Large bore pierce pin for an inflator
A pierce pin for an inflator for piercing the frangible seal of a gas cartridge including in combination a shaft having a axial bore forming a tubular member having a tip with a rim and a pair of slots formed across the rim into the tip into the tubular member to an appreciable depth to form a tab, the tab being bent inwardly into the axial bore after formation of the slots.
1. A pierce pin for an inflator for piercing the frangible seal of a gas cartridge, comprising in combination:
a shaft having a axial bore forming a tubular member having a tip with a rim; and
a pair of slots formed across said rim into said tip into said tubular member to a depth to form a tab, said tab being bent inwardly into said axial bore after formation of said slots.
2. The pierce pin as set forth in claim 1 wherein said shaft is circular cylindrical.
3. The pierce pin as set forth in claim 2 , wherein said axial bore is circular cylindrical.
4. The pierce pin as set forth in claim 3 , wherein said rim is circular cylindrical.
5. The pierce pin as set forth in claim 4 , wherein said slots are formed across a chord of said rim.
6. The pierce pin as set forth in claim 5 , wherein said tab is defined by the angle of said chord which in turn defines the distance from the sagitta of said tab.
7. The pierce pin as set forth in claim 6 , wherein the diameter of said axial bore achieves the desired rate of flow of the gas escaping the gas cartridge of the inflator.
8. The pierce pin as set forth in claim 7 , wherein the lumen and the outside surface of said tubular member are concentric such that the wall thickness extending from the lumen of said axial bore to the outside surface of said tubular member is generally uniform.
9. The pierce pin as set forth in claim 8 , wherein said tip comprises a circular cylindrical rim of uniform thickness.
10. The pierce pin as set forth in claim 9 , wherein said slots are aligned.
11. The pierce pin as set forth in claim 10 , wherein said slots are coplanar.
12. The pierce pin as set forth in claim 11 , wherein after bending inwardly said tab defining a minor arc segment, said rim of said tip comprises a blunt great arc rim.
13. The pierce pin as set forth in claim 12 , wherein upon impact of said tip with the frangible seal of the gas cartridge, said great arc rim forcibly punches an arcuate hole into the frangible seal of the gas cartridge, with the arcuate hole having the same great arc dimension as the great arc rim, to thereby define a great arc cored slug from the punched out part of the frangible seal of the gas cartridge, with the cored slug having the same dimension as the great arc rim.
14. The pierce pin as set forth in claim 13 , wherein said tab does not punch through the frangible seal.
15. The pierce pin as set forth in claim 14 , wherein a cored slug of the frangible seal remains attached to the frangible seal along the length of said tab.
16. The pierce pin as set forth in claim 15 , wherein said cored slug is precluded from separating from the frangible seal.