US1922598A

US1922598A - Die-casting

Info

Publication number: US1922598A
Application number: US513803A
Authority: US
Inventors: Louis H Morin
Original assignee: DOEHLER DIE CASTING CO
Current assignee: DOEHLER DIE CASTING CO; DOEHLER DIE-CASTING Co
Priority date: 1931-02-06
Filing date: 1931-02-06
Publication date: 1933-08-15
Anticipated expiration: 1950-08-15

Description

Aug. 15, 1933. L.. H. MORIN DIE CASTING Filed Feb. s. 1951 N 7 Sheets-Sheet 1 ATTORNEY Allg. 15,1933. L, H, Mom-N 1,922,598

' DIE CASTING Filed Feb. 6, 1931 7 Sheets-Sheet 5 INVENTOR ATTORNEY Aug. 15, 1933. L. H. MoRlN 1,922,593

DIE CASTING Filed Feb. e, 1951 'r sheeis--sheetV 4 'ATTORNEY L. H. MoRlN f 1,922,598

DIE CASTING Filed Feb. e, 1951 rr sheets-sheet 5 Aug. 15, 1933.

Aug. l15, 1933.

l L. H. MORIN DI: CASTING Filed Feb. 6, 1931 '7 Sheets-Sheet 6 L. H. 'MORIN Aug. 15,` 1933.

DIE CASTING Filed Feb. 6, i931 7 Sheets-Sheet '7 mvENToR 04..., wa Mw BY d;

Patented Aug'. 15, 1933 11m-CASTING Louis H. iorin, New York, N. Y., assignor to Doehler Die-Casting Co., a Corporation' of New York Application February 6, 1931, Serial No. .513,803

11 claims. (ci. 2z-2oo) My invention relates to the art of die-casting in which castings aremade by forcing molten metal, under pressure, into a mold or die. Al-

though considerable progress has been made in this art, and castings may now be made which have complicated shapes and with such accuracy that subsequent machining operations are rendered unnecessary, the industry has been restricted to casting articles from certain metals such, l0 Vfor example, .as zinc and aluminum base alloys. Because of the great saving which can be eiected by die-casting parts of intricate shape, which Y otherwise would require extensive and expensive machining operations, it is desirable to produce 15 die-castings from other metals such, for instance,

as brass which are'suitable for many purposes for which the alloys now used in die-castingcannot be used. 'It has been impossible, however, with the known methods and die-casting machines, to die-cast such metals on a commercial basis, and it is a purpose of my invention to render practical the commercial production of diecastings from metals other Athan those in general The vprincipal difliculties arising in die-casting other metals than those in general use in the industry are caused by the high temperatures at which the metals melt. In die-casting brass, for

instance, by known methods, the high tempera' so ture of the molten brass raises the temperature of various parts of the machine and particularly the dies to suchan extent that the dies are weakened and the high shrinkage of brass sets up When these metals are die-cast in accordance strains within the die which impair its accuracy. In fact, after several castings are made the dies A crack and are useless for further casting operations. Since the cost of the dies is'the principal factor in commercial die-casting, this in itself o makes die-castings with metals having. a high melting point prohibitive. Another serious dimculty encountered in the casting of metals of com.

paratively h igh melting point is the fact that it has been practically impossible to produce die-1 castings from such metals which are consistently free from blowholes or shrinkholes.

My invention is based upon minimizing the heat transferred to the machine and the dies, and the utilization of pressures compatible with the Y production of castings ofiuniform density. The

method. of my invention includes forcing the metal into the die while the metal is in a molten condition but near its transition point. That is, the metal is vfluid but the temperature of the metal is such. that a lowering of the temperature `diately. Thus, the two factors which govern the' to any extent will cause the metal to change to the solid state. When the metal 'is introduced into the die in this conditio it passes from the molten condition into the solid state practically instantaneously and may be, and in accordance with my invention is, ejected from the die immheat transferredfrom the molten metal, namely, the temperature at .which the metal is introduced into the die and the length of time the hot metal 05 is in contact with the die, are minimized.

The pressure under which the metal is intro` duced into the die -is also anV important factor; in die-casting metals having a comparatively high melting point as this determines the time requiredY to fill the mold cavity ofthe dieand also the density and uniformity of the casting produced. I have found that in order to produce satisfactory die-castings from 'metals having a comparatively high meltingl point, which are forced into the die at or near the transition point, the metal must be introduced into the, die under a much greater pressure than that used with the ordinary die-casting metals, and in accordance with my method, l introduce the metal into the 8 die under a pressure ranging between 6000 and 9000 pounds per'square inch. Under this metal pressure, the mold cavity of the die is filled prack tically instantaneously, and the casting' produced is free fromblowholes or shrinkholes. e

An advantage of my invention is the fact that it is .equally applicable to die-'casting the ordinary metals used in the die-casting industry.

with my invention, the casting produced has a greatendensity than the ordinary die-casting; it is free from blowholes or shrinkholes; and it exhibits greater strength and a smoother surface.

My method of die-casting may be convenien ly carried out by a machine which I have designed 95 for that purpose. The machine includes a. pres-a sure pot which is adapted to receive a charge of molten metal. The pressure pot is provided with an orice through which molten .metal introduced into the pot is discharged into the mold cavity of a die, and the pot is adaptedto have a, die-part rigidly affixed in operative relation thereto withthe post of the die-part communi-` cating with the orifice through the wall of the w pressure pot. Means are provided for exerting a pressure, on the metal in the pressure-pot to force the metal through the orifice, at a high velocity, and -into the die.

. Associated with the pressure pot, there is a u movable die carrier for .moving a die-part in to and out ofoperative relation with va die-part secured in operative relation to the pressure pot.

