Separable bottom stop assembly for slide fastener

A separable bottom stop assembly of thermoplastic resin comprising a box molded on a lower end of one of opposite slide fastener stringers and an insert pin molded on a lower end of the other fastener stringer. The box has a straight insert-pin receiving hole off to one side. An outer wall of the insert-pin hole has a side slit having at its lower end a stopper. The insert pin is taper toward its lower end and has a straight tape-side edge. A guide ridge is integrally formed with the insert pin with a thin portion between them. When the insert pin is inserted into the insert-pin hole of the box, a lower end of the guide ridge slides along edges of the side slit, guiding insertion of the insert pin to facilitate smooth insertion without exerting load on the insert pin.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a separable bottom stop assembly, for a slide 
fastener, which comprises a box, a box pin and an insert pin molded of 
thermoplastic resin on lower ends of opposite fastener stringers. 
2. Description of the Related Art 
Various types of conventional separable bottom stop assemblies, for slide 
fasteners, which are molded of thermoplastic resin are currently known. 
For example, as shown in FIG. 7 of the accompanying drawings, Japanese 
Utility Model Publication No. Sho 54-31050 discloses a conventional-type 
separable bottom stop assembly, for a slide fastener, in which a first 
reinforcement wing 131, a box pin 102 and a first guide pin 130 are molded 
of thermoplastic resin on a lower end portion of one of opposite fastener 
stringers, while a second reinforcement wing 132, an insert pin 103 and a 
second guide pin 110 are molded of thermoplastic resin on a lower end 
portion of the other fastener stringer. The first guide pin 130 extends 
substantially parallel to the box pin 102 so as to define between them a 
first guide groove 105, and the second guide pin 110 extends substantially 
parallel to the insert pin 103 so as to define between them a second guide 
groove 111. And a box 101, which has a box-pin-receiving hole off to one 
side and an insert-pin-receiving hole 106 off to the other side and is 
molded independently of the box pin 102 and the insert pin 103, is 
attached to the box pin 102 as the box pin 102 is fitted into the 
box-pin-receiving hole. 
Further, as shown in FIG. 8, Japanese Utility Model Publication No. Sho 
59-25225 discloses another conventional-type separable bottom stop 
assembly, for a slide fastener, in which a box 1', a box pin 2', a first 
thin fin 5' outwardly of the box pin 2' and a first auxiliary ridge 4' are 
molded of thermoplastic resin on a first reinforcement tape 18' of 
thermoplastic resin film adhered to a lower end portion of one fastener 
stringer 15', while likewise an insert pin 3', a second thin fin 11' 
outwardly of the insert pin 3' and a second auxiliary ridge 10' are molded 
of thermoplastic resin on a second reinforcement tape 18" of thermoplastic 
resin film adhered to a lower end portion of the other fastener stringer 
15'. The first and second auxiliary ridges 4', 10' extend parallel to the 
box pin 2' and the insert pin 3', respectively, and the first and second 
fins 5', 11' extend between the first auxiliary ridge 4' and the box pin 
2' and between the second auxiliary ridge 10' and the insert pin 3', 
respectively. 
However, according to the first-named known separable bottom stop assembly 
of FIG. 7, the insert pin 103 and the second guide pin 110 which is longer 
than the insert pin 103 as well as the reinforcement wing 132 are 
integrally molded of thermoplastic resin on the fastener stringer at one 
end, and the insert pin 103 and the second guide pin 110 are arcuate in 
order to conform to the configuration of the flange 121 of a slider 120 so 
that the flange 121 of the slider 120 and a vertical side wall of the box 
101 are to be inserted in the second narrow guide groove. During 
insertion, since the insert pin 103 is positively guided, smooth insertion 
of the insert pin 103 into the box 101 cannot be realized. Further, since 
the second guide pin 110 and the second reinforcement wing 132 extend 
upwardly beyond the top end of the insert pin 103, the fastener tape 
around the lowermost coupling element touching the insert pin 103 is not 
flexible so that the lowermost coupling element is pressed firmly against 
the central guide post of the slider, thus causing great wear of the 
coupling head and resulting in an insufficient durability for use for a 
long time. Also, partly since the insert pin 103 is curved and partly 
since the box pin 102 is separate from the box 101, manufacturing of such 
separable bottom stop assembly would be very meticulous. 
