Note: Descriptions are shown in the official language in which they were submitted.
Docket M-298-C t 1~7534
~ackqround of the Invention
Field of the Invention
This invention relates to the field of fasteners
and to methods of using same.
Brief Description of the Prior Art
The following U.S. patents disclose fasteners, each
having a socket, a projection extending into an opening in
the socket and a post or end which is used to prevent with-
drawal of the body portion or strap portion from the socket:
Patentee Patent No. Issued
Geisinger 3,339,246 Sept. 5, 1967
Geisinger 3,590,442 July 6, 1971
Waddington 3,735,448 May 29, 1973
The following U.S. patents disclose fasteners, each
having a socket and a head joined by a filament:
Patentee Patent No. Issued
_
Merser 3,402,435 Sept. 24, 1968
Merser 3,462,802 Aug. 26, 1969
Merser et al 3,816,879 June 18, 1974
Summary of the Invention
The purpose of the invention is to provide a low
cost fastener of the loop type which is not adapted to be
uncoupled once it is coupled. Certain prior art fasteners
are relatively expensive to mold in that the costs of con-
ætructing and maintaining the mold are high. Fasteners accord-
ing to the invention can be produced in a relatively simple multi-
cavity mold. In accordance with a specific embodiment of the
invention, there is provided a socket and a head joined by a
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5;~4
Docket M-298-C
flexible filament. The fastener is constructed by molding
using polymeric plastics material. The one-piece fastener
which results from the molding operation can be used as
molded or the filament can b~ stretched to increase the length
and strength of the filament. The socket has a through-opening.
Projections formed integrally with the socke~ body extend
into the opening. It is preferred that each projection have
an integrally formed post or stop adjacent the side wall.
While the head is inserted into the socket, the projections
flex and consequently the posts move away from the side wall.
The head terminates at a shoulder. When the shoulder has
cleared the projections, the projections and conse~uently
the posts return substantially to their initial positions.
It is preferred that the projections be essentially flat and
that the one sides of the projections lie in the same plane
as the one side of the body; this construction allows for a
relatively simple mold. It is preferred also that the pro-
jections lie in the same plane; The projections are shown to
take the form of lobes having generally circular outer
peripheries. The posts are preferably column-shaped. It
is also a feature of the invention that the projections are
so close that there is only a small space therebetween through
which the head can be inserted. The plastics material of which
the projections are molded yields upon passage of the head
through the socket with concomitant localized deformation and
work-hardening of the projections. The work-hardened projections
offer increased resistance to withdrawal of the head through the
socket.
The method of the invention comprises the steps of:
providing a fastener comprised of flexible, molded, polymeric,
753~
Docket M-298-C
plastics material, the fastener having a socket, a head and
a flexible filament connected at its one end to the head and
at its other end to the socket, the socket having an opening
which is small relative to the size of the head, and deforming
the socket by inserting the head into the socket with con-
comitant work-hardening of the socket, whereby withdrawal of
the head is resisted by the work-hardened socket.
Brief Description of the Drawings
FIGURE 1 is a perspective view of a fastener in
accordance with the invention used to attach a tag to an
article;
FIGURE 2 is an enlarged fragmentary view of the
fastener;
FIGURE 3 is a sectional view taken along line
3--3 of FIGURE 2;
FIGURE 4 iS a sectional view taken along line 4--4
of FIGURE 2;
FIGURE 5 is a view of the opposite side of a socket
of the fastener from that shown in FIGURE 2;
FIGURE 6 iS a fragmentary view of the fastener,
showing the head being inserted into the socket;
FIGURE 7 iS a view similar to FIGURE 6, but showing
the head as havin~ been inserted through the socket, thereby
effecting coupling of the head and the socket;
FIGURE 8 is a view similar to FIGURE 7, but showing
attempted removal of the head from the socket;
FIGURE 9 is a fragmentary view of the sides of
the socket depicting permanent deformation of the projections
effected by insertion of the head into the socket;
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Docket M-298-C
FIGURE 10 is a fragmentary view of an alternative
form of the invention, on a somewhat reduced scale from tha~
used in FIGURES 2 through 9;
FIGURE 11 is an enlarged fragmentary view showing
the fastener in the coupled position in which at least one
of the ratchet teeth has passed through the socket;
FIGURE 12 is a sectional view of fragmentary portions
of a pair of mold sections and a core pin for molding the
fasteners; and
FIGU~E 13 is a fragmentary perspective view of the
core pin and one of the mold sections.
