US1760610A - Die-casting machine - Google Patents

Description

May 27, 1930. M, TERN 1,760,610

DIE CASTING MACHINE Filed June 4. 1926 5 Sheets-Sheet 1 gwvento'c 724;? Jim May 27, 1930. M. STERN DIE CASTING MACHINE Filed June 1926 5 Sheets-Sheet 2 Filed June 1926 5 Sheets-Sheet 3 m m m an 4 awe/114300 May 27, 1930. M. STERN 1,760,610

DIE CASTING MACHINE Filed June 4, 1926 5 Sheets-Sheet 4 Z/r. 7 v 3140mm fij Q 72622? $272 E May 27, 1930. M. STERN DIE CASTING MACHINE 5 Sheets-Sheet 5 Filed June 4, 1926 Patented May 27 1930 UNITED STATES PATENT OFFICE MARC STERN, F FLINT, MICHIGAN, ASSIGNOR TO A C SPARK PLUG COMPANY, OF FLINT, MICHIGAN DIE-CASTING MACHINE Application filed June 4, 1926. Serial No. 113,707.

This invention relates to the problem of making castings. It aims to provide an improved die casting machine. The machine has been designed particularly for making speedometer parts, but it will be understood that dies or molds for all sorts'of castings may be substituted for that shown in this application, and that the usefulness of the machine is "ery extensive. 7

It is an object of the invention to make a machine of the kind indicated, which is automatic in its action. It may be continuously automatic, or automatic for a single cycle of operations only.

It aims to employ a die or mold of two sections, one of which is a stationary rear section, the other is a forward movable section. This is for the purpose of rigidity and perfection of alinement.

A further object is the removability of a melting pot and a furnace therefor as a unit.

As another object the invention provides automatically removable cores and in this connection employs means to remove a core or cores from the front movable die 1nemher. as well as from the fixed or ejector part of the die.

The invention has for a further object to provide means to wipe off from the nozzle and the adjoining die opening any metal which may stick to these parts after the die has been charged with molten metal.

A further objectto be attained is the provision of means to extract the .cores, not

only in the cover half of the die but also from the fixed or ejector portion and to draw these cores out in any direction necessary.

The adaptability of the machine for a wide variety of uses will be understood from the above brief statment of the objects of the invention. To these objects others might be added. These need not be enumerated, however, as they will be obvious upon reading x the appended specification.

The specification is to be read together with the drawing, which is to be understood as illustrative only, as modifications may be made to produce other castings in which the shape of the casting dilfers and in which different cores may be required,

form 5 by bolts 6 is a melting pot 7.

In the drawing:

Figure 1 is a plan View of the machine,

certain parts being shown in section to betterillustrate the structure.

Figure 2 is aside elevation.

Figure 3 is a front elevation.

Figure 4 is a rear elevation.

Figure 5 shows in transverse elevation the means for wiping the metal from thenozzle.

Figure 6 is an elevation at right angles to Figure 5, showing the same parts.

Figure 7 is a transverse section through the clutch.

Figure 8 is a transverse section taken between the parts of the mold.

Figure 9 is a longitudinal sectional "iew of the melting pot.

Referring to the drawing by reference characters, numeral 1 represents the frame or bed of the machine. T 0 each side of frame 1 at the front of the machine are secured for vertical adjustment by screw members 2 knee members 3.

Upon these knee members is slidably mounted a platform 5. Secured to the plat- Enclosing the melting pot is a furnace 35. Lugs 38 extending from furnace slidably engage bolts 40 depending from the platform, there preferably being at least three of such bolts, as shown. Upon each bolt are a pair of springs 37, one on each side of lug 38. By this method of mounting the furnace from the platform, a resilient support is obtained so that the shocks of the reciprocating platform are absorbed, in part, before reaching the furnace.

