U.S. patent application number 11/258122 was filed with the patent office on 2007-04-26 for textured vinyl pull cap.
This patent application is currently assigned to Caplugs LLP. Invention is credited to Frederick W. Zeypang.
Application Number | 20070090122 11/258122 |
Document ID | / |
Family ID | 37984388 |
Filed Date | 2007-04-26 |
United States Patent
Application |
20070090122 |
Kind Code |
A1 |
W. Zeypang; Frederick |
April 26, 2007 |
Textured vinyl pull cap
Abstract
A vinyl pull cap having a texturized grip surface is provided
comprising a tubular vinyl dip-molded tubular member having a
closed end and an open end, with the tubular member having an outer
second texturized dip-molded vinyl surface layer covering at least
a portion of said tubular member comprising particles of a size and
in an amount sufficient to provide a texturized outer vinyl
surface.
Inventors: |
W. Zeypang; Frederick;
(Erie, PA) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
Caplugs LLP
|
Family ID: |
37984388 |
Appl. No.: |
11/258122 |
Filed: |
October 26, 2005 |
Current U.S.
Class: |
220/805 |
Current CPC
Class: |
B65D 59/06 20130101;
F16L 55/115 20130101 |
Class at
Publication: |
220/805 |
International
Class: |
B65D 43/04 20060101
B65D043/04 |
Claims
1. A vinyl pull cap having a texturized grip surface comprising a
tubular vinyl dip-molded tubular member having a closed end and an
open end, said tubular member having an outer second texturized
dip-molded vinyl surface layer covering at least a portion of said
tubular member comprising particles of a size and in an amount
sufficient to provide a texturized outer vinyl surface.
2. The vinyl pull cap of claim 1, wherein said particles have a
size ranging from 50 to 200 microns.
3. The vinyl pull cap of claim 1, wherein said particles comprise
vinyl resin particles.
4. The vinyl pull cap of claim 1, wherein said particles comprise
filler particles.
5. The vinyl pull cap of claim 3, wherein said vinyl resin
particles have a size ranging from 50 to 200 microns.
6. The vinyl pull cap of claim 4, wherein said filler particles
have a size ranging from 50 to 200 microns.
7. The vinyl pull cap of claim 1, wherein said tubular member
includes a molded grip surface configured to assist gripping by
cooperative finger engagement which surface is at least partially
covered by said second texturized vinyl surface.
8. The vinyl pull cap of claim 7, wherein said molded grip surface
comprises a flattened portion adjacent said closed end of said
tubular member.
9. The vinyl pull cap of claim 7, wherein said molded grip surface
comprises a portion of said closed end having a reduced diameter in
relation to the diameter of the tubular member at said open
end.
10. The vinyl pull cap of claim 1, wherein said tubular member is
comprised of polyvinyl chloride.
11. The vinyl pull cap of claim 1, wherein said texturized surface
layer is comprised of polyvinyl chloride.
Description
BACKGROUND OF THE PRESENT INVENTION
[0001] The present invention is directed to a pull cap having a
textured grip surface.
[0002] Pull caps have been used commercially for many years. These
caps have many uses, such as sealing the ends of tubes, pipes, or
other articles of manufacture that may have an open end which needs
to be temporarily sealed during manufacturing, storage,
transportation, etc.
[0003] By way of example, U.S. Pat. Nos. 3,574,312 and 6,520,212
disclose several embodiments of protective plastic end caps for use
in protecting the open end of a tube, etc. As shown by U.S. Pat.
No. 3,574,312, such end caps can easily be made by means of a vinyl
dip molding process.
[0004] Current commercially-produced vinyl end caps have an
inherently slippery surface due to the lubricity properties of the
vinyl material, the inherently smooth surface of the vinyl
material, as well as the presence of plasticizers (oily softeners)
that tend to leach from the surface of the vinyl material over
time.
[0005] As protective end caps generally are not provided with
ergonomically-friendly configurations which might serve to assist
in gripping of the end cap, it is sometimes difficult to remove the
end cap from engagement with an article to be protected if the
respective fit between the end cap and the article is snug or
tight. As the degree of protection is enhanced by a snug or tight
fit, this problem tends to occur with some frequency. Also, over
time the surface of the end cap tends to adhere to the surface to
be protected more aggressively, thus further hindering removal of
the end cap from engagement.
