U.S. patent application number 10/945472 was filed with the patent office on 2006-03-23 for deformable grip for a writing implement.
Invention is credited to Jeffrey Hautzinger, Ken Kostecki.
Application Number | 20060062628 10/945472 |
Document ID | / |
Family ID | 35636752 |
Filed Date | 2006-03-23 |
United States Patent
Application |
20060062628 |
Kind Code |
A1 |
Kostecki; Ken ; et
al. |
March 23, 2006 |
Deformable grip for a writing implement
Abstract
A deformable grip for a writing implement having a rigid barrel
includes a grip layer connected to the rigid barrel. The grip layer
is formed of a solid viscoelastic grip material having a hardness
of approximately 1 to 80 Shore OO durometer allowing the grip layer
to achieve a deformed shape under manual pressure. The grip
material further has a shape retention adapted to retain the
deformed shape for at least 1 second. A coating is disposed over
the grip layer and is formed of a coating material having a tensile
strength of at least approximately 50 to 1000 psi and an elongation
ratio of at least approximately 50 to 2000 percent. The grip may be
formed over a majority of the barrel length to accommodate a
variety of grip points and to improve comfort to a user.
Inventors: |
Kostecki; Ken; (Westchester,
IL) ; Hautzinger; Jeffrey; (Chicago, IL) |
Correspondence
Address: |
MARSHALL, GERSTEIN & BORUN LLP
233 S. WACKER DRIVE, SUITE 6300
SEARS TOWER
CHICAGO
IL
60606
US
|
Family ID: |
35636752 |
Appl. No.: |
10/945472 |
Filed: |
September 20, 2004 |
Current U.S.
Class: |
401/6 ;
16/430 |
Current CPC
Class: |
Y10T 16/476 20150115;
B43K 23/008 20130101 |
Class at
Publication: |
401/006 ;
016/430 |
International
Class: |
A46B 5/02 20060101
A46B005/02 |
Claims
1. A deformable grip for a writing implement having a rigid barrel,
the grip comprising: a grip layer connected to the rigid barrel,
the grip layer being formed of a solid viscoelastic grip material
having a hardness of approximately 1 to 80 Shore OO durometer
allowing the grip layer to achieve a deformed shape under manual
pressure, the grip material further having a shape retention
adapted to retain the deformed shape for at least 1 second; and a
coating disposed over the grip layer, the coating being formed of a
coating material having a tensile strength of at least
approximately 50 to 1000 psi and an elongation ratio of at least
approximately 50 to 2000 percent.
2. The deformable grip of claim 1, in which the coating comprises a
spray coating applied to the grip layer.
3. The deformable grip of claim 1, in which the grip material
comprises silicone material.
4. The deformable grip of claim 1, in which the grip material
comprises a polyurethane material.
5. The deformable grip of claim 4, in which the polyurethane
material comprises a two-part urethane gel material.
6. The deformable grip of claim 1, in which the coating material
and grip material adhere to one another.
7. The deformable grip of claim 1, in which the grip material
comprises a polyurethane material and the coating material
comprises a polyurethane material.
8. The deformable grip of claim 7, in which the grip layer is
formed by low pressure casting, and in which the coating layer is
formed by spray coating.
9. The deformable grip of claim 1, in which the grip material has a
hardness of approximately 5 to 70 Shore OO durometer.
10. The deformable grip of claim 1, in which the grip material has
a hardness of approximately 10 to 50 Shore OO durometer.
11. The deformable grip of claim 1, in which the coating material
has a tensile strength of at least approximately 100 to 900
psi.
12. The deformable grip of claim 1, in which the coating material
has a tensile strength of at least approximately 150 to 800
psi.
13. The deformable grip of claim 1, in which the coating material
has an elongation ratio of at least approximately 100 to 1500
percent.
14. The deformable grip of claim 1, in which the coating material
has an elongation ratio of at least approximately 200 to 1000
percent.
15. The deformable grip of claim 1, in which the grip material has
a hardness of approximately 10 to 50 Shore OO durometer, and in
which the coating material has a tensile strength of at least
approximately 150 to 800 psi and an elongation ratio of at least
approximately 200 to 1000 percent.
16. The deformable grip of claim 1, in which the grip layer is
permanently adhered to the rigid barrel.
17. A method of forming a deformable grip for a writing implement
having a rigid barrel, the method comprising: forming a grip layer
directly onto a portion of the rigid barrel thereby to bond the
grip layer to the rigid barrel, the grip layer being formed of a
solid viscoelastic grip material; and forming a coating layer on
the grip layer, the coating layer being formed of a coating
material selected to bond with the grip material.
18. The method of claim 17, in which the grip material has a
hardness of approximately 1 to 80 Shore OO durometer allowing the
grip layer to achieve a deformed shape under manual pressure, the
grip material further having a shape retention adapted to retain
the deformed shape for at least 1 second.
