Separable slide fastener

A separable terminal assembly of a separable slide fastener includes a separable pin mounted on one stringer tape along one longitudinal edge thereof, the separable pin including a pair of plates interconnected at one longitudinal edge and disposed one on each side of the stringer tape. Each of the plates has a flange extending along the other longitudinal edge of the plate and a bevelled upper end wall held in abutting engagement with the endmost coupling element disposed next to the separable pin. The bevelled upper end walls slope down in a direction from the one toward the other longitudinal edge of each plate. The flanges terminate short of the respective bevelled upper end walls so as to define between the plates and the flanges a pair of openings for allowing the one longitudinal tape edge to flex laterally toward the other longitudinal edge of the stringer tape while the endmost coupling element passes through a branch of the Y-shaped guide channel in a slider. The separable pin thus constructed can easily be inserted into and removed from a mating retainer without special manipulation.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a slide fastener and more particularly to 
a separable type of slide fastener having a separable terminal assembly. 
2. Prior Art 
A separable terminal assembly (normally referred to as separable bottom end 
stop) of a separable slide fastener comprises a box-like retainer or 
socket mounted on one stringer tape at one end thereof, and a separable 
pin mounted on the other stringer tape at one end thereof and releasably 
engageable with the socket for interconnecting the two stringer tapes. The 
separable pin is of a generally tube-like element and normally separated 
by configuration into two types, one being a substantially straight or 
slightly curved separable pin and the other being a doglegged or angularly 
bent separable pin. 
A disadvantage of the substantially straight separable pin proposed 
heretofore lies in the difficulty of its insertion into and extraction 
from a mating socket with a slider positioned next to the separable 
terminal assembly. A muscular effort is necessary since the straight pin, 
as is moved along a bent channel defined jointly by the slider and the 
socket, abuts against interior walls of the slider and the socket. The 
doglegged separable pin is disadvantageous in that while the pin is 
inserted into or removed from the socket through the slider, a corner 
portion of its dogleg shape impinges against the interior walls of the 
slider, thus hindering a smooth movement of the pin. Further, the 
doglegged separable pin is likely to accidentally separate from the socket 
when a pull in opposite directions is exerted on the stringer tapes. For 
production, the doglegged pin requires a bending process which would cause 
the difficulty of reducing the manfacturing cost and maintaining a uniform 
quality in mass production. A drawback common to both types of separable 
pin is in that during insertion and removal of the separable pin, the 
endmost coupling element located next to the separable pin is thrusted by 
the sidewall of a slider's guide post, in a lateral direction away from 
the slider. The stringer tape tends to become ruptured at its longitudinal 
edge that has been stretched by such thrusted endmost coupling element, 
rendering the fastener useless. 
SUMMARY OF THE INVENTION 
It is therefore an object of the present invention to provide an improved 
separable slide fastener which will eliminate the above-noted difficulties 
of the prior art devices. 
A more specific object of the present invention is to provide a separable 
slide fastener including a separable terminal assembly which is so 
constructed as to allow smooth engagement and disengagement of a separable 
pin with respect to a mating retainer, and to prevent a splitting of the 
meshing coupling elements due to an accidental rupture of a stringer tape. 
Another object of the present invention is to provide a separable slide 
fastener with a separable terminal assembly having a separable pin which 
is simple in construction and hence can be manufactured less costly by 
mass production, and which can be retained stably and securely in position 
on a stringer tape against accidental withdrawal from a mating retainer 
under lateral pulling forces. 
According to the present invention, a separable slide fastener includes a 
separable terminal assembly mounted on lower ends of two stringer tapes at 
lower ends of two rows of coupling elements for interconnecting or 
separating the two stringer tapes. A separable pin of the separable 
terminal assembly is mounted on one stringer tape over one longitudinal 
edge thereof and includes a pair of substantially rectangular plates 
disposed one on each side of the one stringer tape and interconnected at 
respective one longitudinal edges. Each of the plates has a flange on the 
other longitudinal edge thereof engaging the stringer tape, and a bevelled 
upper end wall held in abutting engagement with the endmost coupling 
element and sloping down in a direction from the one toward the other 
longitudinal edge of the plate at an angle to a line transverse to the 
slide fastener. The longitudinal flanges terminate short of the bevelled 
upper end walls of the respective plates so as to provide a pair of 
openings. With the openings thus provided, the longitudinal tape edge is 
allowed to flex in a lateral direction toward the other longitudinal edge 
of the stringer tape when a lateral thrust is exerted to the stringer tape 
in response to abuttment of the endmost coupling element against the guide 
post of a slider. 
