Feeder system

Abstract

A feeder system for metal casting comprising a feeder sleeve mounted on a tubular body. The tubular body has a first end and an opposite second end and a compressible portion therebetween so that upon application of a force in use, the distance between the first and second ends is reduced. The feeder sleeve has a longitudinal axis and comprises a continuous sidewall extending generally around the longitudinal axis that defines a cavity for receiving liquid metal during casting, the sidewall having a base adjacent the second end of the tubular body. The tubular body defines an open bore therethrough for connecting the cavity to the casting. The feeder sleeve has at least one cut-out that extends into the sidewall from the base and the second end of the tubular body projects into the cut-out to a fixed depth. The cut-out can be a groove which is separate from the cavity. The invention also resides in a process employing the feeder system.

Claims

1. A feeder system for metal casting comprising a feeder sleeve mounted on a tubular body; the tubular body having a first end and an opposite second end and a compressible portion therebetween so that upon application of a force in use, the distance between the first and second ends is reduced; the feeder sleeve having a longitudinal axis 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 adjacent the second end of the tubular body; 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 and the second end of the tubular body projects into the at least one cut-out to a fixed depth, and the feeder sleeve is supported by a portion of the tubular body that projects into the at least one cut-out and that is substantially parallel to the longitudinal axis of the feeder sleeve.

2. The system of claim 1, wherein the compressible portion consists of a single step or kink constituted by first and second sidewall regions.

3. The system of claim 2, wherein (i) the angle formed between a pair of the first and second sidewall regions is from to 60 to 90; (ii) the angle formed between the first sidewall region(s) and the longitudinal axis of the tubular body is from 30 to 60; and/or (iii) the angle formed between the second sidewall region(s) and the longitudinal axis of the tubular body is from 30 to 60.

4. The system of claim 2, wherein the step or kink of the compressible portion of the tubular body is located outside of the feeder sleeve.

5. The system of claim 4, wherein the step or kink of the compressible portion of the tubular body is spaced from the at least one cut-out.

6. The system of claim 1, wherein the compressible portion consists of an alternating series of first and second sidewall regions thereby providing multiple steps or kinks.

7. The system of claim 6, wherein the alternating series of first and second sidewall regions together form four steps or kinks.

8. The system of claim 6, wherein each of the steps or kinks has a diameter measured in a direction perpendicular to the longitudinal axis and all of the steps or kinks have the same diameter.

9. The system of claim 6, wherein each of the steps or kinks has a diameter measured in a direction perpendicular to the longitudinal axis and the diameter of the steps or kinks decreases towards the first end of the tubular body to form a frustoconical compressible portion.

10. The system of claim 9, wherein the frustoconical compressible portion is inclined from the longitudinal axis at an angle of no more than 15.

11. The system of claim 6, wherein all of the steps or kinks of the compressible portion of the tubular body are located outside of the feeder sleeve.

12. The system of claim 6, wherein the compressible portion of the tubular body projects partly into the at least one cut-out in the feeder sleeve.

13. The system of claim 1, wherein the tubular body is metal.

14. The system claim 1, wherein the at least one cut-out extends away from the base to a first depth and the tubular body projects into the at least one cut-out to the first depth.

15. The system of claim 1, wherein the at least one cut-out is a groove.

16. The system of claim 1, wherein the at least one cut-out is contiguous with the feeder sleeve cavity.

17. The system of claim 1, wherein the feeder sleeve is an exothermic feeder sleeve.

18. The system of claim 1, wherein the feeder sleeve has a crush strength of at least 25 kN.

19. A feeder system for metal casting comprising a feeder sleeve mounted on a tubular body; the tubular body having a first end and an opposite second end and a compressible portion therebetween so that upon application of a force in use, the distance between the first and second ends is reduced; the feeder sleeve having a longitudinal axis 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 adjacent the second end of the tubular body; 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 and the second end of the tubular body projects into the at least one cut-out to a fixed depth, and wherein a portion of the tubular body between the second end and the compressible portion projects into the at least one cut-out and is substantially parallel to the longitudinal axis of the feeder sleeve.