Projecting upwardly from the platform on each side thereof is a cross head guide 9. Slidable on the guides is a cross head 11 into which is detachably engaged the enlarged end of a plunger rod 13. The latter extends into a cylinderl5 within the melting pot, which cylinder communicates with 30 desirable to rovide means for automaticalsecured to an upwardly extending rod 19 attached to the lower end of a piston rod 21 by means of a. pin 23 passing through an opening in the rod 21 and through openings in the sides of an open cylindrical extension 25 of rod 19, as best shown in Figure 3. The upper end of rod 21 .carries a piston 27 within a cylinder 29. Into the latter. on each side ofthe piston, compressed air may be admitted by flexible pipes 31. These flexible pipes communicate with the valve 33 which is actuated'in timed relation to the other operative parts in a way to be explained. The fuel for the furnace will also be supplied by flexible members connecting at the bottom of the'furnace as shown at 39 in Figure 2. i

The cylinder 15 communicates with the nozzle 41 of s herical'shape by means of a passage 43. he opening from the nozzle 41 into the die is shown by dotted lines in Figure 9. Fi ure 9 also shows the two parts of the die, a font section 44, which is mov-' able and a rear portion 45, which is fixed. At 42 is shown a water pipe intended to show that the die may be water cooled by appropriate passages if desired. Inthecourse of the operation molten metal is apt to stick to the nozzle of the melting pot and to the mouth of the die. For that purpose it is l v wiping 0 such molten metal as may collect on these surfaces. It should be stated that durin the operation of the parts, as

will be explained below, the nozzle is moved away from the die. For the purpose of wiping off the metal the structure shown in Figres 5 and 6 has been devised.

An angular longitudinally postioned slot -18 is provided in the bed "frame. The movable platform in the vicinity of the nozzle carries a reciprocally mounted rod 47, the lowemend of which carries an anti-friction roller 49 movable in the slot 48. As the platform reciprocates the roller moves up andv down in the angular part of the slot, as shown in Figure 6. It thereby swings a bell crank 51 pivoted at 53. The bell crank shaft carries an arm 5-1 with a wiper 56, which moves over the'discharge opening as shown by dotted lines in Figure 5.

For producing the movements of the several parts in proper timed relation power is taken from an external source as from the motor, not shown, by means of a belt 57 (Figure 1) to a pulley 59 rotatably mounted on the shaft- 61. The pulley carries a driving cone member 63 of a clutch, see Figure 7. The driven clutch member 65 is slidably, but not rotatably, carried on shaft 61, a key 67 affording the sliding relation. The clutch member 65 is surrounded by a rotatable sleeve 68, which has projections or pins 70 extending into an annular groove in the hnb of the clutch member to hold the member and sleeve against relative axial movement, and which sleeve also carries a pin 69, (see Figure 4) movable in a cam slot 71 of a fixed housing member 73. For manually operating the clutch, a reciprocable member 7 5 is moved by a lever 77 and a connecting link 7 9. The member 7 5 has a plurality of teeth 80 to engage corresponding teeth on sleeve 68, whereby movement of the lever 7 7 givesa rotary movement to the sleeve 68, which rotary movement is converted by the pin and slot connection into a reciprocating movement such as to effect clutch engagement for the purpose of driving shaft 61.

Theshaft 61 carries at its other end a pinion 81 in driving engagement with a gear 83. This gear is mounted on a shaft 85, and a pinion 87 on the end of the shaft 85, drives a gear shaft 89 by engagement with gear 91. Also carried on shaft 89 is a pinion 93 which drives a large gear 95 mounted on a transverse shaft 97. Also secured to said transverse shaft 97 are driven members 99 and 101. Three members 95, 99 and 101 serve to 1 upper end is pivoted to a'link 107. The forwardly extending link 107 is pivoted to a cross bar 109 carried on the ends of pivoted arms 111. Extendingforwardly from the ends of cross bar 109 are links 113 which are connected to the movable platform, as perhaps best shown in Figure 2. Operatively associated with the pivoted ends of lever 103 and link 107 is a rubber block 106. )Vhen the movable member is moved so that the nozzle is moved to its active position the rubber cushion 106 insures a tight fit between the melting pot and the die members and compensates for any variation in the expansion of the hot members which are to be locked together. \Vhile the yielding means may be something other than a rubber block, the rubber block is preferred because of its greater dependability.

In a cam slot on the other side of gear 95 is a roller 115 connected to a dove tail slidable member 117. This member reciprocates a cross head 119 from the ends of which extends rods 121 passing through/guides 123 and carrying the forward half of the die for the casting.

The lever 125, Figure 2, is rotated about its pivot 127 by a roller 100, at its upper end moving in a cam slot in member 99. By means of link 129 connected to the lower end of lever 125 a bell crank 131 is rotated to impart vertical reciprocation to a rod 133. This rod is connected to the end of a cross bar 135. y

The other end of the cross bar may be c0nnect cd to a similar vertical rod pivoted to a rocking member on the other side corresponding to a bell crank 131, this being for the purpose of proper control of the cross bar 135.