Detailed Description of the Preferred Embodiments
With reference to FIGURE 1, there is shown a loop-
type fastener generally indicated at 20 being used to attach
a tag T to an article A, although it is readily apparent that
the fastener 20 has a variety of other uses as well. With
reference now also to FIGURES 2 through 9, the fastener 20
includes a socket generally indicated at 21, a head generally
indicated at 22, and a filament 23 connected to the socket 21
at one end. A relatively stiff roughened manually graspable
section generally indicated at 24 is connected to the other end
of the filament 23 to a neck 25 which is in turn connected to
the head 22. The neck 25 is shown to be circular in section,
and the head 22 is shown to be generally conical and to converge
generally to its rounded free end 26. The other end of the
head 22 terminates at an annular shoulder 27, The section 24,
the neck 25, the head 22, and the filament 23 all have the same
a~is.
Docket M-298-C
The socket 21 preferably has a generally disc-shaped
body 28 which is preferably relatively thin, unlike the socket
body disclosed in U.S. patent No. 3,590,442 which has an
elongated or tubular shape. Thinness of the body 28 means
that the materials costs can be kept to a minimum. The socket
21 has a short through-opening generally indicated at 29 which
is considered to extend in the transverse direction. The
shortness of the opening 29 means that socket 21 can be easily
released from the mold. The opening 29 is comprised by a side
wall 30. The diameter of the section 24 is too large to pass
through the opening 29 as is evident from the drawings,
especially FIGURES 7 and 8. The projactions 32 are joined
to the body 28 at their bases 33. The bases 33 of the projections
are sufficiently small in section to flex to allow the head 22
to pass through the socket opening 29 as shown in FIGURE 6 to
the position shown in FIGURE 7. As the head 22 passes through
the socket opening 29, the posts 36 move inwardly away from
the side wall 30 as the projections 32 flex. If the posts 36
are long enough to contact head 22 as the projections 32 flex
and posts 36 move inwardly, the posts 36 can flex slightly to
permit the passage of the head 22 completely through the socket
opening 29, whereupon the projections snap in behind the shoulder
27 of the head 22. The projections 32 are shown to extend
inwardly. The projections 32 are shown to comprise lobes, the
outer peripheries 31 of which are shown to be circular in
FIGURES 2 and 5. The individual projections 32 are shown to
be spaced-apart so that they will flex independently. The one
sides 34 of the projections 32 lie in a common flat plane with
one side 35 of the body 28, as seen in FIGURES 3, 4 and 5. The
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Docket M-29 a -c
other sides 34a of the projections 32 lie in a common flat plane
parallel to the plane in which sides 34 and 35 lie. Although
it is preferred to have four proiections 32 in the illustrated
embodiment, a greater number such as five or a lesser number
such as two or three can be provided.
It is preferred that each projection 32 has a post
or stop 36 formed integrally therewith and extending from
surface 34a. The projections 32 are shown to be column-
shaped. The axis of each projection 32 is preferably
generally parailel to the side wall 30. ~lore particularly,
the posts 36 converge slightly to their free ends as best
shown in FIGU~E 4. This aids in removal of the fastener 20
from the mold. It is preferred that the sides 36a of the posts
36 be closely adjacent the side wall 30. If an attempt is
made to uncouple the head 22 from the socket 21, the sides
36a of the posts 36 are urged into abutment with the side
wall 30 as best shown in FIGURE 8. It is readily apparent
that the loop formed by coupling the head 22 with the socket
21 cannot be undone without destroying the fastener 20.