OBJECTS AND SUMMARY OF INVENTION
[0006] It is thus an object of the present invention to provide a
protective end cap which has the capability to both effectively
serve a sealing or capping function, as well as to be more easily
removed from engagement with the object to be sealed or capped.
[0007] In accordance with the present invention, there is thus
provided a protective vinyl end cap for use in sealing the end of a
tube or pipe or other article of manufacture in need of a
protective end cap. The end cap has a grip surface which includes a
textured grip surface generally different from the surface of the
remaining portion of the end cap. The grip surface in association
with the textured surface assists in enhancing the ease of
installation and/or removal of the end cap from engagement with the
article to be capped.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a side view of an end cap of the present
invention.
[0009] FIG. 2 is an oblique view of the end cap of FIG. 1.
[0010] FIG. 3 is a side view of another end cap of the present
invention.
[0011] FIG. 4 is an oblique view of the end cap of FIG. 3.
[0012] FIGS. 5 and 6 are side views of another end cap of the
present invention.
[0013] FIG. 7 is an oblique view of the end cap of FIGS. 5 and
6.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0014] The invention will be described in connection with FIGS.
1-7.
[0015] The end cap 1 of the present invention is made by dip
molding. Dip molding processes are well known in the art, and have
been used for decades to produce vinyl-based plastic articles.
[0016] In a dip molding process, a heated mold form or mandrel is
dipped into a plastisol bath whereupon a layer of gelled
(fused)_plastisol forms about the mandrel. The coated mandrel is
removed from the plastisol dipping tank and the coated layer cured,
resulting in a molded article corresponding in configuration to the
configuration of the mandrel employed. For instance, when a
cylindrical mandrel (or pin) is employed, a tubular article with a
closed bottom can be produced. Beverage containers, bicycle
handles, gloves and tubular hose bend restrictors are but a few of
the products that are presently produced by dip molding by use of a
variety of mandrel configurations.
[0017] The mandrel may be comprised of any suitable metal such as
aluminum, steel, cast iron, brass, copper, titanium, and other
ferrous metal combinations. The mandrel may also be coated with a
non-ferrous metal. The mandrel is attached to suitable supporting
means during the molding process which causes the mandrel to be
dipped into and subsequently removed from the plastisol bath, and
also permits the coated mandrel to be moved along the molding line
to other manufacturing stations.
[0018] The mandrel is preheated to a temperature sufficient to
cause the plastisol in the bath to gel/fuse and to form a layer on
the heated mandrel upon the mandrel being dipped into the plastisol
bath. The mandrel is generally preheated to a temperature ranging
from about 350 degrees F. +/-50 degrees F. by means such as being
passed through an oven, placed into a heated liquid bath, heated by
internal heating element, etc. The particular heating means is not
critical as long as the temperature of the mandrel is sufficiently
high to cause the required gelling of the plastisol on the outer
circumferential surface of the mandrel once the mandrel is placed
into the plastisol bath.
[0019] The composition of the plastisol bath is not critical, as a
variety of plastisol compositions are conventionally employed. The
plastisol (polyvinylchloride) bath may include various colorants
(to cause the formation of a molded article of a particular color),
additives, fillers, and/or blowing agents (to cause formation of a
foamed layer). Once placed in the plastisol bath, the mandrel is
permitted to contact the plastisol for a time sufficient to result
in formation of a gelled layer on the metallic surface of the
mandrel. The time during which the mandrel is caused to remain in
contact with the plastisol bath is determined by a number of
factors, such as the temperature of the mandrel and the thickness
of the gelled plastisol layer which is desired to be formed on the
metallic surface of the mandrel. Generally, it has been found that
the mandrel may remain in contact with the plastisol bath for a
period of time ranging from about 4 seconds to several minutes
depending on material gellation properties, tooling geometry, and
wall thickness desired.
