Vaccum drum for different sized media

A vacuum drum for securing and retaining larger-sized and smaller-sized sheets of flexible material thereon, comprising:

• an elongated tubular sleeve member having a hollow interior and a cylindrical wall with an outer surface including a first surface zone corresponding in size to the size of the smaller-sized sheet, and a second surface zone located adjacent to said first zone and which, when combined with said first zone, corresponds in size to the size of the larger-sized sheet;
• first and second unconnected sets of longitudinally extending bores drilled in said wall at respective angularly-spaced locations internally adjacent said surface;
• a first multiplicity of holes in said wall respectively arranged to place said first set of bores in communication with said first zone;
• and a second multiplicity of holes in said wall respectively arranged to place said second set of bores in communication with said second zone;
• and
• shaft means, having first and second evacuation ports, for mounting said elongated sleeve member for axial rotation;
• said member further having a first channel for communicating said first set of bores with said first port externally of said sleeve, and a second channel for communicating said second set of bores with said second port externally of said sleeve;
• said first and second channels beings respectively dimensioned, configured and adapted so that connection of said first port to a vacuum source will evacuate the holes of said first multiplicity to provide sucking forces to hold the smaller sized sheet on said surface peripherally over said first zone, with no evacuation within said sleeve interior;
• and connection of both said first and second ports to a vacuum source will evacuate the holes of both said first and second multiplicities to provide sucking forces to hold the larger-sized sheet on said surface peripherally over said combined first and second zones, with no evacuation within said sleeve interior.

A vacuum drum for securing and retaining larger-sized and smaller-sized sheets of flexible material thereon, comprising:

• an elongated tubular sleeve having a hollow interior, left and right ends, and a cylindrical marginal wall portion with an outer surface including a first surface zone corresponding in size to the size of the smaller-sized sheet, and a second surface zone located adjacent to said first zone and which, when combined with said first zone, corresponds in size to the size of the larger-sized sheet;
• first and second unconnected sets of longitudinally extending bores drilled in said wall portion at respective angularly-spaced locations internally adjacent said surface, said first set bores opening to said left end and said second set bores opening to said right end;
• a first multiplicity of holes in said wall portion respectively arranged to place said first set of bores in communication with said first zone;
• and a second multiplicity of holes in said wall portion respectively arranged to place said second set of bores in communication with said second zone;
• left and right end plates respectively attached to said left and right ends of said sleeve;
• and
• left and right shaft sections respectively attached in axially outwardly protruding positions to said end plates for rotatively mounting said drum;
• said shaft sections being respectively provided with left and right axially outwardly extending evacuation ports;
• said left end plate being provided with a first radial bore for communicating said first set of bores with said left port, externally of said sleeve through said left end plate, and said right end plate being provided with a second radial bore for communicating said second set of bores with said right port, externally of said sleeve through said right end plate;
• said first and second radial bores being dimensioned, configures and adapted so that connection of said left port to a vacuum source will evacuate the holes of said first multiplicity to provide sucking forces to hold the smaller-sized sheet on said surface peripherally over said first zone, with no evacuation within said sleeve member interior;
• and connection of both said left and right ports to a vacuum source will evacuate the holes of both said first and second multiplicities to provide sucking forces to hold the larger-sized sheet on said surface peripherally over said combined first and second zones, with no evacuation within said sleeve member interior.

A vacuum drum for securing and retaining larger-sized and smaller-sized sheets of flexible material thereon, comprising:

