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US 5,669,578 AGranted
Crush-proof extrusion core
AssigneeNCR Corporation
InventorMing Ma
Life of this patent
Estimating the term…
Abstract
A core includes coaxial inner and outer tubes having a plurality of ribs extending therebetween defining a plurality of empty pockets. The inner tube has a thickness which is at least as large as the thickness of the outer tube for increasing crushing resistance of the core. In a preferred embodiment, each of the pockets includes four corners having a radius greater than the thicknesses of the inner or outer tubes or both.
Claims9
A core for a paper roll comprising:
- an inner tube having an inner diameter and a radial wall inner thickness;
- an outer tube having an outer diameter and a radial wall outer thickness, and disposed coaxially with said inner tube and spaced radially outwardly therefrom;
- a plurality of ribs extending radially between and integrally joined with said inner and outer tubes, and circumferentially spaced apart from each other to define empty pockets therebetween;
- each of said pockets being bounded on four sides by an adjacent pair of said ribs and respective portions of said inner and outer tubes extending therebetween to define four corresponding corners each having a radius which is greater than said outer thickness;
- and
- said inner thickness being at least as large as about said outer thickness for increasing crushing resistance of said core.
3 more elements
A core for a paper roll comprising:
- an inner tube having an inner diameter and a radial wall inner thickness;
- an outer tube having an outer diameter and a radial wall outer thickness, and disposed coaxially with said inner tube and spaced radially outwardly therefrom;
- a plurality of ribs extending radially between and integrally joined with said inner and outer tubes, and circumferentially spaced apart from each other to define empty pockets therebetween;
- each of said pockets being bounded on four sides by an adjacent pair of said ribs and respective portions of said inner and outer tubes extending therebetween to define four corresponding corners each having a radius which is greater than said inner thickness;
- and
- said inner thickness being at least as large as about said outer thickness for increasing crushing resistance of said core.
3 more elements
A core for a paper roll comprising:
- an inner tube having an inner diameter and a radial wall inner thickness;
- an outer tube having an outer diameter and a radial wall outer thickness, and disposed coaxially with said inner tube and spaced radially outwardly therefrom;
- a plurality of ribs extending radially between and integrally joined with said inner and outer tubes, and circumferentially spaced apart from each other to define empty pockets therebetween;
- each of said pockets being bounded on four sides by an adjacent pair of said ribs and respective portions of said inner and outer tubes extending therebetween to define four corresponding corners each having a radius which is greater than both said inner and outer thicknesses, respectively;
- and
- said inner thickness being at least as large as about said outer thickness for increasing crushing resistance of said core.
3 more elements
A core for a paper roll comprising:
- an inner tube having an inner diameter and a radial wall inner thickness;
- an outer tube having an outer diameter and a radial wall outer thickness, and disposed coaxially with said inner tube and spaced radially outwardly therefrom;
- a plurality of ribs extending radially between and integrally joined with said inner and outer tubes, and circumferentially spaced apart from each other to define empty pockets therebetween;
- each of said pockets being bounded on four sides by an adjacent pair of said ribs and respective portions of said inner and outer tubes extending therebetween to define four corresponding corners each having a radius which is greater than said outer thickness;
- and
- said inner thickness is substantially equal to said outer thickness for increasing crushing resistance of said core.
3 more elements
A core for a paper roll comprising:
- an inner tube having an inner diameter and a radial wall inner thickness;
- an outer tube having an outer diameter and a radial wall outer thickness, and disposed coaxially with said inner tube and spaced radially outwardly therefrom;
- a plurality of ribs extending radially between and integrally joined with said inner and outer tubes, and circumferentially spaced apart from each other to define empty pockets therebetween;
- each of said pockets being bounded on four sides by an adjacent pair of said ribs and respective portions of said inner and outer tubes extending therebetween to define four corresponding corners each having a radius which is greater than said inner thickness;
- and
- said inner thickness is substantially equal to said outer thickness for increasing crushing resistance of said core.
3 more elements
A core for a paper roll comprising:
- an inner tube having an inner diameter and a radial wall inner thickness;
- an outer tube having an outer diameter and a radial wall outer thickness, and disposed coaxially with said inner tube and spaced radially outwardly therefrom;
- a plurality of ribs extending radially between and integrally joined with said inner and outer tubes, and circumferentially spaced apart from each other to define empty pockets therebetween;
- each of said pockets being bounded on four sides by an adjacent pair of said ribs and respective portions of said inner and outer tubes extending therebetween to define four corresponding corners each having a radius which is greater than both said inner and outer thicknesses, respectively;
- and
- said inner thickness is substantially equal to said outer thickness for increasing crushing resistance of said core.
3 more elements
A core for a paper roll comprising:
- an inner tube having an inner diameter and a radial wall inner thickness;
- an outer tube having an outer diameter and a radial wall outer thickness, and disposed coaxially with said inner tube and spaced radially outwardly therefrom;
- a plurality of ribs extending radially between and integrally joined with said inner and outer tubes, and circumferentially spaced apart from each other to define empty pockets therebetween;
- each of said pockets being bounded on four sides by an adjacent pair of said ribs and respective portions of said inner and outer tubes extending therebetween to define four corresponding corners each having a radius which;
- and
- wherein said inner thickness is greater than said outer thickness.
3 more elements
Dependencies are inferred from the claim text.