Core pulling and ejecting mechanisms are provided which are actuated upon movement of the die carrier to open the dies, the core pulling and ejectinginechanisms pulling the cores and eject.

ing the casting. The automatic operation of the core pulling and ejecting mechanisms is an important factor in my invention as it renders possible immediate ejection of the cast metal which if allowed to remain in the die any length of time freezes fast t the cores, and, of course, the heat transferred to the die from the hot metal is proportional to the time the metal is in contact with the die.

An advantage'of this machine is the fact that the pressure pot is separate from the melting pot. This construction renders practical the casting of pure aluminum as the molten aluminum is not in contact with the pressure pot a sufhcient length of time to absorb iron from the pressure pot, and the high pressure which the machine is adapted to exert upon themolten metal is sufficient to force pure molten aluminum into -the die without the addition to the aluminum of some agent such as silicon to increase the fluid' ity of the molten aluminum. This advantage is of great practical importance because pure aluminum does not tarnish when exposed to prevailing conditions of service, and it is therefore only necessary to polish the casting which is produced in the machine.

I shall now describe the invention in connection with the machine illustrated in the accompanying drawings which machine constitutes one embodiment of .my invention and which'is designed for carrying out my method. r

In the drawings:

Fig. 1 is a side elevation of a die-casting machine constructed in accordance withrmy invention;

Fig. 2 is a-n end elevation of the same as viewed from the right in Fig. 1 and showing the pressure end of the machine;

- Fig. 3 is a plan of the same partly in section on the irregular line 3--3 of Fig. 1; Y

Fig. 4 is a diagrammatic arrangement ill trating the system and apparatus used in obtaining the high pressures usedby the machine;

5 is a longitudinal section of a pressure cylinder;

Fig. v6 is a. transverse section of the same takenon the line 6-6 of Fig. 5

Fig. '1 is a longitudinal section of a manual control valve for the pressure cylinder;

. Fig. 8 is an end elevation of the same;

Fig. 9 is a longitudinal section of .the pressure pot and its associated mechanism;

Fig. 10 is an enlarged 'fragmentary plan taken on the line 10-10 of Fig.,9 and showing a. cross beam with a cover plate removed;

Fig. 11 is an enlarged fragmentary, SQtional end elevation of the parts shownin Fig. 10;

12 is a fragmentary, sectional end elevation of the cams for operating the die carrier;

Fig. 13 is a fragmentary, sectional, side eleva-A Fig. 16 is an enlarged sectional elevation of a clutch mechanism.

'I'he machine shown in the drawings comprises Vsupport a plate 4 which spans 4the frame members and is secured thereto by means of bolts 5 extending through the plate. On this frame, there is mounted a standard 6 which is secured to the plate by means of bolts 7 extending through a lateral flange 8 formed on therlower end of the standard. 'Ihis standard includes two solid upstanding side portions 9 and a central portion 10 which forms a vertical slot in which a block 11 forming the pressure pot proper is received.'

The block forming the pressure pot is formed kin two parts, one of which 11a is bored longitudinally thereof to form a pressure chamber which is adapted to receive a charge of molten metal and the other part 11b forming the base of the pressure chamber. The two parts are held in proper relation to each other by an overlapping flange connection as shown in Fig. 9. -A hole is provided through one wall of the pressure pot, and in this hole, there is a bushing 12 which has a discharge orice that communicates with the pressure chamber of the pressure pot. The discharge orifice of the bushing 12 tapers outwardly from the chamber of the pressure pot, so that metal solidifying in the orifice will be drawn out of the orifice with the casting. A llateral flange formed on the outer end of the bushing abuts against the outer surface of the pressure block and serves to hold the bushing in place. The ope'n side of the slot in the standard in which the pressure block is received is closed by a die plate 13 which extends across the slot vand is secured to the side of the standard by bolts which engage T-shaped slots formed in the surface of the standard. The surface of the die plate abutting against the side of the pressure pot is recessed to receive the flange of the .bushing 12.

The opposite face of the die plate is also recessed and carries'a die-part 14 with the post of the diepart communicating with the discharge orifice of -the pressure pot. The pressure pot is held The base of the pressure chamber formed inf the pressure pot tapers to an opening of lesser diameter that extends through the base of the -pressure pot and the standard which forms a receptacle for the pressure pot. This latter opening is aligned with an opening which extends through the plate of the frame. Within th'e pressure p'ot there is a piston 18 the lower end of which is complementary to the taper of the base of the pressure chamber. A projection 19 on. the lower end of this piston extends into and is secured in a recess in the end of a rod 20 which extends through the aligned openings in the base of the pressure pot, the standard and the plate of the frame. The opposite end of the rod is also recessed and receives the end of a rod 21 of lesser diameter which is secured to the rod and forms a continuation thereof. The reduction in diameter of the composite rod formed by the

rods

20 and 21 forms aledge for apurpose which will hereinafter appear. The lower end of the rod 21 normally rests upon a resilient support which is of sufficient height so that the piston is held in the pressure pot at approximately the transverse center of the pressure chamber. and covers the discharge orice. The circumference of the piston is provided with two semicircular grooves which' are .adapted to catch and retain any molten metal flowing past the piston.

. The resilient support, upon which the end of the composite rod extending from the piston rests,

V includes a bracket having legs 22 which end in lateral anges 23 that may be secured to the floori or a base upon which the machine -is mounted, and a cross piece 24 that extends between these legs and is integral-therewith. The cross piece is provided with two vertical openings which are adapted to receive bolts 25 which extend upwardly therefrom. A plate 26 extends between these bolts and has openings to receive the bolts. Between the plate andthe cross piece of the bracket, there is a compression spring 27 surrounding each of the bolts, and the plate'is prevented from moving oif of the bolts by nuts 28 threaded on the ends thereof. At the center of the plate, there is provided an abutment 29'upon which the end of the composite rod extending from the piston in the pressurechamber rests.

