U.S. patent application number 16/891631 was filed with the patent office on 2021-12-09 for roll material dispenser tear bar.
The applicant listed for this patent is San Jamar, Inc.. Invention is credited to Michael Young.
Application Number | 20210380367 16/891631 |
Document ID | / |
Family ID | 1000004884452 |
Filed Date | 2021-12-09 |
United States Patent
Application |
20210380367 |
Kind Code |
A1 |
Young; Michael |
December 9, 2021 |
ROLL MATERIAL DISPENSER TEAR BAR
Abstract
A web material dispenser tear bar, a dispenser assembly
comprising a tear bar and a method of forming the same. The tear
bar includes a cutting edge that is defined by a plurality of teeth
that extend along a longitudinal edge of a body of the tear bar.
The teeth include a first group of teeth that have a triangular
shape defined by linear edges of the respective teeth and a second
group of teeth where at least one side of each tooth of the second
group of teeth have a curved edge that extends in a radial
direction toward an adjacent one of the plurality of teeth. The
tear bar is preferably disposed in the housing of a dispenser and
oriented to engage a web material to selectively perforate and/or
sever a portion of the web material from the roll.
Inventors: |
Young; Michael; (Mukwonago,
WI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
San Jamar, Inc. |
Elkhorn |
WI |
US |
|
|
Family ID: |
1000004884452 |
Appl. No.: |
16/891631 |
Filed: |
June 3, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65H 35/008 20130101;
B65H 20/02 20130101; B65H 2301/51532 20130101; A47K 10/36 20130101;
B65H 2301/51514 20130101; B65H 2701/1924 20130101; B65H 16/005
20130101 |
International
Class: |
B65H 35/00 20060101
B65H035/00; B65H 16/00 20060101 B65H016/00; A47K 10/36 20060101
A47K010/36; B65H 20/02 20060101 B65H020/02 |
Claims
1. A tear bar for use in a web material dispenser, the tear bar
comprising: a body that extends in a longitudinal direction between
a first end and a second end of the body; and a cutting edge that
is defined by a plurality of teeth that extend along a longitudinal
edge of the body, the plurality of teeth comprising: a first group
of teeth that have a triangular shape relative to a direction
normal to a plane of the body; and a second group of teeth wherein
at least one side of each tooth of the second group of teeth has a
curved edge that extends in an outward radial direction toward an
adjacent one of the plurality of teeth.
2. The tear bar of claim 1 wherein each tooth of the second group
of teeth are adjacent to at least one other tooth of the second
group of teeth such that the curved edge of a first one of the
second group of teeth faces a curved edge of a second one of the
second group of teeth.
3. The tear bar of claim 2 wherein, the curved edge of the first
one of the second group of teeth and the curved edge of the second
one of the second group of teeth are separated by an arcuate trough
therebetween.
4. The tear bar of claim 3, wherein the curved edge of the first
one of the second group of teeth, the curved edge of the second one
of the second group of teeth and the arcuate trough defines a first
arcuate channel.
5. The tear bar of claim 4 wherein at least one tooth of the first
group of teeth has a linear edge that is adjacent to a linear edge
of at least one other tooth of the first group of teeth.
6. The tear bar of claim 5 wherein the linear edge of the at least
one tooth of the first group of teeth intersects the linear edge of
the at least one other tooth at an acute angle to define an acute
channel.
7. The tear bar of claim 6 wherein the acute angle is less than
65.degree..
8. The tear bar of claim 7 further comprising a plurality of acute
channels disposed between the first arcuate channel and a second
arcuate channel.
9. The tear bar of claim 8 wherein the linear edge of the at least
one tooth of the first group and the linear edge of the at least
one other tooth at an acute angle are separated by a rectilinear
trough.
10. The tear bar of claim 9 wherein the linear edge of the first
one of the first group of teeth, the linear edge of the second one
of the first group of teeth and the rectilinear trough defines a
first gap channel.
11. The tear bar of claim 10 further comprising a plurality of
acute channels disposed between the first arcuate channel and the
first gap channel.
12. A web material dispenser comprising: a housing defined by a
cover that movably cooperates with a base; a hub assembly disposed
in the housing and oriented to support a roll of a web material; a
drive mechanism supported the housing and oriented to advance the
roll of the web material; a tear bar disposed in the housing and
oriented to engage the web material to selectively perforate a
portion of the web material from the roll; a first set of teeth
defined by a portion of an edge of the tear bar, each tooth of the
first set of teeth having linear edges that intersect one another
at an apex; and a second set of teeth defined by another portion of
the edge of the tear bar, each tooth of the second set of teeth
having at least one arcuate edge having a radius of curvature that
extends across an axis that extends in a lateral direction across
the tear bar and is coincident with an apex of the tooth having the
at least one arcuate edge.
