US3220066A

US3220066A - Squeeze molding machine

Info

Publication number: US3220066A
Authority: US
Priority date: 1961-07-28
Filing date: 1961-07-28
Publication date: 1965-11-30
Anticipated expiration: 1982-11-30
Also published as: DE1433977A1; DE1433976A1; GB965136A

Description

Nov. 30, 1965 E. K. HATCH ETAL 3,220,066

SQUEEZE MOLDING MACHINE Filed July 28. 1961 8 Sheets-Sheet 1 INVENTOR. EDMOND K. HATCH a BY LEON F. MILLER mlmuhuqlflomdlu ATTORNEYS Nov. 30, 1965 E. K. HATCH ETAL 3,220,066

SQUEEZE MOLDING MACHINE Filed July 28, 1961 8 Sheets-Sheet 2 I45 4 A- I l4 G54 -FQ L :H' uo ua F I0 Nu T Q l I F1 4 E1 y: i

" R I. INVENTOR- EDMOND K. HATCH a :29 By LEON E MILLER ATTORNEYS Nov. 30, 1965 E. K. HATCH ETAL SQUEEZE MOLDING MACHINE 8 Sheets-Sheet 5 Filed July 28, 1961 I33 A s \W g ms 4 INVENTOR.

EDMOND K. HATCH 8 BY LEON F. MILLER Obaiin. milky 4L flomulg ATTORNEYS Nov. 30, 1965 E. K. HATCH ETAL 3,220,066

SQUEEZE MOLDING MACHINE Filed July 28, 1961 8 Sheets-Sheet 4 O O O 0 O O O O O g o O O O 0 O 0 0 FIG 5 o E 6 -|6O I63 0 U o g 0 O 0 I74 FIG 6 I73 I I69 3 I79 //////I I 2 W I78 -I67- I76 FIG 7 INVENTOR.

EDMOND K. HATCH 8 LEON F. MILLER oherlmmamllmlly ATTORNEYS Nov. 30, 1965 E. K, HATCH ETAL 3,220,066

SQUEEZE MOLDING MACHINE Filed July 28. 1961 8 Sheets-Sheet 5 HVVENTDR. EDMOND K. HATCH a BY LEON F. MILLER -"WWW ATTIXUVEYS Nov. 30, 1965 E. K. HATCH ETAL 3,220,065

SQUEEZE MOLDING MACHINE Filed July 28, 1961 8 Sheets-Sheet 6 IN V EN TOR.

EDMOND K. HATCH a FIG 9 BY LEON F. MILLER ATTORNEYi Nov. 30, 1965 E. K. HATCH ETAL 3,220,056

SQUEEZE MOLDING MACHINE Filed July 28, 1961 8 Sheets-Sheet '7 INVENTOR. EDMOND K. HATCH a BY LEON F MILLER FIGIO OMMMWMM ATTORNEYS Nov. 30, 1965 E. K. HATCH ETAL 3,220,066

SQUEE'ZE MOLDING MACHINE Filed July 28. 1961 8 Sheets-Sheet 8 A329 INVENTOR.

EDMOND K. HATCH a 330 By LEON F. MILLER ATTORNEYS United States Patent 3,220,066 SQUEEZE MOLDING MACHINE Edmond K. Hatch, Brecksviile, and Leon F. Miller, Rocky River, Ghio, assiguors to The Osborn Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Filed .luly 28, 1961, Ser. No. 127,616 Claims. (Cl. 22-41) This invention relates generally, as indicated, to a squeeze molding machine and more particularly to a foundry molding machine adapted to produce foundry molds of uniform desired hardness quickly and automatically.

Relatively thin flexible diaphragms have heretofore been employed in foundry molding machines to provide a uniform squeeze pressure on the top surface of a sand mold within a flask. However, at the extremely high squeezing pressures necessary to obtain molds of the proper uniform hardness, such diaphragms frequently rupture necessitating the replacement of the entire squeeze head. This results in considerable down time for the molding machine and where an entire molding system is involved, the loss of time and money is substantial.

It is accordingly a principal object of the present invention to provide a simplified machine which will quickly and rapidly produce sand foundry molds of uniform hardness.

It is another main object to provide a foundry molding machine utilizing a shuttle type head wherein the head may be shifted into and out of operative position to facilitate the direct overhead gravity filling of foundry flasks within the machine.

It is a further important object to provide a squeeze head for such foundry molding machine which is accessible and easy to replace and which will provide a uniform squeezing pressure over the entire surface of the sand mold.