The side upright members 9 of the standard 6 forming the frame for the pressure pot are bored.

longitudinally thereofl to receive upstanding supporting rods 30. These rodshave a reduced end portion which extends through the plate of the frame; and the ends of the rods are threaded to receive nuts 31 which secure the rods -to .the frame. The upper ends of these rods are also reduced and extend through lugs 32 formed on the sides of a cylinder 33 which lugs are bored so that the reduced ends of the rods may pass therethrough, one end of each lug resting upon the ledge'formed by reducing the diameter of the rods and the other end abutting against a nut 34 threaded on the end of the rods and securing the cylinder on the reduced end of the rods. The cylinder is formed by boring the block 33 longitudinally thereof. The lower end of this bore is closed by a head 35 which has a projection 36 extending into the cylinder, vthe inner end of the l projection abuttingagainst a shoulder formed in the cylinder wall. This head is provided with'an opening therethrough for a piston rod, a bushing 36a being interposed between the sides of the opening through the head and the piston rod. The bushing is provided with a ange at its inner end and on this flange there is a circular packing strip 37 of U-shape in cross section. The headis secured to the end of the cylinder by bolts38 and' is positioned by the projection 36 extending into the cylinder and ani` annular positioning lug 39 which is received in `a. complementary groove in the end of the cylinder. The head 40 closing the upper end of the cylinder is of dome shape. This 'head is likewise secured to the end of the cylinder by means of bolts 41 and positioned by n annular positioning lug 42 received in a complementary groove. The head is'.V also provided with a cylindrical projection 43 extending into the bore ofthe cylinder.

there is a transverse passage 50 extendingf through the valve .chest. This passage communicates with thecenter of the valve chamber through a series of ports 50' and is adapted to supply fluid under pressure to the valve chamber to be distributed. to the cylinder by a piston ,valve 51 having a reduced central portion which is` slidably mounted within the valve chamber. The piston valve 51 has rods 51a and 51b extending from the ends thereof into the hub. shaped heads. On the side of the valve chamberopposite to the cylinder there is an Aexhaust passage 52 which communicates withV the valve chamber throughA branch passages 52a and 52h at both ends of the valve chamber.

In the cylinder, a piston is reciprocally mounted. The piston includes a solid central portion 53 which is tted 'on-a reduced portion of a piston rod 54. This solid portion of the piston has peripheral grooves formed in each end thereof, andtliese grooves form housings for U-shaped packing strips 55. The grooves formed in` the lower end of the piston are closed by a plate 56 that abuts against the shoulder formed by reducing the diameter of the piston rod. vThe pis-- ton rod iis further reduced in diameter beyond `the solid portion of the piston and on this reduced portion of the piston rod, there is mounted a collar 57 which is provided with a lateral flange 58 which forms the upper face or head end of the piston, and with the grooves formed in thel upper end of the solid portion of the piston constitutes a housing for one of the packing strips 55. `The collarv has a small piston 59 formed on the upper endthereoi and is secured in place by a nut 60 threaded on the end of the piston rod, a washer 61 beinginterposed` between the nut and the end of the collar. The piston formed on the upper end of the collar is adapted to enter the cylinder formed by the cylindrical projection extending from the dome-shaped head on the upper end of the cylinder. This piston is provided with a groove in which a packing ring 62 is placed, one side of the, groove being formed by the washer 61 between the collar and the nut. The -piston traps some of the pressure fluidl medium in the dome shaped head of the cylinder and the trapped fluid acts as acushion to cushion the upward stroke of the piston. The piston; through the piston rod, 'and the cross head 63 is adapted to actuate a plunger 64 which is aligned with the pressure chamber of the pressure pot. Y

The crosshead 63 extends between the cylinder supporting rods which pass through hub shaped portions formed on the sides of the -cross head, the cross head being slidably mounted on is provided with a recess which receives a lateral flange 6 5 formed on the end of the piston rod. Acollar 66 surrounding the piston rod and having an annular flange 67 is secured to the upper surface of the cross head by bolts 68 which extend through the flange of the collar and serve l to secure the flange of the piston rod n the recess formed in the cross head. The plunger 64 is secured to the lower surface of the cross head in the same manner, that is, a ange 69 is provided on the end of the plunger which ange is received in a recess in the lower surface of the cross head. An annular plate 70 surrounding the plunger is secured to the cross head by means l0f bolts 71 which clamp the flange of the plunger in the recess in the cross head. The plunger, as hereinbefore explained, is aligned with the pressure chamber of the pressure pot. The length o f stroke of the piston 53 is such that when the piston is in its lowermost position; the plunger extends into the pressure pot and forces the piston in the pressure pot against the bottom of the pressure chamber.

Extending from each of the hubs of the cross head surrounding the cylinder supporting rods, there is a lug 72 which has an opening therethrough to receive the reduced end portions of rods 73 which reduced end portions extend through the lugs and are secured therein by nuts 74 threaded on the. end of the rod. These rods pass' through openings provided therefor in the plate of the frame and are slidably mounted in these openings. The lower ends of the rods are also reduced inY diameterA and extend through openings in the ends ofv a cross beam 75 which spans the rods. The cross beam is held in position on the reduced end of the rods by nuts 76 threaded on the rods.