19. The method of claim 18, in which the grip layer is formed on
the rigid barrel by a forming process selected from a group of
forming processes comprising casting and molding.
20. The method of claim 18, in which the grip material comprises a
polyurethane material.
21. The method of claim 20, in which the polyurethane material
comprises a two-part polyurethane gel material.
22. The method of claim 21 in which the grip layer forming
comprises casting.
23. The method of claim 17, in which the coating material has a
tensile strength of at least approximately 50 to 1000 psi and an
elongation ratio of at least approximately 50 to 2000 percent.
24. The method of claim 23, in which the coating layer is formed on
the grip layer by a coating process selected from the group of
coating processes comprising spraying, plasma vapor depositing, dip
applying, in-mold coating, heat shrink tubing, and elastic fabric
forming.
25. The method of claim 23, in which the coating material comprises
a polyurethane material.
26. The method of claim 25, in which the coating layer forming
comprises spray coating.
27. The method of claim 17, in which the grip material comprises a
polyurethane material and the coating material comprises a
polyurethane material.
28. The method of claim 27, in which the grip layer forming
comprises casting, and in which the coating layer forming comprises
spray coating.
29. A writing implement comprising: a rigid barrel having a length;
a writing tip coupled to the barrel; and a deformable grip disposed
over the rigid barrel, the deformable grip extending over at least
half of the rigid barrel length and being formed of a solid
viscoelastic grip material.
30. The writing implement of claim 29, in which the grip material
has a hardness of approximately 1 to 80 Shore OO durometer allowing
the grip layer to achieve a deformed shape under manual
pressure.
31. The writing implement of claim 30, in which the grip material
further has a shape retention adapted to retain the deformed shape
for at least 1 second.
32. The writing implement of claim 29, in which the grip material
comprises a viscoelastic polyurethane having a hardness of
approximately 40 to 50 Shore OO durometer.
33. The writing implement of claim 32, in which the polyurethane
comprises a two-part polyurethane and the deformable grip is formed
by casting.
34. The writing implement of claim 33, in which the deformable grip
is formed around the barrel so that the deformable grip is
permanently bonded to the barrel.
35. The writing implement of claim 32, further comprising a coating
disposed over the deformable grip.
36. The writing implement of claim 35, in which the coating
comprises a coating material having a tensile strength of
approximately 50 to 1000 psi and an elongation ratio of
approximately 50 to 2000 percent.
37. The writing implement of claim 29, in which the deformable grip
covers at least 80 percent of the barrel length.
38. The writing implement of claim 29, in which the barrel has a
tip end adjacent the writing tip and a back end opposite the
writing tip, and in which the deformable grip defines a tip end
spaced approximately 1/2 inch from the writing tip and a back end
spaced approximately 1 inch from the barrel back end.
39. The writing implement of claim 29, in which the deformable grip
defines an overall length of approximately 4 inches.
Description
FIELD OF THE DISCLOSURE
[0001] The present disclosure generally relates to writing
implements, and more particularly, to writing implements having
deformable grips.
BACKGROUND OF THE DISCLOSURE
[0002] Various types of deformable grips are known which attempt to
improve comfort during use of a writing implement. Some known grips
employ a grip material that deforms under manual pressure, thereby
to more closely conform to a user's grip. While softer grip
materials are more accommodating, use of such materials has been
limited due to excessive tackiness exhibited by the softer
materials.
[0003] To allow use of softer grip materials while avoiding issues
caused by excessive tackiness, multiple layer grips are known in
the art. The "Alpha-Gel" writing grip marketed by Mitsubishi Pencil
Company, LTD., for example, provides a two-layer grip of resilient
silicone elastomer skin filled with a soft silicone gel. The
silicone gel provides primarily elastic deformation which tends to
immediately return the grip to its non-deformed shape. As a result,
the Alpha-Gel grip exerts a force that resists the manual pressure
applied by the user, thereby generating excessive stress and
causing hand fatigue. In addition, the Alpha-Gel grip is removably
attached to the writing implement body, and therefore the grip is
easily twisted out of position, damaged, or removed from the
writing implement structure. Still further, the silicone skin
material has limited tensile strength and flexibility, and
therefore is easily torn or separated from the inner gel material.
Also, the silicone skin does not bond well with the silicone gel,
and therefore the grip is vulnerable to excessive wear.
