Plate spring for pop-up sheet material dispenser

• US 20030168468A1
• Filed: 03/11/2002
• Published: 09/11/2003
• Est. Priority Date: 03/11/2002
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Thompson, Craig D.
• Granted Patent: US 6,749,084 B2
• Time in Patent Office: Days
• US Class Current: 221/56
• CPC Class Codes: B42D 5/005 Supports for note-pads B42F9/00 takes precedence; underlays B43L3/00
• CPC Class Codes: B65D 83/0817 the articles being automatically urged towards the dispensing aperture, e.g. spring-loaded B65D83/0823 takes precedence

Abstract

A package for dispensing sheet material from a stack includes a novel biasing device for urging the stack of sheet material toward an opening in one side of the package. The biasing device is comprised of a flat sheet of material sized and shaped to be located within the package beneath the stack of sheet material. An elastomeric element having an unstressed length that is less than a diameter of the flat sheet of material is stressed and positioned between opposite edges of the flat sheet of material. As stress is relieved from the elastomeric element, the elastomeric element draws the opposite edges together and elevates a central portion of the sheet of material in the form of an arch to urge the stack toward the opening as the stack of sheet material is depleted.

Claims

1. A device for biasing a stack of sheet material within a dispensing package, wherein the stack of sheet material comprises a plurality of vertically aligned sheets of material which are releasably adhered to each other along opposite edges of successive sheets by a narrow band of pressure-sensitive adhesive, and wherein the dispensing package comprises a bottom, side walls and a top, the top defining an opening that extends between opposing side walls, the device comprising:

a sheet of material sized to fit within the dispensing package between the stack of sheet material and the bottom of the dispensing package, the sheet of material having a top surface, a bottom surface, opposing first and second edges, opposing third and fourth edges, and a circumference;

an elastomeric member positioned between the first and second edges of the sheet and secured to opposite sections of the sheet, the elastomeric member having an unstressed length that is less than a length of one of the third and fourth edges of the sheet of material, the elastomeric member thereby drawing the first and second edges of the sheet toward one another.

2. The device of claim 1 wherein the device comprises first and second elastomeric members, the first and second elastomeric members positioned proximate the third and fourth edges, respectively.

3. The device of claim 2 wherein the first and second elastomeric members comprise first and second portions of a band of elastomeric material, the band of elastomeric material having a circumference less than the circumference of the sheet of material.

4. The device of claim 3 wherein sheet of material comprises a first pair of spaced recesses associated with the third edge and a second pair of spaced recesses associated with the fourth edge, and wherein the band of elastomeric material is positioned in the first and second pair of recesses.

5. The device of claim 1 wherein the sheet of material is a polymer material.

6. The device of claim 5 wherein the first and second edges of the sheet generally are parallel to one another, and wherein the third and fourth edges are formed to define a radially tapered width of the sheet.

7. The device of claim 5 wherein the sheet of material is formed to define one or more openings through the sheet, the openings generally being spaced from the first, second, third and fourth edges.

8. The device of claim 1 wherein the sheet of material is a card stock material.

9. The device of claim 8 wherein the card stock material includes at least one crease, the at least one crease generally being parallel to and spaced from the first and second edges.

13. The dispenser package of claim 8 wherein the resilient means comprises first and second portions of an elastomeric material, the first and second portions having an unstressed length less than a length of one edge of the first pair of edges.

10. A dispenser package for sheet material comprising:

a container having a bottom, side walls and a top, the top defining an opening extending between opposing side walls;

a stack of sheet material positioned within the container, the stack comprised of a plurality of vertically aligned sheets of material which are releasably adhered to each other along opposite edges of successive sheets by a narrow band of pressure-sensitive adhesive, a first sheet of material capable of passing through the opening in the top of the container; and

means between the stack of sheet material and the bottom of the container for biasing the stack toward the top of the container.

11. The dispenser package of claim 10 wherein the biasing means comprises:

a flat sheet of flexible material having a top surface in contact with the stack of sheet material, a bottom surface, a first pair of opposing edges and a second pair of opposing edges; and

resilient means engaging the flexible material for flexing the sheet of flexible material in a direction toward the stack.

12. The dispenser package of claim 11 wherein the resilient means comprises an elastomeric element, the elastomeric element having an unstressed length that is less than a length of one edge of the first pair of opposing edges of the flat sheet of flexible material.

14. The dispenser package of claim 10 wherein the biasing means comprises:

a flat sheet of material having a top surface in contact with the stack of sheet material, a bottom surface, a first pair of opposing edges and a second pair of opposing edges, the flat sheet of material including a pair of creases, the pair of creases spaced from and generally parallel to the first pair of opposing edges; and

resilient means engaging the sheet of material for bending the sheet of flexible material along the pair of creases in a direction away from the stack.

15. The dispenser package of claim 14 wherein the resilient means comprises an elastomeric element, the elastomeric element having an unstressed length that is less than a length of one edge of the first pair of opposing edges of the flat sheet of material.

16. The dispenser package of claim 14 wherein the resilient means comprises first and second portions of an elastomeric material, the first and second portions having an unstressed length less than a length of one edge of the first pair of edges.

17. In a dispenser package for sheet material comprising a container having a base, a cover and side walls which define an interior space, the interior space containing a stack of sheet material, an opening in the cover to permit removal of individual sheets from the stack, and means for biasing the stack of sheet material toward the cover, the improvement comprising:

a flexible plate sized to fit in the interior space of the container between the stack of sheet material and the base of the container, the flexible plate having a top surface, a bottom surface, first and second opposing edges, third and fourth opposing edges, and a circumference;

an elastomeric band having an unstressed circumference that is smaller than the circumference of the flexible plate, the elastomeric band being positioned over the top surface of the flexible plate such that first and second portions of the elastomeric band are near the first and second opposing edges of the flexible plate, and third and fourth portions of the elastomeric band are positioned below the bottom surface of the flexible plate near the third and fourth opposing edges, the third and fourth portions of the elastomeric band having an unstressed length less than a length of the third and fourth edges of the flexible plate.