It is a still further object to provide such squeezing head which will exert a variable uniform squeezing pressure on the sand mold and yet which will be extremely durable during operation of the machine requiring less downtime for repairs and squeeze head changes.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features herein after fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

FIG. 1 is a front elevation of a machine in accordance with the present invention employing a unique diaphragm squeeze head;

FIG. 2 is a side elevation of such machine as seen from the right in FIG. 1;

FIG. 3 is a top plan view of the machine of FIG. 1 on a somewhat enlarged scale;

FIG. 4 is a horizontal section taken substantially on the line 4-4 of FIG. 2 illustrating the flask latching mechanisms;

FIG. 5 is a top plan view of the diaphragm squeeze head employed in the machine of FIG. 1;

FIG. 6 is a longitudinal vertical section of such squeeze head taken substantially on the line 66 of FIG. 5;

FIG. 7 is a transverse vertical section of such squeeze head taken substantially on the line 77 of FIG. 6;

FIG. 8 is a schematic piping diagram of the hydraulic and pneumatic controls of the machine of FIG. 1;

FIG. 9 is a front elevation of a further embodiment of the present invention utilizing a multiple piston squeeze head;

FIG. 10 is an end elevation of the machine of FIG. 9 as seen from the right thereof;

FIG. 11 is an enlarged vertical section of a squeeze piston-cylinder in accordance with the present invention;

FIG. 12 is a similar vertical section on a smaller scale of a slightly modified form of squeeze piston and cylinder; and

FIG. 13 is a schematic piping diagram illustrating the manner of manifolding and pressurizing such pistoncylinder assemblies.

Referring now to the annexed drawings and more particularly to the machine shown in FIGS. 1 and 2, it will be seen that such machine is mounted on the floor 1 by means of nut and bolt assemblies 2 and 3 extending through flanges 4 at the corners of the triangular base 5. Transverse frame members 7 and 8 support vertically extending

legs

9, 10, 11 and 12. Secured between the top inside of the

legs

9 and 12 is a frame plate 13 and similarly a frame plate 14 is secured between the top insides of the

legs

10 and 11. Both of these plates are provided with arcuate openings 15 therein as seen more clearly in the end elevation of FIG. 2. Subadjacent the transverse frame members 13 and 14, there is provided two longitudinally extending frame members 17 and 18 extending between the pairs of

legs

9, 10 and 11, 12, the member 17 being shown broken away in FIG. 1.

A sand hopper 20 is mounted on top of the machine within a top box frame composed of the

members

21, 22, 23 and 24 (note also FIG. 3) with such frame being mounted on relatively

short legs

25, 26, 27 and 28, such short legs being provided with bottom flanges or bed plates which are bolted directly to top plates mounted on the

legs

9, 10, 11 and 12 as shown at 30. The hopper 20 is secured to the

frame members

24 and 22 by means of

brackets

31, 32, 33 and 34. A pair of

cutoff slides

35 and 36 are supported for horizontal reciprocation on parallel rows of

rollers

37 and 38 mounted respectively on roller supporting bars 39 and 40 secured to the

legs

28, 27 and 25, 26 as seen in FIG. 3. Each of the

plates

35 and 36 are provided with elevated side flanges 42 and 4-3 as seen in FIG. 2 which enclose the

rollers

37 and 38 so that the

plates

35 and 36 are employed in cooperation with the flanges to provide grooves in which the rollers fit. A center sand distributing ridge 44 is provided in the hopper and as seen the

plates

35 and 36 extend beneath such ridge in the closed position shown. Such plates are actuated for movement by respective piston-

cyclinder assemblies

45 and 46 which are mounted on pairs of

brackets

47 and 48 on the

top frame members

24 and 22 respectively. The rods 49 and 50 of such piston-cylinder assemblies are connected to the

cutoff plates

35 and 36 as shown at 51 and S2.

The sand measuring box 66 is positioned sub-adjacent the

cutoff slide plates

35 and 36 on

brackets

61 and 62 secured to the tops of the frame plates 13 and 14 respectively. Telescoped over the bottom of the measuring box is a louvered opening assembly 63 mounted on pairs of adjusting

screws

64 and 65 mounted on the plates 13 and 14 respectively. Pairs of

brackets

66 and 67 are employed to support the assembly through the adjusting screws 64 and 65. The brackets 67 additionally support a piston-cylinder assembly 68, the rod 69 of which is connected to a louver actuating bar 70. This bar pivots louvers 71 which are in turn pivoted to the frame of the assembly 63 to open and close the bottom of the sand measuring box 69. It can now be seen that by adjustment of the

screws

64 and 65, the depth of the box or the distance of the louvers from the cutoff plates can closely be controlled thus to increase or decrease the amount of said within the measuring box 60.