[0004] Another known deformable grip is the "Sensa" pen developed
by Willat Ergonomic Technologies, LLC. The Sensa pen has a silicone
bladder filled with a highly viscous liquid silicone gum. While the
grip exhibits viscoelastic properties (i.e., deforms elastically
but also has a shape retention that holds the deformed shape for a
period of time before returning to the undeformed shape),
manufacture of this grip is overly complex. The silicone bladder
must first be formed and placed on the pen, and then the silicone
gum must be manually filled into the bladder using a pneumatic or
hydraulic syringe. In addition, the Sensa grip is susceptible to
punctures during use, which may cause the silicone gum to leak,
thereby minimizing the utility of the grip.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Exemplary aspects and features of deformable grips for
writing implements in accordance with disclosure are described and
explained in greater detail below with the aid of the drawing
figures in which:
[0006] FIG. 1 is a perspective view of a writing implement having a
deformable grip according to the present disclosure;
[0007] FIG. 2 is a side elevational view of the writing implement
of FIG. 1;
[0008] FIG. 3 is a cross-sectional view of the writing implement
taken along line 3-3 of FIG. 1; and
[0009] FIG. 4 is a cross-sectional view of the writing implement
similar to FIG. 3 but showing the grip in a deformed shape.
DETAILED DESCRIPTION
[0010] Deformable grips for writing implements in accordance with
this disclosure generally comprise a grip layer adhered to a
structural portion of the writing implement, such as a barrel. A
coating layer is disposed over the grip layer to provide a more
durable skin for the grip and to mask any tackiness exhibited by
the material used for the grip layer. The deformable grip may be
formed on the writing implement using relatively inexpensive
automatic processes. For example, the grip layer may be formed by
low pressure casting while the coating may be sprayed over the grip
layer, thereby to form a composite grip. Still further, the
deformable grip may be formed over a majority of the barrel
surface, thereby to accommodate a greater variety of grip positions
and to more comfortably fit a user's hand.
[0011] In the exemplary embodiment illustrated as FIGS. 1-4, a
writing implement 10 includes an elongate, rigid barrel 12. The
barrel 12 defines a chamber 14 for housing a marking medium, such
as an ink stick cartridge 16. The cartridge 16 may include a
writing tip 18 that extends from a front end 20 of the barrel 12. A
rear end 22 of the barrel may include an actuator button 24 for
selectively extending or retracting the writing tip 18, as is
generally known in the art. While a retractable tip pen is shown,
other types of pens, such as those having a removable cap, may be
provided without departing from the scope of this disclosure. In
addition, the writing implement 10 may include a clip 26.
[0012] The barrel 12 is preferably made of a rigid material to
provide structural support for the writing implement 10. The barrel
material may be plastic, metal, or other rigid material. Currently,
it is preferred to form the barrel 12 of ABS plastic, which may be
accomplished by injection molding, liquid injection molding,
extrusion, or other known processes for forming rigid, structural
elements out of plastic.
[0013] A deformable grip is disposed over at least a portion of the
barrel 12 to improve comfort to a user's hand during use. As best
shown in FIG. 3, the deformable grip 30 includes a grip layer 32
and a coating layer 34. Materials for the grip and coating layers
are selected so that the deformable grip 30 exhibits viscoelastic
properties, wherein the material deforms elastically (similar to a
solid) but also is slow to recover to its uncompressed shape
(similar to a viscous liquid). In particular, the grip 30 readily
yields under manual pressure to a deformed shape and has shape
retention that holds the deformed shape for a period of time.
[0014] More specifically, the grip layer 32 may be formed of a grip
material having desirable hardness and shape retention
characteristics. For example, the grip material may have a hardness
of approximately 1 to 80 Shore OO durometer. The range of hardness
is preferably approximately 5 to 70 Shore OO durometer or
approximately 10 to 50 Shore OO durometer. In particular, it has
been found that a hardness of approximately 40 to 50 Shore OO
durometer provides a comfortable grip.
[0015] When selecting a material having suitable hardness, care
should be taken that it also exhibits other desirable
characteristics such as shape retention, durability, and feel,
among others. As used herein, shape retention is the ability of the
material to hold a deformed shape momentarily before returning to a
regular, undeformed shape. A typical undeformed shape is
illustrated in FIG. 3, where the writing implement 10 is not held
by a user. FIG. 4 illustrates a deformed shape where the user's
fingers are applying pressure to the grip 30. The grip material
should retain the deformed shape for at least approximately one
second, and preferably at least approximately 5 seconds, if
possible. It has been found that a two-part polyurethane gel
exhibits the above characteristics; however other materials, such
as silicone, may also exhibit the desired characteristics.
