CA1264011A

CA1264011A - Fastener

Info

Publication number: CA1264011A
Application number: CA000479588A
Authority: CA
Inventors: Masami Kato
Original assignee: Toska Co Ltd
Current assignee: Toska Co Ltd
Priority date: 1984-05-09
Filing date: 1985-04-19
Publication date: 1989-12-27
Also published as: NL192357B; DE3516174A1; JPH0360745B2; NL192357C; AU4147585A; JPS60234829A; KR920009603B1; NL8501227A; FR2564223A1; KR850008235A; GB8509988D0; DE3516174C2; IT1184546B; FR2564223B1; IT8520584A0; AU570318B2; GB2158868A; GB2158868B

Abstract

ABSTRACT
A novel fastener is disclosed for use in attaching tags or labels to indicate price and quality, to seal caps, to bind articles, or to close the mouth of a bag.
The fastener comprises a filament, a socket fixed to one end of the filament and a head fixed to the other end of the filament, all integrally made of a synthetic resin.
The socket includes a through hole and a coaxial annular flange projecting radially inwardly from the walls thereof.
The head of the fastener includes a recess and a projection, the recess extending axially of the head and being defined by a front end portion, side wall, and a bottom wall of the head. The projection extends axially from the front end portion of the head and towards the socket of the fastener. The projection has an annular end portion which is radially enlarged with respect to the rest of the projection, the radially enlarged annular end portion including a circumferential portion interrupted by the recess. The head of the fastener is receivable in the through hole of the socket and is resiliently collapsible, for a snap-fit engagement with the aforesaid annular flange.

Description

FASTENER
Back~round The present invention relates to a fastener for attaching to articles tags or labels to indicate the price or quality, sealing caps for use in instruments, binding articles such as slippers, sandals or the like, and closing the mouth of a bag.
Such fastener ls normally made of synthetic resin and has hitherto been known for example in Japanese Patent No. 1,121,605 and the corresponding U.S. Patent No. 4,240,183.
A conventional fastener generally comprises a filament 21, a socket 22 fixed to one end of the filament 21 and a head 23 fixed to the other end of the filament 21, said head 23 being inserted into a through hole 25 of the socket 22 so as to engage the socket 22 as shown in Figs. 1 and 2.
Namely, in the above fastener, two tongues 24 and 24 project from the rear edge of the head 23 while an annu~ar flange 26 in the form of a ~rojection is formed on the inner peripheral surface of the socket 22.
As shown in Fig. 3, the fully opened tongues 24 and 24 come into contact with the upper surface of the annular flange 26 after passing through the annular Elange 26~
In this manner, release of the head 23 from the socket 22 is prevented.

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Also, upon contact of a stop 27 with the lower surface of the annular flange 26, further insertion of the head 23 is prevented.
In such prior art fastener, however, the following requirements (1) to (3) must be met:
(1) The two tongues 24 and 24 are necessary to project from the head 23.

(2) These tongues 24 and 24 are closed as passing through an annular hole 25A of the annular flange 26 and are opened thereafter. Thus, the tongues 24 and 24 need be joined to the rear edge of the head 23 with such strength as to slightly swing.

(3) The tongues 24 and 24 must be extremely small in order to minimize the whole fastener, particularly the head 23.
As a result, the following problems are encountered:
(a) The head 23 is of a complicated construction due to the provision of the tongues 24 and 24 on the head 23. Accordingly, the construction of a mold prepared to manufacture the fastener also becomes complicated and the useful life of the mold may be reduced. Hence, the mold is expensive to manufacture, thereby increasing the cost of the fastener.