- The bar 135 is intended to raise a core 139' The lever is connected by a link 138 with the rock arm 147. This rock arm rocks the shaft 146. From shaft 146 upwardly projecting arms 148 carry the head 149. Projecting upwardly from head 149 is an arm 151.

This arm is connected at its upper end to link 145, which has been referred to as the'operating means for the bell crank 143. The head 149 also has a depending arml53, shown in dotted lines in Figure 2. From the lower end of arm 153 a link 155 extends forward to actuate a core which enters horizontally into the die. The action may be effected by crank 150 connecting the forward end of rod 155 to a vertical shaft 152. This shaft may horizontally reciprocate the core member by means of a pinion and rack. Figure 8 is intended to show this construction part 156 representing the horizontal core member and 154 the pinion on the vertical shaft.

. of member 101.

Movable with the cross head 149 is a sliding passage therethrough a rack member associated with a plunger and ejecting pins to be described below.

In Figure 4 will be seen a shaft 157 with a crank 159, the roller at the end of which moves in a cam slot 161 on the peripheral face The consequent periodical rotary movements of shaft. 157 are transferred to shaft 163 by means of a sprocket and chain connection at 165, as shown. The periodical rotary movements of shaft 163 actuates the valve 33 for determining the reciprocation of the plunger in the cylinder of molten metal. as explained above.

At 167 is seen another roller engaging the cam slot in the further side of member 101. This roller 167 effects a reciprocation of a rod 169. in much the same way that roller 115 actuates the rod 117. The last named rod, by means of a crank 171, rocks the shaft 173 carrying a pinion 174 engaging the rack 176, mentioned above. As explained above, this rack has a sliding engagement in the memlZ-Ql 158 which moves with the cross head 149. It will be understood that the member 158 is cut away to provide for the rack and pinion engagement, as described. The movement of the rack effects the movement of the plunger 175 connected therewith. The plunger 175 carries pins 177 which move to eject the casting from the mold, after the separation of the halves of the mold.

Carried 011 the end of the main shaft (Figure 1 and Figure 2) is an arm 181 to which is pivotally connected a rod 183. The rod 183 is guided between upwardlyconnected lugs 18.) of a frame bracket. Rod 183 has a roller 187 which is arranged to travel on a horizontal part 189 of the bracket. The rod 183 has a notch 191 for engagement with a lug 192 on the driven clutchm1ember'65 during its reciprocating movements. The arrangement is such that the clockwise reciprocation of the main shaft shall, during the forward movement of-th'e rod 183, engage the driven clutch and by its rotary and reciprocatory l n-oven'ient due to the pin and cam slot effect a clutch release after the mechanism has formed ,1

the casting and opened the die. After the clutch is released the roller 187 rides horizontally on the bracket 185 and lifts the rod from the clutch and the mechanism is out of operation until a subsequent manual operation of the lever 77. It should be noticed that the ordinary clutch release mechanism in the clutch releasing action also moves the rack 75 back to its starting position, so that when the operator again wishes to start the mechanism, the lever 77 may be swung forward to start the machine. It will also be noticed that if the rod 183 is removed from the machine, or. if it is swung back out of operating condition, the machine will continue to function automatically to make castings, one after another.- lVhen the rod 183 is in operation, the automatic action is for a single cycle of operations only, after each of which the operator will again put the parts into operation by movement of the lever 77.

The operation may be briefly described as follows: Assuming that the furnace is in position and that the melting pot is supplied with molten metal. and that the die members are separated and the cores removed, the operator swings the lever 77 to the right. to the position shown in Figure 2. This slides the driven clutch member 65 into engagement with the driving clutch member 63. The gear train thereupon rotates the driving means 95, 99 and 101, on shaft 97. By means of the mechanism described, the front die section is drawn back into alignment with the fixed rear part; the several core members are inserted into the die; the platform with the melting pot is pulled back to bring the nozzle into engagement with the mouth of the die; and the compressed air valve is actuform forward, the metal sticking to the nozzle and the mouth of the die is wiped off and the forward die section moves away from the rear portion. The ejector pins on the plunger then push the casting from the die. If now the rod 183 is not in use, the cycle of operations is repeated and continues until the lever 77 reverses the motion of the driven clutch member .65 and stops the machine. If, however, the rod 183 is in position, as shown in Figure 2. as the cycle of operations becomes complete, the rod 183 tie-clutches the machine from the driving means and, in order to again throw it into operation, the operator must swing lever 77. v The several instrumentalities are all thus operated in proper timed relation and the machine may be operated continuously or by the use of rod 183 may automatically stop after each cycle of operations. a