The cross beam 75 has a slot formed therein at the center thereof through which the composite rod extending from the piston in the pressure chamber of the pressure pot passes. The cross beam has an arcuate portion 76a, concentric with the center of the rod passing therethrough, which has an, annular recess formed therein, a slot being cut in the side of the annular recess. In this semi-annular recess there isa hook-shaped cam77 which is adapted to rotate about the central hub 78 formed by cutting the annular recess. The cam is provided with diametrically opposed radial extensions 79, and a lug 80 that extends into the slot formed in the side of the annular recess. One end of the cam extends beyond the'cross beam and is secured to a handle 81 by means of rivets 82. The cam is held in the position shown in Fig. l0 by a spring 83 that is secured at one end to the handle and at the other end to a pin 84 extending from the cross beam. Above the cam, slidably mounted in rectangular recesses, there are two opposed plates 85 which extend over the cam. These plates are urged towards each other by springs 86 which surround pins 87 extending into holes formed in the plates. Each ofthe plates has a pin 89 extending therethrough into the annular recess below the plates. These pins form shafts for cam followers 90 which cooperate with the cam in the annular recess. In the position shown in Fig. 10, the radial extensions of the cam are to one side of the cam followers and the plates engage the rod 21 extending from the piston in the pressure pot. As the handle is moved to the left, the radial extensions of the cams engage the cam followers secured to Athe plates and move the plates so as to release the rod. Movement of the cam is limited by the lug 80 extending into the slot in the side of the annular recess.

plate 91 that is secured to the beam by machine screws.

AAs the piston 53 in the cylinder 33 is forced The plates 85 and the cam 77- are held in the recesses in the beam by a cover' downwardly to cause the plunger to enter the pressure chamber of the pressure pot, the cross head also moves downwardly and through the rods 73 moves the cross beam 75. As the cross beam passes the shoulder formed on the composite rod by the reduction in diameter from the rod 20 to the rod 21 the plates 85, under the action of the springs 86, engage the reduced portion of the rod, and as the cross beam is lifted by the upward movement of the cross head, the plates 85 engage the end of the rod 20 secured to the piston in the pressure chamber' of the pressure pot and the piston is moved upwardly to the position shown in Fig. 1. It will be apparent that if a, charge of molten metal is introduced into the pressure chamber when the piston is in its normal position it willbe prelvented from entering the discharge orifice as this is covered by the piston. As the plunger moves downwardly, it will force the piston to the base of the pressure chamber and the molten metal will be s'queezed'between the plunger and the piston and will be forced through the discharge orifice. lower position the cross beam extending between the rods which are secured to the cross head is below the shoulder formed by reducing the diameter of the rod extending from the vpistonin the pressure chamber and the plates abut against the reduced portion of the rod. When the piston in the pressure chamber is moved upwardly by the cross beam, the metal remaining in the pressure chamber will becarried upwardly on the piston, the metal in the pressure pot being separated from the metal in the Adischarge orifice by the action of the piston i'n the pressure chamber. When the piston in the pressure chamber reaches' the vposition shown in Fig. l the metal may be brushed from the top of the piston and returned to the melting pot.

In casting metals having a higher melting point than those commonly used in the diecasting industry, it is necessary to use much higher pressures than are now commonly employed. In fact, for a metal such, for example, as brass, a pressure of from 6000 to 9000 pounds is required. It is impossible, therefore, jor all practical purposes, to luse a pressure medium such as compressed air as the apparatus required and the energy expended in compressing air to a suitable pressure is so expensive that the use of ,compressed air as an energy transfer medium is prohibitive. AI have, therefore, devised a system by means of which I may obtain high hydraulic pressure and at the same time obtain that -rapidity of movement that is characteristic of an expansible fluid. I obtain the rapidity of movement. of a hydraulic pressure medium by building up a pressure on the medium against a cushion of air so that the rapid expansion of air, when the medium is released, is transmitted through the inexpansible uid. In the system shown in the drawings, I utilize a tank 9 2 for storing a supply of oil and acting as a reservoir for the system. The reservoir is provided with a visible level indicator 93 and the base of the reservoir has a coupling 94 for a pipe connection which .is connected in the system shown through a valve 95 to a supply pipe 96. A This supply pipe is connected by a T-fitting 97 to two

pipes

98 and 99, one side of the T-fitting being connected through a valve 100 to the pipe 98 which is connected to a supply of oil from which the oil in the system is'replenished. The other side of the When thev plunger is in the d of the tank 92 so that the oil from the cylinder isA Thus, in the system' reached the motor is stopped.

T-tting is connected `to the pipe line 99 in which there is interposed a check valve 101. The pipe line 99 supplies oil to the low pressure side of Da pump 102 to which it is connected through a T'tting 103. The pump is driven by a motor 104 to which it is directly connected. The high pressureA side of the pump is connected to a T=tting 105, oneside of which is connected to a safety valve 106. A pipe 107 extending between the T-tting 103 and the safety valve 106 forms a bypass around the pump when the pressure exceeds that for which the valve is set. The side of the` T-tting at the high pressure side of the pump opposite to the safety valve is connected to a pipe 108 which is connected through a -cross-tting 109 to one end of the passage 50 through the valve chest of the cylinder. The other end of the passage 50 is connected through apipe line 110 to a pressure tank 111, a valve 112 being interposed in the pipe line. which is a cast iron tank, is connected through a pipe 113 in which a valve-114 is interposed to a supply of compressed air under a pressure of approximately 200 to 300 lbs. per square inch.

Compressed air at this pressure is admitted into` the pressure tank and thevalve 114 in the air supply valve is closed.

