US3233291A

US3233291A - Explosive force molding machine and method

Info

Publication number: US3233291A
Application number: US226930A
Authority: US
Inventors: Leon F Miller; Robert W Ellms
Original assignee: Osborn Manufacturing Corp
Current assignee: Osborn Manufacturing Corp
Priority date: 1960-09-26
Filing date: 1962-09-28
Publication date: 1966-02-08
Anticipated expiration: 1983-02-08

Description

Feb. 8, 1966 F. MILLER ETAL EXPLOSIVE FORGE MOLDING MACHINE AND METHOD 5 Sheets-Sheet 1 Filed Sept. 28, 1962 FIG. I

INVENTORS LEON F. MILLER 6 ROBERT W. ELLMS 65mm ATTORNEYS Feb. 8, 1966 L. F. MILLER ETAL EXPLOSIVE FORCE MOLDING MACHINE AND METHOD 5 Sheets-Sheet 2 Filed Sept. 28, 1962 FIG. 2

INVENTORS LEON E MILLER 6 ROBERT W. ELLMS BY ATTORNEYS Feb. 1966 L. F. MILLER ETAL 3,233,291

EXPLOSIVE FORCE MOLDING MACHINE AND METHOD Filed Sept. 28, 1962 5 Sheets-Sheet 5 INVENTORS LEON F. MILLER 6 ROBERT W. ELLMS WWW ATTORNEYS Feb. 8, 1966 F. MILLER ETAL EXPLOSIVE FORGE MOLDING MACHINE AND METHOD FIG. 5

5 Sheets-Sfieet 4 Filed Sept. 28, 1962 INVENTORS LEON F. MILLER 6 ROBERT W. ELLMS ATTORNEYS I 1966 L. F. MILLER ETAL 33 EXPLOSIVE FORCE MOLDING MACHINE AND METHOD Filed Sept. 28, 1962 5 Sheets-Sheet 5 I34 F |G.6

FIG? INVENTORS LEON E MILLER 6 ROBERT W. ELLMS MMMM ATTORNEYS United States Patent Ofliice 3,233,291- Patented Feb. 8, 1966 3,233,291 EXPLOSIVE FORCE MOLDING MACHINE AND METHOD Leon F. Miller, Rocky River, and Robert W. Ellms, North Olmsted, Ohio, assignors to The Osborn Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Filed Sept. 28, 1962, Ser. No. 226,930 17 Claims. (Cl. 22-4ll) This invention relates generally as indicated to a molding machine, and more particularly to a foundry molding machine utilizing explosive force in the high speed production ramming of foundry molds.

There has been an increasing demand in the operation of modern high production foundries for foundry molding machines capable of rapid production of relatively large molds. Such machines have been provided employing squeeze means and optional jolt means operated and controlled by various types of fluid pressure devices. When extremely high pressure air is utilized to operate such devices, the cost tends to become excessive and there may also be some danger involved to the operators in the event of failure of certain parts of the machine. While hydraulic fluid is rather more safe, the equipment and devices required to supply, regulate and control its flow are expensive and add disproportionately to the cost of the molding operation, especially when it is desired to provide high squeeze pressures in a machine designed for rapid operation and corresponding high mold production.

It is accordingly a principal object of the invention to provide a foundry molding machine capable of obtaining the desired high squeeze capacities without the heretofore required complex hydraulic or pneumatic equipment.

It is a further principal object to provide a foundry molding machine utilizing controlled explosive force to ram foundry molds.

Another important object is the provision of a foundry molding machine utilizing explosive force to ram instantaneously and uniformly the entire upper surface of a foundry mold at the required high pressure.

Still another object is the provision of an internal combustion operated foundry molding machine utilizing the means to assemble a sand filled flask and pattern to compress the combustive mixture employed prior to combustion and the attendant instantaneous ramming action obtained.

Yet another object is the provision of such machine wherein the sand will be prepacked as the combustive mixture is compressed.

A still further object is the provision of a simplified and less costly foundry molding machine which will yet obtain the desired sand mold qualities.