Mounted on the legs 9, 1t}, 11. and 12 beneath the louver opening frame assembly 63, there is provided a carriage supporting frame 81} which includes two elongated

side frame members

81 and 82 supporting inwardly directed row of

rollers

83 and 84. The carriage supporting frame 80 includes a transversely extending end frame member 35 and an opposite cylindrical end frame member 86 on which is mounted a piston-cylinder assembly 37 by means of brackets 88. The rod 89 of such pistoncylinder assembly is connected as shown at 96 to the carriage frame 91 of squeeze head 92. The rod 89 is covered by a shield 93 so that when in its extended position it will not be exposed to loose sand falling from the measuring box 60 and the louver assembly 63. The shield 93 is preferably mounted on the carriage frame 91 for movement therewith and thus with the rod 89. The carriage 91 is provided with a top plate 94, the side marginal edges of which overlie the inwardly directed rows of

rollers

83 and 84. Such marginal edges also underlie the frame members 17 and 18 (see FIG. 2) when the squeeze head 92 is in the operative squeezing position shown in FIG. 1 to provide a firm top backstop for the squeeze head.

A sand filling chute fit? is similarly mounted on a plate 97 having a central aperture therein and the chute carriage is connected to the squeeze head carriage by links 98. Thus the piston-cylinder assembly 87 is effective horizontally to reciprocate both the squeeze head and the filling chute. Such filling chute includes a flared top portion '99 which receives the sand from the opened louvers 75 and deposits it through the discharge opening 101) in the bottom thereof. A strike-off blade 161 is secured to the bottom edge of the chute to strike oh the excess sand on the flask as the chute is moved from the filling position to the position shown in FIG. 1.

The flask F shown in phantom lines is, of course, conventional and is supported on its bottom flange by conveyor rollers 111 inwardly directed from conveyor

roller supporting bars

112 and 113. These bars may be bolted or otherwise suitably secured directly to the legs 9 through 12 of the machine frame. Mounted on each

bar

112 and 113 are a pair of

pneumatic cylinders

114 and 115, the rods of which are connected as shown at .116 and 117 respectively to fill frame 118. As seen in FIG. 2, the fill frame 118 is provided with a depressed center portion in the side walls 119 and 120 thereof to accommodate the strike-ofl blade 191. The piston-

cylinder assemblies

114 and 115 act as air springs to maintain the fill frame in its lowermost position resiliently to be raised by the elevation of the table T which will lift the flask F off the rollers 110 to engage and lift the fill frame 118 against the pressure of the

air cylinders

114 and 115 to cause the thus formed mold box composed of the fill frame, flask and table to move upwardly against the squeeze head 2. It is noted that the fill frame 118 and accordingly the flask F are dimensioned peripherally to telescope over the outside of the marginal peripheral dimension of the squeeze head. There will be a very slight peripheral clearance between the fill frame and flask and the marginal portions of the squeeze head 92 as shown by the phantom line position of the flask and fill frame at 121 in FIG. 1. If desired, a brush or like sliding seal may be incorporated between the squeeze head and the fill frame and flask.

The table T is supported on the

rods

125 and 126 of

hydraulic cylinders

127 and 128 respectively which extend through the apex of the triangular base 5. The blind end of each of the piston-cylinder assemblies may extend into a pit or slight depression 129 in the floor 1.

Referring now to FIG. 4, it will be seen that air operated

stops

130 and 131 are pivoted to the interior surfaces of the

frame legs

12 and 11 respectively as shown at 132. and 133. A flask entering the machine in the direction of the arrow 134 will then engage the distal ends of the stops as shown at 135 and 136 to be in proper position for the loading operation. When the flask is to be taken out of the machine, piston-

cylinder assemblies

137 and 138 will be caused to extend their

rods

139 and 140 pivoted to the proximal ends of the latches 13d and 131 as shown at 141 and 142 respectively, thus to pivot the distal ends of such latches clear of the flask so that it may be removed from the machine in the direction of the arrow. A new flask 145 will be pushed into the machine and the previously made mold will be ejected. After the next flask enters the machine, the piston-

cylinder assemblies

137 and 138 again retract and the stops are positioned to contact the next flask 145. On the way into the machine, spring loaded

latches

146 and 147 are depressed by the bottom of the flask and as it clears the latch mechanisms, springs 148 and 149 return them to the slightly elevated position shown more clearly in FIG. 2 abutting the end or edge of the bottom flask flange to eliminate the possibility of the flask rolling back out of the machine during the molding cycle. In this manner, the flask will firmly be held between the

latches

146 and 147 and the

stops

130 and 131. Suitable conveyors comprised of rollers similar to those shown at 119 may be employed to convey flasks to the machine as at 150 and to discharge finished molds as at 151.