' The exhaust passage 52 of the valve chamber is'connected through a pipe 115 to the upper end returned vto -the reservoir. shown, oil is taken from the reservoir by the pump and delivered under pressure to the pressure tank which, as explainedabove, has an air cushion formed therein by admitting air into the tank under apressure of 200 or 300 lbs. per square inch. 4The pump is such that it will de. velop a pressure of approximately 2500 lbs. per square inch which is impressed upon the oil in the system. The areaof the plunger 64 is pro` portioned with respect to 'the area of the piston 53 so that a pressure of 2500 lbs.-per square inch in the cylinder produces a pressure on the metal in the :pressure pot exceeding 6000 lbs. per

A pressure gauge 116'is connected to the crosstting 109 through which the pump is connected to the valve chest, by a pipe 117. A T-tting 118 is interposed in this pipe and a tap is taken from the pipe to a pressure regulator 119 through a pipe 120. The pressure regulator controls the 4operation. of the motor to which the pump is directly connected. In this way, the pressure in the system is maintained automatically for as the pressure goes down the motor is started up and the pump builds up the pressurev to the normal pressure used. When this pressure is The valve 51 in the 'valvechamber controls the distribution of the oil to the cylinder through the ports 50' and the passages 48' and 49. The valve is actuatedr by the pressurev iluid through the rods 51a'and 51h. These rods act in the capacity of pistons to shift the valvewhen prescasing. The valve has an extension 124 extend` ing through the bushing on the end of which The opposite end of this pressure tank,v

extension a handle 125 is secured for rotating the valve. Extending through the handlethere is a rod 126 which is connected at its lower end to a plunger 127 which has a laterally extending flange 128 that extends under an arcuate member 80.

129 secured to the valve casing by means of bolts 130 extending through a radial ange 131 formed on the arcuate member. The flange 128 of the plunger is adapted to abut against lugs 132 formed on the inner surface of the arcuate 85 member to position the valve, and may be released by pressing a button 133 on the upper end .of the rod to which the plunger-is secured, a

'into which the ends of nipples are threaded.

As shown in Fig. 8, the valve is provided with two passages 136 and 137 each of which is adapted to connect two of the radial passages in the 100 valve casing together. One of these passages Ib in the valve casing is connected through a pipe 138'to the -lower hub shaped head of the valve chamber, andA another 13511 is connected through a pipe 139 to the upper hub shaped head 105 of the valve chamber, suitable ttings 139 being provided for connecting the

pipes

138 and 139 to the hub shaped heads.l One of the remaining passages 135e in the valve chamberis connected through a pipe 140 to the cros's't- 110- ting 109 through which the pumpis connected to the transverse passage in the valve chest, and the other '135a is connected tothe exhaust passage in the valve chest through a pipe 141.

' Fluid underpressure is supplied through the 11'5 4pipe 140 to the valve, and when the valve is positioned as shown in Fig. 8, this fluid is transmitted through the passage 137 in the valve to the pipe 139 connected to the upper head of the valve chamber, and the pipe 138 connecting the 120 lower head of the valve 'chamber' is connected through the passage 136 of the valve to the`pipe 141 leading to the exhaust' passage. The valve therefore is moved downwardly in the. valve chamber to the position shpwn in Fig. 5 in which 125 position the reduced central portion of the valve spans the passages 50 and 49 thereby admitting uid under pressure to the lower end o'f the `cyl-1 indr which forces the'pi'ston upward. 'I'he end of the valve uncovers the passages 48 and 52a 1.30l

so that the upper part of the cylinder is connected to the exhaust passage 52. lDue to the expansion of the air in the pressure tank, the piston is moved upwardly in the cylinder at the rate of approximately ninety feet per second. As 135 the valve 122 is moved to the opposite position, the upper head of the vvalve lchamber is connected through the valve 122 to the source of supply and the lowerl head is connected to the exhaust passage 52 as will be readily apparent. The pis- 140 ton valve is then shifted to the position opposite to that shown in Fig. 5 in which position the reduced portion of the valve spans the passages 48 and 50 and opens .the passage 49 connecting the 1ower end of the minder to the exhaust pas- 145 sage 52 through the passage 52h. The piston is therefore moved downwardly Ain the cylinder.

The power, or operating, end of the machine is carried by a frame which includes a pair of parallel side frame members 142 and a trans-:

' verse end frame member 143. The side frame members are rigidly secured together in spaced relation by a series of tie-rods 144, and the frame is rigidly secured in place with respect to the pressure end of the machine by four parallel frame rods 145 which are arranged in two parallel planes. These frame rods are rmly secured in the standard 6 which holds the pressure pot 11 and extend perpendicularly from the standard and through the side frame members. The two upper frame rods extend through hub shaped projections 146 formed on the sides of the frame members and are slidable therein; the two lower rods extend through the frame members which have hub shaped portions 147 at each end for the rods which are slidably mounted in these hub shaped portions. The frame rods are threaded throughout the portions thereof which extend through the frame members and are rigidly secured to the frame members by nuts 148 abutting against the ends of the hubs in which the frame rods are received. The frame rods are slidably mounted in the frame members so that respect to the pressure end to accommodate different sized dies.

` ed to provide for any tilting of the frame duringY The frame of the power or die carrying end of the machine is supported through brackets 149 that extend downwardly from and forwardly of theside frame members to which they are rigidly secured. A shaft 150 extends between the brackets, and through openings provided'thereforin the brackets. Adjacent each bracket, there is rotatably mounted on the shaft 150 a flanged wheel 151 whichrests upon a track 152 supported by a base 153. vBy loosening the nuts 148 at both ends of the hub portions of the frame mem--` bers throughwhich the frame rods extend, the frame member may be adjusted with respect to the pressure end of the machine by moving the frame along the tracks. For this purpose, an adjusting screw 154 extends through the shaft 150 in. threaded engagement therewith. The Yad-r justing screw is rotatably mounted in an arm 155 pivotally mounted between the arms of a bracket 156. On the end of the adjusting screw extending through the arm 155, there is mounted a spur gear 157 which meshes with a pinion 158 mounted upon andsecured to a short shaft 159 extending through and rotatably mounted in the arm 155 on the opposite side ofthe pivot to that through which the adjusting screw extends. On Ythe end of the shaft 159, there is a hand wheel 160 by means of which the screw shaft may be rotated to move the frame. The arm 155 is pivotally mountthe adjusting thereof.