13. The web material dispenser of claim 12 wherein each tooth of
the second set of teeth further comprises a linear edge that is
opposite the respective at least one arcuate edge.
14. The web material dispenser of claim 12 wherein each tooth of
the second set of teeth are adjacent to at least one other tooth of
the second set of teeth so the arcuate edge of a first one of the
second set of teeth faces an arcuate edge of a second one of the
second group of teeth and are separated by an arcuate trough.
15. The web material dispenser of claim 14 wherein the arcuate edge
of the first one of the second set of teeth, the arcuate edge of
the second one of the second set of teeth and the arcuate trough
defines a first arcuate channel.
16. The web material dispenser of claim 15 wherein the linear edge
of at least one tooth of the first set of teeth is adjacent to and
intersects at an acute angle the linear edge of at least one other
tooth of the first set of teeth to define an acute channel.
17. The web material dispenser of claim 16 further comprising a
plurality of acute channels disposed between the first arcuate
channel and a second arcuate channel.
18. The web material dispenser of claim 17 wherein the linear edge
of at least one tooth of the first set of teeth and an adjacent
linear edge of a second one of the first set of teeth extends
outwardly from the tear bar and are separated by a rectilinear
trough.
19. The web material dispenser of claim 18 wherein the linear edge
of the at least tooth of the first set of teeth, the adjacent
linear edge of the second one of the first set of teeth and the
rectilinear trough defines a first gap channel.
20. The web material dispenser of claim 19 further comprising a
plurality of acute channels disposed between the first arcuate
channel and the first gap channel.
21. A method of forming a perforation bar of a rolled web material
dispenser, the method comprising: forming a cutting body defined by
a thickness and a longitudinal length that extends between a first
longitudinal end and a second longitudinal end of the body; and
forming a cutting edge with a longitudinal edge of the body and
defining the cutting edge to include a first group of teeth that
have a triangular shape relative to a direction normal to the
thickness of the body and a second group of teeth wherein at least
one side of each tooth of the second group of teeth has a curved
edge that extends in an outward radial direction in a plane defined
by the longitudinal length of the body toward an adjacent one of
the plurality of teeth.
22. The method of claim 21 further comprising orienting an apex of
each tooth of the first group of teeth to be collinear with an apex
of each tooth of the second group of teeth.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention generally relates to a tear bar for
perforating and/or severing a portion of a rolled web material such
as a single user portion of a web material, and, more specifically,
is directed to an dispenser assembly that incorporates a tear bar,
and method for dispensing a perforated portion of a rolled web
material through the use of a tear bar in a dispenser assembly.
[0002] Dispensers for dispensing discrete portions of paper or web
material from bulk rolls of such materials have been employed for
many years and across various industries and for various
applications. Such dispensers are widely used in public lavatories
to dispense paper toweling for users to dry their hands. Typically,
a bulk roll of sheet material is supported within a dispenser
cabinet or housing and incrementally rotationally advanced to
dispense discrete portions of the bulk material roll. In manually
operated devices, manual actuation of a button or lever effectuates
operation of a feed mechanism configured to rotationally advance
the bulk roll and dispense a tail end of the sheet material beyond
the confines of the cabinet or housing for use by the user. The
feed mechanism typically includes feed roller that is associated
with a drive roller and an idle roller to effectuate the desired
sequential incremental advancement of the web material from the
bulk roll. The manually actuated lever interacts with the drive
roller so that actuation of the lever rotates the drive roller.
Rotation of the drive roller acts to unwind material from the
material roll.
[0003] Alternative dispensers, which eliminate or limit manual
operation of the roll material dispensing systems, are often
referred to as "contactless" or "touchless" dispensers. Such
dispensers commonly use one or more proximity sensors that detect
the presence of a hand of other part of a user relative to the
dispenser and include a motorized feed assembly that advances the
feed mechanism to effectuate dispensing of the sheet material from
the housing.
[0004] Dispensers for rolls of flexible sheet material, whether
manually operated, operated in the touchless manner, or a
combination thereof, when deployed in restroom, industrial or
commercial environments, are often subject to high volumes of
repetitive usage. Additionally, many dispensers are configured to
receive and dispense various types of web material. For example, in
the context of hand towel dispensers, such dispensers may receive
rolls of single-ply or multi-ply material. Alternatively, the
material may be of variable thickness, absorbency, density, core
structure, etc. Accordingly, such dispensers are often not
customized to dispense a specific material, but rather are provided
with sufficient tolerances as to accommodate various materials.