Referring now additionally to FIGS. 5, 6 and 7, it will be seen that the squeeze head 92 employed with the present invention is mounted on the carriage 91 by means of three I-

beams

160, 161 and 162 extending transversely thereacross. The I-beams may be secured to the carriage 91 by suitable fasteners such as nuts and bolts extending through apertures in the top flanges of the beams as shown at 163. Similarly, the bottom flanges of the beams may be employed to fasten a head or cavity 164 thereto through spacer blocks 165 which may be positioned at opposite ends of each heard. A horizontally extending relatively thick flange member 166 may be secured as by welding to the lower peripheral edge of the cavity member 164. As seen in FIG. 7, the cavity member 164 includes two

side plates

167 and 168 which form, with the cavity member 164 having downwardly turned

end walls

169 and 176, a downwardly opening cavity which is filled with several layers or blocks of gum rubber. The illustrated embodiment discloses a total of four such layers filling such cavity and such layers may, for example, be totally 3 /2 inches thick. The top layer 170 may be /2 inch and the other three layers 171 may be 1 inch thick. Aligned openings 172 in such layers lead to a tapped extension 173 on the top surface of the cavity member 164 into which a coupling 174 is threaded. Two rela tively

thick diaphragms

176 and 177 are peripherally clamped to the bottom side of the flange or ring 166 by a clamping ring 178 of the same peripheral dimension as the flange 166 and the

diaphragms

176 and 177. Such clamping ring is held against the diaphragms thus to clamp the same against the flange by a series of peripherally spaced clamping bolts 179 threaded into the clamping ring 178. It is noted that the interior surface 189 of such ring is slightly outwardly flared and a further ring 181 is secured to the bottom surface thereof by fasteners such as the screws 182. The lower ring 181 also has an outwardly flared interior surface 183 which cooperates with the ring 178 to provide a marginal relatively rigid portion adapted firmly and mechanically to squeeze the periphery of the sand mold, and the interior surfaces and 183 force the sand inwardly to be squeezed by the downwardly bulging relatively thick diaphragms 1'76 and 177. Air at approximately pound per square inch will be supplied to the back of the downwardly bulging diaphragms through line 185 coupled to the tapped boss 173. It is noted that a similar tapped boss 1&6 is employed on the opposite side of the head and either or both may be employed to supply such air under slight pressure to the cavity or space 187 behind the

diaphragms

176 and 177. In the embodiment shown, the opening in.

the tapped boss 186 may be provided with a plug 188. The

layers

170 and 171 as well as the

diaphragms

176 and 177 may, for example, be natural gum rubber, polyurethane rubber, or synthetic rubber such as neoprene. The

layers

170 and 171, which serve to reduce the fluid volume behind the

diaphragms

176 and 177, may be glued together or otherwise suitably fastened to provide a resilient block or backup for the space behind the diaphragms, the lowermost layer 171 being tailored to fit the interior shoulder on the flange 166. The air under slight pressure will cause the

diaphragms

176 and 177 to bulge downwardly as shown. However, during the squeeze operation when it is acting on the sand under pressure, it will tend to flatten out and in high spots of the mold, it will contact and depress the

layers

170 and 171. During the molding operation, the pressure provided by the

hydraulic cylinders

127 and 128 will raise the trapped pound per square inch pressure behind the diaphragm to over 100 pounds per square inch thus giving a uniformly hard mold, the back of which will be contoured to the sand and pattern resistance that the diaphragm meets. It can then be seen that with a 30 x 38 x flask that a total of over 100,000 pounds pressure will be exerted behind the diaphragm.

Operation of the FIG. 1 embodiment Referring now more particularly to FIG. 8, it will be seen that the pneumatic components of the machine are operated by a series of four way solenoid power operated valves having manual overrides. The valve 200 operated by solenoid 201 is effective through /2

inch hose lines

202 and 203, for example, to control the operation of the cutoff slide piston-

cylinder assemblies

45 and 46. Similarly, valve 204 operated by solenoid 205 is effective through 1

inch hose lines

206 and 207 to operate the piston-cylinder assembly 87 to position the carriage which includes the squeeze head 92 and chute 96 to either squeeze position or fill position. Also, the valve 208 operated by solenoid 209 is effective through

lines

210 and 211 which, like the

lines

202 and 203, may be /2 inch hose lines to control the operation of piston-cylinder assembly 68 either to open or close the louvers 75. Flow control units 212 comprised of a variable restriction valve and a check valve in parallel may be provided in each of the lines leading to the piston-

cylinder assemblies

45, 46, 68 and 87.

