Note: Descriptions are shown in the official language in which they were submitted.
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DISPENSER FOR ROLLED PAPER
BACKGROUND OF THE INVENTION
No-touch dispensers, i.e., dispensers that do not require the patron to touch
any
part of the dispenser, are desired for many reasons. No-touch dispensing
reduces the
chance of transferring disease-causing bacteria, viruses and other
microorganisms. No-
touch dispensing also makes the process of obtaining a sheet simpler and
quicker.
Single-sheet dispensers, i.e., dispensers that dispense a consistent, fixed
quantity
of sheet material, are also desired for many reasons. They tend to reduce the
quantity of
sheet material used by an individual patron, thereby saving on material costs,
disposal
costs, and costs associated with the frequency whereby the dispensers must be
refilled.
No-touch, single-sheet dispensers for folded, interleaved sheets are known,
however the manufacturing processes associated with providing the folded,
interleaved
sheets are more expensive and complex than the process associated with
providing roll
products.
No-touch, single-sheet dispensers utilizing knives or other cutting devices to
cut
sheet material from a roll of sheet material are known, but knives and other
cutting
devices may present a danger to either a patron or an individual refilling the
dispenser.
No-touch, single-sheet dispensers for rolled products via zones of weakness
ire
known, but if the sheet material tears before the next zone of weakness
emerges from the
dispenser, the next patron has no sheet material to grasp.
No-touch, single-sheet dispensing of double rolled products via offset zones
of
weakness is also known, but dispensers for these products still have
disadvantages that
have yet to be overcome. As an example, these dispensers can be difficult to
load. As
another example, if the force applied by a patron to remove the sheet material
from the
dispenser is distributed evenly across the width of the sheet material, the
zones of
weakness may not separate, causing more than one sheet to be removed from the
dispenser. The features of the dispenser disclosed herein overcome these and
other .
disadvantages of prior art dispensers.
SUMMARY OF THE INVENTION
The aforesaid needs are fulfilled and the problems experienced by those
skilled in
the art overcome by the apparatus for dispensing rolled sheet material of the
present
invention. In one embodiment, the apparatus includes a housing defining an
interior
adapted to rotatably support rolled sheet material and having a dispensing
opening sized
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to allow sheet material to be dispensed therefrom. The apparatus further
includes a nip
within the housing such as, for example, may be formed by first and second
rollers. In
addition, the apparatus includes a sheet material dispensing surface proximate
the
dispensing opening, the sheet material dispensing surface comprising at least
one
protrusion. By way of nonlimiting example, the sheet material dispensing
surface may
include portions that are partially flat, convex, concave, curved, rounded,
bowed, arched,
warped, creneliated, crenelated, or dished in shape, and so forth, and
combinations
thereof. Desirably, the sheet material dispensing surface at least partially
extends into the
path between the nip and the dispensing opening. Optionally, the sheet
material
dispensing surface may at least partially define the dispensing opening.
In one aspect, the sheet material dispensing surface comprises a fixed member
located between the nip and the dispensing opening. Desirably, the fixed
member is
positioned between the nip and the dispensing opening such that the sheet
material is
allowed to travel along a circuitous path.
In another embodiment, the apparatus includes a housing defining an interior
adapted to rotatably support rolled sheet material and having a dispensing
opening sized
to allow sheet material to be dispensed therefrom, a nip within the housing,
and a roll of
sheet material having a plurality of zones of weakness that substantially
extend across the
width of the sheet material. The apparatus further includes a sheet material
dispensing
surface proximate the dispensing opening, the sheet material dispensing
surface
comprising at least one protrusion. The sheet material is dispensed along a
path that
extends from the roll of sheet material, through the nip, across the sheet
material
dispensing surface, and through the dispensing opening. Desirably, the
protrusion
concentrates force on the portion of the sheet material that contacts the
protrusion when
the sheet material is pulled across the sheet material dispensing surface and
through the
dispensing opening.