With reference to FIGURES 10 and 11, there is shown
an alternative form of fastener 20' which is identical to the
fastener 20, except that its filament 23' has a plurality
of substantially equally spaced-apart generally cone-shaped
ratchet elements or teeth 40 disposed along its length. r~hile
the fastener 20' is capable of being coupled by engagement of
head 22' with socket 21' in the same manner as the fastener
20, section 24' is small enough so that it will pass readily
through opening 29'. The section 24' is preferably no
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Docket M-298-C
larger in diameter and most preferably smaller in diameter
than the maximum diameter of the head 22', which maximum
diameter exists adjacent shoulder 27' in the illustrated
embodiment. If it is desired to draw the coupled fastener
20' into a smaller loop, the section 24' is passed through
the opening and the section 24' and/or the head 22' can be
grasped to draw one or more teeth 40 through the opening 29'.
The teeth 40 each have a maximum diameter adjacent their
respective annular shoulders which is the same or substantially
the same as the maximum diameter of the head 22' so that once
any tooth 40 has passed through the opening as shown in
FIGURE 10, that tooth cannot be withdrawn due primarily to
posts 36' which cooperate with side wall 30'.
As shown in FIGURES 6 through 9 for the fastener
20 and in FIGURE 11 for the fastener 20', the projections
32 and 32', respectively, are shown to be permanently deformed.
The permanent deformation takes place when the heads 22 and 22'
pass through respective sockets 21 and 21'. As this occurs,
the plastics material of which the fastener is composed work
hardens and toughens to inhibit withdrawal of the head 22 of
the fastener 20 or the head 22' and teeth 40 of the astener
20'. Deformation occurs because the plastics material of
which the projections 32 and 32' are composed is compressed
and respective permanent ridges or protrusions 42 and 42'
result.
With reference to FIGURES 12 and 13, there is shown
a fragmentary portion of a simplified drawing of a mold
generally indicated at 50 in which fastener 20 for example
Docket M-298-C 1~ 47534
can be molded in an injection molding machine. One mold
part 5] has a cavity 52 of a relatively simple configuration
and the other mold part 53 is fitted with a core pin 5~.
With reference also to FIGURE 13, the core pin 54 includes a
plurality of recesses 32r for forming projections 32. The
portion of the core pin between the recesses 32r is cross-
shaped and forms the cross-shaped gap between the projections
32 as best shown in FIGURES 2 and 5. The recesses 32r are
simply formed by a rotary milling cutter and hence outer
peripheries 31 of the proj~ctions 32 will be circular. The
posts 36 are simply formed by drilling the core pin 54 with
a slightly tapered drill to form holes 36h. The core pin 54
is considerably simpler to make than the core pins of certain
prior art molds. This is important in that the mold 50 can
be of the 100 cavity type in which 100 such core pins are
required.
The fasteners 20 and 20' are composed of a suitable
flexible, molded, polymeric, thermoplastic, plastics material.
While nylon is the preferred material due to its flexibility,
other materials such as polypropylene can be used. If the
fasteners 20 and 21 are desired to be used as-molded, that is,
unstretched, then polyethylene is also a satisfactory material
from which they can be molded.
By way of example, not limitation, the outer diameter
of the socket body 28 is about 0.296 inch, the annular opening
provided by side wall 30 has a diameter of about 0.125 inch,
the projections 32 have a radius of curvature of about 0.031,
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Docket M- 2 9 8 -C
the distance d of the outer peripheries 31 of a projection
to the side wall 30 is about 0.0456 inch, the projections 32
are about 0.015 inch thick, the length 1 of each post 36 is
about 0.025 inch, and the thickness t of the socket 21 is
about 0.060 inch.
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