US1760258A - Die-casting machine - Google Patents

Description

May 27, 1930. M. STERN DIE CASTING MACHINE Filed July 16 1928 4 Sheets-Sheet.

M. STERN DIE CASTING MACHINE Filed July 16 1928 4 Sheets-Sheet May 27, 1930.

May 27, 1930. STERN DIE CASTING MACHINE Filed July 16 1928 4 Sheets-Sheet May 27, 1930. M. STERN 1,760,258

DIE CASTING MACHINE Filed July 16, 1928 4 Sheets-Sheet 4 Patented May 27, 1930 UNITED STATES PATENT OFFICE MARC STERN, OF FLINT, MICHIGAN, ASSIGNOR TO A C SPARK PLUG COMPANY, OF FLINT, MICHIGAN, A COMPANY OF MICHIGAN nm-cas'rme MACHINE Application filed July 16, 1928. Serial No. 292,941.

This invention relates to improvements in die casting machines, and involves an automatically operated machine embodying separable die sections, and a melting pot or pressure chamber for molten metal, movable relative to the die sections; the present application being a continuation in part of pending application for Letters Patent Serial Number 113,707, filed June 4, 1926.

It is an object of the present invention to provide improved operating mechanism for moving the cover die and the melting pot and furnace, relative to each other and to the stationary die member, in certain predetermined relation and concomitantly.

It is a further object of the invention to provide motion transmitting mechanism for the movable melting pot and cover die, which embodies a motion modifying arrangement to cause the melting pot to move to a greater extent and faster than the cover die and which insures the tight closing of the die members.

Another object is to utilize fluid pressure for ejecting molten metal from the pot into the die cavity, the application of which occurs when the die members are closed.

A still further object is to provide an improved type of melting pot wherein fluid pressure acts directly on the molten metal in the pot to eject the same; the valve controlling the application of fluid pressure being arranged so as to relieve the pressure after a charge of metal has been ejected, and the pot being provided with a closure member for an opening through which metal is introduced at regular intervals to replenish the supply, which closure member is moved ofi the opening between each application of pressure, which besides allowing the addition of metal, serves as a safety factor in relieving pressure within the pot and prevents molten metal being drawn into and clogging the pressure line or from being splashed out of the pot and causing injury to the operator.

A further object is to provide the melting pot with a replaceable discharge nozzle and throat, which will permit the substitution of a new outlet unit should the one in use become damaged, without tying up the machine for any appreciable length of time or disturbing the remainder of the parts.

Other objects will appear from the following detailed specification, when taken in connection with the accompanying drawings forming a part hereof and illustrating a preferred embodiment of the invention.

In the drawing, Figure 1 is a side elevation of the die casting machine with certain parts brol'cn away and shown in section.

Figure 2 is a top plan view of the machine.

Figures 3 and 4 are end elevations from opposite ends.

Figure 5 is a detail section view taken on line 5-5 of Figure 1.

Figure 6 is a sectional View of a pressure control valve on line 66 of Figure 7.

Figure 7 is a sectional View taken on line 7-7 of Figure 6.

Figure 8 is a view of an operating cam element.

Figure 9 is a view showing a sectional cam plate that is secured on the face of the cam element opposite to that shown in Figure 8.

Figure 10 is a section on line 1010 of Figure 8.

Figure 11 is a fragmentary side elevation of the machine, partly in section, and showing one type of melting pot and its associated parts.

Figure 12 is a section taken transversely of the melting pot of the machine shown in Figure 1.

Figure 13 is a transverse section of the furnace or fire box taken on line 13-13 of Figure .1.

Referring by reference characters to the accompanying drawing the numeral 1 indicates the bed or frame of the machine, to the front of which is secured, as by means of L.- shaped bolts or studs 2, a supporting bracket comprising a pair of spaced knees or side portions 3 and a bottom cross portion 4. An adjustable screw stud or jack 5 engages the bottom cross portion 4 and provides for vertical adjustment of the supporting bracket. The top surface of the side portions 3 provide a track or runway for the rollers 6 carried by the platform or carriage 7, whereby the platform may be readily moved back and forth.

Carried by the platform are a number of dependent bolts 8, each carrying a pair of helical compression springs 9 and projecting through a lug 10 of the fire box or furnace 11, the springs being located on opposite sides of the lugs so as to resiliently mount the furnace on the reciprocatory platform and relieve it from strains and shocks. The fire box or furnace 11, which may be provided with a suitable burner for fuel oil or combustible gas, surrounds and encloses a melting pot or container for casting metal indicatedtat 12, that extends through an opening in the platform 7 and is provided with an annular flange resting on a shouldered portion of the platform at the opening (see Figure 12). Bolted to the top of the platform and overlying the annular flange of the melting pot or crucible, are foot portions 13 of a pair of upwardly extending standards or posts 14, that carry at their upper ends an air cylinder 15. Iteciprocable in cylinder 15 is a piston 16 havlng a stem 17 detachably secured by pin 18 in the'head 19 of a rod 20.

