CASTING SLEEVE WITH WILLIAMS CORE

Abstract

A sleeve (110) for use in metal casting has a sleeve body, where a longitudinal axis (B) has a side wall (116) formed around it, defining a sleeve interior. The sleeve body is open at a first end (118). A core (120) is formed integrally along an interior surface extends into the sleeve interior. The sleeve body and the core are formed of a gas-permeable refractory material. At least the core contains material for generating heat when heated by a molten metal. The core extends along the side wall from the first end to a second end. The core has a width that is constant or decreases in a radial direction away from the side wall, especially with a triangular profile, with a base thereof in contact with the side wall. The sleeve body is cylindrical or frustoconical, with a diameter that decreases from the open first end.

Claims

1. A sleeve for use in metal casting, comprising: a sleeve body having a longitudinal axis around which is formed a side wall that defines an interior of the sleeve, the sleeve body being open at a first end thereof; and a core, formed integrally along an interior surface of the side wall and extending into the sleeve interior.

2. The sleeve of claim 1, wherein: the sleeve body and the core that extends into the sleeve interior are each formed of a gas-permeable refractory material.

3. The sleeve of claim 2, wherein: at least the core comprises material selected for generating heat when heated by a molten metal.

4. The sleeve of claim 1, wherein: the core extends along the side wall of the sleeve body from the first end to a second end thereof.

5. The sleeve of one of claim 1, wherein: the core has a width that is constant or decreases in a radial direction away from the side wall.

6. The sleeve of claim 5, wherein: the core has a triangular profile, with a base thereof in contact with the side wall.

7. The sleeve of claim 1, wherein: the sleeve body is frustoconical, with a diameter that decreases from the open first end to a second end thereof.

8. The sleeve of claim 1, further comprising: a cover, sized and adapted to close the sleeve body at a second end thereof.

9. The sleeve of claim 1, further comprising, a cover, formed integrally with the sleeve body at a second end thereof.

10. The sleeve of claim 9, wherein: the cover is provided with at least one aperture therethrough.

11. The sleeve of claim 9, wherein: the cover comprises a gas-permeable refractory material and, optionally, material selected for generating heat when heated by a molten metal.

12. The sleeve of claim 8, wherein: the cover is provided with at least one aperture therethrough.

13. The sleeve of claim 8, wherein: the cover comprises a gas-permeable refractory material and, optionally, material selected for generating heat when heated by a molten metal.

14. The sleeve of claim 3, wherein: the core extends along the side wall of the sleeve body from the first end to a second end thereof.

15. The sleeve of claim 3, wherein: the core has a width that is constant or decreases in a radial direction away from the side wall.

16. The sleeve of claim 15, wherein: the core has a triangular profile, with a base thereof in contact with the side wall.

17. The sleeve of claim 3, wherein: the sleeve body is frustoconical, with a diameter that decreases from the open first end to a second end thereof.

18. A sleeve for use in metal casting, comprising: a sleeve body having a longitudinal axis around which is formed a side wall that defines an interior of the sleeve, the sleeve body being frustoconical, with a diameter that decreases from an open first end to a second end thereof; and a core, formed integrally along an interior surface of the side wall and extending into the sleeve interior, the core having a triangular profile, with a base thereof in contact with the side wall wherein each of the sleeve body and the core are formed of a gas-permeable refractory material, with at least the core further comprising material selected for generating heat when heated by a molten metal.

19. A method of preparing a mold for casting a molten metal, comprising the steps of: providing a sleeve according to claim 1; providing a vertically-split mold; inserting the sleeve in a first part of the vertically-split mold, such that an axis of the sleeve lies horizontally in the mold when the mold is oriented to receive the molten metal, with the core of the sleeve positioned to be gravitationally above a reservoir of the molten metal reservoir formed in the sleeve by a pour of the molten metal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] A better understanding of the disclosed embodiments will be obtained from a reading of the following detailed description and the accompanying drawings wherein identical reference characters refer to identical parts and in which:

[0018] FIG. 1 is a side sectional view of a blind feeder sleeve with a Williams core, as known in the prior art;