In another embodiment, the apparatus includes a housing defining an interior
adapted to contain rolled sheet material and a dispensing opening for allowing
sheet
material to be dispensed from the interior of the housing. The apparatus
further includes a
nip within the housing such as, for example, may be formed by first and second
rollers. In
addition, the apparatus includes a mobile roll support system adapted to
support a roll of
sheet material within the housing wherein the roll of sheet material rotates
to dispense
sheet material and further wherein the mobile roll support system and the roll
of sheet
material move toward the nip as sheet material is dispensed. Desirably, the
housing
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further comprises a first housing section and a second housing section with
the first
housing section being at least partially removably attached to the second
housing section.
In a further aspect, the apparatus comprises first and second tracks, each
track
engaging the mobile roll support system wherein the mobile roll support system
travels
within the tracks as the roll of sheet material is dispensed. Desirably, the
tracks are
parallel to one another, and even more desirably the tracks are angled
downwardly
wherein the mobile roll support system moves toward the nip as the sheet
material is
dispensed and the diameter of the roll of sheet material decreases. By way of
nonlimiting
example, one or both of the tracks may be a slot defined within the side of
the housing.
The slots may have various configurations with respect to the sections that
are part of the
housing. The slots may be defined between the first and second housing
sections, may be
wholly contained within one of the first and second housing sections, or may
extend from
within the first housing section to within the second housing section.
In still a further aspect, the mobile roll support system comprises a
dispensing
roller having first and second ends, each end slideably engaging a track. Such
a mobile
roll support system is desirable for dispensing roils of sheet material that
are wound about
a central core. Alternatively, the mobile roll support system can comprise at
least two
separate mobile supports, each support being slideably engaged within a track.
Such a
mobile roll support system is desirable for dispensing rolls of sheet material
that are
coreless or that are wound throughout their entire diameters. For dispensing
coreless rolls
of sheet material, the mobile roll supports desirably comprise an engaging
member
attached to the supports. The engaging member is adapted to engage one side of
a roll of
sheet material. The engaging member is desirably adapted to extend into the
interior of
the rolled sheet material.
Desirably, the nip comprises at least one roller. More desirably, the nip is
pressurized. As one example, the nip may be pressurized by at least one
spring.
Desirably, the roll of sheet material supported by the mobile roll support
system rests
against one of the nip rollers and the path of the sheet material extends
through the nip
and through the dispensing opening.
Desirably, the roll of sheet material comprises one or more layers of sheet
material
having zones of weakness therein. Even more desirably, the layers of sheet
material
comprise a plurality of offset zones of weakness that substantially extend
across the width
of the sheet material.
Other features and aspects of the present invention are discussed in greater
detail
below.
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BRIEF DESCRIPTIONS OF THE DRAWINGS
FIG. 1 is a perspective view of a dispenser of this invention.
FIG. 2 is an exploded perspective view depicting the interior of the dispenser
of
FIG. 1.
FIG. 2A is an exploded perspective view depicting the interior of an alternate
embodiment.
FIG. 3 is a cross-sectional side view of the dispenser of FIG. 1.
FIG. 4A is a perspective view of an exemplary dispensing surface for the
dispenser of FIG. 1.
FIG. 4B is a front view of the dispensing surface of FIG. 4A.
FIGS. 4C-4E are cross-sectional side views of the dispensing surface of FIG
4A.
FIG. 5 is a perspective view of a dispenser of this invention.
FIG. 6 is a perspective view depicting the interior of the dispenser of FIG.
5.
FIG. 7 is an exploded perspective view depicting the interior of the dispenser
of
FIG. 5.
FIGS. 8A & 8B are fragmentary perspective views depicting the guide roller
within
the dispenser of FIG. 5.
FIG. 9 is a fragmentary cross-sectional side elevation view of the dispenser
of FIG.
5.
FIG. 10A is a perspective view of an exemplary dispensing surface for the
dispenser of FIG. 5.
FIG. 10B is a front view of the dispensing surface of FIG. 1 OA.
FIGS. 10C-10E are cross-sectional side elevation views of the dispensing
surface
of FIG. 10A.