Such wide tolerances may result in some web materials performing at
a higher level than others. That is to say, for example, a given
dispenser may perforate and sever a multi-ply material with more
consistency than a single-ply material. Or alternatively, a given
dispenser may generate undesirable hanging material tabs through
incomplete cuts or may be prone to material folding and jamming in
the feeder assembly when dispensing a given type of webbed
material. That is to say, some applications associated with the use
of such rolled web material dispensers require suitable tolerances
to accommodate multiple material types which may adversely impact
performance of the dispenser.
[0005] Poor performance of the dispenser assembly may include but
is not limited to jamming in the feed mechanism, incomplete tearing
of the material, and/or undesirable overlapping of the web of
material, and/or the imparting of undesired tensile forces to the
remainder of the roll of web material during dispensing during
undesired or incomplete tearing or perforating operations. Such
performance issues may require premature replacement of the roll of
web material and/or service of the dispenser including unloading
and reloading unconsumed rolls of web material in response to
undesired jamming of the web material during use thereof.
Replacement of spoiled rolls of web material, roll realignment, and
jam correction are both a time consuming and wasteful side effect
associated with an underperforming rolled web material
dispensers.
[0006] In an effort to mitigate the detriments of such events, some
dispenser assemblies are configured to receive and dispense only
one specific type of web material. By narrowly defining the
parameters of the web material accepted in the dispenser, the
assembly's tolerances can be narrowly tailored, and performance
optimized for dispensing that specific material. However, customers
often do not wish to be limited to a single web material option,
and desire to have flexibility in selecting the type of material
that will be dispensed from the assembly. In such dispensers, it is
not feasible to narrow the tolerances as to accommodate only a
single web material type. Such considerations and the dispense
operation and separation of discrete portions of the roll of web
material can be exacerbated in instances where the roll of web
material is provided in a non-uniform construction, such as if the
web material is provided with reinforcement members that extend the
longitudinal length of the rolled material. Although such
reinforcements improve the tensile performance of the web material,
particularly when gripped by wet hands, the reinforcements can
frustrate efforts intended to mitigate jamming of web material
during the dispensing operations.
[0007] Accordingly, there is a need for a tear bar, a dispenser
assembly including such a tear bar, and a method for severing web
material from a roll using a tear bar that allows the web material
to be cleanly and repeatedly torn from roll of material,
independent of the material type while mitigating instances of
jamming of the web material in the feed mechanism, incomplete
tearing of the material, undesirable overlapping of the web of
material, and mitigation of communication of tensile forces beyond
the perforation and toward remaining portions of the bulk roll of
web material.
SUMMARY OF THE INVENTION
[0008] The present invention discloses a web material dispenser
assembly that resolves one or more of the shortcomings disclosed
above.
[0009] One aspect of the present application discloses a tear bar
that is configured to perforate and/or cut a web material in a
repeatable manner and in a manner that mitigates side-to-side
and/or longitudinal translation of the roll of web material
relative to the feed mechanism and the tear bar associated
therewith. The tear bar defines a cutting edge that is defined by a
plurality of teeth that extend along a longitudinal edge of a body
of the tear bar. The teeth are dissimilar along the longitudinal
length of the tear bar and include a first group of teeth that each
have a generally triangular shape defined by adjacent linear edges
and a second group of teeth where at least one side of each tooth
of the second group of teeth has a curved edge that extends in a
radial direction toward an adjacent one of the plurality of teeth
of the tear bar.
[0010] Another aspect of the present application usable or
combinable with one or more of the above aspects discloses at least
one arcuate channel disposed in the cutting edge, formed by a
curved edge of the first one of the second group of teeth, an
adjacent curved edge of the second one of the second group of teeth
extends outwardly from the body of the tear bar such that tear bar
includes at least one an arcuate trough formed between adjacent
ones of the second group of teeth.
[0011] Another aspect of the present application usable or
combinable with one or more of the aspects disclosed above includes
at least one acute channel disposed in the cutting edge and formed
by the linear edge of the at least one tooth of the first group
that intersects the linear edge of the at least one other tooth at
an acute angle.
[0012] Still another aspect of the present application usable or
combinable with one or more of the aspects disclosed above includes
at least one gap channel disposed in the cutting edge, formed by
the linear edge of the first one of the first group of teeth and an
adjacent linear edge of the second one of the first group of teeth
that are separated by a the rectilinear trough.
[0013] Another aspect of the present application that is usable or
combinable with one or more of the above aspects discloses a first
and second arcuate channel separated by a plurality of acute
channels.
[0014] Still another aspect of the present application that is
usable or combinable with one or more of the above aspects
discloses a first arcuate channel and a first gap channel separated
by a plurality of acute channels.