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 hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting'forth in detail certain illustrative embodimerits 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 side elevation of a preferred form of found ry molding machine in accordance with the present invention;

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

FIG. 3 is an enlarged fragmentary vertical section of the squeeze head of the machine shown in FIG. 1 taken substantially on the line 3-3 thereof;

FIG. 4 is a horizontal section of such head taken substantially on the line 4-4 of FIG. 3;

FIG. 5 is an elevation partially in section of a further form of molding machine in accordance with the present invention;

FIG. 6 is a fragmentary top plan view of the machine taken substantially on the line 6-6 of FIG. 5;

FIG. 7 is a fragmentary enlarged vertical section of the head of such machine taken substantially on the line 7-7 of FIG. 5; and

FIG. 8 is a schematic fuel and air flow diagram for the present invention.

Referring now to the annexed drawings and more particularly to the preferred form of the invention shown in FIGS. 1 through 4, it will'be seen that the molding machine comprises a frame including a base 1 supporting inverted U-shape

side frame members

2 and 3 which are interconnected at the tops thereof by a transverse arched top framing member 4. The top frame member 4 may be in the form of a large fabricated box or I-beam and is provided with a planar finished contact surface 5 centrally disposed beneath the arch thereof. The legs 6 and 7 of the U-shape frame member 2 are provided with brackets 9 and 10 respectively supporting conveyor rail 11 having inwardly directed horizontally aligned conveyor rollers 12. The legs of the inverted U-shape frame member 3 are also provided with similar brackets shown at 14 supporting conveyor rail 15 having inwardly directed conveyor rollers 16. The

conveyor rollers

12 and 16 are horizontally aligned and form a roller conveyor for the squeeze head 18 and a sand measuring box 19. The sand measuring box and squeeze head are interconnected at 20 for horizontal shuttling movement on the conveyor rolls in tandem, such shuttling movement being obtained.

by a pair of carriage piston-cylinder assemblies 21, the cylinders of which are mounted on brackets 22 secured to the

frame members

2 and 3. Brackets 24 extending horizontally from the top frame member 4 support a sand hopper 25 which will normally be filled with fiuffed green foundry molding sand provided usually from a conveyor or feed system within the foundry. The sand measuring box 19 is provided with a louvered bottom frame 26 which louvers can be opened and closed by actuation of a louver piston-cylinder assembly 27. Such piston-cylinder assembly and its supporting frame 28 are secured to the sand measuring box 19 and horizontally movable therewith when the carriage cylinder assemblies 21 are extended. The sand measuring box 19 is also provided with a cutoff plate 29 adapted to move beneath hopper 25 to maintain the sand therein as the box is thus moved to the right as seen in FIG. 1.

A flask feeding conveyor 3t comprised of rails with inwardly directed rollers 31 thereon is employed to feed foundary flasks F to the machine. A depending bracket 32 mounted on the front of the sand measuring box 19 is provided with a pivotally mounted hook 33 which will engage the top edge of the flask F as it is fed into the position directly beneath the sand hopper 25. A flask discharge conveyor 34 having similar inwardly directed rollers 35 is provided on the opposite side of the machine horizontally aligned with the feed conveyor 30 to deliver the finished sand molds.

Situated centrally in the base 1 is a vertically extending clamp piston-cylinder assembly which supports on the rod thereof a table 41. As is conventional, the top of the table 41 supports a pattern plate having a pattern P thereon about which the foundry sand will be compacted within a flask to form the foundry sand mold. While the piston-cylinder assembly 40 may be pneumatic, for the purposes of the present invention, it is preferred that a hydraulic clamping cylinder be employed. On each side of the piston-cylinder assembly 40, there is provided 8,2 '3 a) draw piston-cylinder assemblies 42 and 43 supported in the base 1 extending vertically upwardy with the

respective rods

44 and 45 supporting horizontally extending

frame members

46 and 47.