The frame rodscarry a movable die plate 161 I which is slidably mounted thereon, the die plate being provided with hub shaped portions 162 through which the frame rods extend. Guide rods 163 are also provided for the die plate which anism. This toggle mechanism consists of two pairs of links, one pair at the top of the machine and the other at the bottom. Each pair of links includes 3a link` connected at one endl to the frame of the machine anda link pivotally connected at one end to the die plate, the opposite ends of the two links being pivotally connected together. The link connected to the die plate has two parallel arms 164 theends of which extend between brackets 165 formed on the die plate and Yare pivotally secured thereto by a pivot pin 166.

pivotally secured to the link secured to the die plate adjacent the arms thereof by a pivot pin 170. The arms of the bifurcated end of thelink are strengthened by an integral cross piece 171. Between the arms of the bifurcated end of the link connected to the frame member, another link 172 is mounted on the pin 170 connecting the two links together. At the end opposite to that mounted on thepin, this latter link is also bifurcated. Each arm 172e and 172D of the bifurcated portion of the link 172 is secured to a member 173 that is slidably mounted on one of the guide rods of the die plate, the two members 173 being connected together and constituting a cross head.

II'he cross head for actuating the toggle mech` anism of the die plate is operated byA cams 174 formed in the sides of a pair of gears 175, the cross head being operated by these cams through a system of links and levers. The gears are mounted on a shaft 176 extending between the two side frame members and through one end thereof, the shaft being rotatably mounted in the frame members. The contour of the cams formed by recessing the opposed faces of the gears, as shown in Fig. 13, is such as to reciprocate a link 177 which is mountedv between the gears and provided with a slot 178 through which the shaft 176 extends. The link 177 has cam followers 179 mounted on both sides thereof which extend into the cam recesses of the gears. The upper end of this link is pivotally mounted between the arms of a lever 180, a pivot pin 181 extending through the arms of the lever and the upper end of the link. The lever is pivotally mounted on a bracket 182 which is secured to the inner surface of the transverse end frame member by a bolt 183 which extends through the frame member. The end of the link 177 is pivoted to the lever 180 between the ends of the lever.l The upper end of the lever is pivotally secured to one end of a link 184`which extends between theA arms of the lever and is secured thereto 'by a pivot pin 185. The opposite end of the link 184 is pivotally mounted on a pin 186 extending between the two members 173 slidably mounted on the die plate guide rods and constituting the cross head.

The gears 175 areoperated from a drive shaft 187 through a train of reducing gears. The drive shaft is journalled in the side frame members and a bracket 188 extending from and secured toone of the frame members. Between the bracket and the side frame member, a drive pulley 189 is rotatably mounted on the drive shaft. Also mounted on the drive shaft is a pinion 190 which meshes with a gear 191'mounted upon the shaft 192. This latter shaft, carries a pair of pinions 193 one on either side of the gear 191 which mesh with the gears 175. An ordinary brake mechanism 187 cooperates with the 'shaft 187 and serves'to take up back lash in the gears.

The drive pulley has a cylindrical ange 194 extending from the spokes of the pulley which ange forms a part of a clutch mechanism for securing the drive pulley to the drive shaft. Adjacent ,the pulley, there is a hub 195 secured to the shaft, to rotate therewith, by a key 195. This hub is provided with a-radial flange 197 which, at four equally spaced points, has slots formed therefthrough. 1 On each side of the radial ange, there is a bracket 198 and 199, which has a projectionv extending parallel to the axis of the cylindrical flange extending from the pulley. The projection of the bracket 198 extends along the outside of the ange and the projection of the bracket 199 y extends along the inside of the flange." Each of these bracketsY carries a friction block 200 which is adapted to engage the flange extending from the pulley. The brackets are moved with respect to the flange of the hub and in opposite directions by a lever 201 that is pivotally mounted in the slot formed in the flange. One end of the lever engages-one bracket and the other end of the lever engages the other bracket. This lever is connected by a link 202 to one end of a rod 203. The opposite end of the rod is connected to one end of a lever 204 that is fulcrumed between its endson a pivot pin 205 secured on a bracket 206 formed on the hub. The opposite end of this. latter lever is secured through a link 207 toa collar 208 that `is slidably mounted on the shaft. This system of links^and.levers'is duplicated at each of four slots in theradial ange 197. When the collar 208, which is shown in ltheoperative position in Fig. '16, is moved away from the hub the system of links'and levers ,above `described will be actuated to cause the'y two brackets to move in Vopposite directions, away from each other, and

release the flange extending from the pulley. Likewise, when the collar is moved to the position y shown, the brackets will be moved' so that the flange extending from the pulley.y is firmly clamped between the friction blocks.

The collar is s hifted along the shaft by a bifurcated bracket 209 the arms of which have projections 210 extending into a circular groove formed on the collar. This bracketisf'secured to a shaft 211 that is journalled in huby shaped projections 212=formed integral with the side frame member.

