US2992463A

US2992463A - Centrifugal casting machine

Info

Publication number: US2992463A
Application number: US797522A
Authority: US
Inventors: Herbert R Berger
Original assignee: JF Jelenko and Co Inc
Current assignee: JF Jelenko and Co Inc
Priority date: 1959-03-05
Filing date: 1959-03-05
Publication date: 1961-07-18
Anticipated expiration: 1978-07-18

Description

July 18, 1961 H. R. BERGER 2,992,463

CENTRIFUGAL CASTING MACHINE IN VEN TOR.

A TTORNEYS July 18, 1961 H. R. BERGER 2,992,463

CENTRIFUGAL CASTING MACHINE Filed March 5, 1959 2 Sheets-Sheet 2 A M JNVENToR. @i o /rfr e/yer f BY @MM b TTONEKS United States iPatent 2,992,463 CENTRIFUGAL CASIHNG MACHINE Herbert R. Berger, Bethel, Conn., assignor to J. F. Jelenlro 8: Co., Inc., 'New York, N.Y., `a corporation of New York Filed Mar. 5, 1959, Ser. No. 797,522 3 Claims. (Cl. `22-6S.1)

This invention relates to centrifugal casting machines.

The primary object of the present invention is the provision of a centrifugal casting machine which is operable to produce metal castings of improved quality, especially in respect to the uniformity of density of each casting. Pursuant to this object of the invention, the mold or flask into which the molten metal is forciblyinjected from the furnace by centrifugal action is rotated about its own longitudinal axis which extends radially of or at right angles to 'the axis about which the furnace is rotated during the centrifugal casting operation. As a result of this rotation of the mold or flask into which the molten metal is introduced by the centrifugal action, the metal flows under pressure against successive wall portions or increments of the mold, thereby obviating uneven distribution of the metal in the mold and uneven pressure on the metal in different parts of the mold cavity.

The above and other objects, features and advantages of the present invention will be fully understood from the following description considered in connection with the accompanying illustrative drawings.

In the drawings:

FIG. l is a top plan view of a centrifugal casting machine embodying the present invention;

FIG. 2 is a view, on a larger scale, partly in velevation and partly in section on the line 2 2 of FIG. l;

FIGS. 3, 4 and 5 are vertical sectional views on the lines 3 3, ri--d and 5--5, respectively, of FIG. 2;

FIG. 6 is a fragmentary horizontal plan view, partly in section, on the line 6-6 of FlG. 2;

FIG. 7 is a fragmentary sectional View, on a larger scale, on the line 7-7 of FIG. 6;

FIG. 8 is a fragmentary side elevational view showing another form of the invention;

FIG. 9 is a vertical sectional view on the line 9-9 `of FIG. 8;

FIG. l is a horizontal View, partly in section, on the line iti-l0 of FIG. 8;

FlG. ll is a vertical sectional view of the flask and a companion removable auxiliary device utilized when forming the mold cavity in the flask; and

FIG. l2 is a top plan View of said auxiliary device.

Referring now to the drawings in detail, the centrifugal casting machine is preferably of the construction illustratecl and described in United States Patent No. 2,752,650, issued to 'the assignee of my present application, but it will be understood that the present invention is not limited in its application to a centrifugal casting machine of the specific construction or operation disclosed in said patent. Briefly described, the centrifugal casting machine includes an electrically heated furnace l0 which is fixed to a bar l2 which is rotated by the shaft i4 of a spring motor M. More particularly, the intermediate or hub portion 16 of said bar is connected for rotation to said shaft 14 by a transverse pin i8 fixed to said shaft and releasably engaging hub portion 16 in a notch 19, and a removable clamping screw 2G is threaded on the upper end portion of the shaft and engages the hub i6 of the bar for releasably holding said bar securely connected to the shaft. The furnace lil is preferably provided with a carbon crucible 22 of the type shown by my United States Patent No. 2,375,463. 4Said Crucible is provided with a sprue 24 through which the molten metal flows by cenice trifugal action from the Crucible 22 to the mold orflask 26 when bar l2. is rotated by motor M.

in accordance with the present invention, the liask or mold 26 is mounted for rotation about its longitudinal axis which extends radially of the axis of shaft 14, so that during the rotation of furnace 1d in the centrifugal casting operation of the machine, the ask 26 can be rotated about its own longitudinal axis whereby the molten metal which flows into the flask by centrifugal force is distributed evenly and under uniform pressure throughout the mold cavity, thereby greatly improving the uniform density of the casting in the mold.