[0020] Once the mandrel contacts the plastisol bath for a period of
time sufficient to form a gelled layer of desired thickness, the
coated mandrel is removed from the bath. The resulting thickness of
the molded article generally ranges from about 0.03 to 0.20 inch.
The mandrel is slowly removed from the plastisol bath to enable
excess non-gelled plastisol to fall from the mandrel. The mandrel
is then cured to solidify the gelled layer on the mandrel. Such
curing may occur by heating to a temperature off from about
390.degree. F. to about 600.degree. F. for a period of time ranging
from about 0.50 to 3 minutes. Alternatively, the plastisol layer
may be cured by dipping the gelled plastisol layer into a heated
bath of molten salt or oil. Such curing means are conventional and
well known to those skilled in the art. The cured plastisol-coated
mandrel is then cooled by conventional means such as by air or
water, and the thus-formed dip molded part 1 removed by either
mechanical means, air pressure either internal or external to the
mandrel, or by other automated methods. The mandrel then typically
has a mold released placed over the molding surface and the form is
reused to produce additional molded parts.
[0021] If multiple layers of the plastisol are desired, the dipping
and/or curing steps are repeated. The formation of multiple (double
dipped) plastisol layers is also well known to those skilled in the
art, as is the use of a blowing agent to form a foamed plastisol
layer. See, for example, U.S. Pat. Nos. 3,904,720 and 4,800,116 in
this regard.
[0022] The end cap 1 of the present invention has a generally
cylindrical or tubular open end 7 and a closed end 9 having formed
therein a gripping surface 5 suitable for gripping between a thumb
and finger. The gripping surface 5 may merely be provided on the
exterior of a cylindrical surface, or the gripping surface may be
provided on a molded portion which has a different configuration
than the rest of the end cap but may be more specially configured
for gripping (such as a thinner or flattened portion as shown in
FIGS. 3-7).
[0023] It has thus been found that at least a portion of the
exterior surface of the end cap should be provided with a thin
second layer of texturized surface 5 to assist gripping as well as
installation and/or removal of the end cap. Such a coating may be
provided by the use of a plastisol bath formulated to provide the
desired texturized coating.
[0024] Texturized vinyl material may be formulated from a
conventional polyvinyl chloride plastisol by substituting up to 50%
by weight of the vinyl dispersion resin (typically having a
particle size of 1 micron or so) with, for example, polyvinyl
chloride suspension resin having a particle size of from 50 to 200
microns, or equivalent course grained fillers. Exemplary fillers
may be selected from a variety of conventional metal or inorganic
fillers having a size and course surface to provide the requisite
texturized surface properties.
[0025] More specifically, various inorganic fillers may be used
such as sand, coarse talc, calcium carbonate, etc. However, in
order to suspend the filler particles in the plastisol, it is
desirable to keep the filler to as close to the specific gravity as
the plastisol as possible. The fillers can be added in an amount of
up to about 30% by weight of the total weight of the plastisol
composition. Suspension grades of polyvinyl chloride with particle
sizes ranging from 50 microns and higher provide a satisfactory
textured surface for the dip molded article. Most dispersion grade
polyvinyl chloride resins have a particle size of from 1 to 5
microns.
[0026] When large vinyl particles are employed, the use of the
larger particle size allows the plasticizer(s) to only slightly
solvate the larger particle in the plastisol In the case of course
non-resinous fillers, the fillers are randomly fused into the
solidifying wall during gellation. As a result, when the plastisol
forms a coating 3 on the dip molded mandrel, or as a second coating
5 on a previously-formed dip molded part, the coated surface is not
smooth but assumes a texturized surface due to the presence of the
unsolvated particles dispersed throughout the plastisol.
[0027] The resulting end cap 1 having a texturized surface 5
provides many advantages. As protective caps and pull caps are
generally not ergonomically friendly and often difficult to remove,
it is highly desirable for the cap to have a texturized grip
surface that is easily formed yet greatly improves the tactile
properties and gripping ability of the cap. This reduces hand and
finger fatigue, and reduces repetitive motion disorders which occur
when a production worker is required to repetitively remove a
protective cap for long periods of time.
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