'. The shaft also carries a bracket 213 having a laterally extending arm 214 through which a pin 215 extends that is secured to the frame member. On this pin, a compression spring 216 acts -between a nut on the end of the pin and the' arm'extending from the bracket, the spring urging .the arm in a'direction to move the shaftso as to disengage the clutch. On vthe end of the shaft, there is a handle 217 by means of vwhich the clutch may be' manually operated. The bracket 213 carrying the lateral arm is also provided with an arm 218 that carries a cam follower in operative relation to a cam 219 secured on the end of the shaft 176 which cam-is adapted to hold the clutch in the operative position against the action of the spring when the .clutch has beenA moved thereto by the handle. vThe cam is such, having one V-shaped groove, that when the clutch is actuated to cause the machine to be operated it is held in the operativeposition while the shaft 176 makes one revolution, until the cam follower again reaches the groovein the cam when the clutch is released. Adjacent the end of the shaft 211, there is mounted a bevel gear 220. This gear meshes with a companion gear 221 mounted upon a short horiz'ontal shaft 222 which carries a spur gear 223 that meshes with a gear 224 secured on the' end of a shaft 225 which is journalled at one end inv av bracket 226 housing the gears 223 and 224. The other end of the shaft 225'extends through a bracket 227 secured on the plate 4 of the frame of the pressure end of the machine, and has'a handle 228 secured on the 'end thereof by means of which handle the clutch-may be operated from the pressure end of the machine as will be readily apparent. r

The power end ofthe machineis also provided with automatic core pulling and ejecting mechanism. The automatic pulling of cores and ejecting the casting fromthe die is a very importantI @factor in the casting of' metals having a high mediately after the metal is introduced into the dies the. metal will freeze fast to the cores. To eliminate this difficulty, 1p1-Ovide an automatic core pulling and ejecting mechanism which ,is actuated by movement of the movable die plate 161. To the die plate there is secured an ejector box 229the sides of which are open. The ejector box carries a die-part 230 which is-adapted to cooperate'with the die-part 14 in the die plate 13. The mold cavities of the die-parts are cut so that when the die-partstar separated-.the cast metal remains in the mold cavity of the die part 230. The die illustrated has three core pins, two lateral core .pins 231 and 232 and one longitudinal core lpin 233. The ends of the lateral core pins are secured to

lateral racks

234 and 235 respecl tively by lugs 236. The racks engage pinions 237 which are mounted in the ejector box. Also engagling these pinions there are longitudinal racks 119 -234a and. 235a which extend intothe open porwhich communicates with a recess in its inner surface. The ,end of the rack 235a extends through the opening in the plate and has a flange 239 on the end thereof which is received.

in the recess communicating with the opening. the flange being= firmly secured between the two plates. The other longitudinal rack 234a ex' tends through the core plate' and has a nut 240 4'on the end'thereof which is of greater diameter than the opening in the core plate through which the .rack extends. The longitudinal core also 35 extends through the core plate and has a nut 241 on the end thereof. It will be seen, therefore, that as -the core plate moves relative to the die plate, in a direction away from the dieplate,

it will move the longitudinal racks, either by virtue of the fact that the rack is secured therein lor by engaging the nut on the end of the rack.

.The racks will rotate the pinions 237. which will move the lateral racks and the core pins which vare secured thereto. The longitudinal core pin .the longitudinal core pin 233 are moved in the opposite direction by the engagement of the core plate with collars 242 secured on the rack and core pin. It will be apparent that the distance the core pins are moved depends upon their engagement with the core plate.

The ends of the core plate extend through openings in the sides of the ejector box. To each of the extended ends of the core plate an operating rod 243 is secured and extends perpendicularly to the core plate along the side of the machine, the rods being supported by projections 244 formed on the sides of the die plate through which they extend. The rods also extend through openings in projections 245 formed on the members 173 constituting the cross head of the toggle mechanism. The rods are slidably mounted in the openings in these projections arid are threadedthroughout the distance that extends throughthe projections. 2461) threaded on the rods on either side of the projections on the cross head are adapted to be engaged by the projections and by the engagement of the projections and the nuts to move the rods and the core plate with the cross head which moves relative to the die plate. Thus, as the cross head moves in one direction the projections will engage one of the nuts and draw the core plate in the direction of movement of the cross head. As the cross head moves inthe opposite direction, for instance, to move the die plate to close the dies, the projection on the cross head will engage the nuts 246a on the rods to move the core plate to insert the cores in the die.

Within the ejector box, there is also an ejector plate 247. This plate, like the core plate, is composed of two plates secured together and carries a plurality of ejector pins 248. The ejector pins have conically shaped heads which are received in a recess in the inner surface of one of the plates and the pins extend through openings in the plate and the die. When the dies are closed, as shown in Fig. 15, the ends of the ejector pins are flush with the Wall of the mold cavity of the die. The ejector plate also extends beyond the sides of the ejector box and has a pair of lugs 249 formed thereon on each side thereof. Through each of the lugs formed on the ends of the ejector plate 'an operating rod 250 extends and is secured to the plate. The rods extend perpendicularly from the plate and parallel to the rods 245 and in the same vertical plane. The ejector plate operating rods extend through plates 251 secured to projections 252 formed on the sides of the frame of the machine and have nuts 253:1 and 2531) threaded thereon on either side of the plate 251. As the die plate moves to open the dies, to the position shown in Fig. 1, the ejector plate moves with the die plate until the nuts 253a on the rods abut against the plates 251 when further movement of the ejector plate is restrained. The die plate, however, continues to move relative to the ejector plate and the ejector pins extend into the mold cavity of the die and force the casting out of he mold cavity. As the die plate is returned to the position in which the dies are closed, as shown in Fig. 15, the ejector plate moves with the die plate untill-the nuts 253b on the ends of the rods engage the `plate and hold the ejector plate from further movement with thedie plate so that the continued movement of the die plate withdraws the core pins from the mold cavity.