According to the second-named separable bottom stop assembly of FIG. 8, 
partly since the second fin 11' between the insert pin 3' and the second 
auxiliary ridge 10' has a large width and partly since the insert pin 3' 
is positively guided during insertion, the insert pin tends to wear. Also, 
because of the large width of the second fin 11', the insert pin 3' tends 
to pivotally move during insertion so that a smooth inserting operation of 
the insert pin 3' is difficult to achieve. Further, since the second fin 
11' and the second auxiliary ridge 10' are aligned with the level of the 
top end of the insert pin 3', the fastener tape about the lowermost 
coupling element touching the insert pin 3' is not flexible, causing a 
stress on the lowermost coupling element during insertion. Furthermore, 
since the lower end portion of the insert pin is curved, molding of the 
insert pin 3' and the box 1' would be meticulous. 
SUMMARY OF THE INVENTION 
With the foregoing problems in view, it is a first object of this invention 
to provide a separable bottom stop assembly of thermoplastic resin, for a 
slide fastener, in which an insert pin can be inserted into and removed 
from a box nimbly and smoothly, with no burden in operation and less wear, 
as the insert pin serves as an auxiliary guide and a guide ridge disposed 
outwardly thereof guide positively. 
A second object of the invention is to provide a separable bottom stop 
assembly, for a slide fastener, in which an insert pin can be inserted 
into a slider and a box in a stable form as the slider is held with no 
lateral movement, thus facilitating inserting and removing of the insert 
pin. 
A third object of the invention is to provide a small-size separable bottom 
stop assembly, for a slide fastener, which can secure adequate softness in 
a fastener tape about an upper end of an insert pin, namely, about the 
lowermost coupling element and in which the insert pin can be inserted 
into and removed from the box with reduced burden on the lowermost 
coupling element and with adequate resistance for a long period of use. 
A fourth object of the invention is to provide a separable bottom stop 
assembly, for a slide fastener, in which either of a box and an insert pin 
has such a shape that it is easy to mold of thermoplastic resin, thus 
improving the productivity. 
A fifth object of the invention is to provide a separable bottom stop 
assembly, for a slide fastener, in which an insert pin can be smoothly 
guided when it is inserted into a box, thus stabilizing an inserted 
posture of the insert pin and hence making the separable bottom stop 
assembly neat in appearance. 
A sixth object of the invention is to provide a separable bottom stop 
assembly, for a slide fastener, in which means for guiding an insert pin 
when it is inserted into a box is disposed on opposite sides or only one 
side of a fastener tape, either of which arrangement may be selected 
according to the kind of use. 
According to a first aspect of the invention, a separable bottom stop 
assembly for a slide fastener, comprises: a box pin of thermoplastic resin 
adapted to be molded on a lower end of one of opposite fastener stringers 
of the slide fastener; a box of thermoplastic resin fixed to the box pin 
and having an insert-pin receiving hole; an insert pin of thermoplastic 
resin adapted to be molded on a lower end of the other fastener stringer 
for being inserted into the insert-pin receiving hole of the box; and a 
guide ridge of thermoplastic resin integrally formed with a tape-side edge 
of the insert pin via a thin portion. The box has a side slit in an outer 
wall of the insert-pin receiving hole, the outer wall having at its lower 
end a stopper. The guide ridge has a lower end slidable along edges of the 
side slit. 
According to a second aspect of the invention, the separable bottom stop 
assembly further includes a guide projection integrally formed with the 
box and upwardly extending parallel to the box pin so as to define with 
the box pin a slider-holding recess having a width substantially equal to 
the thickness of flanges of a slider of the slide fastener. 
According to a third aspect of the invention, in the separable bottom stop 
assembly, the guide ridge disposed parallel to the insert pin has a top 
portion extending upwardly and terminating short of the level of an upper 
end of the insert pin. 
According to a fourth aspect of the invention, the separable bottom stop 
assembly further includes a reinforcement of thermoplastic resin adapted 
to be attached to a lower end of a fastener tape associated with the other 
fastener stringer at a range upper end of which is substantially aligned 
with the level of a top portion of the guide ridge. 
According to a fifth aspect of the invention, in the separable bottom stop 
assembly, the insert-pin receiving hole of the box is straight, and the 
insert pin is taper toward its lower end and has a straight tape-side 
edge. 
According to a sixth aspect of the invention, in the separable bottom stop 
assembly, the thin portion between the guide insert pin and the guide 
ridge has a varying width decreasing toward its upper end and increasing 
toward its lower end, and each thin portion has at its lower end a contact 
recess engageable with the stopper. 
According to a seventh aspect of the invention, in the separable bottom 
stop assembly, the guide ridge and the thin portion are disposed on only 
one side of a fastener tape. 