As seen more clearly in FIG. 1, each of the frame members is provided at its ends with vertically extending piston-

cylinder assemblies

49 and 50, the rods of which support conveyor rail 51 having inwardly directed horizontally aligned conveyor rollers 52. The conveyor rail 54 thus supported on the frame member 47 is provided with inwardly directed conveyor rollers 55 which are, of course, horizontally aligned with the conveyor rollers 52.

Such horizontal alignment is assured for all vertical positions of the

conveyor rollers

52 and 55 by means of a squaring shaft 56 extending transversely through the

frame members

2 and 3.

Crank arms

57 and 58 are keyed or otherwise secured to such shaft to rotate therewith and at their distal ends, such cranks are connected to the

respective frame members

46 and 47 by means of the links shown at 59 in FIG. 1. In this manner, extension of the draw cylinders 42 and 43 will elevate the

conveyor rollers

52 and 55 with the squaring shaft and connecting linkage assuring that such piston-cylinder assemblies move in unison. Adjustable stops 6t) and 61 mounted on

brackets

62 and 63, respectively, limit the upward movement of the

conveyor rollers

52 and 55 and in such upper limited position, the conveyor section formed thereby will be horizontally aligned with the flask feeding and

discharge conveyors

30 and 34, respectively. It is noted that the

conveyor rollers

52 and 55 are positioned closely adjacent the sides of the table 41 on which the flask F will be supported enclosing the pattern P. The bottom flange of the flask 65 will overlie the table 41 sufficiently to permit engagement between the flange and the

projecting rollers

52 and 55 so that the flask may be elevated from the table 41 by the draw piston-cylinder assemblies 42 and 43.

With the exception of the squeeze head 18, that portion of the illustrated machine above described is generally conventional, reference being had to the co-pending application of Edmond K. Hatch, Serial No. 133,700, entitled Overhead Squeeze Molding Machine, filed August 24, 1961, now Patent No. 3,169,285. Referring now to the squeeze head 18 as shown more clearly in FIG. 3, it will be seen that it includes a frame including laterally projecting

support rails

71 and 72 which ride upon the inwardly projecting

rollers

12 and 16. The head frame 70 includes two downwardly

projecting guide pins

74 and 75 which support for vertical guided movement the plate 76 which is provided with downwardly projecting collars 77 and 78. Bushings 79 and 89 may be provided to facilitate such vertical movement of the plate member 76.

Beneath such plate member 76, there is mounted a manifold frame 82 supporting the upper ends of a series of downwardly projecting pneumatic piston-cylinder assemblies 83. The blind end of each of the cylinders 84 of such assemblies 83 is connected to the manifold systern in the frame 82 and the rods 85 thereof project downwardly and are provided with squeeze biscuits 86 on the ends thereof adapted to engage and squeeze the foundry molding sand positioned in the flask F therebeneath. In this manner, each of the cylinders 84 is interconnected by means of the manifold frame so that the air pressure acting on each of the squeeze biscuits 86 will always be the same. Such squeeze biscuits substantially cover the top area of the sand within the flask with a plurality of resiliently displaceable squeeze surfaces. The manifold frame is connected through port 87 to a booster 88 shown in FIG. 2 which will maintain the air within the cylinders 84 at a predetermined high pressure. The booster will, of course, take the line air pressure in the plant which may, for example, be pounds per square inch and elevate it to the desired working pressures.

The plate 76 supporting the cylinders 84 is connected by means of a heavy duty pin 96 extending through annular member 92 on such plate 76 to the bottom of a stepped piston 93 which projects upwardly through the frame '79 into a cylinder 94. Such cylinder 94 is secured to the frame 70 by a plurality of nut and bolt assemblies 95, there being four such nut and bolt assemblies in the illustrated embodiment as seen in FIG. 4. The cylinder 94 is provided with a depending annular portion 96 which projects downwardly through the central opening in the frame 76 and a series of chevron packings 97 held in place by plate 98 may be provided sealing the stepped piston 93 with respect to the bottom end of the cylinder 94. Such cylinder is provided with an annular recess 100 accommodating the enlarged head 101 of the stepped piston 93 for vertical movement. Such enlarged head may be provided with a plurality of piston rings 102 providing a sliding gas seal between the enlarged head and the bore of the cylinder.

