US2172798A - Die casting machine - Google Patents

Description

sept. 12, 1939. A. LITTMANN 2,172,798

DIE CASTING MACHINE Filed Aug. 14, 1937 2 Sheets-Sheet l.

sepglz, 1939. A TMANN 2,172,798

D119 CASTING 111101111113 1 Filed Aug. 14, 19:57` l 2 shuts-sheet 2 Patented sept. 12, 1939 PATENT OFFICE DIE CASTING MACHINE August Littmann, Chicago, Ill., assigner of onehal! to Lewis H. Scurlock, Chicago, Ill.

' Application August 14, 1937, Serial No. 159,085

10 Claims.

This invention relates to die casting machinery, for making die castings of any suitable or desired character, such as type, gears, or other simliar things.

Generally stated, the object of the invention is to provide a novel and improved construction and arrangement whereby removable dies are provided in a rotating casting head, into which dies the molten metal is introduced by centrifugal force, in combination with a lower supporting frame, and an upper frame that carries the upper section of the rotary head, together with means whereby the upper frame is movable upwardly to separate the upper section of the head from the lower section thereof, and whereby the said upper frame with the upper section of the head-depending therefrom is thenmovable laterally about a vertical axis parallel with the vertical axis of the head, so that the'lower section of the latter is uncovered to permit access thereto for the removal of the die castings.

It is also an object to provide certain novel details and features of construction and combina- `tions tending to increase the general elciency and the desirability oi a centrifugal die casting machine of this particular character.

To the foregoing and other useful ends, the invention consists in matters hereinafter set forth and claimed, and shown in the accompanying drawings in which- Fig. i is a side elevation of a die casting machine embodying the principles of the invention, showing'certain portions thereof in vertical section.

Fig. 2 is an enlarged vertical section on line 2 2 in Fig. l of the drawings.

Fig. 3 is a horizontal section on line 3-3 in iig. 2 of the drawings. l

Fig. 4 is' a vertical section of a rotary head, on a smaller scale, showing a different form of the invention.

Fig. 5' isv a perspective of a type slug made by one of the dies used in Fig. 4 of the drawings.

Fig. 6 is a detail horizontal section on line 6-6 45 in Fig. 4 of the drawings. As thus illustrated, the invention comprises4 a main supporting frame I providing a table 2 in 'the middle of which there is a bearing 3 as shown, for the vertical shaft 4 that has an inverted cupshaped clutch member 5 splined thereon, there being a lower cone-shaped clutch member 6 xed on said shaft, which latter is operated by the motor 1 of any suitable or desired character.

An upper frame 8 is provided, of arch-like form or shape,` and cam devices 9' are provided and employed for clamping this upper frame tightly upon-the table 2 'previously mentioned, but in such manner that the upper frame can be quickly released when it is desired to raise this frame. A vertical rod I is rigid with the table 2, at one side thereof, and has a cylindrical rack member Il rotatable thereon, but held. at its lower end as shown, against up and down movement. The pinion I2 engages said rack and is provided with a handle I3 for the'operation thereof, said rack being mounted on a shaft suitably journaled in one side of the frame 8 previously mentioned. By using the said handle I 3, and pressing it downwardly, the frame will be raised to the desired extent, as will hereinafter more fully appear.

Thelower section it of the rotary head is xed on the shaft 4, as shown in Fig. 2 of the drawings, and the said section is formed with pockets I for the lower dies I 6, to form a gear or other article, these lower die sections co-operating with the upper die sections Il for the desired purpose.

'Ihe upper die sections are held in pockets in the upper section I8 of the rotary head, the two head sections being held in proper relation with each other by dowel pins i9 fixed in the lower head section. Radial grooves lead from the center of the rotary head to the entrances to the dies, V and each passage thus formed preferably has a spherical space 2l adjacent the die, vand the lower head section has a cone-shaped distributor 22 that distributes the molten metal to the different radial passages. y

The upper head section I8 has a rigid upstanding tubular portion 23 that has a bearing 24 in the frame t, so that the entire upper section .of the rotary head is thus supported for rotation in unison with the lower section of the head. For the pouring of the molten metal, a funnel 25 is provided, the lower end of the tubelike lower portion of this funnel being adjacent the distributor 22, and the upper head section having passages or a space 26 communicating with Athe passages 20 previously mentioned.. The