Alternatively, according to an eighth aspect of the invention, in the 
separable bottom stop assembly, either of the guide ridge and the guide 
groove are a double form disposed one on each side of the fastener tape. 
According to a ninth aspect of the invention, in the separable bottom stop 
assembly, the guide projection and the slider-holding recess are disposed 
on only one side of the fastener tape. 
Alternatively, according to a tenth aspect of the invention, in the 
separable bottom stop assembly, the guide projection and the 
slider-holding recess are a double form disposed one on each side of a 
fastener tape.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Preferred embodiments of a separable bottom stop assembly according to this 
invention will now be described in detail with reference to the 
accompanying drawings. 
As shown in FIG. 1, the separable bottom stop assembly generally comprises 
three members, i.e., a box 1, a box pin 2 and an insert pin 3. The first 
two members, the box 1 and the box pin 2, are molded of thermoplastic 
resin such as polyamide, polyacetal, polypropylene or 
polybutyleneterephtalate, in a unitary form on a lower end of one fastener 
stringer 15, and likewise the third member, the insert pin 3 to be 
inserted into the box 1, is integrally molded of thermoplastic resin on a 
lower end portion of the other fastener stringer 15. 
For molding the box 1 or the insert pin 3 on the lower end portion of each 
fastener stringer 15, a thermoplastic resin film or a thermoplastic resin 
film laminate is adhered to a lower end portion of a fastener tape 16 to 
form a reinforcement 18, or thermoplastic resin liquid is permeated and 
solidified through a lower end portion of a fastener tape 16 to form a 
reinforcement 18, thus reinforcing the lower end portion of the fastener 
tape 16. Then, a box or an insert pin 3 is molded on opposite surfaces of 
the reinforcement 18 along the fastener-element-attaching marginal portion 
in the reinforcement 18 by injection or extrusion molding using 
thermoplastic resin. 
The box pin 2 extends along the extension of a row of fastener element 17 
attached to the fastener tape 16 beyond the upper edge of the 
reinforcement 18, and the box 1 is integrally formed with a lower end of 
the box pin 2. A guide projection 4 is integrally formed with one side of 
the box 1, extending upwardly in an L-shape parallel to the box pin 2 and 
terminating in an upper end substantially aligned with the upper edge of 
the reinforcement 18 so as to define with the box pin 2 a pair of shallow 
slider-holding recesses 5 one on each side of the stringer 15. The 
slider-holding recesses 5 have a common width corresponding to the 
thickness of a flange 21 in a slider 20 so that the slider 20 can be held 
in a stable posture during insertion. The box 1 has off to the other side 
a straight insert-pin-receiving hole 6 into which the insert pin 3 is to 
be inserted. An outer wall 7 of the insert-pin receiving hole 6 has a side 
slit 8 extending downwardly and terminating in a stopper 9 for receiving 
an lower end of a thin portion 11 which is disposed parallel to the insert 
pin 3. 
On the other hand, the insert pin 3 extends along the extension of a row of 
coupling element 17, which is attached to the other fastener tape 16, 
beyond the upper edge of the reinforcement 18 and is taper toward its 
lower end, having a straight tape-side edge. A guide ridge 10 is 
integrally formed with an outer side of the insert pin 3 in parallel so as 
to define with the insert pin 3 a thin portion 11 extending upwardly and 
terminating in a top portion 14 substantially aligned with the upper edge 
of the reinforcement 18. Therefore, when the thin portion 11 is threaded 
through the upper and lower flanges 21 of the slider 20 and the side slit 
8 of the box 1 as shown in FIGS. 2-4, the inner side of a lower end 13 of 
the guide ridge 10 slides on the outer edges of the side slit 8, 
facilitating insertion of the insert pin 3. With the thin portion 11, a 
guide groove is defined between the insert pin 3 and the guide ridge 10. 
Each thin portion 11 between the insert pin 3 and the guide ridge 10 has a 
varying width decreasing toward its upper end near the upper end 14 of the 
guide ridge 10 and increasing toward its lower end near the lower end 13 
of the guide ridge 10, so as to facilitate insertion of the flange 21 of 
the slider 20, and to easily contact the edge of the side slit 8 of the 
box 1. And the thin portion 11 is formed to be a contact recess 12 
engageable with the stopper 9, making the lower side of the separable 
bottom stop assembly neat in appearance. 