A cylinder head 194 is securely mounted on top of the cylinder by means of a plurality of peripherally spaced fasteners 195 shown in FIG. 4 and such head is provided with a planar top surface 106 which may have approximately a inch clearance with the surface 5 of the top frame member 4 to permit the head to be shuttled beneath such frame member when supported on the

rolls

12 and 16. A suitable gasket may, of course, be provided between the head and the cylinder. The head 1114 provides a combustion chamber 108 exposed to the top of the head 101 of the stepped piston 93.

The combustion chamber 198 provided in the head 104 is generally annular overlying the top of the piston head 101 but includes two projections 110 and 11.1 which overlie the heads of

poppet valves

112 and 113. The poppet valves provide communication between the combustion chamber 108 and inlet and

exhaust passages

114 and 115, respectively.

The stems of the poppet valves project downwardly through horizontal extensions of the cylinder 94 and such are actuated by pneumatic piston-cylinder

assembly valve lifters

118 and 119 respectively. The projecting rods of such piston-cylinder assemblies engage the bottom of the stems of the poppet valves to elevate the heads thereof from their seats in an apparent manner and springs 120 and 121 surrounding the downwardly projecting stems 112 and 115 respectively resiliently maintain such poppet valves in closed position. Air then selectively supplied to the blind ends of the

cylinders

118 and 119 will lift the respective poppet valves. A spark plug 123 of conventional variety is mounted in the head 194 to ignite a combustible fuel mixture Within the combustion chamber 103. An air line conduit 124 containing pressure at approximately 100 pounds per square inch is connected to the cylinder through the internally tapped port 125 which is situated a considerable distance from the bottom 126 of the bore 166. It can now be seen that an explosive force in chamber 108 will drive the piston 93 downwardly, driving the air backed feet 86 into ramming engagement with the sand S in flask F, such feet as a whole cooperating with the flask to enclose the sand since they telescope within the flask.

Referring now to the embodiment of the invention disclosed in FIGS. 5, 6 and 7, it will be seen that there is illustrated a machine having a base 139 supporting four corner column members 131 which in turn support a head 132 comprised of two I-beams 133 and 134 in turn supporting three transverse I-

beams

135, 136 and 137. Pretensioned tie bolts or the like may be employed extending through the columns 131 to hold the head very firmly to the base. The head additionally includes two top plates 1353 and similarly disposed bottom plates 139 extending parallel to the beams 133 and 134. Four elongated tie bolts 140 pass downwardly through such plates, through spacing collars 141 and finally through four later-ally projecting knuckles 142 mounted on cylinder 143. Nuts 144 may be employed firmly to secure the cylinder to the head frame of the machine. The cylinder in this manner is rigidly mounted on the machine frame.

Such cylinder includes two downwardly and outwardly projecting

portions

145 and 146 which support guide pins 147 and 148. These extend through bushings 149 and 150 mounted in head plate 151 and the projecting

collars

152 and 153 extending downwardly therefrom. Securely mounted beneath the plate 151 is the manifold plate frame 155 for a plurality of piston-cylinder assemblies 156 having downwardlyprojecting rods 157 provided with squeeze biscuits or feet 158 on the distal ends thereof. As shown, the centermost squeeze biscuit may be provided with a projecting portion 159 to form a pouring basin in cooperation with an upwardly projecting sprue pin mounted on the pattern P.

A flask 160 mounted on the pattern plate 161 is situated on table 162 which is firmly supported on the base 130. The flask may be provided with an upset 163 which will be filled to its upper marginal edge with fluffed foundry molding sand. The upset, flask, pattern plate and pattern forming the mold box will be vertically aligned with the squeeze head so that the squeeze biscuits 158 will substantially cover the entire upper surface of the sand within such mold box to be impinged thereby as the squeeze head descends.

The plate 151 is provided with an annular projection 166 which is secured to the bottom of stepped piston 167 'which extends upwardly into the bore 168 of the cylinder 143 through the chevron packings 169. The top of the piston is provided with an enlarged head 170 including piston rings 171 slidably gas sealing the head within the cylinder bore.