[0015] Another aspect of the present application that is usable or
combinable with one or more of the above aspects discloses a
dispenser assembly having a housing defined by a cover that
cooperates with a base. A hub assembly is contained by the housing
and is configured to support a roll of web material and a feed
mechanism that is operable to sequentially dispense the roll of web
material. The dispenser includes a tear bar that intermittently
interacts with the web material such that, when the tear bar is
introduced thereto, the tear bar at least perforates the web
material to effectuate separation of discrete dispense portions
thereof. The tear bar includes a first set of teeth having linear
edges that intersect one another at an apex and a second set of
teeth having at least one arcuate edge having a radius of curvature
that extends in a lateral direction across the tear bar toward an
adjacent tooth and is coincident with an apex of the tooth having
the at least one arcuate edge.
[0016] Another aspect of the present application that is usable or
combinable with one or more of the above aspects includes a method
of dispensing web material from a roll using a tear bar in a
dispenser assembly. A further aspect of the present application
that is usable or combinable with one or more of the above aspects
discloses a method of forming a perforation bar of a rolled web
material dispenser. The method of forming the perforation bar
includes forming a cutting body that is defined by a thickness and
a longitudinal length that extends between a first longitudinal end
and a second longitudinal end of the body. The cutting edge is
formed by a longitudinal edge of the body and is defined to include
a first group of teeth wherein each tooth of the first group of
teeth has a triangular shape relative to a direction normal to the
thickness of the body and a second group of teeth wherein at least
one side of each tooth of the second group of teeth has a curved
edge that extends in an outward radial direction in a plane defined
by the longitudinal length of the body toward an adjacent one of
the plurality of teeth.
[0017] These and other aspects, features, and advantages of the
present invention will become apparent from the detailed
description, claims, and accompanying drawings.
DESCRIPTION OF THE DRAWINGS
[0018] A clear conception of the advantages and features
constituting the present invention, and of the construction and
operation of typical mechanisms provided with the present
invention, will become more readily apparent by referring to the
exemplary, and therefore non-limiting, embodiments illustrated in
the drawings accompanying and forming a part of this specification,
wherein like reference numerals designate the same elements in the
several views, and in which:
[0019] FIG. 1 is a perspective view of a roll material dispenser
assembly having a tear bar according to the present invention;
[0020] FIG. 2 is a perspective view of the roll dispenser assembly
of FIG. 1 with the cover and roll of web material removed therefrom
and exposing an interior of the base of the housing or enclosure of
the dispenser assembly;
[0021] FIG. 3 is perspective view of the roll dispenser assembly of
FIG. 2 with the cover removed therefrom and the roll of web
material installed therein with the tail thereof disposed proximate
the feed mechanism thereof;
[0022] FIG. 4 is a partial transverse cross-section top perspective
view of the dispenser assembly of FIG. 1 viewed from above the
rolls of the feed mechanism;
[0023] FIG. 5 is a partial transverse cross-section top perspective
view of the dispenser assembly of FIG. 1 viewed from within the
driver roll of the feed mechanism;
[0024] FIG. 6A is a top plan view of one embodiment of the tear bar
as installed within the dispenser assembly of FIG. 1; and
[0025] FIG. 6B is detailed top plan view of a portion of the
cutting edge of the tear bar of FIG. 6A.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] In describing the preferred embodiments of the invention
which are illustrated in the drawings, specific terminology will be
resorted to for the sake of clarity. However, it is not intended
that the invention be limited to the specific terms so selected and
it is to be understood that each specific term includes all
technical equivalents which operate in a similar manner to
accomplish a similar purpose. The various features and advantageous
details of the subject matter disclosed herein are explained more
fully with reference to the non-limiting embodiments described in
detail in the following description.
[0027] Illustrative embodiments of a dispenser assembly 10 in
accordance with various aspects of the present invention are shown
in FIG. 1 through FIG. 6B. Initially, FIG. 1 shows a dispenser
assembly 10 that includes an internally disposed rolled web
material tear bar 12 (FIG. 5), according to one embodiment of the
present invention, and as explained further below with respect to
FIGS. 4 through 6B.
[0028] Referring to FIGS. 1-3, material dispenser 10 includes a
cabinet, housing or enclosure 14 that is shaped to receive a
replaceable bulk roll of sheet or web material 16. Enclosure 14 is
defined by a base, back, or back wall 17, a first sidewall 18, a
second opposing sidewall 20, a floor 22, and a front cover 24 that
cooperate with one another to define an interior cavity 26 of
enclosure 14. Enclosure 14 may be formed of plastic or other
suitable material. The back wall 17, sidewalls 18, 20, and floor 22
collectively form a rear portion or base of enclosure 14.
