U.S. patent application number 10/871756 was filed with the patent office on 2004-12-23 for sheet dispenser.
This patent application is currently assigned to 3M Innovative Properties Company. Invention is credited to O'Leary, Timothy J., Thompson, Craig D..
Application Number | 20040256405 10/871756 |
Document ID | / |
Family ID | 33551929 |
Filed Date | 2004-12-23 |
United States Patent
Application |
20040256405 |
Kind Code |
A1 |
Thompson, Craig D. ; et
al. |
December 23, 2004 |
Sheet dispenser
Abstract
A dispenser package for durable index tabs includes a housing
attached to a base, in which the housing consists of interconnected
side walls and end walls and a cover. The housing and base define a
chamber for holding a stack of durable index tabs. The cover
comprises a pair of flanges, each of which has one end that is
attached to one of the end walls. The flanges have a pair of
opposing edges that are spaced from the side walls of the housing.
The opposite end of the flanges define a relatively wide opening of
the cover for dispensing index tabs made of a relatively inflexible
material. The flange incorporates an elliptical relief adjacent to
the opening by forming an arched step in the flange wall that
extends from the end of the flange that defines the cover opening
toward the end wall of the housing.
Inventors: |
Thompson, Craig D.; (Inver
Grove Heights, MN) ; O'Leary, Timothy J.; (White Bear
Lake, MN) |
Correspondence
Address: |
3M INNOVATIVE PROPERTIES COMPANY
PO BOX 33427
ST. PAUL
MN
55133-3427
US
|
Assignee: |
3M Innovative Properties
Company
|
Family ID: |
33551929 |
Appl. No.: |
10/871756 |
Filed: |
June 17, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60480637 |
Jun 23, 2003 |
|
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|
Current U.S.
Class: |
221/63 |
Current CPC
Class: |
A47K 10/421 20130101;
B42D 5/005 20130101; B65D 83/0805 20130101 |
Class at
Publication: |
221/063 |
International
Class: |
B65H 001/00 |
Claims
1. A dispenser for dispensing sheets of a material from a stack,
the dispenser comprising: a base; a housing attached to the base,
the housing comprising a pair of opposing side walls and a pair of
opposing end walls extending from and generally transverse to the
base, and a cover, the housing defining a chamber for the stack of
sheets, the chamber having a length greater than that of the stack
of sheets, wherein the cover comprises an opening defined by first
and second flanges, the first flange having a first end, a second
end opposite the first end and a pair of opposing edges extending
therebetween, the first end of the first flange being connected to
a first one of the end walls, the pair of opposing edges of the
first flange being adjacent to and spaced from the respective
adjacent side walls, the second flange having a first end, a second
end opposite the first end and a pair of opposing edges extending
therebetween, the first end of the second flange being connected to
a second one of the end walls, the pair of opposing edges of the
second flange being adjacent to and spaced from the respective
adjacent side walls, wherein the second ends of the first and
second flange define a width of the opening of at least about 0.33
inches; and wherein the stack of sheets in the chamber of the
housing comprises a plurality of sheets, each sheet having a
stiffness greater than or equal to 1.967.times.10.sup.-3
pounds-inch.sup.-2.
2. The dispenser of claim 1 wherein each flange comprises an arched
step extending from the second end of the respective flange so as
to define a stepped upper surface between the first end and the
second end of each respective flange.
3. The dispenser of claim 2 wherein the arched step comprises an
arcuate wall extending generally transverse from the upper
surface.
4. The dispenser of claim 3 wherein the arcuate wall has a height
of about 0.06 inches.
5. The dispenser of claim 1 wherein each sheet in the stack is
formed from PET having a sheet thickness of about 0.0036
inches.
6. The dispenser of claim 1 wherein the base comprises a flat base
and wherein the first and second flanges are generally parallel to
the base.
7. The dispenser of claim 1 wherein each of the first and second
flanges includes an end portion adjacent to the second end of the
respective first and second flanges, the end portion of one of the
first and second flanges overlaping the stack by at least about
0.24 inches when the stack is in contact with one of the end
walls.