A cylinder head 173 is securely fastened to the top of the cylinder and cooperates with the top of the cylinder and the piston head 170 to form a combustion chamber 174 provided with two

extensions

175 and 176. These extensions overlie

poppet valves

177 and 178 providing fluid communication between such combustion chamber 174 and inlet conduit 178' and exhaust conduit 179 respectively. The stems of the poppet valves extend downwardly through the projections in the cylinder to be actuated by the rods of piston-

cylinder assemblies

180 and 181, respectively.

Springs

182 and 183 surround the projecting stems of the poppet valves resiliently to maintain such poppets closed. As seen more clearly in FIG. 7, air supplied through

conduits

185 and 186 to the blind ends of the

cylinders

180 and 181 will elevate the pistons 187 therein to elevate the rods to engage the poppet stems opening such poppet valves. The head, of course, will be bolted directly through a gasket to the cylinder as shown at 189 and a spark plug 196 may be provided centrally in the head to ignite the combustible mixture in the combustion chamber 174.

The wall of the cylinder is provided with an air inlet 91 with air being supplied to such inlet through line 192 at approximately 100 pounds per square inch. The inlet 191 is spaced a considerable distance above the bottom 193 of the bore 168. In this embodiment, the air inlet 191 may be employed as a means to elevate the piston 167 to raise the squeeze biscuits 158 and to compress the combustible gas mixture in the combustion chamber 174. When the spark is created by the spark plug 198, the piston head 170 will be driven downwardly and the air within line 192 will be forced back into the plant system. However, when the head 1711 moves past the inlet port 191, it will close the same, providing a closed air cushion beneath the head 170 in the bore 168 precluding such head from impacting against the bottom 193 of such bore. When the head is driven against the sand within the flask and upset, the squeeze biscuits will yield, increasing the pressure within the manifold plate 155. i The biscuits encountering the least resistance from the sand, generally those about the periphery of the pattern, will accordingly be driven further into the sand by the exploa. sion created in the chamber 174. The explosion drives the head downwardly into impacting engagement with the sand within the flask, ramming the sand mold to the desired hardness. The exhaust poppet 178 will be opened exhausting the spent fuel through the conduit 179 and the inlet poppet 177 will then be opened to blow out the spent gases from the combustion chamber. The exhaust poppet willthen be closed and the new fuel charge will be forced into the combustion chamber and the inlet poppet 177 will then be closed. Air entering the conduit 192 will then be employed to elevate the piston 167, compressing the gas within the combustion chamber preparatory to firing of the next charge. It will, of course, be understood that the sand mold may be explosively rammed in this manner as many times as desired, but it has been found that only one shot is generally required Prior to the firing of the next charge, the flask and the rammed mold therein will be replaced by a further mold box similarly filled with flutfed molding sand.

In general, the cycle of operation of the squeeze head in the FIGS. 5, 6 and 7 embodiment will be substantially that shown in connection with the preferred embodiment of the invention illustrated in FIG. 8 with the exception that the flask filling and mold box assembling operations are not incorporated in the machine. Referring now to such FIG. 8 and to the preferred form of machine shown in FIGS. 1 through 4, with flufl'ed sand in the hopper 25 and with the louvers 26 of the sand measuring box '19 closed, the carriage which includes the head 18 and such measuring box 19 is moved by the carriage cylinders 21 to the position shown in FIG. 1 where the measuring box will be positioned beneath the hopper 25. In this position, the sand falls from the hopper into the measuring box on top of the closed louvers and simultaneously a flask F on the feed conveyor 36 is latched to the carriage by the book 33 on the bracket 32. The cylinders 21 are then energized to move the measuring box, the flask F hooked thereto, and the head 18 to the right until the measuring box and flask are aligned with the center line of the machine frame beneath the top frame member 4. The head 18 will be moved to the right on the

conveyor rollers

12 and 16 out from under the top frame member 4.