DETAILED DESCRIPTION
Reference will now be made in detail to the various embodiments of the
invention,
one or more examples of which are illustrated in the drawings. Each example is
provided
by way of explanation of the invention and is not meant as a limitation of the
invention. For
example, features illustrated or described as part of one embodiment or figure
can be
used on another embodiment or figure to yield yet another embodiment. It is
intended that
the present invention include such modifications and variations.
The present invention provides an apparatus for dispensing rolled sheet
material.
Exemplary sheet materials for which the present invention is suitable include,
but are not
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limited to, absorbent sheet materials such as towels, wipers, tissue, and so
forth. Suitable
sheet materials are disclosed, by way of non-limiting examples only, in U.S.
Patents
5,048,589 to Cook et al., 5,399,412 to Sudall et al., 5,674,590 to Anderson et
al.,
5,772,845 to Farrington, Jr. et al., 5,904,971 to Anderson et al., 6,248,212
to Anderson et
al., and 6,273,996 to Hollenberg et al., the entire contents of which are
herein
incorporated by reference. The sheet materials for which the present invention
is suitable
are desirably wound around a core, yet may, for other embodiments, be
coreless. The
sheet materials for which the present invention is suitable desirably have
regularly spaced
zones of weakness extending substantially across the width of the sheet
material. The
zones of weakness are used to separate the sheet material into individual
sheets and may
be, for example, defined by a series of perforations. The sheet material
having regularly
spaced zones of weakness substantially extending across its width is desirably
double
wound into a roll having inner and outer layers of sheet material wherein the
zones of
weakness for the inner and outer layers are offset as is taught in U.S. Patent
3,770,172 to
Nystrand, herein incorporated by reference in its entirety. Double wound sheet
material
having offset zones of weakness allows the sheet material to tear within the
dispenser
while still providing a tail of sheet material extending from the dispenser to
be grasped by
the next patron.
An embodiment of'the dispenser of the present invention is depicted in FIG. 1
at
10. The dispenser 10 includes a housing 12 that comprises a first housing
section 14 and
a second housing section 16. When the first housing section 14 and the second
housing
section 16 are in the closed position (as depicted in FIG. 1), the first
housing section 14
and the second housing section 16 together define a dispensing opening 22, a
first angled
slot 24, and a second angled slot on the opposite side wall (not depicted).
Sheet material
26 is dispensed through the dispensing opening 22. Optionally, there may be a
window 11
defined in one of the housing sections to allow viewing of the interior of the
dispenser 10.
The window 11 may be open, or may be constructed of a transparent or
translucent
material that permits viewing of the interior of the dispenser 10.
Referring now to FIG. 2 that depicts the inside of the dispenser 10, the first
housing section 14 has a top edge 18, while the second housing section 16 has
a bottom
edge 20. The top edge 18 and the bottom edge 20 fit together to form the
housing 12.
The top edge 18 and the bottom edge 20 are configured such that the first
housing
section 14 and the second housing section 16 will not separate during the
dispensing
operation. However, when it is necessary to reload the dispenser, the first
housing section
14 and the second housing section 16 are readily separated. Methods of
removably
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attaching parts in this manner are well known to those skilled in the art.
Nonlimiting
examples include snaps, latches, buckles, locks, hooks, buttons, pins, cotter
pins, and so
forth.
Within the housing 12 is a dispensing roller 28 that is adapted to support a
roll of
sheet material 29 having a central aperture 31. The dispensing roller 28 has a
dispensing
roller body 30, a first dispensing roller end 32, and a second dispensing
roller end 34. The
dispensing roller body 30 is desirably cylindrical, but may be any other shape
that will
support the weight of the roll of sheet material 29. It is contemplated that
the dispensing
roller 28 may support the roll of sheet material 29 from within the central
aperture 31 or,
alternatively, may support the roll of sheet material 29 through contact with
the outside
surface of the roll of sheet material 29. The first and second dispensing
roller ends 32, 34
are slidingly engaged by the first and second angled slots 24, 25 that form
when the first
housing section 14 and the second housing section 16 are closed together. The
first and
second dispensing roller ends 32, 34 may be fixed with respect to the
dispensing roller
body 30 or may, alternatively, rotate independently from the dispensing roller
body 30.
