US1496429A - Dental casting machine - Google Patents

Description

AQAES? POLLEN Jun@ 3 B924, C. O.

DENTAL CASTING MACHINE Filed July 24, 1922 Patented lune 3, 19243.

D rArEs CLARENCE O. POLLEN, F TACOMAP WASHINGTON.

DENTAL CASTING MACHINE.

application med July 24,

To all whom t may concern Be it known that I, CLARENCE O. POLLEN, a citizen of the UnitedStates, and a resident of Tacoma, county of-Pierce, and State of Washin and useful mprovements in Dental Casting Machines, of which the following is a specification.

This invention relates to improvements in machines for dental casting, and more particularly to machines of that character which utilize the principle of centrifugal force for distributing the metal properly within the mould.

It is known that machines for the above purpose, which utilize the principle of Centrifugal force, are already in use, such machines comprising a mould and a Crucible th-at are mounted on a supporting arm' which is revolved in such manner that the metal will be caused to flow from thecrucible into the mould. In such machines, there are several disadvantages; the principal one being that the metal is force by the centrifugal force to the outer end of the mould and consequently builds up faster there than it does toward the inner part of the mould, thereby causing the walls of the mould to be distorted to such an extent'that it is often necessary to make. a new impression.

lt is the principal object of this invention to improve upon the machines, as above stated, and to thereby overcome the disadvantages as noted, by the provision of additional means whereby the Castin mould will be rotated at a high rate wlthin its supports to cause the metal delivered thereinto to be distributed equally. to all parts thereof while, at the same time, the support, the crucible and mould will be revolved only at such rate of speed that is' suicient to thereby Cause the casting metal l to be delivered-into the mould.

ln accomplishing these and other objects of the invention, l have provided the improved details of construction, the preferred forms of which are illustrated in the accompanying drawings, wherein- Figure 1 is a side view, partly in section, of a dental casting machine constructed in accordance with the present invention.

Figure 2 is a plan view of the same. Referring more in detail to the drawingsj 1 designates a base plate and 2 a gear on, have invented certain new 1922. Serial No. 577,064.

housing mounted thereon; the latter having .a vertical shaft 3 revolubly supported therein and equipped with a gear 4 that operates in mesh with a larger driving gear wheel 5 fixed on a supporting shaft 6 to which a prank 7 is attached,` and whereby vthe gear 5\may vhe rotated to effect rotation of the shaft 3. The upper end ofthe shaft 3 extends through a sleeve 8 that is fixed within the housing and which, at its upper end, has a beveled gear wheel 9 non-rotatably fixed thereto. I

Secured to the upper end of the shaft 3, isa horizontal arm 1() having a Counterbalancing weight 11 adjustably fixed onone end thereof and having a casting mould mounted at the opposite end. The mould comprises a Cylindrical 'Casing 12 clamped at its opposite ends, between supporting discs 13 and 14; the former havin@ a hollow hub portion 15 rotatably mounted within a supporting bracket 16 that is adjustable along the arm and which may be locked at adjusted positions by means of a set screw 17 threaded through the bracket and against the arm. The disc 14 has a supporting shaft 20 mounted revolubly within a standard 22 at the end ofthe arm 10, and, provided at its outer end with a gear wheel 23 that operates in mesh with a similar gear 24 fixed to the outer end of a shaft 25 that extends parallel with and beneath the arm 10, and which, at its inner end, has a beveled gear 27 operating in mesh with the non-rotatable gear Wheel 9. The shaft 25 is revolubly supported in bearings 28 and 29 formed as a part of the arm 10.

The hub portion 15, which supports-the disk 13, is hollow and, extending therethrough, is a spout 32 of a' Crucible 33 ,Y wherein metal for the casting purpose may be melted; the cruCible being supported within a seat 34 formed as a part of the bracket 16.

Assuming that the machine is so Constructed, to use the same, first, the investment is properly made within the mould and this will have a sprue opening leading to the hub 15, of the disc 13, so that the metal may flow thereinto from the spout of the Crucible. The metal is then melted in the Crucible by means of a blow torch and when it is in the proper form the parts are set in motion by turning the crank 7. This causes the entire mould and Crucible to be revolved about the shaft 3, while at the same time the mould 12 is rotated on its supporting axis by means of the gear connection provided; itbeing apparent that since the gear`wheel 9 is ixed, the gear 27 will be caused to rotate as it is carried about the shaft 3 .and this, in turn, will effect rotation of the gears 24 and 23, and the casting mould connected with the latter. When the mould is revolved at sufiicient Speed, the molten metal will be carried, by centrifugal force, from the crucible into the sp1-ue opening of the investment and will fill the mould. At the same time the mould is revolved it is rotated, and this eii'ccts an equal distribution of the metal over all parts of the investment. The gearing ratio is such that the rate of rotation of the Crucible and mould would be only suiiicient to cause a flow of metal from the crucible into the mould while the rate of rotation of the mould would be much faster so as to cause the centrifugal `force of the metal away from the center of the mould to, overcome its centrifugal force with respect to the supporting shaft 3.

It is readily apparent that by the use of n machine of this character, any building up of the metal at the outer portion of the mould will be overcome and that, in this way, the distortion of the Walls of the mould is eliminated.

It. is possible t0 obtain this result by mechanism not like that shown and, for

ramene y ,g this reason, do not wish to be limited only l. A casting machine of the class del scribed, comprising a rotatable su ortng shaft, an arm fixed to extend laterally. from the shaft, a casting mould rotatably fixed on said arm having an end opening, a crucible adjustable on the arm at the inner side of the mould, having a delivery spout extended into registration with said mould opening, means for rotatin the supporting shaft to revolve themou d and Crucible, and means for rotating the ,mould while being revolved by said arm.

2. A casting machine comprisin a rotatable supportin shaft, an arm x extend laterally From the shaft, a casting mould rotatably fixed on said arm having an end opening, a Crucible having a delivery spout into registration with said mould opening, a gear fixed concentric to the supporting shaft, a gear on the supporting axis of the mould and .a driving shaft rotatably supported from the arm having gears thereon meshing with the first gear and the mould gear, and means for rotating the supporting shaft.

Signed at Seattle, Washington, this 18th day of July, 1922.

CLARENCE 0. POLLEN.

ed tol

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