The detachable parts at 23 and 25 afford a convenient means of separating the cylinder 29 and related parts from themelting pot. A convenient manipulation may be had by forcing down piston 27, disconnecting 23 from 25 and thereafter raising the piston 27 leaving the cross head down. The cross head may then be lifted in separating it from part 13.

I claim:

1. In a die casting machine, a pair of cooperating die members, means to stationarily mount one of the die members on the machine, actuating mechanism for moving the other die member relative to said stationary die member, toopen and close the die cavity, said movable die member having a sprue opening leading to the die cavity from a point spaced from the parting surfaces of the die members, whereby cores can be pulled in any direction at right angles to the axis of said sprue opening, a movable furnace-melting ot unit having a discharge nozzle engageal le with said sprue opening, means to move said unit to bring the nozzle into enga ement with the sprue opening when the ie members are clo'sed, cores carried by both the stationary and the movable die sections, projectable into the die cavity, and automatic actuating means for retracting the cores in timed relation with the parting of the die members.

2. A die-casting machine including a die formed in separable sections, one of which is provided with a sprue opening disposed at an angle to the parting line of the die sec-' tions, a furnace and pot unit movable relative to said sections to bring the nozzle of the pot into communication with the sprue opening, a driven member, mechanical connections between the member and the die and the furnace pot unit respectively, for their actuation 1n pre-determined relation through a series of cycles for making castings.

3. In addition to the elements of claim 2, means for rendering the mechanism continuously operative and. other means operable in a pre-determinedposition to limit the operation to a single cycle of movements.

4. A die casting machine havin a stationary main frame, and an ejector ie portion fixedly mounted on the frame and a movable portion, ejecting pins associated with said stationary portion, means for actuating said pins, and means whereby the movable portion is automatically moved to and from a pos1- tion for completing the die.

5. In a die casting machine, a die comprising separable sections and a melting pot and movable furnace adjacent thereto, automatically operated means for moving the melting pot and furnace to and from the die in a direction at right angles to the parting line of the die sections.

6. In .a die casting machine a die, a supporting platform, a melting pot and a furnace both supported by said platform, automatically operated, means for moving the platform to carry the meltin pot and the furnace to and from the die in a direction angularly to the plane of the parting surfaces thereof.

7. In a die'casting machine, a frame, a'die, a melting pot movable on said frame into and out of contact with said die, a wiper movable over the nozzle of the pot and the mouth of the die to wipe the same, and operating means for the wiper automatically actuated by the relative movement of the frame and melting ot. p 8. In a die casting machine, a pair of die members including a stationary member, a

movable member, power driven means to actuate said movable member, a core insertible wholly within said movable member, a second core insertible partly within each' member, means operating automatically to remove said cores in timed relation, an ejector pin associated with the stationary member, and automatically actuating means therefor.

9. In a die casting machine, a stationary main frame, a fixed die member mounted on the frame, a die member movable relative thereto, an ejector for forcing the castingfrom the fixed die member, means automatically operable to open the die and eject the casting.

10. In a die casting machine including a pair of die members, one of which is a fixed ejector part and the other a movable cover part, a clutch, manually operable means for actuating the clutch, a driven shaft, means operable by a single rotary movement of the said shaft to assemble the die, insert the cores, force the metal into the die, restore the parts to initial position and thereafter eject the casting, and, automatically operable means for releasing the clutch after said single series of operations. 7 v

11. Ina die casting machine, an ejector die and a cover die, the former being fixedly mounted on-the machine and the latter being after pull the cores from the fixed ejector die, ejector pins movable through the ejector die, power driven means to move said pins to eject the casting as the last step in the sequence of operations.

13. A die casting machine including die members movable relative to each other in a horizontal plane, and 'a furnace movable relative to said die members also in a horizontal plane and as a part of the operating cycle of the machine.

