Suction roller for transporting flat material blanks
A suction roller for transporting flat material blanks has a roller axis and a mantle surface. The suction roller is independent of format and therefore can be universally used for transporting flat material blanks, particularly label blanks. The suction roller has controllable suction holes or suction zones that lie at the closest possible distance from one another on its mantle surface. To this end, the suction roller has a plurality of suction slits, which run parallel to the roller axis and open into the mantle surface, whereby at least adjacent suction slits can have suction air applied to them independent of one another, and whereby a slit cover provided with passage holes is disposed on the mantle surface, in such a manner that the passage holes align with the suction slits, at least in part.
1. A suction roller for transporting flat material blanks and for use with a slit cover having passage holes, the suction roller comprising: (a) a roller axis; (b) a mantle surface; and (c) a plurality of suction slits running parallel to the roller axis and opening into the mantle surface; wherein suction air is applied to at least adjacent suction slits independently of one another; and wherein the passage holes align at least partially with the suction slits when a slit cover is disposed on the mantle surface in a selected manner; wherein each suction slit receives suction air applied via at least one respective axial channel disposed in at least one face of the suction roller and opening into the suction slit; wherein the axial channels have a circular cross-section, each axial channel having a channel diameter (D) that is at least as great as the sum of twice the suction slit width (B) of the associated suction slit measured in a circumferential direction and the width (A) of a mantle surface region remaining between two adjacent suction slits measured in the circumferential direction.
2. The suction roller according to claim 1 , comprising a plurality of groups of axial channels, each group comprising at least first and second axial channels assigned respectively to first and second circumferentially-adjacent suction slits and lying on respective circle circumferences having different diameters, so that the first and second axial channels open into the respective first and second suction slits at different radial distances from the roller axis.
3. The suction roller according to claim 1 , wherein the axial channels have a circular cross-section, each axial channel having a diameter (D) that is at least as great as the sum of twice the suction slit width (B) of the associated suction slits, measured in a circumferential direction and twice the width (A) of a mantle surface region remaining between two adjacent suction slits measured in the circumferential direction.
4. The suction roller according to claim 1 , comprising a plurality of groups of axial channels, each group comprising at least first, second, third, and fourth axial channels assigned respectively to first, second, third, and fourth circumferentially-adjacent suction slits and lying on respective first, second, third and fourth circle circumferences having different diameters, so that the first, second, third, and fourth axial channels open into the respective first, second, third, and fourth suction slits at different radial distances from the roller axis.
5. The suction roller according to claim 4 , wherein the first axial channel assigned to the first suction slit lies on the first circle circumference having the largest diameter, the second axial channel assigned to the second suction slit that follows the first suction slit in a circumferential direction lies on the second circle circumference having the third-largest diameter, the third axial channel assigned to the third suction slit that follows the second suction slit in the circumferential direction lies on the third circle circumference having the second-largest diameter, and the fourth axial channel assigned to the fourth suction slit that follows the third suction slit in the circumferential direction lies on the fourth circle circumference having the smallest diameter.
6. A suction roller assembly comprising a suction roller for transporting flat material blanks and a slit cover having passage holes, the suction roller comprising: (a) a roller axis; (b) a mantle surface; and (c) a plurality of suction slits running parallel to the roller axis and opening into the mantle surface; wherein suction air is applied to at least adjacent suction slits independently of one another; and wherein the slit cover is disposed on the mantle surface so that the passage holes align at least partially with the suction slits; wherein each suction slit receives suction air applied via at least one respective axial channel disposed in at least one face of the suction roller and opening into the suction slit; wherein the axial channels have a circular cross-section, each axial channel having a channel diameter (D) that is at least as great as the sum of twice the suction slit width (B) of the associated suction slit measured in a circumferential direction and the width (A) of a mantle surface region remaining between two adjacent suction slits measured in the circumferential direction.
7. The suction roller assembly according to claim 6 , wherein the passage holes assigned to adjacent suction slits are disposed offset relative to one another, in an axial direction of the suction roller.
8. The suction roller assembly according to claim 6 , wherein the passage holes assigned to adjacent suction slits differ by hole geometries that are different in a top view.
9. The suction roller assembly according to claim 6 , wherein the slit cover is made of a non-rusting material.
10. The suction roller assembly according to claim 6 , wherein the slit cover is releasably attached to the mantle surface.
11. The suction roller assembly according to claim 10 , wherein the slit cover is attached to the mantle surface by magnetic force.