The lower end of the rod 20 is secured to the cross head 21 slidable on the posts 14. A plunger rod 22 having its upper end detachably engaged with the under side of the cross head 21, extends into a charge cylinder 23 into which the molten metal enters through a port 24 and is then discharged or ejected through the passageway 25 leading to a nozzle, that is brought into communication with the die cavit when the die sections 26 and 27 are close The front section 26 is the movable or cover die, while the die section 27 is stationary or fixed to the frame of the machine, and this latter may be provided with suitablecores and ejector devices depending upon the nature of the castings to be made.

Power to move the several parts in timed relation is supplied from some external source, as from a continuously operating motor (not shown), that drives a pulley 28-- associated with suitable clutch mechanism enclosed with a case 29 to rotate-the shaft 30, the engagement of the clutch being controlled by a manually operable lever 31. A gear box 32 houses suitable gearing for transmitting the rotation of the shaft 30 to a transverse shaft carrying a bull pinion 32, that meshes with a pair of spaced gear wheels 33 and 34 fixed or keyed on the main shaft 35. Fixedly secured on the end of the main shaft 35 is a crank 36, having pivoted thereto the end of a link or bar 37 which carries adjacent its opposite end, a roller 38 that rides on the top surface of a bracket 39 upon rotation of the main shaft and consequent reciprocation of the bar. As the throw of the crank 36 approaches its forward limit, the end of the bar 37 engages with a lateral pin or projection 40 on the hand lever 31, and upon further movement swings the lever forward to disengage or release the clutch and thereby throw the machine out of operation. At the same time the roller 38 is moved up the inclined surface 41 of the bracket 39 to clear the pin 40, whereby the lever may once more be moved by the operator to effect clutch engagement, it being understood that one complete rotation of the main shaft actuates the several parts of the machine in their proper relation to bring about one complete casting operation. Obviously, the bar 37 can be omitted if it is desired to have the machine operate through continuously repeating cycles to automatically produce one casting after another without'interru'ption. The provision of the bar, however, causes the parts to come to rest at the same point after the machine has gone through a single cycle of the operation and enables the operator to remove finished castings from the machine, after which he can again put the machine into operation for another automatic cycle by swinging the hand lever to engage the clutch.

The inner or adjacent faces of the spaced gear elements 33 and 34 are provided with complementary cam grooves, such as shown at 45 in Figure 8, and a swinging lever 46 pivoted on the frame of the machine at 47 and positioned between the gear wheels, carries on opposite sides thereof, a pair of antifriction rollers that project into the cam grooves and cause movement of the lever to and fro upon rotation of the gear wheels. The pin 48 at the upper end of the lever 46 serves as a pivotal mounting for a yoke member 49 and a pair of links 5050. The yoke member 49 has a screw threaded stem 51 that carries a cushion or buffer 52, preferably consisting of a block of rubber or other elastic material, andprojects through and is secured by nuts -53 to a cross bar 54. To support the Weight of the bar and permit its to and fro movement, the link 55 pivoted at 56 to the frame 1 and at 57 to the cross bar has been provided. Tie rods 58 connect the cross bar with the carriage or platform 7 to impart the movement of the lever 46 directly thereto. The elasticity of .the cushion 52 serves to maintain a tight fit of the melting pot nozzle in the sprue opening of the cover die and to compensate for slight irregularities such as would be caused by relative expansion of v above and low the rod 61, the pin 66 extending vertically through the rod serving -to pivotally mount the plates 67 and 68 there- 1 and 2, swings the toggle link and tends tov straighten out the links 69-71 and 70-72, whereby the force of the movement is greatly increased and the tight closure or clamping together of the die sections is insured. At the same time, of course, the extent of movement is cut down and since the platform carrying the furnace and melting pot is di-- rectly connected with the swinging lever, its movement will be more rapid and of greater distance. Therefore, the relation of the movement is such that the discharge nozzle of the melting pot moves entirely away or free from the cover die as the die sections separate, the rate of movement of the nozzle in relation to the rate of movement of the cover die section, being greatest during the initial opening movement, as well as during the final closing movement of the die sections.

