Feeder element
An elongate collapsible feeder element for use in metal casting and a feeder system with attached feeder element and feeder sleeve. The feeder element has an A end and an opposite B end measured along the height, and a C end and an opposite D end measured along the length. The A end is for mounting on a mold pattern or swing plate and the opposite B end is for receiving a feeder sleeve. A bore is between the A and B ends defined by a sidewall having a stepped collapsible portion. The feeder element is compressible in use to reduce the distance between the A and B ends. The bore is offset from the centre of the feeder element along the length towards the C end and a second sidewall region is non-planar, contiguous with a third sidewall region and located between the bore axis and the D end.
1. An elongate feeder element ( 20 ; 40 ) for use in metal casting, said feeder element ( 20 ; 40 ) having a length, a width and a height, said feeder element ( 20 ; 40 ) comprising:
an A end and an opposite B end measured along the height, and a C end and an opposite D end measured along the length, said A end for mounting on a mould pattern or swing plate and said opposite B end for receiving a feeder sleeve; and a bore between the A and B ends defined by a sidewall comprising a stepped collapsible portion;
said feeder element being compressible in use whereby to reduce the distance between the A and B ends;
wherein said sidewall has a first sidewall region ( 24 ; 52 ) defining the B end of the feeder element which serves as a mounting surface for a feeder sleeve in use, and a second sidewall region ( 38 ; 50 ) contiguous with the first sidewall region ( 24 ; 52 ), wherein said stepped collapsible portion comprises a series of third sidewall regions ( 32 a,b,c,d ; 44 a,b ) in the form of concentric rings of decreasing diameter interconnected and integrally formed with a series of fourth sidewall regions ( 34 a,b,c,d ; 46 a,b ) in the form of concentric annuli of decreasing diameter;
characterised in that
said bore has an axis that is offset from the centre of the feeder element along the length towards the C end and
said second sidewall region ( 38 ; 50 ) is non-planar, contiguous with a third sidewall region and located between the bore axis and the D end.
2. The feeder element of claim 1 , wherein the bore axis is offset from the centre of the feeder element by at least 10% of the length.
3. The feeder element of claim 1 , wherein the second sidewall region ( 38 ; 50 ) has a height measured in the direction of the bore axis of from 10 to 25% of the height of the feeder element.
4. The feeder element of claim 1 , wherein the second sidewall region ( 38 ) curves away from the B end, toward the A end and back toward the B end across the width (W) and thereby forms an arch.
5. The feeder element of claim 1 , wherein the first sidewall region ( 24 ; 52 ) is inclined relative to the bore axis by an angle α where 0<α<90.
6. The feeder element of claim 5 , wherein α is from 50 to 70°.
7. The feeder element of claim 1 , wherein the second sidewall region ( 38 ; 50 ) is symmetrical about a mirror plane that passes through the bore axis from the C end to the D end.
8. The feeder element of claim 1 , wherein the stepped collapsible portion and the second sidewall region ( 38 ; 50 ) have substantially the same width.
9. The feeder element of claim 1 , wherein the length of the stepped collapsible portion is from 35 to 70% of the length of the feeder element.
10. The feeder element of claim 1 , wherein the stepped collapsible portion comprises from 2 to 6 steps.
11. The feeder element of claim 1 , wherein the second sidewall region ( 50 ) flares outward from the collapsible portion to the first sidewall region ( 52 ).
12. The feeder element of claim 1 , wherein the second sidewall region ( 38 ; 50 ) makes an angle (β) relative to the bore axis at the D end of at least 60°.
13. The feeder element of claim 1 , wherein the second sidewall region ( 50 ) makes an angle (γ) relative to the bore axis at the C end of at least 5°.
14. The feeder element of claim 1 which is oval, elliptical, rectangular, non-regular polygonal or obround when viewed along the bore axis.
15. The feeder element of claim 1 , which is of unitary construction.
16. The feeder element of claim 15 , which is press-formed from a single steel sheet of uniform thickness.
17. The feeder element of claim 1 , having an initial crush strength of at least 250N.
18. The feeder element of claim 17 , having an initial crush strength of less than 7 kN.
19. The feeder element of claim 18 having an initial crush strength of from 1 to 3 kN.
20. The feeder element of claim 1 , wherein the bore axis is located substantially centrally with respect to the width of the feeder element and/or the second sidewall region ( 38 ; 50 ).
21. A feeder system for metal casting comprising a feeder element in accordance with claim 1 and a feeder sleeve secured thereto, the feeder sleeve being profiled to match the first sidewall region.
22. The feeder system of claim 21 , wherein the feeder sleeve has an open side which is oval, elliptical, square, rectangular, polygonal or obround.
23. The feeder system of claim 21 , wherein at least 75% of the feeder sleeve contact area is with the first sidewall region.
24. The feeder system of claim 21 , wherein the feeder sleeve has a crush strength of at least 5 kN.