`upper end of this funnel is preferably rigidly secured, by the bolts or screws shown, to the frame member 8, so that this funnel is held against rotation. Thus, the molten metal can be poured into the funnel while themachine is running or not running, if desired, without danger of throwing it out of the funnel by centrifugal force. Thus any metal poured into the 'funnel will be distributed in to the passages 20 and from the latter forced by centrifugal force into the removable dies I6 and I1 previously mentioned.

vertically disposed cores 21 are provided, for

the said dies, and it is desirable to pull these cores upwardly, when the metal has sufficiently cooled, and this is done by the rack and pinion devices 28 formed by the teeth on the cores which engage the pinions shown. The pinions have arms 29 with slots 33 therein that engage the pins 3I on the brackets 32 that are on the periphery of the threaded nut 33, which latter engages the threaded sleeve 34 that is carried by the tubular portion 23 previously mentioned, but which is loose thereon. 'I'he upper end of the sleeve 34 is cupshaped to receive a clutch cone 35 that is splined to slide up and down on the portion 36 which is rigid with the frame 8 Ipreviously mentioned. A cam device 3T is operable by a handle 38 to force the member 35 downwardlyjnto the tapered cup, and when this is done the sleeve member 34 is held stationary. This member 34 has threads for engaging the threads of the ring nut 33, and while lthe latter rotates the ring is traveling downward, until it reaches the reduced portion 39 of the sleeve 34, at which point the operation of the rack and pinion devices comes to a stop. The

rotation of the pinions, until the arms 29 are in the dotted positions shown in Fig. 2, raises the cores 21 until they are out of the castings in the dies. After the castings are removed, the parts are thenreturned to the positions shown in Fig. 2 of the drawings, by the restoration of the hand lever 38 to its normal position.

When the castings are finished, and sufficiently cooled, the frame 8 is then raised by the operation of the handle I3, until the upper section I8 is clear of the lower section I4, and the frame 8 is then swung around horizontally about the axis aorded by the rod IIJ previously mentioned, leaving the top of the lower section I4 accessible for the purpose of removing the castings from the lower section I4 oi' the rotary head.

The spaces 2I serve as a means of insuring a full amount of molten metal in each die, as these spaces are larger than the passages 28, and hence the metal cools less rapidly in the spaces 2| than in the said passages 28, thereby insuring the complete illng of each die casting mold. The distributor 22 may be removable upwardly, as shown, if desired, so that when impaired a new one may be inserted in its place.

For the purpose of starting the machine, a foot pedal 4U is provided for operating the link; 4I, that connects to the lever arm 42 by which the upper member 5 of the clutch is forced down into frictonal contact with the cone-shaped member 6 previously mentioned.

It is obvious that any suitable or desired number of die casting molds can be provided in the rotary head, with as many cores 21 as there are molds. l,

In Figs. 4, 5, and' 6 the construction is the same as that previously described, except that in this case the dies 43 are of a diierent construction, having a type formation on the end portion thereof facing the ends of the radial passages 44 through which the molten metal flows by centriiugal force. In this case, therefore, the cores 21 are not necessary, and the automatic screw mechanism 33 and 34 are not employed. It will be understood, however, that in Figs. 4, 5, and 6 the lower frame I and table 2 and upper frame 8,

together with the rack and pinion device II and I2 and the hand lever I3, and the funnel 25, are employed as shown in Fig. 1 of the drawings, so that the upper section 45 of the rotary head may be raised from the lower section 48 when the castings are sunciently cooled. It will loe underpassages 44 are preferably square or rectangularv in cross section, so that the type shown in Fig. 5 will be formed in the end portions of the passages 44 when the metal is suiciently cool. In Fig. 4 the expansion chambers 2I of Fig. 2 are not necessary, inasmuch as the passages 44 do not empty into molds or die chambers of larger area or capacity, as do the passages 20 in Fig. 2 of the drawings.

It will be seen that the rotary head shown in Fig. 2, comprising the two head sections I4 and I8, and the rotary head shown in Fig. 4, comprising the two head sections 45. and 46, are interchangeable with each other on one and the same machine, on the upper end of the shaft 4, so that the latter maybe employed for making type or gears or other articles. In other Words, each head is composed of upper and lower separable sections, and each head can he used alone for its particular purpose, all on one and the same structure.

In Fig. 4 the expansion chambers 2I of Fig. 2 are not necessary, inasmuch as the passages 44 do not empty into molds or die chambers of larger area or capacity, as do the passages 20 in Fig. 2 of the drawings.