Many other advantages and features of the present invention will become 
manifest to those versed in the art upon making reference to the detailed 
description and the accompanying sheets of drawings in which a preferred 
structural embodiment incorporating the principles of the present 
invention is shown by way of illustrative example.

DETAILED DESCRIPTION 
As shown in FIG. 1, a separable slide fastener 10 generally comprises a 
pair of stringer tapes 11, 12 each carrying on and along its one 
longitudinal edge 13 a row of discrete coupling elements 14, a separable 
terminal assembly 15 mounted on lower ends of the stringer tapes 11, 12 at 
a lower end of the rows of coupling elements 14, 14, and a slider 16 
slidably mounted on the rows of coupling elements 14, 14 for taking them 
into and out of interdigitating engagement with each other to close and 
open the separable slide fastener 10. 
Each of the coupling elements 14 has a bifurcated leg portion 17 mounted 
astride the longitudinal tape edge 13, and a coupling head portion 18 
projecting from the leg 17 transversely beyond the longitudinal tape edge 
13. The coupling head 18 includes a lateral projection 19 and an opposite 
recess or pocket 20 for receiving the projection 19 of an adjacent 
coupling element 14. The longitudinal tape edge 13 is beaded or enlarged 
in cross section as it includes, as shown in FIGS. 3 and 4, a pair of 
reinforcing cords or stuffer warps 21, 21 disposed one on each surface of 
the stringer tape 11, 12. The reinforcing cords 21, 21 are united with the 
tape 11, 12 during the formation of the tape 11, 12. A pair of reinforcing 
films 22, 22 is mounted on the stringer tapes 11, 12, respectively, at the 
lower ends thereof. Each of the reinforcing films 22, 22 overlies the 
beaded longitudinal edge 13 of a corresponding one of the stringer tapes 
11, 12 and extends substantially the entire width of each surface of the 
stringer tape 11, 12. 
The separable terminal assembly 15 includes a box-shaped retainer or socket 
23 and a retainer pin 24 extending therefrom, the retainer 23 and the 
retainer pin 24 being secured by clinching to the lower end of the 
stringer tape 12 along the beaded longitudinal edge 13 thereof, and a 
substantially straight separable pin 25 secured by clinching to the lower 
end of the stringer tape 11 along the beaded longitudinal edge 13 thereof 
and receivable in a longitudinal opening 26 in the retainer 23. 
As shown in FIG. 2, the separable pin 25 has a generally C-shaped cross 
section and includes a pair of substantially rectangular front and rear 
plates 27, 28 interconnected at one edge by a sidewall 29 to define 
therebetween a longitudinal groove 30 for receiving therein the beaded 
longitudinal edge 13 and the reinforcing film 22 that are located at the 
lower end of the stringer tape 11. The front and rear plates 27, 28 have, 
at the respective other edges, a pair of longitudinal flanges 31, 32 
extending toward one another. Each of the front and rear plates 27, 28 has 
a bevelled upper end wall (FIG. 1) extending obliquely across the beaded 
longitudinal edge 13 of the stringer tape 11 and sloping down in a 
direction from the one edge to the other edge of the plate 27, 28 at an 
angle .theta. (FIG. 1) to a line perpendicular to the separable slide 
fastener 10. The bevelled upper end walls 33 of the separable pin 25 are 
held in abutting engagement with a sidewall 34 of the leg portion 17 of 
the endmost coupling element 14a so that the longitudinal axis of the 
endmost coupling element 14a tilts downwardly away from the longitudinal 
axis of the second endmost coupling element 14 at the angle .theta.. The 
longitudinal flanges 31, 32 of the separable pin 25 extend from lower ends 
of the plates 27, 28 toward the upper end walls 33 and terminate short of 
the upper end walls 33 so as to define a pair of openings 35, 35 between 
the ends of the flanges 31, 32 and the plates 27, 28, respectively. With 
the openings 35, 35 thus provided, the longitudinal edge 13 is allowed to 
flex, as shown at 13a in FIG. 6, in a lateral direction toward the other 
longitudinal edge of the stringer tape 11 when the endmost coupling 
element 14a is subjected to a lateral thrust applied in the direction of 
the arrow A during engagement or disengagement of the separable pin 25 
with the retainer 23. 