'Ihe operation of the machine is as follows: When the machine is about to be operated, the dies are closed, in the position shown in Fig. 15, and the plunger 64 is withdrawn from the pressure pot as shown by Figs. 1 and 2, the piston in Y the pressure chamber being at the transverse Nuts 2 46a and' center thereof. `The operator ladles metal from the melting-pot (not shown) which is separated from the machine and introduces the metal into the pressure chamber of the pressure pot. He then actuates the valve controlling the plunger and the plunger is caused to descend at a speed exceeding'60 feet per second, as hereinbefore explained. As the plunger moves downwardly, yit forces the piston in the pressure pot to the bottom of the pressure pot, thereby opening the discharge orifice. The metal in the pressure pot is squeezed between the plunger and the piston under a pressure of from 6000 to 9000 pounds per square inch and is forced through the discharge orifice. The operator then draws the valve to the opposite position to raise the plunger and at the same time operates the handle 228 to start the power end of the machine. As the clutch engages, and the shaft 176 is rotated through the 'train of gears hereinbefore described the cam 219 engages the cam follower on the shaft 211 and holds the clutch in the operative position. Rotation of the gears 175 causes, through the cam and cam followers, the link 177 to operate the lever 180, moving the lever upwardly. The lever operates to draw the link 184 and the cross head in a direction away' from the pressure end of the machine. Movement of the cross head breaks the toggle and causes the die plate to move along the frame rods to the position shown in Figs. 1 and 3. The core pulling and ejecting mechanism are actuated upon movement of the die plate as hereinbefore explained and the casting is ejected from the die. As the gears continue to rotate, the l'mk 177 is moved downwardly and the lever is actuated to move the cross head towards the pressure end of the machine. The die plate is thus nroved to close the dies and is lockedin the closed position by the toggle mechanism. The machine is then in position to repeat the cycle just described.

It is obvious that various changes may be made by those skilled in the art in the steps of my method above described for carrying out that method within the principle and scope of my invention as expressed in the appended claims.

I claim:

1. The method of casting metal which includes introducing the metal in a molten condition into the mold cavity of a die under a pressure exceeding 6000 pounds per square inch, and ejecting the metal from the die immediately after the mold cavity of the die is filled.

2. The method of casting metals which includes introducing the metal in a molten condition into the mold cavity of a die under a pressure exceeding 6000 pounds per square inch, maintaining the pressure on the metal until the mold cavity is lled and immediately thereafter ejecting the metalpfrom the die.

3. The method of casting metals which includes introducing the metal in a molten condition and near its transition point into the mold cavity of a die under a pressure exceeding 6000 pounds per square inch, maintaining the pressure on the molten metal untilthe mold cavity of the die is filled, and immediately thereafter ejecting the metal from the die.

4. The method of casting metals having a high melting point, which includes introducing the metal in a molten condition and near` its tran# sition point into a pot having a discharge nozzle registering with the mold cavity of a die, confining the molten metal in the pot, exerting a pressure exceeding 6000 pounds per square inch' on the metal in the pot, permitting the metal to sol now through the discharge nozzle into the mold cavity of the die under the action of the pressure exerted on the metal, and' ejecting the metal from the die immediately after the mold cavity of the die is lled.

5. The method of casting metal having a high melting point which includes introducing the metal in a molten condition and near its transition point into a pot having a discharge nozzle registering with the mold cavity of .a die, the nozzie being closed when the metal is introduced into the pot, confining the metal in the pot, exerting a pressure exceeding 6000 pounds per square inch on the metal in the potand simultaneously opening the discharge nozzle of the pot to permit the metal to :flow into the mold cavity ofthe die, and ejecting the casting from the die.

6. The method of casting metal having a high melting point such as brass which includes introducing the metal in a molten condition and near its transitionpoint into a pot having a, discharge nozzle lregistering with the mold cavity of a' die,

Athe nozzle being closed when the molten metal is introduced into the pot, confining the metal in the pot, exerting a pressure exceeding 6000 pounds per square inch on the metal and simultaneously .opening the discharge nozzle, maintaining the pressure on the metal until the mold cavity of the die is filled with the metal, separating the metal remaining in the pot from the metal entering the die, and ejecting the casting from the die.

f1. The method of die casting substances having a high melting point and viscous when molten which comprises confining the substance in a molten condition within a pressure chamber having a passage communicating with the mold cavity of a closed die,` exerting a pressure on the molten substance exceeding 6000 pounds per square inch to force the substance at a high velocity into the mold cavity of the die, and ejecting the substance from the die immediately after the mold cavity of the die is iilled.

8. The method of die casting a substance having a high melting' point and viscous when molten which comprises conning the substance in a molten condition Within a pressure chamber having a passage communicating with the mold cavity o a closed die, exerting a pressure on the molten substance in the form of an impact and exceeding 6000 pounds per square inch to force the substance at a high velocity into the mold cavity of the die, and ejecting the substance from the die immediately after the mold cavity of the die is illed.

9. The method of casting metal having a high melting point which includes confining the metal in a molten condition Within a pressure chamber having a passage communicating with the mold Acavity of a closed die, exerting a pressure on the molten metal in the form of an impact and exceeding 6000 pounds per square inch to force the metal at a high velocity into the mold cavity of the die, and ejecting the metal :from the mold cavity of the die immediately after the mold cavity of the die is lled.

10. The method of casting metal having a high melting point which includes confining the metal in a. molten condition and near its'transition point Within a pressure chamber having a passage communicating-with the mold cavity of a closed die, exerting a pressure on the molten metal in the form of an impact and exceeding 6000 pounds per square inch to force the metal at a high velocity into the mold cavity of the die, and ejecting the metal from the mold cavity of the die immediately after the mold cavity of the die is lled.

11. The method of casting metal having a high meltingv point which includes introducing the metal in a molten condition and near its transition point into an open pressure chamber having a discharge passage 4communicating with the mold cavity of a closed die, the discharge passage being closed when the molten metal is introduced into the pressure chamber, confining the Y metal in the pressure chamber, exerting a pressure on the metal in the form of an impact and follow up pressure, the pressure on the metalV