20. A process for preparing a mould comprising placing a feeder system on a pattern plate, the feeder system comprising a feeder sleeve mounted on a tubular body; the feeder sleeve comprising a continuous sidewall that defines a cavity for receiving liquid metal during casting, the sidewall having a base adjacent the tubular body; the tubular body defining an open bore therethrough for connecting the cavity to the casting, the tubular body having a first end and an opposite second end and a compressible portion therebetween, wherein a cut-out extends into the sidewall from the base and the second end of the tubular body projects into the cut-out to a fixed depth; 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 compressible portion is compressed and the distance between the first and second ends is reduced; and wherein the feeder sleeve is supported by a portion of the tubular body that projects into the cut-out and that is substantially parallel to the longitudinal axis of the feeder sleeve.

21. The process of claim 20, wherein the compacting the mould material comprises applying a ram up pressure of at least 30 N/cm.sup.2.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

(2) FIGS. 1a to 5 are schematic diagrams showing feeder systems in accordance with embodiments of the invention.

DETAILED DESCRIPTION

(3) Referring to FIG. 1a there is shown a feeder system 10 before compression. The feeder system comprises an exothermic feeder sleeve 12 mounted on a tubular body 14. The feeder sleeve 12 has a longitudinal axis Z and a continuous sidewall 16 extends generally radially around the axis to define a cavity for receiving molten metal during casting. The upper part of the feeder sleeve 12 is not shown.

(4) The tubular body 14 tapers inwardly at a first end 18 to form a feeder neck in contact with a pattern plate 20. The tubular body 14 has a second end 22 that projects into a groove 24 that extends from the base 16a of the sidewall 16. The groove 24 is separate from the cavity. The second end 22 and the groove 24 are sized and shaped to provide a friction fit, which secures the tubular body 14 in place at a fixed depth.

(5) The tubular body 14 defines an open bore therethrough for connecting the cavity to the casting in use. In this example the bore axis lies along the longitudinal axis Z.

(6) The tubular body 14 comprises two steps 26 between the first end 18 and the second end 22, which constitute a compressible portion. The steps 26 can be considered to be an alternating series of first sidewall regions 26a and second sidewall regions 26b. The first sidewall regions 26a are perpendicular to the bore axis Z and the second sidewall regions 26b are parallel to the bore axis Z. The angle between a pair of the first 26a and second sidewall regions 26b is 90. The diameter of the first and second sidewall regions decreases in a direction away from the feeder sleeve, the compressible portion can be considered to be frustoconical. The distance between the first and second ends 18, 22 of the tubular body 14 is shown as D1.

(7) Referring to FIG. 1b there is shown the feeder system 10 after compression. The application of a force along the axis Z during ram-up causes the tubular body 14 to collapse thereby reducing the distance between the first end 18 and the second end 22 to D2. The feeder sleeve 12 moves closer to the pattern 20 on ram-up.

(8) Referring to FIG. 2a there is shown a feeder system 28 before compression. The feeder system comprises the exothermic feeder sleeve 12 mounted on a tubular body 30 and a support pin 32. The tubular body 30 tapers inwardly at a first end 34 to form a feeder neck in contact with the pattern plate 20. The tubular body 30 has a second end 36 that projects into the groove 24.

(9) The top of a moulding pin 32 is located in a complementary recess 38 in the roof 40 of the sleeve 12, and on ram up, as the sleeve 12 moves downwards, the top of the moulding pin 32 pierces the thin section at the top of the roof 40. If desired a collar could be fitted in the recess 38 to avoid the risk of fragments of sleeve breaking off when the pin 32 punctures the roof 40. Alternatively a narrow aperture could extend through the roof 40 in place of the recess 38 and thereby accommodate the support pin 32. In this case the aperture would have a diameter corresponding to approximately 15% of the maximum diameter of the feeder sleeve cavity.

(10) The tubular body 30 is shown without the feeder sleeve in FIG. 2b. The tubular body 30 comprises a single outward kink 40 between the first end 34 and the second end 36, which constitutes a compressible portion. The kink 40 is formed by a first sidewall region 40a and second sidewall region 40b. The first sidewall region 40a makes an angle with the longitudinal axis Z and the second sidewall region 40b make an angle with the longitudinal axis Z. The angles and are the same (both approximately 50)-. The angle formed between the first and second sidewall regions 40a,40b is approximately 80. It will be understood that ++=180.

(11) On ram-up a force will be applied in the direction of the axis Z causing the tubular body to collapse thereby reducing the distance D1 between the first and second ends 34, 36 and reducing the angle .