Thus it will be seen that the invention provides a vertical tubular portion for the pouring of the molten metal into the molding head, and which has a bearing for raising and lowering the said upper section of the mold, which is also laterally movable, in order to move the upper section of the mold laterally and thereby afford access to the castings in the lower section of .the rotary molding head. This tubular pouring element 23, as shown in Fig. 2 of the drawings, is preferably integral with the upper section I8 of the rotary molding head, but it is obvious that it may be separately formed and connected to the molding section in any suitable or desirable manner. The bearing 24 is preferably located near the upper end of this tubular pouringA element 23, but it may be suitably located, and may be suitably supported, for both axial and lateral displacement, without departing from the spirit of the invenion.

The arch 8 is a part of the devices whereby the bearing 24 may have both 'axial and lateral displacement, to facilitate the removal of the castings, but it is important, in the construction shown and described, that said bearing 24 and its tubular portion 3B are held absolutely rigid and against any displacement whatever while the machine is running, and the support 2 with the means 3 or any equivalent thereof may be used for this purpose.

Obviously, the weight of the upper mold section I8 may be sufcient to hold it tightly and firmly down upon the upper side of the lower section I4, and i that connection the bearing 24 may be formed to insure the requisite downward pressure of the upper section I8 upon the lower section I4, when the frame 8 is tightly clamped down upon the table by the devices 9, and in this Way the tubular portion 23 of said upper mold section is supported by said bearing 24 in a manner to insure said downward pressure, as well as to pull up on the tubular portion 23 when it is desired to lift the section I3 the necessary or desired distance above the lower section I4, when the time comes for the removal of the castings.

What I claim as my invention is:

1. A centrifugal molding machine comprising a rotary molding head, a table or body frame on which said head is mounted to rotate about a vertical axis, said head comprising upper and k lower sections formed to fit together with molding space between them, the upper section having an upstanding central tubular portion rigid therewith, an upper frame member provided with a bearing for the uppejr end of said tubular portion, fastening means for rigidly but dreleasably securing the opposite lower ends of said frame member in position on said body frame, at opposite sides'of said head, so that said bearing is movable laterally at will, and mechanism for lifting said frame member when it is released, to lift the upper mold section, said bearing being formed to support said tubular portion thereon in a manner to keep the two mold sections tight together, when said upper member is secured in place, and to pull up on said tubular portion, when the upper member is raised, therebyto lift the upper mold section a distance from the lower section, means to rotate said head, and means forming in effect a Vfunnel mounted on said upper member to pour molten metal downwardly in said tubular portion to the interior of the head.

2L A structure as specied in claim 1, comprising vertical' cores on said upper section, and clutch controlled mechanism on said tubular portion for using the rotation of the head to raise said cores out of the castings.

3. A structure as specied in claim 1, said lift.;- ing mechanism comprising a rack and pinion, with the latter journaled on and carried by said upper frame member, so that the pinion moves up and down with the frame member, and with the rack held at its lower end against upward displacement.

' 4. A structure as specified in claim 1. said lifting mechanism comprising a rack and pinion with the latter journaled on and carried by said upper frame member, so that the pinion moves up and down with the frame member, and with the rack held at its lower end against upward displacement, together with a vertical guide 'rod in said stationary rack, forming an axis about which said upper frame member and the upper section of the head may swing laterally when raised.

5. A Astructure as specified in claim '1, having vertical cores for said molding spaces. and means including racks and pinions operated by the rotation `of the head to lift said cores out of the castings, before said bearing is moved laterally.

6. In a centrifugal casting machine, a rotary head having molding spaces therein, a core for each space, and screw mechanism operated by the rotation of the head to pull the cores out of the castings, together with means whereby said mechanism is both axially and laterally movable. after the removal of theA cores.

7. A structure as speciiied in claim 1, comprising a vertical shaft rigid with said lower section, with a thrust bearing therefor on said table, interlocking connection between the two sections, and power transmitting means below the table to rotate said shaft, thereby torotate the two sections in unison.

8. A structure as specified in claim 1, comprising a vertical shaft rigid with said lower section, with a thrust bearing therefor on said table, interlocking connection between the two sections, and power transmitting means below `the table to rotate\said shaft, thereby to rotate the two sections in unison. said power transmitting means comprising a friction clutch, with a motor axially aligned through said clutch with said shaft, and means to operate said clutch. which latter is normally open.

9. A structure as specined in claim 1, comprising means holding said funnel against rotation, so that the molten metal can safely be poured into the, funnel whether the machine lis running or not.

1c. `A structure as specified 1n claim 1, said nfty ing mechanism having a fixed vertical axis for

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