8. A sheet dispenser comprising: a base; and a housing attached to
the base, the housing comprising a pair of opposing side walls and
a pair of opposing end walls extending from and generally
transverse to the base, and a cover having an opening defined by
first and second flanges, the first flange having a first end, a
second end opposite the first end and a pair of opposing edges
extending therebetween, the first end of the first flange being
connected to a first one of the end walls, the pair of opposing
edges of the first flange being adjacent to and spaced from the
respective adjacent side walls, the second flange having a first
end, a second end opposite the first end and a pair of opposing
edges extending therebetween, the first end of the second flange
being connected to a second one of the end walls, the pair of
opposing edges of the second flange being adjacent to and spaced
from the respective adjacent side walls, the second ends of the
first and second flanges defining the opening of the cover, wherein
each flange comprises a stepped upper surface between the first end
and the second end of each respective flange.
9. The sheet dispenser of claim 8 wherein each flange comprises an
arched step extending from the second end of the respective
flange.
10. The sheet dispenser of claim 9 wherein the arched step
comprises an arcuate wall extending generally transverse from the
upper surface.
11. The sheet dispenser of claim 10 wherein the arcuate wall has a
height of about 0.06 inches.
12. The sheet dispenser of claim 8 wherein the second end of the
first flange is spaced at least about 0.33 inches from the second
end of the second flange.
13. The sheet dispenser of claim 8 and further comprising a stack
of sheets contained within the housing, the stack having a length
less than that of the housing, wherein each sheet has a stiffness
equal to or greater than 1.967.times.10.sup.-3
pounds-inch.sup.2.
14. The sheet dispenser of claim 13 wherein the stack of sheets
comprises a plurality of sheets of PET having a sheet thickness of
about 0.0036 inches.
15. The sheet dispenser of claim 8 wherein the base comprises a
flat base and wherein the first and second flanges are generally
parallel to the base.
16. A shuttling dispenser for dispensing sheets of a material from
a stack, the dispenser comprising: a flat base; a housing attached
to the base, the housing comprising a pair of opposing side walls
and a pair of opposing end walls extending from and generally
transverse to the base, and a cover, the housing defining a chamber
for the stack of sheets, the chamber having a length greater than
that of the stack of sheets and a height closely approximating that
of a full stack of sheets, wherein the cover comprises an opening
defined by first and second flanges, the first and second flanges
being generally parallel to the base, the first flange having a
first end, a second end opposite the first end and a pair of
opposing edges extending therebetween, the first end of the first
flange being connected to a first one of the end walls, the pair of
opposing edges of the first flange being adjacent to and spaced
from the respective adjacent side walls, the second flange having a
first end, a second end opposite the first end and a pair of
opposing edges extending therebetween, the first end of the second
flange being connected to a second one of the end walls, the pair
of opposing edges of the second flange being adjacent to and spaced
from the respective adjacent side walls, wherein the second ends of
the first and second flange define a width of the opening of at
least about 0.33 inches; and wherein the stack of sheets in the
chamber of the housing comprises a plurality of sheets, each sheet
having a stiffness greater than or equal to 1.967.times.10.sup.-3
pounds-inch.sup.2.
17. The dispenser of claim 16 wherein each flange comprises an
arched step extending from the second end of the respective flange
so as to define a stepped upper surface between the first end and
the second end of each respective flange.
18. The dispenser of claim 17 wherein the arched step comprises an
arcuate wall extending generally transverse from the upper
surface.
19. The dispenser of claim 18 wherein the arcuate wall has a height
of about 0.06 inches.
20. The dispenser of claim 16 wherein each of the first and second
flanges includes an an end portion adjacent to the second end of
the respective first and second flanges, the end portion of one of
the first and second flanges overlaping the stack by at least about
0.24 inches when the stack is in contact with one of the end walls.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent
Application No. 60/480,637, filed Jun. 23, 2003, which is
incorporated by reference in its entirety herein.
TECHNICAL FIELD
[0002] The present invention relates to a dispenser package for
dispensing individual sheets of a limited flexibility material from
a stack.
BACKGROUND OF THE INVENTION
[0003] Dispenser packages for dispensing relatively thin and
flexible polymeric sheet material, also known as repositionable
flags, include a narrow slot in the top surface of the dispenser
through which extends a top-most flag of a stack of the flags. Such
a stack of flags is formed by adhering adjacent flags together
along a portion of alternating opposing ends with a repositionable
adhesive layer, e.g., in a Z-fold manner. As the top-most flag is
withdrawn from a shuttling-type dispenser, the stack of flags moves
from one end of the dispenser to the other and an end portion of
the subsequent flag is folded and drawn through the narrow slot.