The first and second dispensing roller ends 32, 34 are desirably cylindrical,
but may be
any other shape that will slideably engage the first and second angled slots.
Alternatively, referring now to FIG. 2A, the dispensing roller 28 of FIG. 2
may be
replaced by first and second mobile roll supports 28A. This embodiment may be
particularly desirable if the roll of sheet material is a coreless roll such
as, for example, is
taught in U.S. Patents 5,875,985 to Cohen et al. and 6,070,821 to Mitchell.
The mobile roll
supports 28A have mobile roll support ends 32A that slideably engage the
angled slots
24, 25. The mobile roll supports 28A also have an engaging member 28B adapted
to
engage one side of a roll of sheet material 29A. The engaging member 28B can
have any
one of numerous shapes. Desirably, the engaging member 28B further includes a
chamfered surface 28C. In other embodiments, the engaging member 28B may be
adapted to extend into the interior of the rolled sheet material 29A.
Referring again to FIG. 2, in one embodiment the roll of sheet material 29 may
rotate independently from the dispensing roller body 30. In this embodiment,
the roll of
sheet material 29 will rotate around the dispensing roller body 30 as the
sheet material 26
is dispensed. In another embodiment, the entire dispensing roller 28 including
the
dispensing roller body 30 and the dispensing roller ends 32, 34 may rotate
with the roll of
sheet material 29 as the sheet material 26 is dispensed. In a further
embodiment, the
dispensing roller body 30 may rotate with the roll of sheet material 29 while
the dispensing
roller ends 32, 34 remain fixed in the angled slots 24, 25 with respect to the
rotating
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dispenser roller body 30 and roll of sheet material 29. In another embodiment,
some
combination of the aforementioned relationships between the angled slots 24,
25, the
dispensing roller 28, and the roll of sheet material 29 may be used to
effectively dispense
the sheet material 26.
As the sheet material 26 is dispensed and the diameter of the sheet material
roll
29 decreases, the dispensing roller ends 32, 34 travel down the angled slots
24, 25. As
depicted in FIG. 2, the angled slots 24, 25 may be formed between the first
housing
section 14 and the second housing section 16. Alternatively, in other
embodiments the
first and second angled slots 24, 25 may be defined entirely within the sides
of the first
housing section 14, may be defined entirely within the sides of the second
housing section
16, or may cross over from the first housing section 14 to the second housing
section 16.
It is desirable that the angled slots 24, 25 be open to the housing section
edges 18, 20 to
facilitate placement of the dispensing roller 28 in the angled slots 24, 25.
The angled slots 24, 25 have the added benefit of providing a window through
which it is possible to detect how much sheet material 26 remains on the roll
of sheet
material 29 inside the housing 12. However, other embodiments may have tracks
on the
inside of the first housing section 14 and/or second housing section 16 with
which the
dispensing roller ends 32, 34 slidingly engage. As the roll of sheet material
29 is depleted,
the dispensing roller ends 32, 34 travel within the tracks.
Referring again to FIG. 2, within the housing 12 is a feed roller 36 that
provides
further support to the roll of sheet material 29. The feed roller 36 has a
feed roller body
38, a first feed roller end 40, and a second feed roller end 42. The first
feed roller end 40
engages a first feed roller aperture 44 in the side of the first housing
section 14. The
second feed roller end 42 engages a second feed roller aperture 46 in the
opposite side
of the first housing section 14. The first and second feed roller apertures
are positioned .
wherein the outer surface of a roll of sheet material 29 on the dispensing
roller 28 will rest
against the feed roller 36 as the roll of sheet material 29 is dispensed.