The

draw rollers

52 and 55 will have been elevated to their top position against the stops 60 and 61 so that the draw rollers constitute a continuation of the feed and discharge

conveyors

30 and 34, respectively. The draw rollers are then lowered by means of the pistoncylinder assemblies 42 and 43 to place the flask F over the pattern P on the pattern plate on the table 41. With the mold box, comprising the pattern, pattern plate and flask, now assembled, the louvers 26 are opened by means of cylinder 27 and sand in the measuring box falls onto the pattern and into the flask. The louvers are then closed. With the sand measuring box extended by the cylinders 21, the cut-off plate 29 will move beneath the hopper 25 precluding the sand therein from dropping out. As the flask F is lowered by the downward movement of the draw rollers, it will automatically disengage the book 33 so that the sand measuring box may be returned to the position shown in FIG. 1. The head 18 will then also be pulled back beneath the top frame member 4.

The sand filled flask is now situated on the table 41 directly beneath the head 18 and the mold compacting cycle will now be initiated. Fluid pressure is applied to the piston-cylinder assembly 40 to elevate the table and thus the sand filled flask until the sand in the flask engages the feet 86 elevating the entire plate assembly 76 and the piston 93 attached thereto as seen in FIG. 3. A charge of combustible gas will have been placed in the combustion chamber 108 and the elevation of the piston 93 by means of the piston-cylinder assembly 40 will compress the gas in the combustion chamber with both

poppet valves

112 and 113 closed. The feet 86 will vertically adjust depending upon the depth of the sand therebeneath, precompressing the sand to a certain degree since: the mass of the piston and the vertically movable portion of the head is substantial and considerable pressure will be required to elevate the piston to the position shown: in FIG. 3. The air pressure acting through the inlet 125 will also serve to elevate the piston to the position shown, compressing the fuel charge within the combustion chamver. Valve V shown in FIGS. 1 and 2 may now be closed to lock the hydraulic fluid beneath the piston of assembly 40, firmly to support table 41 and the sand-filled flask thereon.

The spark plug 123 will then be energized to create an explosion in the combustion chamber driving the relatively massive multiple piston squeeze head downwardly against the sand, ramming the sand within the flask with'. the feet 86 serving to spread the explosive force evenly over the top surface of the mold. Due to the manifold provided for the cylinders 84-, the explosive pressure ex erted on each of the feet 86 will be the same although.- the extent -of sand penetration will vary depending on the resistance encountered. The compressed air within the; bore will normally be forced back through the line 124s into the air system of the plant.

As seen in FIG. 8, the solenoid 201 is then energized through the control panel 202 to admit air under pressure to line 203, energizing piston-cylinder assembly 119 to lift the poppet valve 113 exhausting the combustion chamber- This then permits the piston 93 to be elevated for the next cycle. However,

solenoid Valves

205 and 206 will now additionally be energized. The opening of valve 205 will admit air from air pressure source 207 through air pressure regulator valve 208, mixing chamber 209, and check valve 210 into conduit 211. The opening of solenoid valve 206 will admit air from such pressure source 207 to line 212, energizing the piston-cylinder assembly 118 opening the inlet poppet 112. The air pressure then in line 211 will be forced through the combustion chamber 108 purging such combustion chamber. valve 201 is now deenergized closing the exhaust poppet 113. Solenoid valve 215 is now energized, sending a fuel charge such as liquid propane gas from reservoir 216 through a gas pressure regulator 217 into the mixing chamber 209 through a check valve 218. The propane charge Will then be forced. into the combustion chamber under pressure through the mixing chamber 209. The solenoid valve 215 is then deenergized after the desired fuel charge has been admitted. Solenoid valve 206 is now deenergized closing the inlet poppet 212. With both the inlet and exhaust poppets now closed, a desired fuel charge is within the combustion chamber 108'. The charge within the chamber 108 will, of course, be now compressed by the elevation of the piston 93 by the clamp cylinder 40 as the next sand filled flask engages the bottom of the head prior to the ignition of the spark plug 123. The top frame member 4 serves as a backup for the head 18 as the clamp cylinder 40 precompresses the sand S and the fuel charge, and also prevents recoil of the cylinder and head. Pressure gauges 220 and 221 may be provided in conjunction with the

regulators

208 and 217, respectively. Although it has been found that only one explosive ramming of the mold has been quite adequate, it will be understood that the above cycle may be repeated as often as desired to compact the sand mold. Accordingly, the cylinder and head may be Water or air cooled if desired.