14. A die casting machine including relatively movable die members, a furnace and a melting pot associated with the furnace,

said furnace being movable relative to and in the same direction as said die members to bring the melting pot into communication with the die cavity as a part of the operating cycle'of the machine.

15. A die casting machine including a pair of die members, means to open and close said die members, a furnace, a melting pot carried by the furnace, and means to move said furnace relative to said die members and at an angle to the parting line thereof to bring the pot into communication with the die cavity through a sprue opening in one of the members that extends angularly to the parting line 'each time the die members are closed.

16. A die casting machine including a pair of die members, one of which is movable, a furnace and a melting pot carried by the furnace, said furnace and melting pot being movable as a unit relative to said 'die members in a direction angular to the plane of the parting surfaces when the die members are closed.

17. A die casting machine including a pair of relatively movable die members, a furnace movable relative to said die members as a part of the operating cycle of the machine and a melting pot fixedly mounted on the furnace for movement therewith and having communication with the die cavity at one limit of relative movement, through a sprue opening that extends through one of the die members at an angle to the parting line, said furnace and pot being removable as a unit from the machine.

18. A die casting machine, including a pair of relatively movable die members, a melting pot furnace, and means to detachably and movably mount said furnace on the machine for movement in the plane of the movement of the die members as a part of the operating cycle of the machine.

19. An automatically operating die casting machine including apair of die members, means to periodically open and close said die members, one of said members having a sprue opening extending therethrough at an angle to the parting line of the members, a melting pot furnace, and means to move the furnace in a direction angularly to the parting line of said die members and in timed relation to the opening and closing operations, to permit communication between the pot and die cavity through said sprue opening for a portion of the inter :11 during which the die members are closed.

20. The structure of claim 19 and means to exert pressure on the metal in the pot and a contra-l device therefor, automatically oper able to permit said means to act during the period of communication of the pot with the cavity.

21. The structure of claim 19 and means to exert pressure on the metal in the pot and a control device therefor, automatically operable to permit said means to act during the period of communication of the pot with the cavity, a core associated with one of said die members and mechanism for moving the core into the cavity after the die is closed and prior to the casting operation and to withdraw said core after completion of the casting operation and prior to the separation of the die members.

22. The structure of claim 19 and means to exert pressure on the metal in the pot and a control device therefor, automatically operable to permit said means to act during the period of communication of the pot with the cavity, a core associated with one of said die members, mechanism for moving the core into the cavity after the die is closed and prior to the casting operation and to withdraw said core after completion of the casting operation and prior to the separation of the die members, an ejector associated with the other of said die members and movable relative thereto after separation of the dies.

23. The structure of claim 19 and means to exert pressure on the metal in the pot and a control device therefor, automatically operable to permit said means to act during the period of communication of the pot with the cavity, and means associated with one of the die members to eject the completed casting when the die members are opened.

24. An automatically operated die casting machine including a stationary die member, a relatively movable die member, a melting pot furnace movable relative to and in the same direction of movement of said movable die member, a main drive shaft, cam elements carried thereby and associated respectively with the furnace and movable die member, said cam elements bemg arranged to close and open the die members and to move the furnace and place the melting pot into and out of communication with the die cavity when the die members are closed.

25. The structure of claim 24, and means governed by drive shaft rotation to discharge metal from the melting pot when communication is established with the die cavity.

26. The structure of claim 24,'and means governed by drive shaft rotation to discharge metal from the melting pot when communication is established with the die cavity, an ejector associated with the stationary die member and actuated by a cam element on the drive shaft to push a completed casting from the die member.

27. The structure of claim 24, and means governed by drive shaft rotation to discharge 1 metal from the melting pot when communication is established with the die cavity, an ejector associated with "the stationary die member and actuated by a cam element on the drive shaft to'push a completed casting from .the die member, and a core having an operable connection with a cam element on said driven shaft so as to be projected into the die cavity prior to the casting operation and to be withdrawn therefrom after the casting operation.

28. The structure of claim 24, and means governed by drive shaft rotation to discharge metal from the melting pot when communi cation is established with the die cavity, and a core having an operable connection with a cam element on said drive shaft so as to be projected into the die cavity prior to the casting operation and to be withdrawn therefrom after the casting operation.

29; The structure of claim 24, a clutch controlling the transmission of power to rotate said shaft and means operated by the shaft to disengage the clutch after the shaft has made a complete rotation.