• an elongated member having a cylindrical body with an outer surface including a first surface zone corresponding in size to the size of the smaller-sized sheet;
• a second surface zone located adjacent to said first zone and which, when combined with said first zone, corresponds in size to the size of the larger-sized sheet;
• and a third surface zone corresponding in size to the size of a leading edge of the larger-sized sheet, said third zone including a first surface subzone located adjacent said first zone and corresponding in size to the size of a leading edge of the smaller-sized sheet;
• first and second unconnected sets of longitudinally extending bores drilled in said body at respective angularly-spaced locations internally adjacent said surface;
• a first multiplicity of holes in said body respectively arranged to place said first set of bores in communication with said first zone;
• a second multiplicity of holes in said body respectively arranged to place said second set of bores in communication with said second zone;
• and a third multiplicity of holes in said body respectively arranged to place said first set of bores in communication with said third zone at least at said first surface subzone;
• and
• shaft means, having first and second evacuation ports, for mounting said elongated member for axial rotation;
• said member further having first channel means for communicating said first set of bores with said first port, and second channel means for communicating said second set of bores with said second port;
• said first and second channel means being respectively dimensioned, configures and adapted so that connection of said first port to a vacuum source will evacuate the holes of said first and third multiplicities to provide sucking forces to hold the smaller sized sheet on said surface peripherally over said first zone and first subzone, and connection of both said first and second ports to a vacuum source will evacuate the holes of said first, second and third multiplicities to provide sucking forces to hold the larger-sized sheet on said surface peripherally over said combined first and second zones and said first subzone.

A vacuum drum for securing and retaining larger-sized and smaller-sized sheets of flexible material thereon, comprising:

• an elongated member having a cylindrical body with an outer surface including a first surface zone corresponding in size to the size of the smaller-sized sheet, and a second surface zone located adjacent to said first zone and which, when combined with said first zone, corresponds in size to the size of the larger-sized sheet;
• first and second unconnected sets of longitudinally extending bores drilled in said body at respective angularly-spaced locations internally adjacent said surface;
• a first multiplicity of holes in said body respectively arranged to place said first set of bores in communication with said first zone;
• a second multiplicity of holes in said body respectively arranged to place said second set of bores in communication with said second zone;
• and first and second annular chambers respectively in communication with said first and second sets of bores;
• shaft means, having first and second evacuation ports, for mounting said elongated member for axial rotation;
• said member further having at least one first radial bore for communicating said first annular chamber with said first port, and at least one second radial bore for communicating said second annular chamber with said second port;
• said at least one first and second radial bores being respectively dimensioned, configured and adapted so that connection of said first port to a vacuum source will evacuate the holes of said first multiplicity to provide sucking forces to hold the smaller-sized sheet on said surface peripherally over said first zone, and connection of both said first and second ports to a vacuum source will evacuate the holes of both said first and second multiplicities to provide sucking forces to hold the larger-sized sheet on said surface peripherally over said combined first and second zones.

A vacuum drum for securing and retaining larger-sized and smaller-sized sheets of flexible material thereon, comprising:

• an elongated central section having left and right ends and a hollow cylindrical marginal wall portion with an outer surface including a first surface zone corresponding in size to the size of the smaller-sized sheet, a second surface zone located adjacent to said first zone and which, when combined with said first zone, corresponds in size to the size of the larger-sized sheet, and a third surface zone corresponding in size to the size of a leading edge of the larger-sized sheet, said third zone including a first surface subzone located adjacent said first zone and corresponding in size to the size of a leading edge of the smaller-sized sheet;
• first and second unconnected sets of longitudinally extending bores drilled in said wall portion at respective angularly-spaced locations internally adjacent said surface, said first set bores opening to said left end and said second set bores opening to said right end;
• a first multiplicity of holes in said wall portion respectively arranged to place said first set bores in communication with said first zone;
• a second multiplicity of holes in said wall portion respectively arranged to place said second set bores in communication with said second zone;
• and a third multiplicity of holes in said wall portion respectively arranged to place said first set of bores in communication with said third zone at least at said first surface subzone;
• left and right end plates respectively attached to said left and right ends of said sleeve;
• and
• left and right shaft sections respectively attached in axially outwardly protruding positions to said end plates for rotatively mounting said drum;
• said shaft sections being respectively provided with left and right axially outwardly extending evacuation ports;
• said left end plate being provided with a first plurality of radial bores for communicating said first set of bores with said left port, and said right end plate being provided with a second plurality of radial bores for communicating said second set of bores with said right port;
• said first and second pluralities of radial bores being dimensioned, configures and adapted so that connection of said left port to a vacuum source will evacuate the holes of said first and third multiplicities to provide sucking forces to hold the smaller-sized sheet on said surface peripherally over said first zone and first subzone, and connection of both said left and right ports to a vacuum source will evacuate the holes of both said first, second and third multiplicities to provide sucking forces to hold the larger-sized sheet on said surface peripherally over said combined first and second zones and said first subzone.