A valve 214 operated by solenoid 215 is effective to supply air under pressure selectively during the cycle of the machine through pipes 216 to a pattern blow-cit, and similarly a valve 217 operated by solenoid 218 is effective to supply air through lines 219 to a pattern spray unit, not shown. Air for the

valves

200, 204, 208, 214 and 217 is supplied from a source 220 through an air line filter 221 which leads to supply line 222. A radial flow exhaust mufller 223 may be provided in exhaut line 224. A branch 225 in the supply line leads to the pairs of upset frame hold-down piston-

cylinder assemblies

114 and 115. Such upset cylinders may be provided with a 2 /2 inch bore and a 14 inch stroke with cushioning at the blind end only.

Hydraulic fluid under pressure may be supplied alternately to the lines 227 and 228 or the line 229 from a hydraulic power unit, respectively to raise and lower the table T through the piston-

cylinder assemblies

127 and 128. The hydraulic power unit which may, for example, be one commercially sold by Brown & Sharpe will have a pressure responsive device so that when the desired pressure is obtained, the pressure will be switched from lines 227 and 228 to line 229. As the table with the flask supported therein descends and as the flask approaches the rollers 110, the downward speed of the table will be slowed or reduced so that the drawing of the pattern from the produced sand molds will be at a relatively low speed. The table may be provided with a bracket 231 having a cam 232 thereon adapted to operate a vibrator valve 233 supplied through line 234 which leads through valve 200 so that the vibrator will be operative only when the

cutoff plates

35 and 36 are closed and when the valve 233 is open governed by the position of the table T. The vibrator may be employed to assist in the compaction of the sand within the flask and/or to facilitate the drawing operation.

Air may be supplied to a pressure regulating valve 236 which will increase the pressure in line 237 until a diaphragm type unloading valve 238 unloads, such valve being set to unload at 1 pound per square inch. When the valve 238 relieves, the setting of the valve 236 can be reduced one turn so that the pressure supplied through check valve 239 through line 185 to the chamber 187 behind the diaphragm will remain somewhat less than 1 pound per square inch or A of a pound per square inch.

The latch operating piston-

cylinder assemblies

137 and 138 may be operated, for example, through

lines

240 and 241 with a flow control unit 242 being provided in the line 240 leading to the blind end of the piston-cylinder assembly 137. The air supply in such lines can be controlled by suitable solenoid operated valves signalling the condition of the machine at the completion of the cycle so that the flask F can be cleared for movement from the machine.

With the machine shown in the position of FIG. 1, the first operation is to shuttle the squeeze head out from under the measuring box 60 with the carriage pneumatic piston-cylinder assembly 87. At the same time, the

hydraulic squeeze pistons

127 and 128 will raise the table with the pattern and plate P positioned thereon lifting the flask F from the rollers until the flask contacts the upset frame 118. When the flask and upset are in contact, the table stops rising and the louvers of the sand box are opened by the piston-cylinder assembly 68 for the desired length of time. Since the upper cutoff slides 35 and 36 are closed whenever the louvers 75 are opened, only the amount of sand, which is determined by the height of the louver assembly 63, within the measuring box 60 is dropped into the flask. The sand will drop through the chute 96 which has been placed in alignment between the measuring box 60 and the flask F. Before the table again begins to move upwardly, the squeeze head and chute will be shuttled to the position shown in FIG. 1 by the extension of the piston-cylinder assembly 87 The movement of the chute will cause the excess sand within the flask and fill frame to be struck off. When in the position shown, the table will start to move upwardly and the live air on the rod end of the pairs of

cylinders

114 and 115 holding the fill frame down will be compressed and forced back into the supply line 225. Continued upward movement of the table causes the sand within the flask and fill frame to be compressed to a hardness which is a function of the hydraulic pressure in the

squeeze cylinders

127 and 128. When the desired pressure is obtained, the cycle is reversed and the flask and fill frame will start to lower away from the head with the live air which is kept on the rod end of the pairs of

cylinders

114 and 115 keeping the upset on top of the flask as it is lowered. As the flask approaches the rollers 110, the downward speed of the table T is reduced to slow the drawing operation and continued downward movement of the table will draw the pattern from the sand mold. The latching piston-

cylinder assemblies

137 and 138 will then be actuated to clear the flask for discharge from the machine and a new flask will be positioned in its place so that the above-described cycle may be repeated.