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; ~ , (b) The tongues 24 and 24 projecting from the head 23 are more Eragile than the other parts of the fastener.
Upon strongly pulling the filament after engagement of the head 23 with the annular flange 26, the head 23 may, from time to time, be released from the socket 22 irrespective o~ the presence of the tongues 24 and 24.
From the above, the size of the tongues may be increased so as to prevent release of the head 23 from the socket 22 after the head 23 is brought into engage-ment with the socket 22. However, swinging movement ofthe tongues may deteriorate due to such increase in the size thereof and insertion of the head 23 into the socket 22 becomes difficult.
That is, the tongues 24 and 24 naturally become large if engagement of the head 23 with the flange 26 are more positively effected by the tongues 24 and 24.
As a result, insertion of the head 23 into the through hole 25 may not readily be effected. On the other hand, easy insertion of the head 23 into the through hole 25 causes the head 23 to be readily released from the socket 22 after the head 23 is brought into enSagement with the socket 22.
(c) The head 23 is of a complicated construction due to the provision of the tongues 24 and 24.
Accordingly, inferior molding may often occur when the fa~tener is molded from s~vnthetic resin.

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- - ' In order to prevent occurrence of such inferior molding, constant maintenance is necessary for the mold, and molding conditions must properly be controlled, so that it is difficult to obtain an improvement in or relating to the productivity.
(d) Since the tongues 24 and 24 project from the head 23, as the operator takes one fastener out of a plurality of fasteners bound, the fastener just taken out may be caught on the remainder of the fasteners, thereby the taking-out of the fasteners is disturbed and the operation efficiency is lowered.
(e) When the operator handles a multiplicity of fasteners, he may injure his fingers because of the projecting tongues 24 and 24. Such in~ury often occurs, particularly if the ends of the tongues are acutely sharpened.
Summary A first object of the present invention is to provide a fastener of the mentioned type, having a head of a simplified structure in that it no longer includes the tongues provided to the head of the conventional fastener.
A second object of the invention is to simplify the structure of the mold by simplifying the structure of the head of the fastener and improve the durability in use of the mold.

A third object of the invention is to reduce the production cost of the mold by simplifying the structure of the mold and thereby lower the production cost of the fastener.
A fourth object of the invention is to simplify the structure of the mold and thereby suppress the time and trouble required for the maintenance of the moldO
A fifth object of the invention is to simplify the structure of the mold so that limiting conditions in the molding of the fastener can be moderated and the productivity of the fastener can be enhanced.
~ sixth object of the invention is to provide a fastener which has a head of a structure simplied in that it no longer includes the tongues provided to the head of the conventional fastener and which nevertheless has such a highly strong locking performance that the locking engagement between the head and the socket, if once made, cannot be released unless the fastener is destroyed.
A seventh object of the invention is to provide a fastener which does not have tongues provided to its head and which no longer is likely to undergo inter-fastener tangling which is likely between tongues of one fastener and those of another fastener.

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An eighth object of the invention is to eliminate the danger of injuring an operator's finger or fingers, which is likely where tongues are provided to the head of the fastener.
In order to achieve the foregoing objects, according to the present invention a fastener is provided, which comprises a filament, a socket fixed to one end of said filament, and a head fixed to the other end of the filament. Also, the fastener is molded in one piece from synthetic resin. Further, the socket is formed with a through hole in which is coaxially provided an annular flange. The head is inserta~le into the through hole, the head including a projection projecting in the circumferential direction relative to the axis and a slot formed along the axis of the head by cutting-off of the projection. The projection is in engagement with the annular flange.
The Drawings Figure 1 is a plan view of a conventional fastener;
Figure 2 is a front view, partly sectioned, of the fastener shown in Figure l;
Figure 3 is a sectional view, in part, showing the manner in which a head is in engagement with a socket;
Figure 4 is a plan view showing a first embodiment of the present invention;

Figure 5 is a front view in section showing the fastener of Figure 4;
Figure 6 is a side view showing the fastener of Figure 4;
Figure 7 is a front view in section showing a fastener according to a second embodiment of the invention;
Figure 8 is a front view in section of a fastener according to a third embodiment of the invention;
Figure 9 is a front view of a head according to a fourth embodiment of the invention;
Figure 10 is a side view of the head shown in Figure 9;
Figure 11 is a front view of a head according to a fifth embodiment of the invention;
Figure 12 is a side view of the head shown in Figure 11;
Figure 13 is a plan view of a head according to a sixth embodiment of the invention;
Figure 14 is a front view of the head shown in Figure 13;
Figure 15 is a side view of the head shown in Figure 13;
Figure 16 is a side view of a head according to a seventh embodiment of the invention;