Preferably, sidewalls 18, 20, floor 22, and back wall 17 are
provided in a unitary single body construction. Cover 24 movably
cooperates with the rear or base portion of enclosure 14 to
selectively expose cavity 26 associated with receiving discrete
sequential rolls of web material 16 associated therewith. As
disclosed above, it is appreciated that the rearward portion of
enclosure 14 or that portion that is generally rearward of cover 24
may be formed as a single or multiple piece assembly formed by
injection, blow, or roto molding. Alternatively, the various walls
or panels that define enclosure 14 may be separately manufactured
parts that are connected by methodologies such as welds, moldings,
fasteners, solder, overlapping snap fit connections, or the
like.
[0029] Referring to FIGS. 2 and 3, material dispenser 10 includes a
feed assembly or feed mechanism 28 that is contained within
enclosure 14. Although shown as an assembly that cooperates with
enclosure 14, it is appreciated that in other embodiments, the feed
mechanism 28 can be provided in the form of a cassette that can be
assembled prior to being associated with enclosure 14. Regardless
of the specific configuration, feed mechanism 28 includes one or
more rollers such as a drive roller 30 and an idle roller 32 that
are positioned relative to one another to effectuate the dispensing
of web material 16 beyond the confines of enclosure 14 and to a
user. The drive roller 30 and the idle roller 32 form a pressure
nip 34 through which the web material is drawn prior to being
dispensed beyond the confines or perimeter edge of enclosure 14.
The drive roller 30 and the idle roller 32 extend transversely with
respect to and are supported from the sidewalls 18, 20 of enclosure
14 such that the same are rendered rotatable about respective
parallel axes. It will be appreciated that these axes are also
generally parallel to the rotational axis of the roll of sheet or
web material supported therein.
[0030] Still referring to FIGS. 2 and 3, the roll of sheet or web
material 16 is configured to be retained within the cavity 26 of
the enclosure 14, above the feed mechanism 28. For example, a first
retaining arm 36 may extend outwardly from the back wall 17
adjacent the first side wall 22 and an opposing second roll
retaining arm 38 may extend from the back wall 17 adjacent the
second side wall 24. The first and second retaining arms 36, 38 may
be received and retained within first and second receiving slots
40, 42 adjacent the first and second side walls 18, 20,
respectively. A hub 44 extends inwardly from an outwardly extending
end of the first and second arms 36, 38, and when used in
combination are configured to rotatably receive the opposing
longitudinal ends or sides of the roll of sheet or web material
16.
[0031] In this configuration it will be appreciated that the roll
of sheet or web material 16 is rotatably suspended above the feed
mechanism 28, to spin about an axis that extends transversely with
respect to the sidewalls 18, 20 of enclosure 14 and generally
parallel to the rotational axis of the drive roller 30 and the idle
roller 32. From this rotatably mounted position, an end of the web
material extends downwardly for cooperation with the pressure nip
34 and is advanced out of the enclosure 14 though a downwardly
directed opening in the enclosure 14 upon activation and rotation
of the drive roller 34. In one embodiment of the present invention,
where the dispenser is a contactless system, the drive roller 34 is
advanced by user interaction with a touchless operator such as a
proximity sensor or the like to effectuation operation of the feed
mechanism.
[0032] In an alternative embodiment of the present invention, where
the drive roller 30 is advanced by manual activation an actuator
46, such as a wheel or lever, the actuator 44 may be manually
engaged by the user to advance the material from roll 16 through
the rollers 30, 32 and therefrom toward the dispense opening
defined by enclosure 14.
[0033] Still referring to FIGS. 2 and 3, a plurality of mounting
holes or apertures 48 are located in the back wall 16 of the
enclosure 14. The apertures 48 are configured to receive mounting
hardware, such as a threaded fastener or peg, therein such that the
material dispenser 10 may be affixed to a wall 16. When the
dispenser is mounted and the roll of webbed material 16 has been
loaded into the cavity 26, with an end of the web material 16
extending downwardly within the pressure nip 34, the enclosure 14
is closed such that the cover 24 movably cooperates with the rear
or base portion of enclosure 14 as shown in FIG. 1. Preferably,
dispenser assembly 10 includes a lock mechanism 50 that is
configured to provide only selective access to cavity 26 of
enclosure 14 for service and/or reloading operations.
[0034] Lock mechanism preferably includes a resilient barb 52 that
extends outwardly from the rear wall 16 of the base portion of the
enclosure 14 near the top of the dispenser 10. When closed, the
resilient barb 52 deflects about and engages a corresponding fixed
barb (not shown) disposed at the interior surface of a top portion
54 of the cover 24. Such a configuration allows the overlapping
barbs to maintain a friction fit closure between the cover 24 and
base portion of the enclosure 14 when enclosure 14 is closed. A
keyhole 56 is positioned in the top 54 of the cover 24, at a
location that overlies the resilient barb 52 when the dispenser
assembly 10 is in the closed configuration. Inserting a
corresponding elongated key 58 through the keyhole 56 allows the
key 58 to downwardly deflect the resilient barb 52 and release the
cover 24 from its engagement with the rear portion of the enclosure
14 to allow opening of dispenser assembly 10.
