US1142840A - Centrifugal casting-machine. - Google Patents

Description

Patented June 15, 1915.

10 ,M' wenfi fei'i'irelf P. 1. PANKRATZ: CENTRIFUGAL CASTING MACHINE. v APPLICATION FILED MAR 5 1914 I I'ETER J. PANKTtATZ, 0F STAFFORD, KANSAS.

GENTRIFUGAL CASTING-MAC HINE.

Specification of Letters Patent.

Patented June 15, 1915.

Application filed March 5, 1914. Serial No. 822,617.

To all whom it may concern:

Be it known that 1, PETER J. PANKRA'rz, a citizen of the United States, residing in Stafford, in the county of Stafford and State of Kansas, have invented new and useful Improvements in Centrifugal Casting-Machines, of'which the following is a specification.

This invention relates to centrifugal casting machines and has for its principal object the production of a simple and efiicient device adapted more particularly for casting dental inlay fillings and other arm ticles or pieces of irregular shape.

Other objects and advantages to be vattained will hereinafter more fully appear.

The invention consists in the parts and in the arrangements and combinations of parts hereinafter described and claimed.

In the accompanying drawing illustrating an embodiment of the invention in a dental casting machine, and wherein like symbols refer to like parts wherever they occur in the several views, Figure 1 is a plan view with portions of the casing-removed to expose in vertical section. Fig. 3 is a horizontal section on an enlarged scale on the line 3-3 of Fig. 2; Fig. 4 is af-ragmentary vertical section on the line 4.-4= o f Fig. 3; and Fig. 5 is a view of the parts shown in Fig. 4, showing the manner in which the latch pin on' the rotatable column member engages the recess in the motor sleeve. 4

The machine illustrated in thedrawing comprises a circular supporting base 1 at the center of which is a post or spindle 2.

At the top of the base 1 is an annular flange 3 which constitutes a housing for a motor spring 4; Thisspring, as shown, is an ordinary spiral or clock spring, one end of which is fastened to the flange 3, as at 5, the fastening means being a bolt which is passed through perforations provided therefor in the motor spring; Fig. 2- is a view partly in side elevation and partly' flange 16 is ment 22.

motor sleeve,

provided with a central. opening thr ugh, which the motor sleeve 6 projects, said sleeve 1 having an annular flange 10 overlying the adjacent portion of the cover plate.

Sleeved over the post 2 so as to rotate thereon is a tubular column member 11.

This column member is closed at its upper end and is provided with a counterpart socket or" seat 12 which receives the rounded end portion 13 of said post 2, and which constitutes a journal bearing. The post 2 is provided near its upper end with-an annular groove 14, and a pin 15 is inserted transversely through the column 11 and tangentially through said groove 14, so that the tube is free to rotate on the post 2, but is held against endwise movement thereon.

The lower end of the tubular column 11 just clears the top of the motor sleeve 6, and it is provided with an annular flange 16 which is of larger diameter than the flange 1001? said sleeve 6. The flange 16 is provided with a peripheral notch 17 adapted to be engaged by a lateral projection 18 on a latch member or pawl 19, which latter is pressed against said flange 16 by a spring handle extension 21 whereby it may be 5 moved and held out of engagement with said flange 16.

Diametrically opposite the notch 17 the l provided with a boss or enlarge- This portion of the flange is provided with a vertical opening'through which works a latch pin 23, a spring 23 being provided to move said pin downward and yieldingly hold it in engagement with the flange port1on'10 of said motor sleeve 6.

The lower end portion of the pin 23 is beveled, as at 24:, and the flange 10 of the motor sleeve 6 is provided with a correspondingly beveled recess 25, at one end of which is a shoulder 26 against which the pin 23 engages when the column 11 is rotated in one direction, whereby this motion is imparted to said sleeve 6, and whereby, also, when said sleeve 6 is rotated in the opposite direction its motion is imparted to said column 11; By this arrangement it is obvious the column 11 the latch pin 23 will ride out of the recess 25, whereby said sleeve 6 may remain idle and the member 11 is free to. rotate independently thereof. Near the upper end of .the column 11 it is provided with oppositely disposed radial arms 27, 28. On the arm 27 is fastened, either fixedly that on the reverse rotation of I or removably a crucible or container 29. This crucible, as shown, is tubular and it is provided with a horizontally elongated slot or mouth 30 in its side. The crucible is open at its inner end, but it is provided with an upstanding flange 31 at the bottom there of. The outer end portion of the crucible is convergent or frusto-conical, as at 32, and is provided with an annular flange 33 whose outer face is preferably beveled or tapered. The crucible is lined throughout with asbestos or some suitable refractory material.

The outer portion of the arm 27 is inclined downwardly, as at 34, and it has slidably mounted thereon a flask-holding device 35. As shown, this device comprises a plate which is mounted on a block 36 having an opening therethrough which is slidably fitted to said downwardly inclined portion 34 of the arm 27. The flask, 37 is detachably supported between the flange 33 of the crucible and the plate 35; and said plate may be held in its cooperative position by a spring 38 which is connected at one end to a stud 39 on the under side of the arm 27 and at its opposite end to the block 36. In some cases the tension of the spring 38 alone may i be depended upon to hold the flask in position, butit is preferable to provide a locking device for the block 36. As shown, the block is provided with a set-screw 40 which engages the arm 27. i

The flanged end portion 33 of the crucible is set at an inclination corresponding rectangularly to the inclination of the portion 34 of the arm 27, and the relative position of the flask-holding plate 35 thereto. The principal object in thus inclining the parts is to support the mold so that, in forming castings of irregular shape, such, for example, as dental inlay fillings, no cavity 'in the mold will be in a horizontal plane higher than the sprue and level of the surplus molten metal, or other fluent substance of which the casting ismade, whereby the force of gravity assists rather than retards the centrifugal force in filling each and every cavity and the formation of a well-defined counterpart contour for the finished casting is secured. It is also preferable to set the crucible at an angle to the arm 27 in a horizontal plane so that the crucible is disposed tangentially instead of directly radial with respect to the axis of the machine. This is to facilitate the discharge of the molten or fluent substance from the crucible. A weight 41 is sildably mounted on the arm 28 so that it may be adjusted toward and away from the axis of the machine to counterbalance the weight of the crucible and mold. This weight may be locked in adjusted position by any suitable means.