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: , ' F'igure 17 is a side view of a head according to an eighth embodiment of the invention;
Figure 18 is a plan view in section showing the fastener in its engaged state according to the first embodiment.
Figure 19 is a front view in section of the fastener shown in Figure 18;
Figure 20 is an enlarged view of the fastener enclosed in broken line B of Figure l9; and Figure 21 and Figure 22 are front views in section showing the prior art fastener in its engaged state.
The Preferred Embodiments Preferred embodiments of the present invention will now be described with reference to the accompanying drawings.
Fig. ~ is a plan view of a fastener according to the present invention. F'ig, 5 is a front view in section of the fastener. Fig. 6 is a side view of the fastener.
~ ccording to the present invention, a fastener F comprises a socket l, a filament 2 extending from the side of the socket l and a head 3 formed at the end of the filament 2. The fastener F is molded in one piece from synthetic resin such as nylon or polypropylene.

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The socket 1 is formed with a through hole 4 in which is provided an annular flange 5, which is coaxial with the through hole 4O
Although the position of the flange 5 is not specifically limited, it should preferably be located at a central portion of the through hole 4.
~ he flange 5 has a hori~ontal center line B, which is perpendicular to the axis A of,the through hole 4.
As shown in Fig. 5, the flange 5 is radially outwardly tapered to form annular upper and lower surfaces 5A and 5B which are converging from the wall edge of a hole 4A through the flange 5 toward the socket wall shown at lA so as to facilitate positive engagement of the head 3 with the socket 1 as will later be described.
The head 3 has a front end 6 of a semi~circular configuration. Extending rearwardly from the front end 6 along the axis C of the head 3 and projecting in the circumferential direction relative to the axis C is a projection 7. Further, a stop 9 of an increased diameter extends from the projection 7.
Now, an important aspect of the present invention is that part of the projection is cut off so as to form a recess 8 extended between the front end 6 and the stop 9 and that no projection is formed in the recess 8.

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Namely, in the recess 8, resin is cut off in such a manner as to substantially form a thin wall 10 only therein. As shown in Fig. 6, the recess 8 is of a U-shape in section.
Since the recess 8 is formed in the projection 7, the diameter of the projection 7 decreases as the head 3 passes through the through hole 4A of the flange 5 and is, then, returned to its original diameter after having passed therethrough.
The diameter of the stop 9 is greater than that of the through hole 4A of the flange 5. When the projec-tion 7 passes through the through hole 4A, the stop 9 is intended to close the entrance of the through hole 4A so as to prevent further insertion of the head 3.
Additionally, the stop 9 ser~es to hold the fastener F upon insertion of the head 3 into the through hole 4.
The filament 2 is stretched so as to improve its strength and has an unstretched portion 2A adjacent to the head 3.
In the presence of the unstretched portion 2A, various length of fasteners may be manufactured by changing the ratio to stretch the filament 2. Further, the filament 2 is given a cushioning effect to prevent cutting thereof during stretching process.

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Importantly, stretching of the filament 2 is initiated at a portion adjacent to the socket 1. ~amely, the unstretched portion 2A is present only at a portion adjacent to the socket 1. In this manner, the appearance of the fastener may aesthetically be improved and cutting of the filament 2 is prevented during stretching process.
In an attempt to stretch the filament 2 at a portion adjacent to the socket 1, the diameter of the filament 2 in proximity to the socket 1 may be reduced to a minimum while the diameter of the filament 2 in proximity to the head 3 may be increased so that the filament 2 may be formed to a tapered configuration.
Or, the filament 2 in the proximity to the head 3 may be of various diameters. sy so doing, when the filament 2 is stretched, maximum stress occurs at the smallest diameter portion of the filament 2 adjacent to the socket 1.
Fig. 7 shows a second embodiment of the invention. In this embodiment, the annular surfaces 5A
and 5B of the flange 5 formed on the inner peripheral surface of the socket 1 are foxmed at right angles to the axis of the through hole 4.
Fig. 8 is a sectional view of the socket 1 according to a third embodlment of the invention. In this embodiment, the annular projection 5A projects from , :