[0019] FIG. 2 is a side sectional view of an exemplary embodiment of a sleeve having a Williams core, arranged in the same manner as the FIG. 1 sleeve; and

[0020] FIG. 3 is a perspective view of a section of the FIG. 2 embodiment sleeve, rotated to show the sleeve with a longitudinal axis arranged horizontally.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

[0021] FIG. 1 shows a side-sectional view of a typical blind feeder sleeve 10 with a Williams core 12, in the manner generally taught by Trinkl in the prior art. This sleeve 10 has the Williams core 12 integrally formed as a part of the cover 14. The sleeve 10 has a longitudinal axis A, with a side wall 16 that is preferably symmetrical about the axis. In the depicted embodiment, the side wall 16 appears to be somewhat frustoconical, with the larger diameter at the open lower end 18. However, it would also be known to provide a cylindrical sidewall 16. The blind feeder sleeve 10 is arranged with the axis A aligned in a vertical direction, facilitating outflow through open lower end 18 of the molten metal contained therein. Although not shown in FIG. 1, it would be known to provide one or more vent apertures through cover 14 to enhance the gas-permeability of the material comprising the sleeve 10.

[0022] If the FIG. 1 embodiment 10 were to be placed in a mold with the axis A aligned in a horizontal manner (rather than the illustrated vertical manner), the beneficial effect of the Williams core 12 would be lost.

[0023] FIG. 2 shows, in side-sectional view, an embodiment that incorporates the concept of a Williams core for a feeder sleeve 110 that can be used with effect in a horizontal position. The sleeve 110 has a cover 114 and a side wall 116. As in the prior art example provided in FIG. 1, and subject to an exception required by the Williams core that will be described, the side wall 116 is designed for symmetry about a longitudinal axis. In this case, the axis is designated as B. To facilitate comparison with the prior art, the sleeve 110 in FIG. 2 is shown in the same orientation as the FIG. 1 sleeve. It can thus be seen that the side wall 116 can have a frustoconical or cylindrical design. The cover 114, which is needed in the prior art to provide a base for the Williams core, is not needed for that purpose in the FIG. 2 sleeve 116. Opposite the cover 114 is an open end 118, which is substantially the same as the open lower end 18 of the FIG. 1 prior art. The cover 114 can be either formed integrally with the sidewall 116 or it can be separately formed in a size to fit into an otherwise open second end of the sleeve 110.

[0024] While continuing to consider FIG. 2, FIG. 3 is now introduced as a section view of the FIG. 2 embodiment 110 that allows a view down the longitudinal axis B. In these views, it is readily seen that a portion 120 of the side wall 116 has been formed to project in a radial direction into the interior of the sleeve 110. As shown, the portion 120 extends in the longitudinal direction essentially from the cover 114 to the open end 118. In the depicted embodiment, the portion 120 is shaped as a wedge, with the larger base of the wedge formed along the side wall 116. The portion 120 need not be a wedge, but it is preferred for the portion to have a constant profile along the entire length that extends from the cover 114 to the open end 118. The portion 120 also does not need to decrease in width in the manner shown in FIGS. 2 and 3, but it is preferred that the width does not increase as one moves from the side wall towards the longitudinal axis.

[0025] When the portion 120 that exemplifies the features of a Williams core is integrally formed during manufacture of the sleeve 110, it will have essentially the same properties of gas-permeability, exothermicity, etc. as that provided by the side wall 116 of the sleeve. However, the projection of the portion 120 into the interior space defined by the side wall 116 provides the improvement over a sleeve lacking the Williams core structure.

[0026] As also seen in FIGS. 2 and 3, the cover may be provided with one or more vent apertures 122. In the embodiment of FIGS. 2 and 3, there are two vent apertures 122 provided and they are placed near the portion 120.

[0027] When placed into a sand mold where the longitudinal axis needs to be arranged horizontally, the preferred orientation for the embodiment 110 is shown in FIG. 3. In this situation, the portion 120 is positioned at the top or 12 o'clock position, so that it is gravitationally above the molten metal reservoir formed in the sleeve 110 by the pour.