FEEDER SYSTEM

Abstract

A feeder system for metal casting comprising a feeder sleeve mounted on a tubular body. The feeder sleeve has a first end and a second end and a longitudinal axis extending generally between said first and second ends. The feeder sleeve comprises a continuous sidewall that extends generally around the longitudinal axis that defines a cavity for receiving liquid metal during casting and the sidewall has a base at the first end of the feeder sleeve. The tubular body defines an open bore therethrough for connecting the cavity to the casting in use. The feeder sleeve comprises at least one cut-out that extends into the sidewall from the base to a first depth and the tubular body projects into the cut-out to a second depth, the tubular body having at least one abrading region in contact with a surface of the feeder sleeve within the cut-out. The second depth is equal to or less than the first depth so that upon application of a force in use the abrading region abrades the surface of the feeder sleeve with which it is in contact such that the tubular body is pushed towards the second end. The invention also resides in a feeder sleeve for use in the system and a process for preparing a casting mould employing the system.

Claims

1. A feeder system for metal casting comprising a feeder sleeve mounted on a tubular body; the feeder sleeve having a first end and a second end and a longitudinal axis extending generally between said first and second ends, and comprising a continuous sidewall extending generally around the longitudinal axis that defines a cavity for receiving liquid metal during casting, the sidewall having a base at the first end of the feeder sleeve; the tubular body defining an open bore therethrough for connecting the cavity to the casting, wherein at least one cut-out extends into the sidewall from the base to a first depth and the tubular body projects into the cut-out to a second depth, the tubular body having at least one abrading region in contact with a surface of the feeder sleeve within the cut-out and the second depth being equal to or less than the first depth so that upon application of a force in use the abrading region abrades the surface of the feeder sleeve with which it is in contact such that the tubular body is pushed towards the second end, wherein the cut-out is a groove in the sidewall.

2. The system of claim 1, wherein the groove is inwardly tapered towards the second end of the feeder sleeve.

3. The system of claim 1, wherein the cut-out is castellated.

4. The system of claim 1, wherein retaining means are employed to hold the tubular body in position at the second depth within the cut-out.

5. The system of claim 4, wherein (i) the abrading region constitutes the retaining means; (ii) the cut-out and the tubular body are sized such that the retaining means is a friction fit; and/or (iii) the tubular body is releasably fixed to the feeder sleeve by adhesive.

6. The system of claim 1, wherein the abrading region comprises at least one outward projection which abuts the feeder sleeve within the cut-out.

7. The system of claim 6, wherein the projection is a fin.

8. The system of claim 1, wherein the abrading region comprises (i) at least one sharp edge or (ii) at least one sharp point.

9. The system of claim 1, wherein the tubular body is a metal tubular body or a plastics tubular body.

10. The system of claim 9, wherein the metal is steel with a carbon content of less than 0.05% by weight.

11. The system of claim 1, wherein the feeder sleeve has a height measured along the longitudinal axis and the first depth corresponds to 10 to 40% of the height.

12. The system of claim 1, wherein the feeder sleeve has a crush strength of at least 20 kN.

13. A feeder sleeve for use in the feeder system of claim 1, the feeder sleeve having a longitudinal axis and comprising a continuous sidewall extending generally around the longitudinal axis and a roof extending generally across the longitudinal axis, the sidewall and roof together defining a cavity for receiving liquid metal during casting, wherein the sidewall has a base spaced from the roof and a groove extends from the base into the sidewall.

14. A process for preparing a mould comprising placing the feeder system of claim 1 on a pattern plate, the feeder system comprising a feeder sleeve mounted on a tubular body; the feeder sleeve having a first end and a second end and a longitudinal axis extending generally between the first and second ends, the feeder sleeve comprising a continuous sidewall extending generally around the longitudinal axis that defines a cavity for receiving liquid metal during casting, the sidewall having a base at the first end of the feeder sleeve; the tubular body defining an open bore therethrough for connecting the cavity to the casting, wherein a cut-out extends into the sidewall from the base to a first depth and the tubular body projects into the cut-out to a second depth, the second depth being equal to or less than the first depth, and the tubular body having at least one abrading region in contact with a surface of the feeder sleeve within the cut-out; surrounding the pattern with mould material; compacting the mould material; and removing the pattern from the compacted mould material to form the mould; wherein compacting the mould material comprises applying pressure to the feeder system such that the abrading region abrades the surface of the feeder sleeve with which it is in contact such that the tubular body is pushed towards the second end of the tubular body.