(12) Referring to FIG. 3a there is shown a feeder system 42 before compression. The feeder system 42 comprises the exothermic feeder sleeve 12 mounted on a tubular body 44. The tubular body 42 tapers at a first end 46 to form a feeder neck in contact with the pattern plate 20. The tubular body 42 has an inwardly directed lip or flange 48 at its base that sits on the surface of the pattern plate 20 in use, and produces a notch in the resulting metal feeder neck to facilitate its removal (knock off). The tubular body 42 has a second end 50 that projects into the groove 24 to the full depth of the groove 24. It will be understood that a tapered groove could be employed whereby the tubular body is unable to project fully to the end of the groove where the groove becomes too narrow.

(13) The tubular body 44 comprises four inward kinks 52 between the first end 46 and the second end 50, which constitute a compressible portion. The kinks 52 are formed by an alternating series of first sidewall regions 52a and second sidewall regions 52b. The first sidewall regions 52a make an angle with the longitudinal axis Z and the second sidewall regions 52b make an angle with the longitudinal axis Z. The angles and are the same (both approximately 50). The use of two or more kinks 52 can be considered to provide a bellows-type construction. The internal angle formed between a pair of the first and second sidewall regions 52a, 52b is approximately 80. It will be understood that ++=180.

(14) Referring to FIG. 3b there is shown the feeder system 42 after compression. The application of a force along the axis Z during ram-up causes the tubular body 44 to collapse thereby reducing the distance between the first end 46 and the second end 50 to D2. The feeder sleeve 12 moves closer to the pattern 20 on ram-up.

(15) Referring to FIG. 4a there is shown a feeder system 54 before compression. The feeder system comprises an exothermic feeder sleeve 56 mounted on a tubular body 58. The feeder sleeve 56 has a longitudinal axis Z and a continuous sidewall 60 extends generally radially around the axis to define a cavity for receiving molten metal during casting. The continuous sidewall 60 has a base 60a from which a cut-out 62 extends. The end of the cut-out 62 is defined by a ledge 60b in the sidewall 60. The cut-out 62 has a width W measured in a direction perpendicular to the bore axis Z.

(16) The tubular body 58 tapers inwardly at a first end 64 to form a feeder neck in contact with the pattern plate 20. The tubular body 58 has a second end 66 that projects into the cut-out 62 and abuts the ledge 60b. The tubular body 58 and the cut-out 62 are sized and shaped so that the tubular body 58 fits snugly against the sidewall 60. The tubular body 58 defines an open bore therethrough for connecting the cavity to the casting in use. In this example the bore axis lies along the longitudinal axis Z.

(17) The tubular body 58 comprises three inward kinks 68 between the first end 64 and the second end 66 which together constitute a bellows-like compressible portion. The kinks 68 are an alternating series of first sidewall regions 68a and second sidewall regions 68b. Each of the first sidewall regions 68a make an angle with the longitudinal axis Z and each of the second sidewall regions 68b make an angle with the longitudinal axis Z. The angles and are the same (both approximately 50). The internal angle formed between a pair of the first and second sidewall regions 68a, 68b is approximately 80. It will be understood that ++=180.

(18) FIG. 4b shows the feeder system 54 after compression. The tubular body 58 collapses reducing the distance from the first end 64 to the second end 66 to D2. The kinks are compressed reducing the angle to approximately 5.

(19) FIG. 5 shows a tubular body 70 for use in combination with a feeder sleeve such as feeder sleeve 12 (FIG. 1) or feeder sleeve 56 (FIG. 4). The tubular body 70 has a first end 72 and a second end 74 and defines an open bore therethrough. The bore has a longitudinal axis Z (the bore axis). The tubular body has a compressible portion that consists of 4 inward kinks 76 having an alternating series of first 76a and second 76b sidewall regions. The compressible portion is frustoconical, the diameter of the kinks 76 decreases slightly from the second end 74 to the second end 72 i.e. the tubular body tapers inwards toward the pattern plate 20. The angle of the taper is less than 10 (measured with reference to the bore axis Z).

(20) The first sidewall regions 76a make an internal angle with the bore axis and the second sidewall regions 76b make an internal angle with the bore axis. The angle is slightly greater (approximately 60) than the angle (approximately 45). The angle between the first and second sidewall regions is approximately 75 (whether measured inside or outside the tubular body).

