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US 9,254,526 B2Granted
Punch profile for a punch, and the assembly in which the punch is used
AssigneeTextron Innovations Inc.
InventorsWilliam F. Nordlin, Peter Czyzewski
Life of this patent
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Abstract
A punch assembly includes a punch, a sleeve, a draw stud and a die. The punch has a punch profile which provides a cutting edge that has a uniform “sharpness” along entire perimeter of the punch. The punch assembly provides additional punch-to-die clearance over what was done in the prior art. This reduces excessive punching forces which result from axial deflection of the draw stud and “tipping” of a large diameter punch as the draw stud deflects under a load.
Claims10
A punch comprising:
- a cylindrical punch body having a first end surface and a second, opposite end surface, said punch body defining a perimeter;
- a punch wall extending upwardly from said second end surface and having a free end, said punch wall extending around the entire perimeter of said punch body, said punch wall having an exterior surface and an interior surface, said punch wall formed of a plurality of alternating flutes and lobes, each said lobe having a pair of walls angling from a piercing point;
- a punch profile formed on said free end of said punch wall and extending between said exterior and interior surfaces of said punch body, said punch profile formed by a cutting surface having a thickness and a shearing surface having a thickness, wherein each of the cutting surface and the shearing surface extend continuously around the perimeter of the punch wall,
- said cutting surface having a first end and a second end and a positive cut edge geometry, said cutting surface extending between said exterior surface of the punch wall and said shearing surface, said cutting surface extending inwardly from said exterior surface toward said second end surface of said punch body at an angle such that said first end of said cutting surface is spaced from said second end surface of said punch body at a distance which is greater than a distance said second end of said cutting surface is spaced from the second end surface of said punch body,
- the shearing surface having a first end and a second end, the first end of the shearing surface overlapping the second end of the cutting surface, said shearing surface extending inwardly from the cutting surface to the interior surface of the punch wall at an angle, the angle of the shearing surface is different than the angle of the cutting surface, said shearing surface being spaced from said second end surface of said punch body at a lesser distance than a distance at which said first end of said cutting surface is spaced from said second end surface of said punch body;
- and
- a passageway extending through said punch body, said passageway spaced from said punch wall.
4 more elements
Dependencies are inferred from the claim text.