Due to the thin and flexible characteristics of the flags, the
flags are not prone to creasing as they pass through the narrow
slot.
[0004] The force required to withdraw individual flags that are
highly flexible through the narrow slot of a shuttling-type
dispenser is relatively low. While such dispensers are suitable for
flexible flags, they are not suited for sheets formed of thicker
and/or stiffer materials, such as polyethylene teraphthalate (PET).
Sheet material formed from PET, known as index tabs, for example,
is more durable than preexisting flexible flags. Durable index tabs
formed of such materials are prone to creasing as they pass through
the narrow slot of the dispenser. The present invention addresses
the need for a low profile dispenser package that can dispense
durable index tabs having reduced flexibility from a stack without
excessive dispensing forces and without creasing of the index
tabs.
BRIEF SUMMARY OF THE INVENTION
[0005] The dispenser of the present invention comprises a base and
a housing attached to the base. The housing comprises a pair of
opposing side walls and a pair of opposing end walls that extend
from and are generally transverse to the base, and a cover, which
together define a chamber for a stack of sheets. The chamber has a
length greater than that of the stack. The cover is comprised of an
opening that is defined by first and second flanges. The first
flange has a first end, a second end opposite the first end and a
pair of opposing edges extending therebetween. The first end of the
first flange is connected to a first one of the end walls of the
housing. The pair of opposing edges of the first flange are
adjacent to and spaced from the respective adjacent side walls. The
second flange also has a first end, a second end opposite the first
end and a pair of opposing edges extending therebetween. The first
end of the second flange is connected to a second one of the end
walls. The pair of opposing edges of the second flange are also
adjacent to and spaced from the respective adjacent side walls. The
second ends of each flange define a width of the opening of at
least about 0.33 inches. The stack of sheets comprises a plurality
of sheets, each of which has a stiffness equal to or greater than
1.967.times.10.sup.-3 pounds-inch.sup.2.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a perspective view of a dispenser package of the
present invention.
[0007] FIG. 2 is a top view of the dispenser package of FIG. 1.
[0008] FIG. 2a is a top view of the dispenser package of FIG. 1
with a stack of index tabs therein.
[0009] FIG. 3 is a cross-sectional view of the dispenser package of
FIG. 2 taken along line 3-3.
[0010] FIG. 3a is a cross-sectional view of the dispenser package
of the present invention with a stack of index tabs therein.
[0011] FIGS. 4-6 are cross-sectional views of the dispenser package
of the present invention that depict the dispensing sequence of a
index tab from a stack.
[0012] While the above-identified drawing figures set forth one
preferred embodiment of the invention, other embodiments are also
contemplated, as noted in the discussion. In all cases, this
disclosure presents the present invention by way of representation
and not limitation. It should be understood that numerous other
modifications and embodiments can be devised by those skilled in
the art which fall within the scope and spirit of the principles of
this invention. It should be specifically noted that the figures
have not been drawn to scale as it has been necessary to enlarge
certain portions for clarity.
DETAILED DESCRIPTION
[0013] A perspective view of dispenser package 10 of the present
invention is shown in FIG. 1. Generally, dispenser package 10
comprises a housing 12 for containing a stack of index tabs (or
"sheets"), and a base 14 connected to the housing 12. While the
sheet material dispensed from the dispenser package will be
referred to as "index tabs" or "durable index tabs", it should be
understood that the invention contemplates the use of any sheet
material formed from a variety of materials (including paper) and
having a variety of thicknesses and shapes. The housing 12 is
formed by injection molding a rigid polymer, such as a general
purpose polystyrene, so as to form a pair of opposing side walls
16, 18, a pair of opposing end walls 20, 22, a perimeter flange 24
and a cover 26 each having a wall thickness of about 0.03 inches.
Perimeter flange 24 extends from walls 16, 18, 20 and 22 adjacent
to base 14 to connect housing 12 to base 14. The cover 26 is
comprised of a pair of opposing flanges 28 and 30. Each of flanges
28 and 30 has one end 32 thereof connected to a respective one of
the end walls 20, 22, an opposite end 34 that frames an opening 33
of cover 26, and a pair of opposing edges 36 that are spaced from
the respective side walls 16, 18 so as to define an elongated slot
38 on either side of housing 12. In one representative embodiment,
dispenser package 10 has a length L of about 2.73 inches and a
width W of about 1.54 inches.