In the foregoing embodiment, the box 1 and the box pin 2 are molded in a 
unitary form. Alternatively, the box pin 2 may be solely molded on the 
lower end portion of one fastener stringer 15, and the box 1 may be molded 
independently and may be fixed to the lower end of the box pin 2. Further, 
in the foregoing embodiment, each of the guide projection 4 and the guide 
ridge 10 is a double form disposed one of each side of the fastener tape 
16 as shown in FIG. 5; alternatively, each of the guide projection 4 and 
the guide ridge 10 may be a single form disposed on only one side of the 
fastener tape 16 as shown in FIG. 6, leaving the other side flat. In FIGS. 
2-4, reference number 22 designates a central guide post of the slider 20. 
The separable bottom stop assembly of this invention as thus constructed 
has the following advantageous results: 
In this invention, in the separable bottom stop assembly molded of 
thermoplastic resin, the guide ridge 10 is integrally molded at a 
tape-side edge of the insert pin 3 via the thin portion 11, and the side 
slit 8 with the stopper 9 being formed at the lower end of the outer wall 
7 of the insert-pin-receiving hole 6 of the box 1 is provided, and the 
inner side of the lower end 13 of the guide ridge 10 is formed to be 
guided along the edge of the side slit 8. As a result, at the time of 
inserting the insert pin 3 into the box 1, the guide ridge 10 contacts the 
edge of the side slit 8 to slide as being guided, so that the insertion 
can be done nimbly and smoothly. Furthermore, the insert pin 3 serves 
merely as an auxiliary, the insert pin 3 does not wear and can be durable 
for a long time use. 
Partly since the slider-holding recess 5 is disposed between the box pin 2 
projecting upwardly from the box 1 and the guide projection 4 extending 
upwardly and terminating short of the level of the upper end of the box 
pin 2 and has a width substantially equal to the thickness of the flange 
21 of the slider 20, it is possible to insert the insert pin 3 into the 
slider 20 and the box 1 in a stable form with the slider 20 being held so 
as not to move laterally, thus facilitating inserting and removing of the 
insert pin 3. 
Since the guide ridge 10 integrally formed with the insert pin 3 parallel 
extends upwardly and terminates short of the level of the top portion 14 
of the insert pin 3, it is possible to reduce the entire size of the 
separable bottom stop assembly and to facilitate insertion of the insert 
pin 3 as well as to finish the product neatly in appearance. 
Since the reinforcement 18 of thermoplastic resin arranged over the lower 
end portion of the fastener tape 16 has an upper edge substantially 
aligned with the level of the top portion 14 of the guide ridge 10, it is 
possible to facilitate molding of the guide ridge 10 and to secure 
adequate softness of the fastener tape 16 at an area near the lowermost 
coupling element as well as to prevent the fastener elements 17 from being 
pressed against the central guide post 22 of the slider 20, thus 
protecting the coupling elements 17 and making the separable bottom stop 
assembly durable for a long period of use. 
Partly since the insert-pin receiving hole 6 of the box 1 is straight and 
partly since the insert pin 3 is taper toward its lower end 13 and has a 
straight tape-side edge, it is possible to mold the box 1 and the insert 
pin 3 much more simply as compared to the conventional product, in which 
both the box 1 and the insert pin 3 are arcuate in shape, thus improving 
the productivity. 
Since the thin portion 11 between the insert pin 3 and the guide ridge 10 
has a varying width decreasing toward its top portion 14 and increasing to 
its lower end 13 and terminates in the contact recess 12 to contact with 
the stopper 9, it is possible to guide the insert pin 3 reliably without 
rattling during insertion and to hold the insert pin 3 stably in an 
inserted posture. 
When each of the guide ridge 10 and the thin portion 11 is a double form 
disposed one on each side of the fastener tape 16, it is possible to 
insert and remove the insert pin 3 into and from the box 1 smoothly and 
accurately and to make the separable bottom stop assembly adequately 
tough. 
When the guide ridge 10 and the thin portion 11 are disposed on only one 
side of the fastener tape 16, it is possible to reduce the quantity of 
material so that a large-size separable bottom stop assembly can be 
manufactured with a minimum amount of material. 
When the guide projection 4 and the slider-holding recess 5 are a double 
form disposed one on each side of the fastener tape 16, it is possible to 
hold the slider 20 reliably without rattling during insertion, thus 
facilitating insertion of the insert pin 3 and making the separable bottom 
stop assembly equately tough. 
When the guide projection 4 and the slider-holding recess 5 are disposed on 
only one side of the fastener tape 16, it is possible to reduce the 
quantity of material so that a large-size separable bottom stop assembly 
can be manufactured with a minimum quantity of material.