As shown, it is provided with a set-screw t5 42 which engages thearm 28.

In the operationof the machine the arms 27, 28, are turned in a direction the reverse to that indicated by the arrows in Fig. 1, and the tubular column member 11 being fixed with respect to said arms is rotated therewith. The latch pin 23 engages the shoulder 26 of the recess 25 in the motor sleeve 6 and the latter is thereby rotated to wind the spring 4. When the spring is wound the spring-pressed latch member 19 is allowed to engage the peripheral recess 17 in the flanged portion 16 of said tubular member 11, as shown more clearly in Fig. 1. The flask with the prepared mold therein is then placed in positlon, as shown in Figs. 1 and 2. The material of which the casting is made is next placed in the crucible or container 29, and in case metal is used the flame from a blow pipe or torch is applied thereto through the opening 30 in the side of the crucible until the metalhas become molten. The latch member 19 is then released from the notch 17 in said flange portion 16 of the rotatable colunm 11, and the .rotatable elements are thereupon instantly whirled rapidly by the reaction of the spring '4. The column member 11 with the arms 27 and 28 thereon will continue to rotate by momentum after the force of the spring is spent, as the pin 23 rides out of the recess 25 owing to the beveled arrangement of the end of the pin and the bottom of said recess. The molten or fluent mass in the crucible or container 29 is thrown into the mold by centrifugal force due to the rapid rotation of the parts; and it has been found in practice that the mold becomes filled quickly during the first few turns of the device, the continued rotation compacting the material in the mold while it is cooling and hardening, thereby avoiding distortion of the object molded, as sometimes occurs by shrinkage during the ordinary method of gravity molding.

The mold of itself and the manner of its preparation forms no part of the present invention. It-may behere stated, however, that for practical purposes, the mold material 43, or investment compound, as 1t is termed in dental practice, should be sufficiently porous to permit the forcing out of the contained air in the cavity by the incoming casting material. The mold cavity 44 may he of any desirable contour and the sprue 45 may or may not be contracted, as desired, but if contracted it is preferably provided with an outwardly flared or enlarged mouth 46, as shown.

While the invention is shown in the drawing as embodied in a dental casting machine, obviously it may be employed in other arts, and the machine admits of considerable modification, not only in construction and arrangement but also in sized proportion, without departing from the splrit of the invention. Therefore, I do not wish to be limited to the exact constructionand arrangement shown, nor to the application of the invention in any particular art.

I claim:

1. In a centrifugal casting machine, a carrier rotatable in a horizontal plane, a con tainer on said carrier for a fluent casting material, said container extending to one side of the axis of said carrier and having an open outward outlet, and means on said- 3. In a centrifugal casting machine, a ver- 4 tical rotatory column, a motor for rotating said column, a lateral arm on said column, a container on said arm for a. fluent casting material, sald contamer having an open outward outlet, means on said arm for supporting a mold in cooperative relation to, and at a downward inclination from, said container, and means for counterbalanci-ng said arm with the parts mounted thereon.

4:. In a centrifugal casting machine, a

supporting base, an upstanding 'spindle thereon, a motor sleeve rotatable on said spindle, a spring for rotating said sleeve, a tubular column rotatable on said spindle above said motor sleeve, ratchet means forengaging said sleeve and column member so that the one may be driven by the other in one direction, a releasable device for holda ing said column member from rotation, a

lateral arm on said column member, a tubular crucible disposed lengthwise on said arm and having a longitudinal opening in its forward side with respect to the direction of-rotation and a discharge opening in its outer end, and means on said arm for detachably supporting a mold in coiiperative relation to the outer end of said crucible.

. 5. In a centrifugal casting machine, a carrier rotatable in a horizontal plane, a tangentiallydisposed tubular crucible mounted on said carrier to one side of the axis thereofand having a longitudinal opening in its forward side with respect to the direction of rotation and a discharge opening at its outer end, and means-on said carrier for detachably supporting a mold in cooperative relation to the outer end of said crucible. y I

6. In a centrifugal casting machine, a carrier rotatable in a horizontal plane, a tangentially-disposed tubular crucible mounted on said carrier to one side of the axis thereof and having a discharge opening at its outer end, and means on said carrier for detachably supporting a mold in cooperative relation to, and at a downward inclination from, the outer end ofsaid crucible.

7. In a centrifugal casting machine, a carrier rotatable in a horizontal plane',-a tangentially-disposed tubular crucible mounted on said carrier to one side of the axis thereof and having a discharge opening at its outer end, and means on said carrier for detachably supporting a mold with its sprue in coiiperative relation to the dlscharge opening of said crucible and with its cavity in a zone below the sprue.

8. In a centrifugal castmg-machine, a rotatable carrier, a crucible on said carrier to. one side of the axis thereof, said crucible having an open outlet outward from the axis of said carrier and a tapered end face surrounding said-outlet, and means on said carrier for supporting an open ended mold flask endwiseagainst said tapered end face of the crucible. y

In testimony whereof, I have hereunto set my hand in presence of two subscribing witnesses.

PETER J. PANKRATZ. Witnesses:

V. B. New, ARA JALLY.

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