the annular flange 5 toward the central axis of the through hole 4A. Formed between the annular projection 5A and the socket body lA are annular recesses 5B.
By fitting the configuration of the projection 7 with the cross sectional configuration of the annular projection 5A, engagement of the head 3 with the socket 1 may be more positlvely effected.
Fig. 9 is a front view of the head 3 of the fastener according to a fourth embodiment of the invention. Fig. 10 is a side view of the head 3. In this embodiment, axial recesses 8A and 8B are formed at both sides of the head 3 and extend from the front end of the head 3 to the stop 9. A V-shaped reinforcing portion 15 is axially formed at a border of the recesses 8A and 8B.
In other words, the head 3 is axially divided by the recesses so as to form front ends 6A and 6B~
These front ends 6A and 6B are connected together and reinforced by the reinforcing portion 15 which in turn defines the two recesses 8A and 8B.
Projections 7A and 7B of a same length are circumferentially and coaxially formed at the front ends 6A and 6B respectively.
Namely, no projection is formed in the recesses 8A and 8B.

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As the head 3 is divided via the reinforcing portion 15, there is an advantage that insertion of the head 3 into the through hole 4 of the socket 1 in the fourth embodiment is much easier than that in the first embodiment. When the head 3 is clamped from around, the diameter of the head 3 decreases under the influence of the reinforcing portion 15 and the head 3 is, then, returned to its normal state when the head 3 is free from clamping.
Fig. 11 is a front view of the head 3 according to a fifth embodiment of the invention. Fig. 12 is a side view of the head 3. In this embodiment, a U-shaped recess 8C is axially formed between the front end of the head 3 and the stop 9 with the resin removed from one side to the other side thereof. The front ends 6A and 6B are interconnected via a thin portion 16.
This thin portion 16 functions as the reinforcing portion 15 employed in the fourth embodiment (Figs. 9 and 10).
Namely, in the fifth embodiment, the head 3 is split by the deep recess 8C within the range from the front end of the head 3 to the stop 9. With this arrangement, when clamping force is applied to the head from around, the diameter of the head 3 readily decreases so that insertion of the head 3 into the through hole 4A
of the socket 1 may easily be effected.

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Figs. 13, 14 and 15 respectively show a sixth embodiment of the invention. The opposite recesses 8A
and 8B are axiall~ formed within the range from the semi-circular front end 6 of the head 3 to the stop 9 so as to form the front ends 6A and 6s in the head 3. The reinforcing portion 15 of a V-shape in section is formed at a border of the recesses 8A and 8B along the axis of the head 3.
Further, the projections 7A and 7B are formed in the circumferential direction relative to the axis of the head 3. No projection is formed in the recesses 8A
and 8BA
In this embodiment, the diameter of the head 3 also readily increases and decreases under the influence of the recesses 8A and 8B so that insertion of the head 3 into the socket 1 is facilitated.
Figs. 16 and 17 show the respective modified forms of the reinforcing portion according to a seventh and an eighth embodiment. In these embodiments, the two recesses 8A and 8B are formed in the head 3 via the reinforcing portion 15 whereby the head 3 is divided as at 3m and 3n. In Fig. 16, the reinforcing portion 15 is inclinedly provided between the two front ends 3m and 3n.
Also, the front ends 3m and 3n are formed with the projections 7A and 7B respectively.

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The reinforcing portion 15 functions to xeduce the diameter of the head 3 when the head 3 is clamped from around and is, then, returned to its normal state when the head 3 is free from clamping.
Operation and advantages of the present invention will now be described with reference to the first embodiment (Figs. 4 to 6).
(1) In the invention, the recess 8 is formed in the head 3. That is, the resin is partly removed in the recess 8 so as to form the thin portion 10. In this manner, when the head 3 is clamped from around, the diameter of the head 3 decreases and is, then, returned to its normal state when the head 3 is free from clamping.
Namely, upon insertion of the head 3 into the through hole AA of the socket 1, the diameter of the head 3 decreases so as to pass through the through hole 4A and is, then, returned to its normal state after having passed therethrough.
It is to be noted that the head 3 may be inserted into the through hole 4 from either direction, above or below.
Thus, according to the present invention, the diameter of the head 3 per se decreases and its reduced ~ ~ diameter may be returned to its normal diameter.