After the mold has been rammed by the explosion within the chamber 108, fluid pressure is then released from beneath the piston-cylinder assembly 40 in the base 1 to lower the flask, sand, pattern, and pattern plate. The draw cylinders 42 and 43 are now extended, elevating the flask from the pattern drawing the mold therefrom. When the mold has reached its highest position determined by the stops 60 and 61 wherein the

rollers

52 and 55 will The solenoid form a continuation of the flask feed and discharge

conveyors

30 and 34, the next flask entering the machine engaged with the hook 33 carried by the sand reservoir 19 will push the finished mold onto the discharge conveyor 34. The cycle will then be repeated for ramming of the next mold.

It will, of course, be understood that a confined explosion may be employed beneath the sand filled flask driving the sand upwardly against a relatively fixed squeeze head. It will also be understood that the precompression of the sand and fuel may be obtained by moving the entire head downwardly against the sand.

While liquid propane gas has been found quite suitable for the explosive ramming of foundry molds in this manner, it will, of course, be understood that many other explosive fuels, either gaseous or gasified, may be employed such \as gasoline, kerosene, diesel oil, methane, butane, any of the natural gases, or for that matter explosive cartridges employing compounds similar to TNT or nitroglycerine may also be employed. Certain additives may be employed slowing the rate of combustion to obtain a longer more uniform power stroke.

It can now be seen that there is provided a foundry molding machine which will ram a foundry mold over the entire upper surface thereof with but a single explosive blow eliminating the heretofore required high pressure hydraulic or pneumatic mechanism and the appurtenant complex controls.

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 foundry molding machine comprising a table adapted to support a sand filled flask and pattern plate thereon, a squeeze head vertically above said table, and means explosively vertically relatively to move said table with respect to said squeeze head operative to cause said squeeze head to ram such sand filled flask.

2. A foundry molding machine comprising means firmly to support a sand filled flask, a squeeze head di mensioned to cover substantially the entire exposed surface of sand within such flask, and internal combustion means operative explosively relatively to drive said head and sand filled flask to ram a foundry mold within such flask.

3. In a foundry molding machine, means to support a flask and pattern therein with such flask filled with sand, and means operative explosively instantaneously to ram the sand in such flask against such pattern to produce a foundry mold.

4. A foundry molding machine as set forth in claim 3, wherein said latter means comprises an explosively driven squeeze head operative to telescope within such flask.

5. A foundry molding machine as set forth in claim 4 including a combustion chamber explosed to said head, means to charge such chamber with explosive fuel, means to ignite such fuel charge to drive said head against such sand, and means to purge such chamber after the firing of sUCh charge.

6. A foundry molding machine as set forth in claim 5 including means to move said head toward such combustion chamber to compress such fuel charge prior to firing.

7. A foundry molding machine as set forth in claim 6, wherein said last mentioned means comprises a clamp cylinder operative to move such sand. filled flask toward said head simultaneously prepacking the sand within such flask.

8. A foundry molding machine as set forth in claim 4, wherein said head includes a stepped piston, a cylinder surrounding said piston, and means operative to entrap air between said piston and cylinder as said piston approaches the end of its explosively driven stroke.

9. The method of ramming a foundry mold comprising the steps of filling a flask and pattern with sand and explosively relatively driving a squeeze head With respect to such sand while spreading such explosive force uniformly over the sand surface impinged by such head.

10. The method of ramming a foundry mold comprising the steps of filling a flask and pattern with sand, substantially enclosing the sand within such flask with a squeeze head by causing the latter to engage such sand, and explosively driving such head into such sand.

