spud 154 of the core handling attachment 152, 
the core handling apparatus 10 will be equipped with the attachment 152 by 
bolting the plate 156 onto the rotary mandrel 118. An operator will then 
control an overhead crane to raise or lower the apparatus 10 and 
manipulate the apparatus 10 through the grips 230-234 to insert the spud 
154 into the hole provided in the core. The crane will then be controlled 
to effect lifting of the apparatus 10 plus the engaged core. If the lifted 
load appears to be too unbalanced relative to the point of attachment of 
the clevis with the hoist eyelet plate 20, the clevis may be appropriately 
moved to a different attachment hole 22. Once the desired weight balance 
is achieved, the core is lifted by the overhead hoist and lowered into a 
dip tank filled with wash material. The hoist is then operated to raise 
the core from the dip tank. Assuming that the core is of a configuration 
requiring it to be inverted in order to drain excess wash therefrom, the 
stop pin 34 will be inserted through the receptacle 31 so as to limit 
rotation of the plate 122 and hence the mandrel plate 118 to about 
180.degree.. Drainage of such excess wash is then accomplished by pivoting 
the valve control lever 250 rightwardly, as viewed in FIG. 1, so as to 
shift the valve element 248 rightwardly and thereby connect the source of 
air pressure 254 respectively to the top and bottom of the cylinders 64 
and 66 while respectively coupling the bottom and top of the cylinders 64 
and 66 to the restricted exhaust line 288. The piston rods 98 and 100 will 
then lower and raise respectively to effect clockwise rotation of the 
sprockets 46 and 50 and of the stop plate 122 and mandrel 18. Such 
rotation of the stop plate 122 will cease upon the stop screw 134 coming 
into engagement with the pin 34 whereupon the valve control lever 250 may 
be pivoted back to the left so as to reverse the connections of the top 
and bottom ends of the cylinders 64 and 66 with the source and exhaust 
lines so as to effect upward movement of the rod 98 and downward movement 
of the rod 100 and hence counterclockwise rotation of the sprocket 46 and 
50 and of the stop plate 122 and mandrel 188, the later rotation ceasing 
upon the stop screw 138 coming into engagement with the pin 34. 
In the event the core to be handled is configured such that only about 
90.degree. rotation is required to drain excess core wash from the top 
thereof, the pin 34 will be inserted through the upper receptacle 30 once 
the valve control lever 250 has been moved to effect shifting of the valve 
element 248 to control operation of the cylinders 64 and 66 so as to turn 
the plate 122 sufficiently to align the opening 142 with the receptacle 
30. The pin 34 then extends through the opening 142 so as to be positioned 
for engagement by the screws 144 and 148 which respectively limit 
counterclockwise and clockwise rotation of the plate 122, as viewed in 
FIG. 1. 
Assuming the core to be handled is of such a size and configuration that 
movement thereof is best accomplished using the core handling attachment 
160, the latter will be mounted to the mandrel plate 188 and the core will 
be provided with vertical holes 218 and 220 sized for respectively 
receiving the expansible sleeves 188 and 212 of the front and rear air 
arbor assemblies 174 and 194. The quick coupler connections 270 and 282 
respectively at the ends of the hoses 266 and 280 will be interconnected 
to thereby establish a connection of the arbor control valve 236 with the 
lower fittings 184 and 210 of the arbor assemblies 174 and 194. Similarly, 
the quick coupler connections 268 and 278 respectively at the ends of the 
hoses 264 and 276 will be interconnected to thereby establish a connection 
of the arbor control valve 236 with the upper fittings 183 and 208 of the 
arbor assemblies 174 and 194. 
The selection of 90.degree. or 180.degree. rotation of the mandrel will be 
made as discussed above. Engagement of the attachment 160 with a core 222 
will be accomplished by lowering the apparatus 10 through use of an 
overhead hoist and guiding the arbor sleeves 188 and 212 into the holes 
218 and 220, respectively, with the valve control lever 240 being in its 
rearward arbor, disengage position, as shown in FIG. 8, wherein the valve 
element 239 is positioned for connecting the upper ends of the arbor 
cylinders to the source of air 254 so that the rods 186 and 206 are 
extended and the sleeves 188 and 212 are unexpanded. Once the sleeves 188 
and 212 are located within the holes 218 and 220, the core 222 is "locked" 
onto the attachment by effecting expansion of the sleeves by pushing 
forward on the control lever 240 so as to shift forwardly the valve 
element 239 of the arbor control valve 236 and connect air pressure to the 
bottom of the arbor cylinders, causing the piston rods 186 and 206 to 
retract and compress the sleeves 188 and 212 through means of the washers 
190 and 214. The core 222 may then be handled as in the manner described 
above in conjunction with the core handling attachment 152.