Mounted on the outer side or face of the gear element 33, as by means of dowel pins, is a cam element 75, which for convenience and economy of manufacture may be formed in two halves. as shown in Figure 9. Projecting into and riding on the surface of the cam groove 76 is an anti-friction roller mounted on a bell crank 77 that is connected by link 78 to an arm 79 fixed on a rock shaft 80. The arm 81 fixed on the end of the rock shaft 80 is connected by a tie rod 82 with the arm 83 on a shaft 84 carrying the valve member 85 within the housing 86. The valve member 85 has two positions of adjustment to which it is moved by the engagement in the cam groove 76 of the roller on the bell crank 77 during a rotation of the mainshaft. In the position shown in Figures 6 and 7, air or other suitable fluid under pressure, supplied from a pressure tank 87 thru the conduit or pipe 88, enters the space or chamber 89 in the valve casing and passes through an opening 90 in the valve member 85 that is in communication with a chamber 91 connected by a flexible hose or conduit 92 with the cylinder 15 below the piston 16. The pressure tends to force the piston upward and as the piston rises the air above the same will escape'through the flexible'hose or conduit 93 connected with a chamber 94 in the valve housing, which chamber atthis time communicates with a groove 95 in the valve that is open to the atmosphere at all times through the mediumof a chamber 96 and pipe 97. In the other position of the Valve member 85, the opening 90 is brought into alinement with the chamber 94 and the groove 95 places the chamber 91 in communication with atmosphere, whereby the fluid under pressure acts on the top side of the piston and the space below the descending piston is vented.

The operators station is beside the machine close to the parting line of the die. To put the machine through its operatin cycle he throws the hand lever 31 toward t e rear of the machine to engage the clutch and set in motion the main shaft 35 which carries the several cams that are so arranged as to actuate the various parts as heretofore referred to in predetermined sequence. That is, the lever 46 is swung rearwardly moving through the toggle mechanism, the cover die section toward and into closed relation with the stationary die section and shifting the carriage 7 through its direct connection with the lever to bring the discharge nozzle into communication with the sprue opening in the cover die, that extends at right angles to the parting line of the die sections. At this time the valve 85 is actuated by its cam to admit air under pressure on the upper side of the piston 16 forcing down the plunger 22 to eject molten metal from the pot into the die cavity, the lever 46 during this time being held stationary at its rearmost limit by reason of-cam contour. Continued rotation of themain shaft 35 and movement of the cam 7 5 actuates the valve 85 to direct air under pressure to the underside of the piston 16 to restore the plunger 22. After the die cavity has received its charge, the melting pot nozzle is moved away from the cover die with the forward swinging of the lever 46 which swinging movement also separates the die sections. As the main shaft 35 nears-the end of one complete rotation, the crank 36 pushes forward on the rod 37 which engages the pin 40 and throws the lever 31 to automatically disengage the clutch and stop the machine. The operator may then remove and inspect the completed casting and the machine is ready for a repeat cycle.

Thus it will be seen that engagement of the clutch mechanism effects an automatic operation of the machine through a given cycle, the power acting through the gear train, cam elements and linkage to open and close the die members, move the furnace and melting .pot relative to the die members and reciprocate the plunger to force a charge of molten metal into the die cavity, all in proper timed relation.

The melting pot or crucible embodying. the plunger and charging cylinder is especially adaptable for use with low temperature casting metals such as tin, lead and zinc. However, there are certain metals, such as aluminum, that require the direct application of fluid pressure thereon because of their great corroding tendencies on plungers, and the arrangement illustrated in Figure 11 is particularly intended for use with such metals. In this case, the gear element 34 may be provided on its outer face with a plate 100, corres onding' to the arrangement of the plate 5 and gear element 33. A bell crank 101 may be provided with an anti-friction roller for projection into the camgroove 102 in the plate 100, to swing the same upon rotatransmitted by the'link 103 to a bell crank 104 connected by a rod 105 with a lever 106 pivoted at 107 on the valve housing 108. Enclosed within the housing 108 are a 'pair of valves 109 and 110, having stems pro ecting from the housing which carry compressionsprings 111 and 112 respectively that tend to seat the valves. The swinging movement of the lever 106 to the position shown in Figure 11 causes it to bear on the stem of the valve 109 to open the valve against the pressure of its spring and allow the fluid under pressure to flow from the pressure line 113 through the flexible hose 114 to the top of the melting pot115. where it acts on the molten metal therein to force the samethrough the outlet passageway 116 and discharge nozzle communicating with the cavity in the die members. When the lever 106 is swung in the opposite direction the valve 109 moves to closed position and the valve 110 is opened to relieve the pressure by allowing the air or other fluid to escape to atmosphere. In place of the plunger previously described, there is substituted a valve or closure member 117 for an opening 118 in the top of the melting pot. Reciprocation of the piston 16 in the cylinder 15, in this instance, opens and closes the valve 117 in accordance with the application of pressure on the contents of the melt ing pot. The purpose of the valve or closure member is twofold. First, it allows the introduction into the melting pot of ingots or additional metal to replenish the supply, and, second, it supplements the action of the valve 110 in relieving pressure after a charge of metal has been ejected. This latter is intended as a safety factor to prevent injury to workmen by splashing of hot metal after discharge nozzle moves away from the die sections, in event the pressure is not entirely relieved by the opening of the valve 110, or.