In one embodiment, the entire feed roller 36, including the feed roller body
38 and
ends 40, 42, may rotate with the roll of sheet material 29 as the sheet
material 26 is
dispensed. In another embodiment, the feed roller body 38 may rotate with the
roll of
sheet material 29 while the feed roller ends 40, 42 remain fixed in the feed
roller apertures
44. In a further embodiment, some combination of the aforementioned
relationships
between the roll of sheet material 29, the feed roller body 38, and the feed
roller ends 40,
42 may be used to effectively dispense the sheet material 26.
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Within the housing 12 is a guide roller 48 having a guide roller body 52, a
first
guide roller end 54, and a second guide roller end 56. The first guide roller
end 54
engages a first guide roller slot 57 in the side of second housing section 16.
The second
guide roller end 56 engages a second guide roller slot 59 in the opposite side
of the
second housing section 16. Referring now to FIG. 3, the guide roller 48 forms
a nip 50
with the feed roller 36. The nip 50 has an entrance side 50A and an exit side
50B.
Referring again to FIG. 2, the first and second guide roller slots 57, 59 are
positioned in
the sides of the second housing section 16 wherein the nip 50, shown in FIG.
3, is formed
between the guide roller body 52 and the feed roller body 38 when the second
housing
section 16 is closed against the first housing section 14. The guide roller 48
is biased or
pressurized against the feed roller 36 by first and second springs 58 having
first and
second spring ends 60, 62. The first spring ends 60 are connected to hooks 61
that hook
over the first and second guide roller ends 54, 56. The second spring ends 62
engage first
and second pegs 66 attached to the inside of the second housing section 16.
The guide
roller slots 57 allow the guide roller 48 to move and the first and second
springs 58 to
compress as the first and second housing sections 14, 16 are closed together.
Alternatively, other mechanisms known to those skilled in the art may be used
for biasing
or pressurizing the guide roller 48 against the feed roller 36.
The force exerted by the guide roller 48 against the feed roller 36 must be
such
that the tension required to be applied to the sheet material to pull it
through the nip 50
exceeds the breaking strength of the zones of weakness in the sheet material
yet does
not exceed the breaking strength of the remainder of the sheet material 26.
Therefore,
force applied to the sheet material 26 extending from the dispensing opening
22 will
advance the sheet material 26 until a zone of weakness emerges from the nip 50
between
the guide roller 48 and the feed roller 36. At that point the zone of weakness
will break,
providing a single sheet to the patron, and leaving an extended tail of sheet
material 26
for the next patron to grasp. A detailed description of the desired force
balance can be
found in United States Patent Number 3,770,172 to Nystrand.
In one embodiment, the entire guide roller 48, including the guide roller body
52
and first and second guide roller ends 54, 56, may rotate as the sheet
material 26 is
dispensed. In another embodiment, the guide roller body 52 may rotate with the
movement of the sheet material 26 while the guide roller ends 54, 56 remain
fixed in the
guide roller slots 57. In a further embodiment, some combination of the
aforementioned
relationships between the guide roller apertures 57, the guide roller 48, and
the feed roller
38 may be used to effectively dispense the sheet material 26.
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Referring again to FIG. 3, within the housing 12 and situated between the
dispensing opening 22 and the exit side 50B of the feed nip 50, a sheet
material
dispensing surface 70 is positioned wherein during the dispensing operation
the sheet
material 26 travels over and upon the sheet material dispensing surface 70. In
FIG. 3 the
sheet material dispensing surface 70 is depicted beneath the path of the sheet
material
26, but in other embodiments the sheet material dispensing surface 70 may
alternatively
be positioned above the path of the sheet material 26, or there may be first
and second
dispensing surfaces 70 positioned both above and below the path of the sheet
material
26. Referring now to FIGS. 2, 4A, and 4B, the sheet material dispensing
surface 70 has at
least one protruding area 74 that contacts the sheet material 26 as the sheet
material 26
is dispensed. The sheet material dispensing surface 70 also has at least one
depressed
area 76 that contacts the sheet material 26 with less force than does the
protruding area
74, or not at all, during dispensing. Desirable shapes for the sheet material
dispensing
surface 70 include, but are not limited to, partially flat, convex, concave,
convex, concave,
curved, rounded, bowed, arched, warped, dished, crenellated, crenulated, and
so forth,
and combinations thereof. An exemplary profile for the dispensing surface 70
is depicted
in FIGS. 4C-4E.