[0016] The coating layer 34 may comprise a coating material having
sufficient strength and stretch to accommodate local deformation
without tearing. In general, it is preferable to have as high of a
tensile strength and elongation ratio as possible. In particular,
the coating material may have a tensile strength of at least
approximately 50 to 1,000 psi. The tensile strength range is
preferably at least approximately 100 to 900 psi, and more
preferably at least approximately 150 to 850 psi. As defined
herein, the stretch of the material is quantified by the elongation
ratio, which compares the extended length of a material at its
failure point to the relaxed length of the material. The coating
material may have an elongation ratio of at least approximately 50
to 2,000%. Preferably, the elongation ratio of the coating material
is at least approximately 100 to 1,500%, and more preferably at
least approximately 200 to 1,000%. While the currently preferred
coating material is a polyurethane, other materials, such as
elastic fabric, silicone, epoxy, vinyl, latex, or other organic
based elastomeric coatings, may exhibit the desired characteristics
for the coating layer.
[0017] In addition to the individual layer material characteristics
noted above, the grip and coating materials may be selected to
achieve other characteristics desired in the composite deformable
grip 30. For example, it is advantageous for the grip and coating
layers 32, 34 to adhere to one another. To improve bonding between
the layers, similar materials may be used. For example, the grip
and coating layers 32, 34 may be formed of polyurethane materials
to promote bonding therebetween.
[0018] The grip layer material may further be selected to promote
permanent adhesion to the barrel 12, thereby to improve durability
of the grip. The barrel 12 and grip layer 32 materials may be
selected such that a bond is formed therebetween. For example, the
barrel may be formed of an ABS plastic, while the grip layer 32 is
formed of a polyurethane material.
[0019] From the foregoing, a deformable grip exhibiting
viscoelastic properties, minimal tackiness, and resistance to wear
is disclosed. The grip includes a solid, viscoelastic grip layer.
The grip layer is sufficiently soft to readily deform under manual
pressure and exhibits a shape retention to minimize hand fatigue.
The coating layer masks any tackiness exhibited by the grip layer
material and provides a strong, flexible covering to extend the
life of the grip.
[0020] The writing implement 10 may be formed by an automatic
process, thereby simplifying manufacture. As noted above, the rigid
barrel 12 may be formed using injection molding, liquid injection
molding, or other similar processes. The grip layer 32 may be
formed directly on at least a portion of the rigid barrel 12 so
that the grip layer 32 bonds to the rigid barrel 12. While it has
been found that low pressure casting provides desirable results,
other processes, such as molding or other casting processes may be
used. With the grip layer 32 in place, the coating layer 34 may be
applied to the grip layer 32. Suitable processes for applying the
coating layer include spray coating, plasma vapor depositing, dip
applying, in-mold coating, and heat shrink tubing, among
others.
[0021] In the currently preferred embodiment, the grip layer 32 is
formed of a two-part polyurethane gel material that is low pressure
casted in a mold defining a cavity surrounding a rigid structural
member of the writing implement, such as the barrel 12. The
two-part urethane gel is mixed, metered, and injected at a very low
pressure into a silicone mold. After the polyurethane cures in
approximately two to four minutes, the silicone mold is opened and
the formed grip layer is removed and placed on a coating line.
[0022] In the coating line, barrels 12 with grip layers 32 formed
thereon are covered with the coating material. For example, the
barrel/grip layer assemblies may be advanced past one or more spray
coating guns that completely coat the grip layer 32 with the
sprayed material, and the coating layer is then dried. The coating
material discharged by the spray coating gun is preferably a
polyurethane material to promote bonding with the polyurethane gel
used for the grip layer 32.
[0023] Accordingly, an automatic process is disclosed for forming a
deformable grip directly on a barrel of a writing implement. The
method does not require manual injection of a material or manual
placement of the grip over the barrel, thereby reducing
manufacturing costs and simplifying the manufacturing process.
[0024] The deformable grip 30 further may be sized to accommodate a
variety of grip positions and to provide additional comfort to a
user's hand in addition to the user's fingertips. As noted above,
the grip and coating materials are selected to provide a
viscoelastic grip. The grip 30 may be sized to extend over a
majority of the length of the barrel 12. In the illustrated
embodiment, the deformable grip 30 extends over approximately 80%
of the barrel length.
[0025] More specifically, the deformable grip 30 has a tip end 36
positioned proximate the barrel front end 20 and a back end 38
positioned proximate the barrel rear end 22. In the illustrated
embodiment, the tip end 36 is positioned approximately 1/2 inch
from the writing tip 18 and a back end 38 of the deformable grip 30
is positioned approximately 1 inch from the barrel rear end 22, so
that the deformable grip 30 has an overall length of approximately
4 inches. The additional length of the grip allows users to grasp
the writing implement 10 at locations farther away from the writing
tip 18, such as at a point located 1.5 inches or more from the
writing tip. In addition, the portion of the deformable grip 30
located near the back end 38 provides a cushioned contact surface
for the crease of the user's hand located between the thumb and
forefinger.
[0026] While particular embodiments of the present disclosure have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications can
be made without departing from the spirit and scope of the
invention. It is therefore intended to cover in the appended claims
all such changes and modifications that are within the scope of
this disclosure.
* * * * *