in case some of the metal should be splashed or-drawn into the passageway of the hose fitting in the top of the melting pot and thereby 'clog the same.

It will be noted that the discharge passageway 116, instead of being formed in an integral part of the melting pot as has heretofore een the custom, is provided in a replaceable unit removably secured to the melting pot by one or more studs or bolts 1 20 and which comprises the nozzle 121 and dependent extension or throat 122. This arrangement is found to be particularly advantageous in that it permits ready replacement of the unit in the event of damage due to corrosion or otherwise, without disturbin j the furnace or melting 0t and associate parts. Furthermore, it eliminates the neces: sity for the user to keep on hand a number of spare melting pots to take care of such emergency and thus materially reduces oper- I ating costs and saves storage space.

In certain cases where the size of the castings call for comparatively large die members it may be found desirable to employ a pair of connecting rods 64 at each side of the bearing block in vertically spaced relatype of work on hand. Each pair of vertically spaced rods is preferably connected to a cross bar 124 provided with a screw threaded stem 125 extendin thru the cross bar 63 and secured thereto %y the ad'ustable nuts 126. Thus the adjustment of our connectingrods will be substantially the same as for two, and much difficulty in efl'ecting the proper alignment of the die section is avoided.

While the die casting machine forming the present subject matter has been described more or less specifically, it is'to be understood that the invention is not limited to the exact details shown, but that such modifications may be made as come within the scope of the appended claims.

I claim:

1. In a die casting machine, a movabl melting pot member, a movable die member movable in the path of movement of said pot member, means common to said members to concurrently move them thru the same path, connections between said means and the respective'members, one of the connections including a motion modifying device, whereby the concurrent movement of the members is thru different limits.

2. In a die casting machine, a stationary die member, a movable cover die member having a sprue opening extending from a point spaced from the parting line, a melting pot movable relative to said movable die member in the plane of movement-thereof to bring its discharge nozzle into or out of engagement with said sprue opening, a work performing membeflmovable in reverse directions as a part of the operating cycle of the machine, a direct connection between said work performing member and one of said movable members, and a toggle link connection between the work performing memberand the other of said movable members, whereby they are simultaneously moved thru means associated with the direct connection.

4. In a die casting machine, a movable die member. a movable container for the casting material movable in the path of movment of the die member, operating means common to said movable parts, a motion modifying connection between said means and the die member, and a direct connection between said means and the container, whereby they are simultaneously moved in the same path at different rates.

5. The structure of claim 4, wherein a resilient expansion compensating means is associated with the connection between the operating means and the container.

6. In a die casting machine, a stationary die member, a movable container for the casting material, a movable die member interposed between the stationary die member and the container and movable in the path of the container, operating means common to said movable parts to move them concurrently, and a toggle link connection between said means and the die member to vary its rate of movement relative to that of the container.

7. In a die casting machine. a stationary die member, a movable cover die member, a melting pot movable relative to and in the plane of movement of said cover die member, a work performing member, movable to and fro as a part of the operating cycle of the machine. a connection between the work performing member and the melting pot and a connection between the work performing member and cover die member, one of said connections including a motion modifying device to differentiate the movement of the cover die and pot.

8. In a die casting machine, a rotating cam element, a swinging lever having a part engageable n th the cam element, a movable container for the casting material and a movable die member, each having an operative connection with said swinging lever, the connection between the lever and die member including a motion modifying device.

9. In a die casting machine, the combination with a statioary die member, a movable cover die member and a container for casting material movable relative to said cover die member, of operating means for said parts including a cam element, a member engage-able with said cam element for to and fro movement and connections between said member and the cover die and the container respectively, the connection with the cover die including a set of toggle links.