15. The process of claim 14, wherein the second depth is less than the first depth such that compacting the mould material causes the tubular body to abrade the sides of the cut-out and move further into the cut-out to a third depth.

16. The process of claim 14, wherein the second depth is equal to the first depth such that compacting the mould material causes the tubular body to abrades the feeder sleeve at a base of the cut-out, effectively making the cut-out deeper.

17. The process of claim 14, wherein compacting the mould material comprises applying a ram-up pressure of at least 30N/cm2.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

[0072] FIG. 1 is a schematic diagram of a feeder system in accordance with an embodiment of the invention;

[0073] FIG. 2a is a schematic diagram of a feeder system in accordance with another embodiment of the invention. FIG. 2b is the tubular body from the feeder system of FIG. 2a;

[0074] FIG. 3a is a tubular body for use the feeder systems of FIG. 3b and FIG. 3c;

[0075] FIG. 4a is a tubular body for use in a feeder system in accordance with the invention, and FIG. 4b is a top view of the tubular body showing a circular cross section.

[0076] FIG. 5a shows a feeder sleeve for use in the feeder system of FIG. 5b.

DETAILED DESCRIPTION

[0077] Referring to FIG. 1 there is shown a feeder system 10 comprising a feeder sleeve 12 having a strength of 8-12 kN mounted on a tubular body 14. The feeder sleeve 12 has a continuous sidewall 16 which extends generally around a longitudinal axis Z; the sidewall 16 defines a cavity for receiving molten metal in use. The sidewall has a base 16a from which a groove 18 having parallel sides extends to a depth D1. The groove 18 is separate from the cavity.

[0078] The tubular body 14 is pressed from sheet steel and defines an open bore therethough (the bore axis lies along the longitudinal axis Z). The tubular body 14 tapers at its end away from the feeder sleeve to form a feeder neck 20 in contact with a moulding pattern plate 22. The opposite end 24 of the tubular body is sharpened to form a circular blade that projects into the groove 18 and is in contact with the feeder sleeve 12. The tubular body 14 projects to the full depth of the groove (D2=D1). On ram-up the sharpened end 24 of the tubular body 14 cuts into the feeder sleeve 12, thereby increasing the depth of the groove to D3 (shown in dotted lines) and allowing the feeder sleeve to move closer to the casting.

[0079] The top of a moulding pin 26 is located in a complementary recess 28 in the roof 30 of the sleeve 12, and on ram up, as the sleeve 12 moves downwards, the top of the moulding pin 26 pierces the thin section at the top of the roof 30. If desired a collar could be fitted in the recess 28 to avoid the risk of fragments of sleeve breaking off when the pin 26 punctures the roof 30. Alternatively a narrow aperture could extend through the roof 30 in place of the recess 28 and thereby accommodate the support pin 26. In this case the aperture would have a diameter corresponding to approximately 15% of the maximum diameter of the feeder sleeve cavity.

[0080] Referring to FIG. 2a there is shown a feeder system 32 comprising a feeder sleeve 34 having a strength of at least 20 kN mounted on a tubular body 36. The feeder sleeve 34 has a continuous sidewall 38 which extends generally around a longitudinal axis Z to define a feeder sleeve cavity. The sidewall has a base 38a and a tapered groove 40 extends from the base to a first depth D1. The groove 40 has its maximum width at the base 38a.