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Accordingly, the construction of the head 3 is simplified and the tongues em~loyed in the prior art fastener as before mentioned need not be provided on the head 3.
(2) Along with the simplification of the head structure, the construction of a mold may also naturally be simplified, thereby prolonging the useful life thereof~
Therefore, the manufacturing cost of the fastener, as well as the mold will be reduced.
(3) Furthermore, according to the invention, the projections 7 are formed on the head 3 and the annular flange 5 is formed on the inner peripheral surface of the socket 1. With this arrangement, after the reduced diameter of the head 3 is returned to its original diameter, the projections 7 are caught on the flange 5 whereby the head 3 is brought into engagement with the socket 1.
Hence, according to the invention, after the projections 7 on the head 3 are engaged with the flange 5, the head 3 is firmly joined to the socket 1. Such joinning may not be released unless the fastener per se be broken (often, cutting of the fastener occurs).
This may be explained as follows:
Namely, as shown in Figs. 18 and 19, the flange 5 is in contact with -the projection 7 in the form .

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of an arc, except for the recess 8 with no projection.
Fig. 20 is an enlarged view of a contact portion B
(Fig. 19) between the flange 5 and the projection 7.
As is clear in Fig. 20, the flange 5 and the pro~ection 7 are contacted in a face-to-face relationship and also, in the form of an arc as stated above.
Pulling force C in the direction of the arrow in Fig. 19 is evenly applied to the contact surface in the form of an arc so as to release such joining. Thus, partial application of such force is prevented.
Accordingly, in case that the projection 7 is thin, it may withstand the pulling force C.
On the other hand, the diameter of the head per se of the prior art fastener is fixed and thus, the tongues provided on the head are opened or closed to some extent.
In such an arrangement, the head 23 and the flange 26 are contacted only at two points via the tongues 24 and 24. Consequently, force may be partially exerted on the two tongues.
That is, as shown in Fig. 21, when a force D
in the direction of the arrow is exerted on the tongues so as to release the joining of the head to the socket 1, the tongues 24 and 24 are adapted to press the peripheral wall of the socket 1 for stretching purposes. As a , .

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result, the diameter of a through hole 25 of the flange 26 is temporarily increased and finally, the head is released from the socket as shown in Fig. 22. Or, the tongues are cut off from the head 23.

(4) According to the present invention, as the recess is formed in the head as mentioned above, the diameter of the head readily increases and decreases.
Hence, insertion of the head into the socket is readily effected, thereby improving the operation efficiency.

(5) According to the invention, no tongue is provided on the head as opposed to prior art fasteners.
Hence, entanglement of the fasteners may be prevented during handling of a multiplicity of fasteners and cutting of the fingers due to the tongues is avoided, thereby improving the operation efficiency.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A fastener comprising a filament, a socket fixed to one end of the filament and a head fixed to the other end of the filament, all being integrally made of a synthetic resin, the fastener being characterised in that said socket includes a through hole and a coaxial annular flange radially inwardly projecting from the wall of the through hole; said head including a recess and a projection; said recess extending axially of the head and being defined by a front end portion of the head, side walls of the head and a bottom wall of the head; said projection extending axially from the front end portion of the head and towards the socket, and said projection having an annular end portion which is radially enlarged with respect to the remaining portion thereof, the radially enlarged annular end portion including a circumferential portion interrupted by said recess; said head being receivable in said through hole in the socket and being resiliently collapsible when passing said annular flange, so that the projection may be in engagement with said annular flange.

2. A fastener as claimed in claim 1, in which the thickness of the annular flange increases towards the centre of the through hole.

3. A fastener as claimed in claim 2, in which the annular flange has two inclined surfaces which are formed on opposite sides thereof respectively.

4. A fastener as claimed in claim 2, wherein said annular flange includes annular projections provided in a coaxial relation with the through hole and projecting from opposite surfaces of the flange toward the central axis of the through hole.