Neck-down feeder
The invention provides a neck-down feeder of unitary construction for use in metal casting. The feeder comprises a body portion integrally formed at a first end thereof with a tapered base portion for mounting on a mold pattern. The body portion and the base portion are defined by a continuous sidewall having one or more regions of weakness arranged such that the feeder is breakable in use whereby at least a part of the base portion detaches from the body portion and is received therein.
1. A neck-down feeder of unitary construction for use in metal casting, comprising a body portion integrally formed at a first end thereof with a tapered base portion for mounting on a mould pattern, the body portion and the base portion being defined by a continuous sidewall having one or more regions of reduced thickness arranged such that, under the application of force in the direction of the mould pattern, the feeder is breakable whereby at least a part of the base portion detaches from the body portion and is received therein, and wherein the force required to initiate breakage in the one or more regions of reduced thickness is no more than 5 kN.
2. The feeder according to claim 1 , wherein the one or more regions of reduced thickness in the sidewall are situated at least partially in the base portion of the feeder.
3. The feeder according to claim 2 , wherein the one or more regions of reduced thickness in the sidewall are situated entirely in the base portion of the feeder.
4. The feeder according to claim 1 , wherein the force required to initiate breakage in the one or more regions of reduced thickness is no more than 3 kN.
5. The feeder according to claim 1 , wherein the or each region of reduced thickness is constituted by a continuous band of reduced thickness that extends around the entire circumference of the sidewall.
6. The feeder according to claim 1 , wherein the thickness of the sidewall in the or each region of reduced thickness is less than 70% of the thickness of the remainder of the sidewall of the body portion and/or the base portion.
7. The feeder according to claim 6 , wherein the thickness of the sidewall in the or each region of weakness is less than 50% of the thickness of the remainder of the sidewall of the body portion and/or the base portion.
8. The feeder according to claim 1 , wherein the region of reduced thickness is provided by a groove, channel or one or more cut-outs in the sidewall.
9. The feeder according to claim 1 , wherein the one or more regions of reduced thickness are arranged such that, in use, the feeder is breakable into substantially two pieces.
10. The feeder according to claim 1 , further comprising a lid.
11. The feeder according to claim 10 , further comprising a moulding pin, an end of which is received within a central bore that extends partially or entirely through the lid.
12. The feeder according to claim 1 , wherein the feeder has a density of from 0.8 to 1.0 g cm −3 .
13. The feeder according to claim 1 , wherein the feeder comprises an exothermic composition.
14. A feeder system comprising the feeder of claim 1 and a breaker core.