[0035] Turning now to FIGS. 4 through 6B, and initially FIGS. 4 and
5, the feed mechanism 28 of the dispenser assembly 10 is shown from
above in further detail where a portion of tear bar 12 is visible
proximate pressure nip 34 at a location generally between the drive
roller 30 and the idle roller 32. In one embodiment, the drive
roller 30 is generally cylindrical having a first end 60 rotatably
mounted to a first portion of a spring loaded advancement linkage
62 adjacent the first side 18 of the rear portion of the housing
14, and an opposing second end 64 rotatably mounted to a second
portion of the spring loaded advancement linkage 62 adjacent the
second side 20 of the rear portion of the housing 14. The cylinder
of the driver roller 30 may be bifurcated about its longitudinal
axis to form respective first and second generally corresponding
semicircular cylindrical segments 66, 68.
[0036] As shown in FIG. 4, the first cylindrical segment 66 is
positioned above the second cylindrical segment 68, such that the
second cylindrical segment 68 is obscured from view. The tear bar
12 is partially disposed within the drive roller 30 and between the
first and second cylindrical segments 66, 68. That is to say, the
tear bar 12 is disposed between the two respective cylindrical
segments and is preferably moveable in an outward radial direction
relative thereto during rotation of drive roller 30. Tear bar 12 is
formed by a body that defines a cutting edge 70 that periodically
extends outwardly or protrudes from the outer surface 72 of the
driver roll 30 and into engagement with the webbed material passing
thereof. When introduced to web material 16, cutting edge 70
perforates the web material to define a tear line associated with a
desired amount thereof. The first and second segments 66, 68 of the
driver roll 30 may be formed by injection, blow, or roto molding
and are connected by fasteners 74 that extend between the first and
second segments 66, 68 below the outer surface 72 of the driver
roll 30. In this configuration, the tear bar 12 is securely
moveably retained within the driver roll 30. Alternatively, the
first and second segments 66, 68 of the driver roll 30 may be
affixed to one another by welds, moldings, fasteners, solder,
overlapping snap fit connections, or the like.
[0037] Referring now to FIG. 5, which illustrates a cross section
through the first segment 66 of the driver roll 30, such that the
tear bar 12 is shown overlying the interior of the second segment
68. As described above, the tear bar 12 provides a cutting edge 70
that periodically extends outwardly from the outer surface 72 of
the driver roll, towards the idle roller 32. The cutting edge 70
comprises a generally planer array of teeth 76 wherein the plane of
teeth 76 are generally defined by the thickness of tear bar 12.
Cutting edge 70 is defined by plurality of adjacent teeth 76 that
define discrete channels 78 therebetween as will be described in
further detail below. As disclosed further below, the plurality of
teeth 76 defined by cutting edge 70 are dissimilar relative to the
longitudinal length of cutting edge 70. The cutting edge 70 extends
outwardly along a longitudinal edge of the planar body 80 of the
tear bar 12.
[0038] Still referring to FIG. 5, the body 80 is disposed within or
supported by a housing or carrier 82, which may be affixed about
the body 80 and extend rearwardly therefrom via welds, moldings,
fasteners, solder, overlapping snap fit connections, or the like. A
rear edge 84 of the carrier 82 and a corresponding rear edge 86 of
the body of the tear bar 12 may include one or more indexing
structures, such as a notch 88, which mates with a one or more
corresponding bosses 90 extending inwardly from a respective one or
both of the first and/or second segments 66, 68 of the driver roll
30. Engagement of the notches 88 and their corresponding bosses 90
provides for proper orientation and positioning of the tear blade
12 within the driver roll 30, when the two opposing segments 66, 68
are fastened together to form the assembled driver roll 30.
[0039] During operation, rotation of the drive roll 30 advances the
end of the roll of web material 16 through the feed mechanism 28
and through the pressure nip 34 where it then extends downwardly
through the opening in the floor 22 of the encasement 14. Rotation
of the drive roll 30 intermittently introduces the cutting edge of
the tear bar 12 into contact with the roll of web material 16 once
a desired length of web material 16 has been expelled through the
opening. In one embodiment of the present invention the length of
web material 16 is preferably between 8 inches and 16 inches;
however, it should be understood that the present invention is not
so limited and that other lengths of web material between instances
of interaction of cutting edge 70 therewith are envisioned and
considered within the scope of the present invention.