[0014] As shown in a top view of dispenser package 10 in FIGS. 2
and 2a, housing 12 defines a chamber 40 for containing a stack of
durable index tabs 41 (shown partially in phantom), which in one
embodiment are formed from a plurality of sheets of PET each having
a sheet thickness of about 0.0036 inches. Chamber 40 has opposing
ends and a length defined by a midpoint 42 of walls 20 and 22 and
opposing sides and a width defined by a pair of spaced guides 43
that extend from each of the opposing side walls 16 and 18. In one
embodiment, the stack of index tabs 41 has a length of about 1.50
inches and chamber 40 has a length of about 2.18 inches, which
allows about 0.68 inches of travel for the stack 41 within chamber
40. This travel distance allows the stack to shuttle from one end
of chamber 40 to the other as individual index tabs are removed
from the stack. Chamber 40 has a width of about 1.04 inches, which
approximates the width of the stack of index tabs. Guides 43 extend
past the outermost edge 44 of each slot 38 which centers the
respective side edges 46 of the index tabs within chamber 40 and
prevents edges 46 from interference with outermost edge 44 as each
index tab is removed from the chamber 40.
[0015] As further shown in FIGS. 1, 2 and 2a, each flange 28, 30
comprises an elliptical relief area 48, which is formed by an
arched step down 50 that extends from end 34 of each flange
substantially to second end 32 of each flange. In one embodiment,
the arched step down 50 lowers the upper surface of elliptical
relief area 48 by about 0.06 inches from the upper surface of
adjacent area 49 of flanges 28 and 30. Elliptical relief areas 48
facilitate finger access to grab the topmost index tab from the
stack and further provide structural support to each flange 28, 30
so as to restrict bending of each flange 28, 30 to the respective
second ends 32 when the topmost index tab is removed from the
dispenser package 10
[0016] FIGS. 3 and 3a show sectional views of the dispenser package
10 taken along line 3-3 of FIG. 2. As shown in FIG. 3, flanges 28,
30 are generally parallel to base 14, which is flat. The bottom
surface of flanges 28, 30 define a height of chamber 40 of about
0.18 inches. Each end 34 of flanges 28, 30 is formed with a lip 52,
which in one embodiment extends approximately 0.30 inches from base
14. By contrast, the upper surface of elliptical relief areas 48
extend only 0.20 inches from base 14. Thus, as shown in FIG. 3a,
lips 52 serve to elevate the topmost index tab 54 in the stack
above the elliptical reliefs 48 to allow the topmost index tab to
be easily grasped for removal from dispenser package 10. As further
shown in FIG. 3a, initially, the stack 41 of durable index tabs has
a height closely approximating the height of chamber 40. In the
disclosed embodiment, flanges 28, 30 overlap and end portion of
stack 41 by about 0.24 inches when stack 41 is positioned against
the respective end walls 20, 22 of housing 12.
[0017] The distance of travel of stack 41 within chamber 40 may be
increased by increasing the length of chamber 40 while maintaining
the length of stack 41. Alternatively, the distance of travel of
stack 41 may be decreased by increasing the length of the stack 41
and maintaining the length of chamber 40. In such cases, opening 33
may also be increased by decreasing the length of each flange
sufficient to maintain an overlap of about 0.24 inches of flanges
28, 30 with a respective end portion of stack 41. By ensuring that
an end portion of stack 41 is overlapped by flanges 28, 30 by at
least about 0.24 inches, multiple index tab dispensing during
removal of a single index tab is avoided. Unintended multiple index
tab dispensing is also further avoided, particularly as the index
tabs in the stack are nearly depleted, by attaching the bottom-most
index tab in the stack to a relatively stiff backing material.