The separable pin 25 also has a recessed portion 36 disposed adjacent to 
the coupling head portion 18 of the endmost coupling element 14a, for 
receiving therein the coupling head portion 18 of the endmost coupling 
element 14b disposed next to the retainer pin 24. The sidewall 29 has on 
its upper end an auxiliary projection 37 extending into the recess 36 in 
alignment with the pocket 20 of the endmost coupling element 14a. The 
projection 37 is receivable in the pocket 20 of the endmost coupling 
element 14b when the slide fastener 10 is closed. 
The slider 16 is of a conventional construction and includes a pair of 
parallel spaced wings 38 (one wing being omitted for clarity) joined at 
their one end with a neck or guide post 39 so as to define a substantially 
Y-shaped guide channel 40 for the passage therethrough of the rows of 
coupling elements 14, 14. Each of the wings 38 has on its opposite side 
edges a pair of longitudinal guide flanges 41, 41 projecting toward the 
opposed wing and terminating short of the latter for the entry of the 
stringer tape 11, 12. The guide post 39 has a substantially wedge-shaped 
cross section and includes opposite sidewalls 42, 42 extending 
convergently toward the other end of each wing 38 for guiding the coupling 
head portions 18 of the rows of coupling elements when they are coupled 
and uncoupled together. Each of the sidewalls 42 slopes at an angle to a 
longitudinal central axis common to the slider 16 and the slide fastener 
10 such that the longitudinal axis of the endmost coupling element 14a 
extends at a right angle (FIG. 7) to one sidewall 42 engageable with the 
endmost coupling element 14a. That is to say, the angle of inclination of 
the one wall 42 is the same as the tilting angle .theta. of the endmost 
coupling element 14a. 
Operation of the separable slide fastener 10 is described below. When the 
stringer tapes 11, 12 are to be interconnected as shown in FIG. 1, the 
separable pin 25 is inserted, in such a manner as shown in FIGS. 7 and 8, 
into the opening 26 in the retainer 23 through the Y-shaped guide channel 
40 in the slider 16 with the latter positioned next to the retainer 23. 
During that time, the endmost coupling element 14a is forced to displace 
laterally outwardly from the slider 16. However, partly because of the 
tilted arrangement of the endmost coupling element 14a and partly because 
of the openings 35 in the separable pin 25, the longitudinal tape edge 13 
is allowed to flex for taking up or cancelling out the laterally thrusting 
force applied on the endmost coupling element 14a by the guide post 39 of 
the slider 16. Thus the endmost coupling element 14a can pass through a 
branch of the Y-shaped guide channel 40 while being guided between one 
sidewall 42 of the guide post 39 and the guide flanges 41 of the slider 
16. With the slide fastener 10 thus constructed, the separable pin 25 can 
be smoothly brought into and out of engagement with the retainer 23 
without special manipulation. Thus the stringer tape 11 is free from 
rupture at the longitudinal edge 13 which could otherwise occur when the 
endmost coupling element 14a is laterally displaced in the slider 16 to 
stretch the longitudinal tape edge 13. Then the slider 16 is moved 
upwardly in a fastener closing direction for interdigitating the rows of 
the coupling elements 14, 14. As shown in FIG. 1, the auxiliary projection 
37 is received in the pocket 20 in the endmost coupling element 14b so as 
to prevent substantial reduction of coupling strength of the intermeshing 
rows of coupling elements at a portion adjacent to the tilted endmost 
coupling elements 14a, 14b. Removal of the retainer pin 25 from the 
retainer 23 can smoothly be accomplished in the reverse order of the just 
mentioned insertion. 
As the retainer pin 25 is a substantially straight tubular element it 
therefore is easy to manufacture in mass production; it is attachable to 
the stringer tape 11 with utmost ease and can be stably held in position 
against displacement from the retainer 23. 
The retainer 23 in the illustrated embodiment is integral with the retainer 
pin 24 and fixed to the longitudinal tape edge 13. However, according to 
the invention, the separable terminal assembly 15 may include a movable 
retainer (not shown) which is movably mounted on one stringer tape and 
slidable along the rows of coupling elements to permit separation of the 
two stringer tapes from the lower end, without the necessity of opening 
the slide fastener from the upper end. The movable retainer also performs 
a similar function to that of the fixed retainer 23 and is not removable 
from the lower end of the slide fastener. 
Although various minor modifications may be suggested by those versed in 
the art, it should be understood that we wish to embody within the scope 
of the patent warranted hereon, all such embodiments as reasonably and 
properly come within the scope of our contribution to the art.