[0040] Upon completion of a desired degree of driver roller 30
rotation, the tear bar 12 engages the web material 16 to cut, i.e.
perforate, the web material 16 at the various longitudinal
locations that overly the array of teeth 76 as the web material
passes thereover. Preferably, teeth 76 perforate rather than fully
sever the web materials and perforate the web material in a manner
wherein force applied to an exposed tail of the web material by the
user of the web of material 16 sufficiently completes the
separation of the predetermined length of the web material 16 from
the roll, and initiates presentation of a subsequent length of web
material from dispenser assembly 10 and passage through the feed
mechanism 28 such that the same is presented for subsequent user
initiated tearing in the manner described above.
[0041] Cutting edge 70 is constructed to mitigate jamming of the
web of material 16 in the feed mechanism 28, incomplete tearing,
and/or undesirable overlapping of the web of material 16 during
each dispense event. Referring to FIGS. 6A and 6B, tear bar 12 is
shown removed from dispenser assembly 10. More specifically, FIGS.
6A and 6B illustrates an embodiment of the tear bar 12 that is well
suited for use in a dispenser assembly 10 that is configured to
dispense a roll of web material 16 having a width of approximately
8.0 inches and materials of varied construction such as materials
having a uniform construction and materials that may have
longitudinal reinforcement fibers contained therein. It is
appreciated that alternative embodiments of the present invention,
including a dispenser assembly 10 that is configured to dispense a
roll of web material 16 having a width of approximately 10.0
inches, and/or alternative widths of web material are considered
within the scope of the present invention. That is, it is
appreciated that the longitudinal length of tear bar 12 can be
configured to accommodate use of a tear bar having a cutting edge
70 as defined by the appending claims in dispenser assemblies
configured to dispense web materials having various longitudinal
widths.
[0042] Referring initially to FIG. 6A, tear bar 12 is preferably
defined by elongate body 80, preferably formed of metal such as
stainless steel, that extends between the cutting edge 70 and a
rear edge 86 associated therewith. Body 80 preferably includes one
or more indexing notch(es) 88 that are located about the length of
the rear edge 86 of body 80. A plurality of apertures 92 extend
through the generally elongate body 80 and are preferably dispersed
between a respective first longitudinal end or side 94 and opposing
second longitudinal end or side 96 thereof. One or more of
apertures 92 accommodate tear bar 12 being molded or otherwise
fastened to carrier or housing 82.
[0043] As indicated above, the cutting edge 70 of the tear bar 12
comprises a generally planer array of teeth 76 where adjacent teeth
76 define discrete channels 78 therebetween. As disclosed above,
plurality of teeth 76 are not uniform along the entire longitudinal
length of body 80 but are rather oriented in discrete groups of
differently shaped teeth. Tear bar 12 includes a distinct
configuration of channels 78 as defined by the discrete spaced
between adjacent teeth 76, and which extend outwardly from the body
80 to a distance of approximately 0.25 inches.
[0044] First, the cutting edge 70 provides acute channels 98, which
as used herein are defined by adjacent teeth 76 having linear
cutting edges 100 that are oriented towards one another as they
extend outwardly in the perforating or cutting direction from the
longitudinal axis of the body 80 of the tear bar 12. In a preferred
embodiment, the adjacent teeth 76 which form the acute channels 98
define a relative angle of between 65.degree. and 45.degree., and
more preferably between 60.degree. and 50.degree. relative to one
another. Second, the cutting edge 70 provides arcuate channels 102,
which as used herein are defined by adjacent teeth 76 having
curvilinear or non-linear cutting edges 104 which intersect at an
arcuate trough 106 at the base of the arcuate channel 102 opposite
the tips of the outwardly extending teeth 76. In a preferred
embodiment the adjacent teeth 76 which form the arcuate channels
102 define a relative angle of between 100.degree. and 80.degree.,
and more preferably between 95.degree. and 85.degree. relative to
one another. Third, the cutting edge 70 provides gapped channels
108, which as used herein are defined by adjacent teeth 76 having
generally linear cutting edges 110 that are both oriented at a
linear angle relative to one another and also spaced apart from one
another by a trench 112 disposed at the base of the gapped channel
108. In a preferred embodiment, the adjacent teeth 76 which form
the gapped channels 108 define a relative angle of between
100.degree. and 80.degree., and more preferably between 95.degree.
and 85.degree. relative to one another, and are spaced apart from
one another by a trench 112 having a linear distance of
approximately preferably between 0.05 and 0.25 inches, and more
preferably between 0.10 and 0.20 inches. The trench 112 located at
the base of the gapped channels 108 similarly has a depth of
approximately preferably between 0.05 and 0.25 inches, and more
preferably between 0.10 and 0.20 inches, such that trench 112 is
generally rectilinear. In this configuration the rectilinear trench
112 of the gapped channel 108 is further distinguishable from the
arcuate trough 106 of the arcuate channels 102.