[0018] In one embodiment, the width of opening 33 of cover 26,
defined by the distance between lips 52 of flanges 28 and 30, is
selected to be about 0.33 inches, with opening 33 centered along
the length of chamber 40. The opening 33 of cover 26 is
considerably wider than the openings of shuttling-type dispensers
that contain flags formed of highly flexible polymeric sheets. This
wider opening 33 in cover 26 allows more space for index tabs made
of thicker or more rigid polymers, such as PET, to bow and pass
through opening 33 without causing a crease in the index tab. In a
preferred embodiment, the width of opening 33 of cover 26 is
selected to create an approximate index tab presentation angle A of
about 20 degrees to about 45 degrees. It should be noted that while
opening 33 is defined by lips 52 of flanges 28 and 30 in the
embodiment depicted in FIGS. 1, 2, 2a, and 3, in an alternate
embodiment, elongate slot 38 on either side of housing could be
omitted. In other words, while opening 33 would still be defined
between lips 52, cover 26 would not include elongate slots 38.
[0019] The operation of dispensing durable index tabs from
dispenser package 10 is shown in FIGS. 4-6. As shown in FIG. 4, as
the top most index tab 54 is removed from the stack 41, the stack
41 slides from one end of chamber 40 to the opposite end of chamber
40. At this point, approximately one half to about three quarters
of the repositionable adhesive layer 58 of topmost index tab 54 is
disengaged from the subsequent index tab 60 in the stack.
[0020] As shown in FIG. 5, as the topmost index tab 54 continues to
be pulled, flange 28 is allowed to pivot slightly only at second
end 32, due in part to the arched step down 50. As flange 28
pivots, the size of chamber 40 is increased sufficient to provide
additional clearance space S for index tab 60 to be drawn through
opening 33 in cover 26. Flange 28, however, continues to provide
sufficient frictional resistance against index tabs 54 and 60 to
prevent a premature separation of tab 54 from tab 60 as tab 54
exits chamber 40 and thus to ensure that index tab 60 is not lost
within chamber 40. With the topmost index tab 54 removed from the
stack 41, the subsequent index tab 60 rests on lip 52 of flange 28
for subsequent removal, as shown in FIG. 6.
[0021] The dispensing force of durable index tabs (i.e., the
maximum force required to remove the topmost index tab from the
dispenser) was measured in a dispenser having every feature of
dispenser package 10 except the elongated slots 38 that define
flanges 28 and 30. The dispensing force for the initial index tabs
removed from a full stack was higher than for the remaining index
tabs in the stack. The addition of the elongated slot 38 and
consequent formation of flanges 28 and 30 in dispenser package 10
resulted in a normalization of the dispensing force for each index
tab in the stack. In other words, the dispensing force for each
index tab in the stack was generally the same.
[0022] The combination of the relatively wide opening 33 and a
relatively stiff flange 28 results in minimizing the dispensing
force and providing a generally constant dispensing force of each
durable index tab from the dispenser package 10. The width of
opening 33 further ensures that index tab 60 does not become
creased as it is removed from dispenser package 10.
[0023] The dispenser package 10 of the present invention is
particularly suited for use with relatively inflexible index tabs.
The stiffness of a sheet is characterized by the tensile modulus
(E) times the area moment of inertia about the principle axis (I).
For sheets of PET, the tensile modulus is 506 Kpsi or greater. The
area moment of inertia of PET index tabs having a width of about
1.00 inches and a thickness of about 0.0036 inches is
3.888.times.10.sup.-9 inches.sup.4. Therefore, the stiffness of
such PET index tabs, (E*I), is 1.967.times.10.sup.-3
pounds-inch.sup.2. Thus, in one embodiment, dispenser package 10 is
adapted to dispense sheet materials that have stiffness value that
is equal to or greater than 1.967.times.10.sup.-3
pounds-inch.sup.2.
[0024] The opening width of at least about 0.33 inches combined
with the limited degree of flexing of flanges 28 and 30 allows the
dispenser to maintain a low profile and yet ensures that relatively
stiff sheets of material can be easily dispensed without creasing
the sheets, and maintains a generally constant dispensing force for
each sheet of material as the stack is dispensed. The dispenser
package 10 is therefore useable with desktop holders designed for
existing low profile dispensers of highly flexible polymer sheets
that are dispensed through a narrow opening.
[0025] As used herein, all numeric values expressed with two
decimal places include .+-.0.02 of the stated numeric value.
Although the present invention has been described with reference to
prefered embodiments, workers skilled in the art will recognize
that changes may be made in form and detail without departing from
the spirit and scope of the invention.
* * * * *