11. The method of ramming a foundry mold comprising the steps of filling a flask and pattern with sand, moving such sand filled flask against a squeeze head substantially to enclose and prepack the sand therein while simultaneously moving such squeeze head to com-press a fuel charge exposed thereto, and igniting such charge explosively to drive such head against such sand.

12. In a foundry molding machine having a squeeze head and a flask support adapted to be elevated to squeeze sand in such flask against said head, said head being dimensioned to fit within the confines of such flask, and power means operative thus to elevate said flask support; means including a vertically disposed piston-cylinder assembly mounting said squeeze head for limited vertical reciprocation, means for introducing an explosive gaseous mixture to said cylinder for compression by such limited vertical reciprocation of said squeeze head when the latter engages the sand in such flask elevated by said power means, whereby such sand is also initially compacted, and means operable to explode such mixture to drive said squeeze head downwardiy further to compact such sand.

13. The machine of claim 12 including means operable to lock said flask support in elevated position with such gaseous mixture thus compressed.

14. The method of ramming sand in a foundry molding flask which comprises first relatively slowly bringing squeeze means firmly against the sand surface in such flask preliminarily to squeeze such sand, and then explosively driving the already sand-engaging squeeze means against such sand further to compact the latter.

15. A foundry molding machine comprising a squeeze head, first pressure means operative firmly to force said squeeze head against sand in a flask, and second pressure means thereupon operative much more rapidly to force said sand-engaging squeeze head against such sand.

16. A foundry molding machine comprising means firmly to support a sand filled flask, a squeeze head dimensioned to cover substantially the entire exposed surface of sand Within such flask, internal combustion means operative explosively to drive said head against such sand to ram a foundry mold within such flask, said internal combustion means comprising a piston and cylinder assembly, a combustion chamber, means to ignite a fuel charge in such chamber to drive said piston in said cylinder, said piston being stepped to provide an enlarged piston head, a bore within said cylinder receiving said piston head for reciprocation, a port in said bore spaced from the bottom thereof to supply said bore with air under pressure to preclude said piston head from bottoming in said bore, an intake and an exhaust valve in such combustion chamber, means operative to open said intake valve to admit a charge of air to such chamber, means operative to mix such air and a fuel, and means operative to ignite such combustible mixture within such chamber explosively to drive said enlarged head in said bore.

17, In a foundry molding machine, means to support a flask and pattern therein with such flask filled with sand, means operative explosively instantaneously to ram the sand in such flask against such pattern to produce a foundry mold, said latter means comprising an explosively driven squeeze head operative to telescope within such flask, a combustion chamber exposed to said head, means to charge such chamber with explosive fuel, means to ignite such fuel charge to drive said head against such sand, means to purge such chamber after the firing of such charge, means to move said head toward such combustion chamber to compress such fuel charge prior to firing, said head including a stepped piston, a cylinder surrounding said piston, and means operative to supply air under pressure to said cylinder to force said head toward such combustion chamber.

References Cited by the Examiner UNITED STATES FATENTS 800,753 10/1905 Mistelski 22-41 X 1,482,646 2/1924 Gates 26484 1,711,954 5/1929 Landon 2241 2,482,342 9/1949 Hubbert et al. 2,633,094 3/ 1953 Muller. 2,648,125 8/1953 McKenna et al. 29421 X 2,930,315 3/1960 Tolumin. 2,948,923 8/1960 Rocca et a1. 2,959,828 11/ 1960 Frankenstein 224l 2,968,846 1/1961 Miller 22-41 X 2,968,073 1/ 1961 McWithey 22-42 3,004,290 10/ 1961 Toulmin. 3,012,549 12/1961 Bard et al. 1237 3,030,678 4/1962 Huston et al 22-955 X 3,100,910 8/1963 Martin 264-84 3,170,202 2/1965 Huston et al. 22-193 J. SPENCER OVERHOLSER, Primary Examiner.

WINSTON A. DOUGLAS, ROBERT F. WHITE,

MICHAEL V. BRINDISI, MARCUS'U, LYONS,

Examiners.