[0045] In combination, the orientation of the teeth 76 as to define
the acute channels 98, arcuate channels 102, and gapped channels
108 work in combination to avoid the web of material 16 from
jamming in the feed mechanism 28, incomplete tearing, and/or
undesirable overlapping of the web of material 16 during use of the
dispenser assembly 10. Moreover, in one embodiment of the present
invention the cutting edge 70 of the tear bar 12 formed of the
various channels 98, 102 and 108 is arraigned in a somewhat
repeating pattern along the longitudinal length of cutting edge 70.
For example, a plurality of acute channels 98 may repeat in
succession followed by either an arcuate channel 102 or a gapped
channel 108, and then repeat. As shown in a portion of tear blade
12 shown in FIG. 6A, adjacent the first end 94, a series of three
successive acute channels 98 are followed by either an arcuate
channel 102 or a gapped channel 108. More specifically, the pattern
of channel orientation mirrors on either side of the tear bar 12 as
shown in FIG. 6A. Specifically, working from the outer edge 94, 96
towards the midline, each side of the tear bar 12 provides the
following sequence of channels: one arcuate channel 102, three
acute channels 98, one arcuate channel 102, three acute channels
98, one gapped channel 108, three acute channels 98, one arcuate
channel 102, followed by a final series of three acute channels 98.
The center of the cutting edge 70, about which both sides are
preferably mirror images of one another, may include a large
central trench 114, as illustrated in FIG. 6A. Alternatively, it is
considered well within the scope of the present invention that the
number of acute channels 98 that repeat in a series may be more or
less than three, particularly as is needed to provide for a cutting
edge 70 of a desired length as required by the width of the roll of
web material 16 intended to be perforated and/or cut from the
dispenser assembly 10 during each successive tearing event.
Furthermore, it is considered within the scope of the present
invention that the angles of the cutting edges of the teeth 76
which form the various channels 98, 102, 108 may vary within the
discrete ranges provided above, such that not all channels 98, 102,
108 of a given type need be identical within the tear bar 12.
[0046] Further, it is appreciated that the cutting edge 70 may be
implemented in a variety of configurations, using certain features
or aspects of the embodiments described herein and others known in
the art. Thus, although the invention has been shown and described
in what is perceived to be the most practical and preferred
embodiments, it is to be understood that the invention is not
intended to be limited to the specific features and embodiments set
forth above. Rather, it is recognized that modifications may be
made by one of skill in the art of the invention without departing
from the spirit or intent of the invention and, therefore, the
invention is to be taken as including all reasonable equivalents to
the subject matter of the claims.
[0047] Therefore, one aspect of the present application discloses a
tear bar for use in a web material dispenser wherein the tear bar
includes a body that extends in a longitudinal direction between a
first end and a second end of the body. The tear bar defines a
cutting edge that is defined by a plurality of teeth that extend
along a longitudinal edge of the body. The plurality of teeth
include a first group of teeth that have a triangular shape
relative to a direction normal to a plane of the body and a second
group of teeth wherein at least one side of each tooth of the
second group of teeth has a curved edge that extends in an outward
radial direction toward an adjacent one of the plurality of
teeth.
[0048] Another aspect of the present application discloses a web
material dispenser having a housing that is defined by a cover that
movably cooperates with a base. A hub assembly is disposed in the
housing and is oriented to support a roll of a web material. A
drive mechanism is supported by the housing and is oriented to
advance the roll of the web material. A tear bar is disposed in the
housing and oriented to engage the web material to selectively
perforate a portion of the web material from the roll. A portion of
an edge of the tear bar defines a first set of teeth wherein each
tooth of the first set of teeth has linear edges that intersect one
another at an apex of the discrete tooth. Another portion of the
edge of the tear bar defines a second set of teeth wherein each
tooth of the second set of teeth have at least one arcuate edge
having a radius of curvature that extends across an axis that
extends in a lateral direction across the tear bar and is
coincident with an apex of the tooth having the at least one
arcuate edge.
[0049] A further aspect of the present invention discloses a method
of forming a perforation bar of a rolled web material dispenser.
The method includes forming a cutting body that is defined by a
thickness and a longitudinal length that extends between a first
longitudinal end and a second longitudinal end of the body. A
cutting edge is defined by a longitudinal edge of the body and
includes a first group of teeth that have a triangular shape
relative to a direction normal to the thickness of the body and a
second group of teeth wherein at least one side of each tooth of
the second group of teeth has a curved edge that extends in an
outward radial direction in a plane defined by the longitudinal
length of the body toward an adjacent one of the plurality of
teeth.
[0050] These are other aspects, advantages, features, and
equivalents thereof, are encompassed by the appending claims.
* * * * *