The FIG. 9 embodiment Referring now particularly to FIGS. 9 and 10, there is illustrated a machine similar to the above-described machine using a modified form of squeeze head. The machine is mounted on a base 250 of the similar triangular configuration as the base 5 shown in FIG. 1 and four upstanding legs 251 support the major components of the machine. The legs 251 support on the tops thereof an auxiliary frame in the form of a small stand 252 which in turn supports the hopper 253 for the sand mix. Two piston-

cylinder assemblies

254 and 255 on each side of the hopper 253 are employed to operate the cutoff slides 256 and 257 by which the sand mix is selectively dumped into the sand measuring box 258. Louvers 260, operated by piston-

cylinder assemblies

261 and 262, open to drop the load of sand therein through chute 263 when the

slides

256 and 257 are closed, or close to maintain the proper amount of sand therein when the slides 25-6 and 257 are opened. The squeeze head shown generally at 264 is connected with the chute 263 by means of a link 265 and both are shuttled horizontally back and forth by the piston-cylinder assembly 266. The rod 267 of such piston-cylinder assembly is connected to the carriage of the squeeze head as shown at 268. The bottom of the chute 263 may be in the form of a cloth curtain or the like and both the squeeze head and chute are supported on side flanges which ride on inwardly directed rows of

rollers

269 and 270. Hold-down

bars

271 and 272 supported by brackets 273 and 274 extending downwardly from transverse frame members 275 and 276 serve to overlie and confine the supporting

flanges

277 and 273 of the squeeze head 264 in the squeeze position.

A fill frame 280 is supported on

brackets

281 and 232 secured to the legs 251 of the machine frame. Guide pins 283 extend through such brackets to guide the fill frame for vertical movement. A flask F is brought into the machine on rows of

rollers

284 and 285 mounted on

roller bars

236 and 287 respectively.

The table T is supported for movement on the rods 2% and 291 of piston-

cylinder assemblies

292 and 293. Flexible boots 2% and 295 may be employed to protect the exposed rods extending from such cylinders. A pattern and pattern plate P will be supported on the top of the table T in the same manner as in the FIG. 1 embodiment.

The operation of the machine will be substantially identical to that of the FIG. 1 embodiment wherein the flask is moved into the machine and is engaged by the pattern and plate supported on the table T as the same is elevated. The elevation of the flask and table causes the flask to engage the upset frame 280 to move the same upwardly. However, after the mold box has been formed by the table, flask and fill frame, the piston-cylinder assembly 266 will cause the carriage to shuttle to the position shown in FIG. 9 wherein the squeeze head 264 will be positioned to overlie the thus formed mold box after it has been filled with sand from the measuring box falling through the chute 263. When the squeeze head is in the proper position, the side marginal edges thereof will underlie the

members

271 and 272 to provide a top support therefor and continued upward movement of the table with the mold box formed thereon will cause the sand within the mold box to engage the squeeze head 264 compressing the sand to the desired hardness. At the completion of the sand squeezing operation, the table will start downwardly separating the components of the mold box and drawing the pattern from the sand mold formed within the flask.

The squeeze head employed with the machine of FIG. 9 is comprised of a multiplicity of downwardly projecting piston-cylinder assemblies 3% which are supported on the squeeze head carriage for horizontal shuttling into and out of operative squeeze position.

Referring now to FIG. 11, there is shown one form of piston-cylinder assembly that may be employed with the piston-cylinder squeeze head of the present invention. The squeeze head carriage may be provided with top and

bottom support plates

301 and 302 spaced by collars 333 which may be welded to the plate 301 and held together by nut and bolt assemblies 304. An annular seal 305 may be positioned between the end face of the collar 303 and the plate 302. Stationary piston rods 3% may be inserted in aligned

apertures

307 and 303 in the plates 301 and 392 respectively and a snap ring 369 may be employed cooperating with shoulder 310 to hold the rod in proper position. A dowel pin 311 or the like may be employed to lock the rod in its proper rotative position. The rod is provided with two vertically extending

passageways

312 and 313 with both having tapped

enlargements

314 and 315. The transverse passageway 316 connects the passageway 312 with the interior space 317 between the

plates

301 and 362. A plug may be positioned in the tapped enlargement 314 and the enlargement 315 may be coupled to a vent or the like.