10. In a die casting machine. the combination with a melting pot movable relative to a die member, of a closure cap for an opening in said pot, a fluid pressure actuated device includin a cylinder and piston, means to introduce" uid under pressure to either of the opposite sides of the piston to open or close said cap, a valve controlling the application of pressure on opposite sides of the iston, a valve controlling the application of pressure on the contents of said pot to eject the same, and pair of cam elements rotatable in unison and having cam grooves in the opposite faces thereof, an operative connection having engagement in the cam grooves in the adjacent inner faces of said cam element, for moving said melting pot and oper ative connections governing the operation of said valves having engagement in the cam grooves in the outer faces of said cam elements.

11. In a die casting machine, a movable die member, an operating element therefor, two pair of connecting rods secured at one end to the die member, and means to adjustably connect the opposite ends of the bars to the operating element including a connecting member common to the bars of one pair and a second connecting member common to the bars of the other pair, each of said members being independently adjustable.

12. In a die casting machine, a stationary die section, a movable cover die section having a sprue opening extending therethrough at an angle to the parting line of the die, a melting pot movable relative to and in the plane of movement of the cover die to bring its discharge nozzle into and out of communication with said sprue opening, and a reciprocatory operating member for both the cover die section and the melting-pot, having independent connections with the cover die section and melting pot, one of which connections includes a motion modifying device to differentiate the movement of the pot and die.

13. In a die casting machine, a stationary die section, a movable melting pot, a cover die section interposed between the stationary die section and the pot and movable relative to the stationary die section and to the pot in the plane of movement of the pot, an actuating member movable first in one direction and then in a reverse direction as a part of the machines operating cycle, a direct connection between said member and the pot and a toggle connection between said member and the die section, whereby the movement of the pot is faster and to a greater extent than that'of the cover die section.

14. In a die casting machine, a fixed die, a

cover die movable in a horizontal plane to and from the fixed die, a molten metal container movable in a horizontal plane to and from the cover die, and an actuating member common to the cover die and container movable in reverse directions as a part of the operating cycle of the machine to open and close the die and bring the .container into and out of communication with the die cavity.

15. Inufdie casting machine, astationary die section, a movable die section interposed between the pot and stationary die section, a reciprocatory actuating member for simultaneously moving both the melting pot and the movable die section, motion transmitting means for themovable die section including a bell crank connected thru one leg with the actuating member and thru its other leg with the die section' a'nd at an intermediate point adjacent'the apex of the angle between its legs with a part of the frame.

, 16. In a die casting machine, a frame, a

die section carried by the frame, a movable I cover die, means movably carried by the frame to support the cover die, an actuating member controlling the movement of the cover die, a pair of bell cranks, each pivoted at one end to the actuating member, a pair of links associated with each bell crank, one link of each pair being pivoted at opposite ends to said supporting means and the opposite end of its adjacent bell, crank respectively and the other link of each pair being pivoted at opposite ends to the frame and an intermediate portion of its adjacent bell crank, a molten metal container movable relative to the cover die, and a direct connection between said actuating member and the container, whereby movement of said actuating member moves both the cover die and the container but at different speed and to different extent.

17. In a die casting machine, a frame, a die section carried by the frame, a movable cover die, means movably carried by the frame to support the cover die, an actuating member controlling the movement of the cover die, a pair of bell cranks, each pivoted at the end of one of its angular legs to the actuating member, a pair of toggle links associated with each bell crank, one link of each pair being pivoted at ends to said supporting means and the opposite end of the other leg of its adjacent bell crank respectively and the other link of each pair being pivoted at oppo site ends to theframe and an intermediate portion with the apex of the angle between its legs of its adjacent bell crank whereby the cover die is forcibly moved thru the combined multiple action of the bell cranks and toggle links.

18. In a die casting machine, a movable die carrier, an actuating member therefor, a bell crank'having one leg pivoted at its end to said member, a swinging link having a fixed pivot at one end and a pivotal connection at its other end with an intermediate portion of the bell crank at the apex of its angular legs, and a second link having pivotal connections at opposite ends with the end of the other leg of the bell crank and said carrier respectively.

19. In a die casting machine, a movable die carrier an actuating membertherefor, a lever ivote at one end to said member, a pair of links pivotally connected at adjacent ends with said lever at oints spaced from each other and from the rst mentioned pivot, and at opposite ends with a fixed part and said carrier respectively. 20. In a die casting machine, a fixed die, a movable cover die, a support for the cover die, a series of reciprocatory bars carrying said support, and a bearing block having a series of guides therein for the bars and in which I the bars may be interchangeably mounted in different relations to accommodate dies of varying sizes and shapes.

In testimony whereof'I aflix my signature.

. MARC STERN.

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