[0081] The tubular body 36 is pressed from sheet steel and defines an open bore therethough (the bore axis lies along the longitudinal axis Z). The tubular body 36 tapers at its end remote from the feeder sleeve to form a feeder neck 42 and has an inwardly directed lip or flange 44 at its base that sits on the surface of the pattern plate 22. In use, this produces a notch in the resulting metal feeder neck to facilitate its removal (knock off). The opposite end 46 of the tubular body projects into the groove 40 to a second depth D2. The tubular body 36 is held in place by four fins 48 which project from the sides of the tubular body and make contact with the feeder sleeve 34 within the groove 40. A cross-section of the tubular body 36 is shown in FIG. 2b. The fins 48 are sharpened to provide an abrading region and also serve as retaining means.

[0082] On ram-up, a force is applied in the direction of the axis Z and the fins 48 scrape against the sides of the feeder sleeve within the groove 40. The tubular body 36 is pushed further into the groove 40 to a depth D3 (D3<D1).

[0083] Referring to FIG. 3a there is provided a tubular body 50 for use in a feeder system of the invention. The tubular body 50 tapers inwardly at a first end to form a feeder neck 52. The main sidewall 56 of the tubular body is frustoconical, tapering outwardly toward the second end 54. The end 54 serves as an abrading region in use and can be sharpened if desired.

[0084] Referring to FIG. 3b the feeder sleeve 34 (as in FIGS. 2a-2b) is mounted on the tubular body 50 to provide a feeder system. The outwardly tapering end of the tubular body 50 projects into the groove 40 to a depth D2. The outward taper ensures that the tubular body 50 contacts the sides of the groove 40 and thereby provides a friction fit. On ram-up the tubular body 50 is pushed further into the groove 40 to a depth D3 (D3<D1) and the end 54 abrades the surface of the feeder sleeve 34 within the groove 40.

[0085] Referring to FIG. 3c a feeder sleeve 58 is mounted on the tubular body 50 to provide a feeder system. The feeder sleeve 58 has a continuous sidewall 60 which extends generally around a longitudinal axis Z; the sidewall 16 defines a cavity for receiving molten metal in use. The sidewall has a base 60a from which a cut-out 62 extends to a depth D1. The end of the cut-out 62 is defined by the ledge 34a. The cut-out 62 is contiguous with the feeder sleeve cavity and has a width W measured radially from the axis Z. The outwardly tapering end 54 of the tubular body projects into the cut-out 34 to a depth D2. The outward taper ensures that the tubular body 50 contacts the side of the cut-out 34 and thereby provides a friction fit. On ram-up the tubular body 50 is pushed further into the cut-out 34 to a depth D3 (D3<D1) and abrades the surface of the feeder sleeve 58 within the cut-out.

[0086] Referring to FIG. 4a there is provided a cross-section of a tubular body 64. As previously, the tubular body tapers at one end to form a feeder neck 66. The opposite end of the tubular body 64 is folded inwardly to form an overlap 68. The overlap 68 provides an abrading surface. FIG. 4b provides a top view of the tubular body which shows a circular cross-section. The tubular body 64 can be employed with a feeder sleeve having a groove (including parallel or tapered) so that it partially projects into the groove.

[0087] FIG. 5a shows a view from below of a feeder sleeve 70 for use in a feeder system. The feeder sleeve has a circular cross section and comprises a continuous sidewall 72 that defines a cavity. The base 72a of the sidewall has a cut-out 74 of non-uniform depth, which is castellated. Alternating first regions 74a and second regions 74b have a depth of D1 and (D1+x) respectively, as measured from the base 72a.

[0088] FIG. 5b shows a feeder system comprising the feeder sleeve 70 mounted on a tubular body 76. At one end, the tubular body 76 tapers in two stages to form a feeder neck 78 (which has a different profile from that shown in other embodiments). The feeder neck 78 is thought to provide additional rigidity to the tubular body. The opposite end of the tubular body has a sharp end 80 that projects into the feeder sleeve so that the sharp end 80 abuts the first regions 74a of the cut-out 74 at a depth D1. On ram-up, the tubular body 68 cuts further into the feeder sleeve material and the presence of the deeper cut-outs makes the feeder sleeve easier to abrade.