Seals

318 and 319 may be provided to seal the interior 317. The lower end of the rod is provided with an enlarged portion 320 which serves as the piston for cylinder 321. Sliding seals 322 and 323 seal the piston against the inside of the cylinder. Passageway 312 is provided with a bottom enlarged portion 324 which accommodates a guide rod and oil tube 325 which is secured to a plug member 326 which is sealed as shown at 327 and held to the outer end of the cylinder 321 by a snap ring or the like 328. A square bottom shoe 329 is held to the member 326 by screws or the like 3311 so that the tube 325, member 326 and shoe 329 are all firmly rigidly mounted on the outer end of the cylinder 32]..

Snap rings 331 and 332 are employed to hold annular member 333 in the opposite end of the cylinder and additionally the snap ring 332 holds a wiper 334 adapted to wipe over and clean the exterior 335 of the rod 306. A sliding seal 337 may be employed to maintain the vent end of the cylinder in the proper sealed condition and also a seal 338 similar to the seal 327 may be employed.

It is noted that the hollow rod 325 is oil-center from the center of the cylinder 321 and accordingly relative rotation of the piston and cylinder is precluded. Since the square shoes 329 will be relatively closely juxtaposed over the entire bottom surface of the squeeze head, such rotation could result in interference between the shoes and damage to barred flasks, sprues, gates, etc. It can now be seen that the

plates

331 and 302 can be spaced and sealed to act as a manifold for the oil or fluid pressure acting upon the piston-cylinder assemblies.

In FIG. 12 there is illustrated a slightly modified form of piston-cylinder squeeze head wherein plates 34% and 341 are held together by screws 342 or the like with such screws also being employed to hold cylinders 343 in the proper sealed relationship to the bottom of plate 341. Apertures 344 in the plate 341 are aligned with manifolding passages 345 in the plate 346 so that each of the cylinders will be connected to the same source of fluid under pressure. The rod ends of the cylinders may be closed by plates 346 held thereto by screws 347 and suitable wipers 34 8 may be employed to wipe the shank of rod 349 to preclude excessive wear from sand clinging thereto. The sealing member 350 may be held to the piston 351 by the cap 352 threaded on stud 353 and held thereto by a lock nut or the like. It is noted that the shank of the rod 349 extends through the aperture 354 in the plate 346 eccentrically of the piston rod 353 and this precludes relative rotation of the piston and cylinder. Square shoes 355 or the like may be fastened to the ends of the rods by screws 356 and as seen, the juxtaposed shoe 357 is fairly close and thus relative rotation would cause interference between adjacent shoes, since it will be realized that the shoes may be at different heights during the squeezing operation. Lubricant fittings 358 may be employed properly to lubricate the piston and cylinder.

Referring now to FIG. 13, it will be seen that the pistoncylinder assemblies 3% can be supplied with a source of hydraulic fluid under pressure from a reservoir 360 and air may be supplied to such reservoir through the line 351 to force the hydraulic fluid outwardly through line 362. A check. valve 363 in parallel with a hydraulically operated cutoff valve 364 supplies such hydraulic fluid to the manifold 365 connected to all of the piston-cylinder assemblies. As the

hydraulic pistons

292 and 293 elevate the table to form the mold box and to squeeze the sand therein against the piston-cylinder assemblies 300, the pressure will build up in the lines 366 causing the valve 364 to shift locking the fluid within the piston-cylinder assemblies and fixing it as to quantity. Thereafter, the piston-cylinder assemblies can move relative to each other but for every upward movement of one, there has to be an equalizing downward movement of another or others. A variable restriction valve 367 may be provided in series with the hydraulic cutoff valve 364. The vent lines to the various cylinders may pass through an air filter 368 to atmosphere. The

hydraulic cylinders

292 and 293 may be supplied with hydraulic fluid from a reservoir 369 through filter 370 and pump 371 driven by motor 372. Such is a conventional hydraulic power supply unit.

It can now be seen that intially each of the pistoncylinder assemblies may retract simultaneously due to the force of the sand thereagainst compressing the air source, but as the pressure builds up within line 366, the hydraulic cutoff valve 364 will operate fixing the fluid behind such piston-cylinder assemblies as to quantity. Thereafter, relative movement of the piston-cylinder assemblies may be obtained so that each shoe thereof will conform generally to the surface of the pattern, but further total movement or retreat is precluded.

By way of further explanation, with reference to FIG. 13, it can be seen that the valve 364 is shown schematically as a sliding spool type having a blocking position 375 and an open position 376 which can be registered with line 377 to close and open the same, respectively. Movement of the spool or valve element is afforded by pressure in pilot line 366 connected to the line 377 at 378 urging the valve against the pressure of spring 379 to shift the same from its open to its blocking position. It can now be seen that the variable restriction valve 367 is in series with the blocking valve 364 in line 377. Thus the valve 364 functions to open or close line 377 depending upon the pressure in line 366. After the mold has been squeezed, and the table T is lowered from the head, the spring 379 on one end of the valve element will overcome the pressure exerted by the fluid in pilot line 366 permitting the valve to return to its open position providing communication therethrough between the manifold and the reservoir 360.