While the inventors do not wish to be held to a particular theory, it is
thought that
the dispensing force applied by a user to the sheet material 26 extending from
the
dispensing opening 22 is distributed to the areas of the sheet material 26
where the
protruding area 74 contacts the sheet material 26 as it is dispensed. By
concentrating the
applied force in this manner, separation of individual sheets at the zones of
weakness is
more likely to occur.
An alternate embodiment is depicted in FIGS. 5-10E. Referring to FIG. 5, the
dispenser 10A includes a housing 12A that comprises a first housing section
14A and a
second housing section 16A. When the first housing section 14A and the second
housing
section 16A are in the closed position (as depicted in FIG. 5), the first
housing section 14A
and the second housing section 16A together define a dispensing opening 22A
through
which sheet material 26 is dispensed.
Referring now to FIG. 6 that depicts the inside of the dispenser 10A, the
first
housing section 14A has a top surface 100 to which is attached a first latch
102, while the
second housing section 16A has a rim 104 to which is attached a second latch
106. The
rim 104 fits around and over the first housing section 14A to form the housing
12A. The
first latch 102 and the second latch 106 are configured to removably attach
upon closing
of the second housing section 16A such that the first housing section 14A and
the second
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housing section 16A will not separate during the dispensing operation.
However, when it
is necessary to reload the dispenser, the first housing section 14A and the
second
housing section 16A are readily separated. Methods of removably attaching
parts are well
known to those skilled in the art. Nonlimiting examples include snaps,
latches, buckles,
locks, hooks, buttons, pins, cotter pins, and so forth. With respect to the
particular
embodiment depicted in FIGS. 6 and 7, the first housing section 14A and the
second
housing section 16A are hingedly attached by first and second hinges 17. The
hinges 17
allow the housing 12A to be opened without complete separation of the first
and second
housing sections 14A, 16A.
In reference to FIG. 7, within the housing 12A is a dispensing roller 28 that
is
adapted to support a roll of sheet material 29 having a central aperture 31.
The
dispensing roller 28 has a dispensing roller body 30, a first dispensing
roller end 32, and a
second dispensing roller end 34. The dispensing roller body 30 is desirably
cylindrical, but
may be any other shape that will support the weight of the roll of sheet
material 29. It is
contemplated that the dispensing roller 28 may support the roll of sheet
material 29 from
within the central aperture 31 or, alternatively, may support the roll of
sheet material 29
through contact with the outside surface of the roll of sheet material 29. The
first and
second dispensing roller ends 32, 34 are slidingly engaged by the first and
second angled
tracks 124, 125. The first and second dispensing roller ends 32, 34 may be
fixed with
respect to the dispensing roller body 30 or may, alternatively, rotate
independently from
the dispensing roller body 30. Similarly, as sheet material 26 is dispensed,
the roll of sheet
material 29 may be fixed with respect to the dispensing roller body 30, or
may,
alternatively, rotate independently from the dispensing roller body 30. As the
sheet
material 26 is dispensed and the diameter of the sheet material roll 29
decreases, the
dispensing roller ends 32, 34 travel down the angled tracks 124, 125.
Also within the housing 12A is a feed roller 36 that provides further support
to the
roll of sheet material 29. The feed roller 36 has a feed roller body 38, a
first feed roller end
40, and a second feed roller end 42. The first feed roller end 40 engages a
first feed roller
aperture 144 in the side of the first housing section 14A. The second feed
roller end 42
engages a second feed roller aperture 145 in the opposite side of the first
housing section
14A. The first and second feed roller apertures are positioned wherein the
outer surface
of a roll of sheet material 29 on the dispensing roller 28 will rest against
the feed roller 36
as the roll of sheet material 29 is dispensed. As the sheet material 26 is
dispensed, the
feed roller body 38 rotates with the roll of sheet material 29. The feed
roller body 38 may
be fixed with respect to the first and second feed roller ends 40, 42, in
which case the first
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and second feed roller ends 40, 42 rotate within the first and second feed
roller apertures
144, 145. Alternatively, the feed roller body 38 may rotate independently from
the first and
second feed roller ends 40, 42.
