Iris type cut off knife

Claim 2

Cutting apparatus for stock comprising: a framework supporting a plurality greater than two of rotatable shafts spaced equidistant around said framework, at least three of the shafts lying at the vertices of a hypothetical equilateral triangle centered on stock positioned through said framework and constituting a first set of shafts, the remainder and equal number of rotatable shafts being equidistant around said framework and constituting a second set of shafts, all said rotatable shafts bEing parallel to said stock, each shaft carrying an eccentrically mounted, plate-like circular cutting knife adapted for rotation with the shaft, all knives having the same radius and eccentricity, the knives of the first set being aligned with their cutting edges in the same plane so that when rotated to their innermost positions their edges are tangent to one another, the knives of second set being aligned with their cutting edges in a plane closely adjacent said first mentioned plane and being adapted to overlap the knives of the first set when all knives are in their innermost position, whereby the knives perform a scissorlike action on said stock as the knives approach their innermost positions, and means for causing all the shafts to rotate simultaneously to carry the knives simultaneously toward and away from said stock, the knives at their furthest inward position cooperating for cutting said stock.

Claim 3

The invention claimed in claim 1, in which the shafts are equidistant from said stock, each shaft being locked to a toothed gear wheel, and in which said means includes an internally toothed ring gear meshing with the teeth of each said gear wheel, and means for rotating said ring gear with respect to the framework.

Claim 4

The invention claimed in claim 2, in which said last mentioned means includes a fluid operated cylinder fixed to the framework and having its piston connected to said ring gear such that reciprocation of the piston causes rotary oscillation of said ring gear.

Claim 5

The invention claimed in claim 1, in which said stock continuously advances axially, and in which the framework is mounted on guideway means for reciprocation in the direction parallel with said stock, whereby said stock can be cut by said knives as the stock and the framework advance together.

Claim 6

The invention claimed in claim 4, in which the frame-work is drawn in the direction of stock advance by the engagement of the knives with the stock, and in which resilient means are provided to return the framework after the cut.

Claim 7

Cutting apparatus for stock comprising: a framework supporting six rotatable shafts spaced at 60* intervals around said stock and parallel therewith, three of the shafts lying at the vertices of a hypothetical equilateral triangle centered on stock positioned through said framework and constituting a first set of shafts, the other shafts being equidistant from said stock and constituting a second set of shafts, each shaft carrying an eccentrically mounted, plate-like circular cutting knife adapted for rotation with the shaft, all knives having the same radius and eccentricity, the knives of the first set being aligned with their cutting edges in the same plane so that when rotated to their innermost positions their edges are tangent to one another, the knives of the second set being aligned with their cutting edges in a plane closely adjacent said first mentioned plane and being adapted to overlap the knives of the first set when all knives are in their innermost position, whereby the knives perform a scissor-like action on said stock as the knives approach their innermost positions, and means for causing all the shafts to rotate simultaneously to carry the knives simultaneously toward and away from said stock, the knives at their furthest inward position cooperating for cutting said stock.

Claim 8

Cutting apparatus for stock comprising: a framework supporting six rotatable shafts spaced at 60* intervals around said stock and parallel therewith, three of the shafts lying at the vertices of a hypothetical equilateral triangle centered on stock positioned through said framework and constituting a first set of shafts, the other shafts being equidistant from said stock and constituting a second set of shafts, each shaft carrying an eccentrically mounted, plate-like circular cutting knife adapted for rotation with the shaft, all knives having the same radius and eccentricity, the knives of the first set being aligned with their cutting edges in the same plane so that when rotated to their innermost positions their edges are tangent to one another, the knives of the second set being aligned with their cutting edges in a plane closely adjacent said first mentioned plane and being adapted to overlap the knives of the first set when all knives are in their innermost position, whereby the knives perform a scissor-like action on said stock as the knives approach their innermost positions, and means for causing all the shafts to rotate simultaneously to carry the knives simultaneously toward and away from said stock, the knives at their furthest inward position cooperating for cutting said stock.

Claim 9

Cutting apparatus for axially advancing stock, the apparatus comprising: guidway means parallel with the direction of advance of the stock, a framework adapted to reciprocate on said guideway means, support means for supporting from the framework a first set of three rotatable shafts and a second set of three rotatable shafts, all shafts being parallel, the three shafts of the first set being locatefshafts being parallel, the three shafts of the first set being located at the vertices of a first hypothetical equilateral triangle centered on the stock, the three shafts of the second set being located at the vertices of a secOnd hypothetical equilateral triangle centered on the stock, the second triangle being displaced angularly from the first triangle by 60*, each shaft carrying an eccentrically mounted circular cutting knife keyed to the shaft for rotation therewith, the three knives on a given set of shafts having the same diameter and eccentricity, the knives on the first set of shafts lying in the same plane, the knives on the second set of shafts being positioned to overlap the knives on the first set of shafts when all shafts are rotated, and means for causing all shafts to rotate simultaneously to carry the knives simultaneously toward and away from the stock to cut the same with the knives on the first set of shafts cooperating with the knives on the second set of shafts to perform a scissors-like action on the stock,

Claim 10

Cutting apparatus for axially advancing stock, the apparatus comprising: guidway means parallel with the direction of advance of the stock, a framework adapted to reciprocate on said guideway means, support means for supporting from the framework a first set of three rotatable shafts and a second set of three rotatable shafts, all shafts being parallel, the three shafts of the first set being locatefshafts being parallel, the three shafts of the first set being located at the vertices of a first hypothetical equilateral triangle centered on the stock, the three shafts of the second set being located at the vertices of a secOnd hypothetical equilateral triangle centered on the stock, the second triangle being displaced angularly from the first triangle by 60*, each shaft carrying an eccentrically mounted circular cutting knife keyed to the shaft for rotation therewith, the three knives on a given set of shafts having the same diameter and eccentricity, the knives on the first set of shafts lying in the same plane, the knives on the second set of shafts being positioned to overlap the knives on the first set of shafts when all shafts are rotated, and means for causing all shafts to rotate simultaneously to carry the knives simultaneously toward and away from the stock to cut the same with the knives on the first set of shafts cooperating with the knives on the second set of shafts to perform a scissors-like action on the stock,

Claim 11

The invention claimed in claim 7, in which said last mentioned means includes a toothed gear wheel locked to each shaft, each gear wheel having the same number of teeth, and an internally toothed ring gear meshing with the teeth of each said gear wheel, a cylinder having a reciprocating piston, the cylinder being attached to the framework and the piston being attached to the framework and the piston being attached to the ring gear whereby reciprocation of the piston causes rotary oscillation of the ring gear, thereby rotating the shafts to carry the knives toward and away from the stock.