The provision for mounting the liask 26 for rotation about its own axis and as a unit with the furnace 10 about the axis of shaft i4 comprises a flask holder 28 which is carried by a stub shaft or spindle 3l) journalled for rotation in a bracket 32 which is preferably provided with a ball or other anti-friction bearing 34. Bracket 32 is mounted for sliding movement on bar 12 and for that purpose has a lower bifurcated portion 36 which snugly engages the opposite sides of the bar and which is provided with guide rollers 3S which engage the lower edge of said bar. The flask holder 28 is held releasably, but firmly, in engagement with the outer end of liask 26 by means of a tension spring 40 which is secured at one end 42 thereof to the bar l2 and which is secured Vat its other end dd to the counterweight 46 which is adjustably positioned on the rods i3 which are fixed to the slideable bracket 32.

The inner end of flask 26 is releasably secured to a plate 5t) which is fixed to and rotated by a gear 52. The detachable connection between the inner end of flask 26 and plate 50 is constituted, as here shown, by pins 54 which are fixed to the peripheral wall of said ask in circumferentially spaced relation and engage plate 50 in openings 56. As best shown in FIG. 2, the forward surface of fiask holder 28 is conical and is preferably provided with a plurality of annular flat portions 29 in axial spaced relation and of different circumferential dimensions for engagement by flasks of different diameters, respectively. Similarly, rotary driving plate Sli is provided with openings nearer the axis of its rotation than openings 56 to receive the pins Se of the smaller flask.

Mechanism is provided for rotating plate 50 automatically in response to the rotation of the furnace 16' for the casting operation. Said mechanism comprises a gear 52 journalled for rotation on the hub 53 which is fixed to and projects from the apertured end wall 6i) of furnace ill) through which the sprue of the Crucible projects into the mold. Gear 52 is rotated automatically when bar 12 is rotated by motor M for the centrifugal casting operation of the machine. For this purpose and in accordance with the presently preferred form of this invention, an internal stationary gear 62 is fixed to the top of the housing '6d of the motor M and meshes with `a gear 66 for rotating a shaft 5S which projects through and is journalled for rotation in bar l2 (FGS. 2, 6 and 7). The upper end of rotary shaft 6d is provided with a bevel gear '7d which meshes with a companion bevel gear 72 for rotating a shaft 7d mounted for rotation in bearings 76 and Til carried by bracket Sli fixed to the top of bar l2. Shaft 74 is provided with a gear 82 which meshes with gear S2 for rotating said gear and thereby rotating flask 26 about its longitudinal axis.

It will be understood that the spring motor M is wound up by rotating bar l2 by hand, when the electrical movable contact member 7l is retracted from engagement with the companion stationary contact device '71a by the finger piece 73 as described in the above mentioned patents. After the motor is wound, the contact member 7l is projected into engagement with the contact device 71a to energize the heater winding (not shown) and to hold the furnace stationary until the metal in the furnace becomes molten and the temperature of the molten metal is at the desired value.

In the form of the invention illustrated in FIGS. 8 to 10, the construction is substantially the same as described above, except that a sprocket gear 52a is used instead of the gear 52 and is rotated by a sprocket chain 84 which is driven by a sprocket wheel 86 fixed to a rotary shaft 88. Also, in this form of the invention, a stationary bevel gear 90 which is fixed to the top of the motor housing is used instead of the internal stationary cylindrical gear 62 and said bevel gear 90 meshes with a companion bevel gear 92 for driving shaft 88. It will be observed that said shaft 88 is fixed to the bar 12 so that as said bar is rotating during the centrifugal casting operation, shaft 88 is rotated and drives sprocket gear 52a which rotates the flask 26.

Referring to FIGS. 2, 11 and 12, it will be observed that the flask 26 is provided with a recess 94 which is in communication with the outlet end of the sprue 24 of the crucible when the flask is in posi-tion, and it will be observed that this recess 94 is wider at an intermediate portion thereof than at its inlet end. This lateral enlargement of the intermediate portion of recess 94 provides additional space to receive molten metal from the Crucible of the furnace in order to obviate any tendency of molten metal to escape at the joint between the flask and the plate 50. As illustrated by FIGS. 11 and l2, the recess 94 is formed by the integral projection 96 of the llexible auxiliary device 98 which is formed of rubber or other suitable material. This auxiliary device includes an inner integral rim 100 which fits within the opening in the bottom of the flask, as illustrated by FIG. ll, when the flask is positioned on said auxiliary device for mounting the wax pattern 102 and for providing the llask 26 with the refractory material 104 in which the mold cavity is formed when the wax is removed by heat in the usual way. As here shown, the central part of the auxiliary device 98 is provided wit-h an opening 106 in which a rod 108 is removably positioned for supporting the wax pattern 102 while the plaster or other refractory material is poured into the llask around the pattern. Also, it will be understood that removable rod 108 which supports the wax pattern 102 forms a sprue opening in communication with recess 94 and with the mold cavity, formed after the wax pattern is melted out, for the flow of molten metal into the mold cavity. The base of the auxiliary device 98 is provided with recesses 110 to receive the projecting ends of the ilask pins 54. Said base is also provided with an outer rim or flange 112 which is engaged by the outer surface of flask 26, when the flask is of a larger size, and in such case, the pins 54, instead of being on the outer surface of the ask, are disposed on the inner surface thereof and the same recesses 110 are to receive the pins of such larger flask. Thus, the auxiliary device 98 is designed to be used with flasks of two different diameters, the flask of smaller diameter having the pins 54 on the outside and the flask of larger diameter having said pins on the inside thereof. It will be understood that after the refractory plaster hardens, device 98, being flexible, may be readily removed from the end of the flask, and thereafter the wax may be melted out to form the mold cavity in the usual way.