(21) Embodiments of the invention may be described by the following clauses:

(22) 1. A feeder system for metal casting comprising a feeder sleeve mounted on a tubular body;

(23) the tubular body having a first end and an opposite second end and a compressible portion therebetween so that upon application of a force in use, the distance between the first and second ends is reduced;

(24) the feeder sleeve having a longitudinal axis 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 adjacent the second end of the tubular body;
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 and the second end of the tubular body projects into the cut-out to a fixed depth.

(25) 2. The system of clause 1, wherein the compressible portion comprises a single step or kink constituted by first and second sidewall regions.

(26) 3. The system of clause 1, wherein the compressible portion comprises an alternating series of first and second sidewall regions thereby providing multiple steps/kinks.

(27) 4. The system of clause 3, wherein the alternating series of first and second sidewall regions together form four steps or kinks.

(28) 5. The system of any one of clauses 2 to 4, wherein (i) the angle formed between a pair of the first and second sidewall regions is from to 60 to 90; (ii) the angle formed between the first sidewall region(s) and the longitudinal axis of the tubular body is from 30 to 60; and/or (iii) the angle formed between the second sidewall region(s) and the longitudinal axis of the tubular body is from 30 to 60.

(29) 6. The system of any one of clauses 3 to 5, wherein each of the steps/kinks has a diameter measured in a direction perpendicular to the longitudinal axis and all of the steps/kinks have the same diameter.

(30) 7. The system of any one of clauses 3 to 5, wherein each of the steps/kinks has a diameter measured in a direction perpendicular to the longitudinal axis and the diameter of the steps/kinks decreases towards the first end of the tubular body to form a frustoconical compressible portion.

(31) 8. The system of clause 7, wherein the frustoconical compressible portion is inclined from the longitudinal axis at an angle of no more than 15.

(32) 9. The system of any one of the preceding clauses, wherein the tubular body is metal.

(33) 10. The system of clause 9 wherein the metal is steel having a carbon content of less than 0.05%

(34) 11. The system of any one of the preceding clauses, wherein the cut-out extends away from the base to a first depth and the tubular body projects into the cut-out to the first depth.

(35) 12. The system of any one of the preceding clauses wherein the cut-out extends away from the base to a first depth and the first depth corresponds to from 5 to 30% of the height of the feeder sleeve.

(36) 13. The system of any one of the preceding clauses, wherein the cut-out is a groove.

(37) 14. The system of any one of clauses 1 to 12, wherein the cut-out is contiguous with the feeder sleeve cavity.

(38) 15. The system of any one of the preceding clauses, wherein the compressible portion of the tubular body is spaced from the cut-out.

(39) 16. The system of any one of the preceding clauses, wherein the feeder sleeve is an exothermic feeder sleeve.

(40) 17. The system of any one of the preceding clauses, wherein the feeder sleeve has a crush strength of at least 25 kN.

(41) 18. A feeder sleeve for use in the feeder system of clause 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.

(42) 19. A process for preparing a mould comprising

(43) placing a feeder system on a pattern plate, the feeder system comprising a feeder sleeve mounted on a tubular body;

(44) the feeder sleeve comprising a continuous sidewall that defines a cavity for receiving liquid metal during casting, the sidewall having a base adjacent the tubular body;

(45) the tubular body defining an open bore therethrough for connecting the cavity to the casting, the tubular body having a first end and an opposite second end and a compressible portion therebetween,

(46) wherein a cut-out extends into the sidewall from the base and the second end of the tubular body projects into the cut-out to a fixed depth;

(47) surrounding the pattern with mould material;

(48) compacting the mould material; and

(49) removing the pattern from the compacted mould material to form the mould;

(50) wherein compacting the mould material comprises applying pressure to the feeder system such that the compressible portion is compressed and the distance between the first and second ends is reduced.

(51) 20. The process of clause 19, wherein compacting the mould material comprises applying a ram up pressure of at least 30 N/cm.sup.2.

(52) 21. The process of clause 19 or 20 wherein the compressible portion has a stepped configuration comprising an alternating series of first and second sidewall regions and compression of the compressible portion reduces the angle between a pair of first and second sidewall regions.