Additionally, referring also now to FIGS. 8A and 8B, within the housing 12A is
a
guide roller 48 having a guide roller body 52, a first guide roller end 54,
and a second
guide roller end 56. The first and second guide roller ends 54, 56 engage
first and second
guide roller bushings 150, 152 having first and second guide roller bushing
ends 154, 156.
The first and second guide roller bushing ends 154, 156 slidingly engage first
and second
guide roller bushing slots 158, 160 in first and second guide roller arms 162,
164 attached
to the inside of the second housing section 16A.
The guide roller 48 is biased or pressurized between the second housing
section
16A and the feed roller 36 by first and second springs 170 having first and
second spring
ends 172, 174. The first spring ends 172 engage first and second pegs 176
attached to
the inside of the second housing section 16A. The second spring ends 174
engage first
and second spring caps 178 against which rest the first and second guide
roller bushings
150, 152. Referring now to FIG. 9, the guide roller 48 forms a nip 50 with the
feed roller
36. The nip 50 has an entrance side 50A and an exit side 50B. The first guide
roller arm
162 (not shown), and the second guide roller arm 164, attached to the inside
of the
second housing section 16A, are positioned wherein the nip 50 is formed
between the
guide roller 48 and the feed roller 36 when the second housing section 16A is
closed
against the first housing section 14A. As described above, the force exerted
by the guide
roller 48 against the feed roller 36 must be such that the tension required to
be applied to
the sheet material to pull it through the nip 50 exceeds the breaking strength
of the zones
of weakness in the sheet material yet does not exceed the breaking strength of
the rest of
the sheet material 26.
Referring now to FIG. 9, within the dispenser 10A and situated between the
dispensing opening 22A and the exit side 50B of the feed nip 50, a sheet
material
dispensing surface 70A is positioned such that, during the dispensing
operation, the sheet
material 26 travels over and upon at least a portion of the sheet material
dispensing
surface 70A. In FIG. 9 the sheet material dispensing surface 70A is depicted
beneath the
path of the sheet material 26, but in other embodiments the sheet material
dispensing
surface 70A may alternatively be positioned above the path of the sheet
material 26, or
there may be first and second dispensing surfaces 70A positioned both above
and below
the path of the sheet material 26. Referring now to FIGS. 7, 10A, and 10B, the
sheet
material dispensing surface 70A has at least one protruding area 74A that
contacts the
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sheet material 26 as the sheet material 26 is dispensed. The sheet material
dispensing
surface 70A also has at least one depressed area 76A that contacts the sheet
material 26
with less force during dispensing than does the protruding area 74A. Desirable
shapes for
the sheet material dispensing surface 70A include, but are not limited to,
partially flat,
convex, concave, curved, rounded, bowed, arched, warped, dished, crenellated,
crenulated, and so forth, and combinations thereof. An exemplary profile for
the
dispensing surface 70A is depicted in FIGS. 10C-10E.
While the inventors do not wish to be held to a particular theory, it is
thought that
the dispensing force applied by a user to the sheet material 26 extending from
the
dispensing opening 22A is increased in the areas where the protruding area 74A
contacts
the sheet material 26 as it is dispensed. By concentrating the force in this
manner,
separation of individual sheets at the zones of weakness is more likely to
occur.
While the invention has been described in detail with respect to specific
embodiments thereof, it will be apparent to those skilled in the art that
various alterations,
modifications and other changes may be made without departing from the spirit
and scope
of the present invention. It is therefore intended that all such
modifications, alterations and
other changes be encompassed by the claims.
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