While I have shown and described the preferred embodiment of my invention including two different forms thereof, it will be understood that the invention may be embodied otherwise than as herein specifically shown or described and that in the illustrated forms of the invention, certain changes in the details of construction and in the arrangement of parts may be made without departing from the underlying idea or principles of this invention within the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is: 1. yIn a centrifugal casting machine, a rotary horizontal bar mounted for rotation about a vertical axis, means for rotating said bar, said bar being manually operable for energizing said rotating means for the casting operation, a furnace and a mold carried by said bar at one side of said vertical axis, said mold being mounted adjacent to said furnace at one end thereof and in communication therewith at said one end so that said furnace and said mold are rotatable as a unit with said bar about said vertical axis for the transfer of the molten material from the furnace to the mold for the centrifugal casting operation, means mounting said mold for rotation in relation to said furnace about an axis transverse to said vertical axis, and mechanism operatively connected to said mold for rotating said mold about said transverse axis concurrently with the rotation of said furnace and mold as a unit about said vertical axis, said mechanism comprising a stationary gear co-axial with said vertical axis and companion movable gearing carried by said bar operatively connecting said stationary gear to said mold, said companion movable gearing being rotatable as a unit with said furnace and mold about said vertical axis and being operated by the rotation of said bar, whereby said bar rotating means is operable to concurrently rotate said mold about said vertical and transverse axes for the casting operation simultaneously with the rotation of said furnace and bar about said vertical axis, said movablel gearing including a gear mounted for rotation on said furnace adjacent said one end of said mold and disposed between said furnace and said mold, said furnace mounted gear having an aperture positioned axially thereof to permit flow therethrough of the molten metal from said furnace to said mold for the casting operation.

2. A centrifugal casting machine according to claim 1, wherein said stationary gear comprises an internal cylindrical gear, and a rotary gear is carried by said bar `and is in mesh with said stationary gear and is mounted on a vertical shaft which is journalled for rotation in said bar, and said vertical shaft has a gear which is positioned above said bar and is operatively connected to said gear on said furnace.

3. In a centrifugal casting machine, a rotary horizontal bar mounted for rotation about a vertical axis, spring motor means connected to said bar for the rotation thereof, said bar being manually operable for energizing said spring motor means for the casting operation, a furnace and a mold carried by said bar at one side of said vertical axis, said mold being mounted adjacent to said furnace at one end thereof and in communication therewith at said one end so that said furnace and said mold are rotatable as a unit with said bar about said vertical axis for the transfer of the molten material from the furnace to the mold for the centrifugal casting operation, means mounting said mold for rotation in relation to said furnace about an axis transverse to said vertical axis, and mechanism operatively connected to said mold for rotating said `mold about said transverse axis concurrently with the rotation of said furnace and mold as a unit about said vertical axis, said mechanism comprising a stationary gear co-axial with said vertical axis and companion movable gearing carried -by said bar operatively connecting said stationary gear to said mold, said companion movable gearing being rotatable as a unit with said furnace and mold about said vertical axis and being operated by the rotation of said bar, whereby said spring motor means is operable to concurrently rotate said mold about said vertical and transverse axes for the casting operation simultaneously with the rotation of said furnace Iand bar about said vertical axis, said movable gearing including a gear mounted for rotation on said furnace adjacent said one end of said mold and disposed between said furnace and said mold, said furnace mounted gear having an aperture positioned axially thereof to permit flow therethrough of the molten metal from` said furnace to said mold for the casting operation.

(References on following page) 5 6 References Cited in the file of this patent 2,433,065 Rubissow Dec. 23, 1947 UNITED STATES PATENTS 2,752,650 Bosna July 3J 1956 1,496,429 Pollen June 3, 1924 FOREIGN PATENTS