It can now be seen that there is provided foundry molding machines which will very rapidly produce foundry sand molds of uniform high surface hardness having squeeze heads capable of withstanding high pressures and constant uses, such squeeze heads conforming to the requisite of the pattern, barred flasks, gates, sprues or the like depending upon the particular arrangement desired. For example, it has been calculated that the hydraulic cycle time of the machine need only be 6.6 seconds with the approach taking 2.3 seconds, the squeeze taking 1.5, and the draw 2.8. Rugged squeeze heads providing an equalizing pressure on the entire upper surface of the molds thus rapidly produced are disclosed which can additionally take the continual horizontal reciprocating movements required in the gravity fill machines illustrated.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

We, therefore, particularly point out and distinctly claim as our invention:

1. A squeeze head for foundry molding machines comprising aseries of downwardly projecting piston-cylinder assemblies, means manifolding each of said piston-cylinder assemblies to a common source of fluid under pressure, and means responsive to a predetermined pressure in said manifold means operative to fix the quantity of fluid in said system.

2. A squeeze head as set forth in claim 1 wherein said piston-cylinder assemblies comprise downwardly extending fixed rods, cylinder means movable on said rods, and squeeze biscuits on the bottoms of said cylinder means, said downwardly extending fixed rod means having a vertically extending passageway therein, and a guide rod extending upwardly from said squeeze biscuit being guided in said downwardly opening passage and offcenter from said cylinder means to keep said cylinder from rotating with respect to said rod means.

3. A squeeze head as set forth in claim 1 wherein said piston-cylinder assemblies comprise downwardly extending fixed cylinder means, piston and rod means extending downwardly from said cylinder means and having squeeze biscuits mounted on the ends thereof, said rod means being eccentric with respect to said cylinder means to keep said piston and rod means from rotating with respect to said cylinder means.

4. A squeeze head for foundry molding machines comprising a plurality of projecting sand engaging piston cylinder assemblies, means manifolding each of said piston-cylinder assemblies to each other and to a common source of fluid under pressure, means responsive to a low squeeze pressure of said assemblies against such sand operative to decrease the volume of fluid in said assemblies as the latter retreat against the pressure of such sand, and means responsive to an increased squeeze pressure against such sand to fix the quantity of fluid in said assemblies while nevertheless permitting relative adjustment of said assemblies.

5. A foundry molding machine comprising a squeeze head, a table vertically movable therebeneath and adapted to support a pattern containing sand filled flask, said squeeze head comprising a series of downwardly projecting squeeze members, pressure chambers acting on each of said members, means manifolding each of said chambers to a common source of fluid under pressure, said members being adapted to retreat against the pressure in the respective chambers as said table is elevated to bring such sand filled flask against said squeeze head, and means responsive to a predetermined pressure in said manifold means to fix the quantity of fluid therein.

References Cited by the Examiner UNITED STATES PATENTS 364,948 6/1887 Moore 22-41 1,944,168 1/1934 Camerota 22-65 2,341,012 2/1944 Billman et al 25-41 2,686,345 8/1954 Ypung 22-35 2,850,775 9/1958 Northington et al 22-20 2,852,820 9/1958 Taccone 22-40 2,956,316 10/ 1960 Deakins et a1 22-20 2,959,828 11/1960 Frankenstein 22-45 2,968,846 1/1961 Miller 22-36 3,041,685 7/1962 TaCCOne 22-42 3,049,988 4/1962 Lindemann et a1. -237 3,089,207 5/1963 Miller 22-10 MARCUS U. LYONS, Primary Examiner.

MICHAEL V. BRINDISI, Examiner.

Claims

1. A SQUEEZE HEAD FOR FOUNDRY MOLDING MACHINES COMPRISING A SERIES OF DOWNWARDLY PROJECTING PISTON-CYLINDER ASSEMBLIES, MEANS MANIFOLDING EACH OF SAID PISTON-CYLINDER ASSEMBLIES TO A COMMON SOURCE OF FLUID UNDER PRESSURE, AND MEANS RESPONSIVE TO A PREETERMINED PRESSURE IN SAID MANIFOLD MEANS OPERATIVE TO FIX THE QUANTITY OF FLUID IN SAID SYSTEM.