30. An automatically operated die casting machine, including a stationary die member, a cover die member movable to and from said stationary member, and having a sprue opening leading to the die cavity at an angle to the parting line of the die members, a melting pot having a discharge nozzle and movable relative to said die members to .bring the nozzle into communication with the sprue opening when the die members are closed, and means to automatically move said cover die member and melting pot in predetermined relation and thru continuously repeating cycles.

31 The structure set forth in claim 30, said means comprising a drive shaft, rotatable cam elements carried thereby, and connecting rods having portions engageable with the cam elements and cover die member and melting pot respectively.

32. An automaticall operated die casting machine including'a d rive shaft, a series ofv Y cates' said cover die to closed and opened position, a melting pot, and means associated with another of said cam elements to bring said melting pot into communication with the die cavity for a predetermined period when the die members are closed, ejector pins associated with the fixed die member and operably connected with a cam element on said shaft for ejecting the casting after the die members are opened.

33. An automatically'operated die casting machine including a fi xed die member, a relatively movable die member, cores insertable and-removable from the die cavity, a melting otfurnace movable relative to said die memrs to bring the pot into communication with the die cavity, means to force metal from the pot into the die cavity, ejector pins associated with the fixed die member, a drive shaft and cam elements associated with the shaft and respectively with certain of the elements before mentioned and adapted upon a complete rotation of the shaft to bring such elements into action according to a predetermined sequence.

34. The structure of claim 35, and a clutch governing transmission of driving power to said shaft, and means operated from the shaft to disen age the clutch upon a complete rotation o? the shaft.

35. In an automatically operated machine of the character described, wherein a series of parts are operated in timed relation thruout successive cycles, a rotary shaft, a series of cam elements rotatable therewith to control the movement of said parts in predetermined sequence, a clutch controlling the transmission of power to rotate said shaft, manually operated means to engage and disengage said clutch, and means associated with the shaft to automatically disengage the clutch after a given cycle of operations have been completed said last mentioned means including a crank mounted on the shaft, a reciprocatory link connected with the crank andadapted at one limit of its movement to engage with a clutch release element.

36. In a die casting machine, a pair of separable die, members, one of which is provided with a sprue opening extending angularly to the parting line of the die members, a meltingv pot including a. nozzle to discharge a molten charge into said die through said sprue opening, at least one of said parts be ing movable, knee members upon which said meltmg pot is mounted and means to adjust the position of said knee members and melting pot to accurately position the nozzle relative to the sprue opening.

37. In a die casting machine, a die member, a meltmg pothaving associated therewith a nozzle to charge the die, means to move the melting pot to a position wherein the nozzle is n charging position, sald means including a rocking member, a llnk connecting said rock member and melting pot, the connection between said rocking member and link including resilient means whereby to compensate for variation in the relation between the nozzle and the die. r

38. The invention defined by claim 37, said resilient means being constituted by a rubber block.

39. A die casting machine including a frame, a. die section stationarily mounted on the frame, a movable die section, a unit movable relative to and in the same plane ofmovement of said die section and including'a furnace and a melting pot, and means for automatically moving the movable die section and said unit in predetermined timed rela-' tion. 1 40. A die casting machine including a frame, a die section stationarily mounted on the frame, a movable die section, actuating means for said movable die section to close and open the die, a unit movable relative to said die section and in a plane angular to the meeting faces of the die sections and including a furnace and a melting pot, actuating means for moving the unit to and fro in timed relation with the movement "of said movable die section to automatically place the melting pot in communication with the die cavity when the die sections are closed.

41. The structure of claim 40' and automatically actuated means to force molten material from the pot into the closed die cavity.

42. A die casting machine including a frame, a die section stationarily mounted on the frame, a movable die section, actuating means for said movable die section to close and open the die, a platform slidable on said frame, a melting pot and furnace carried by said platform, and actuating means to slide the platform in predetermined relation to the movement of said movable 'die section to bring the discharge passage of the pot into combination with the closed die cavity through a. sprue opening extending through one of the sections at an angle to the meeting faces of the sections.

43. A die casting machine including a stationary die member, a cover die member movable relative to the stationary die member and having a sprue opening extending therethrough at an angle to the parting surfaces of the die, a furnace and melting pot unit movable relative to the cover die and in the plane of movement of the cover die to bring its nozzle into communication with the sprue opening.

In testimony whereof I aflix my signature.

MARC STERN.

Images