Note: Descriptions are shown in the official language in which they were submitted.
lOS1171
This invention relates generally to slide fasteners -
and particularly to a slide fastener of the type having a pair
of series of discrete fastener eIements carried along the inner
longitudinal edge of opposed stringer tapes.
The prior art includes a wide variety of slide fasteners
of the discrete t~vpe in which a series of interengageable fas-
tener elements are mounted astride the longitudinal beaded
edge of each of the oppositely disposed stringer tapes in ~mi-
formly spaced apart relationship. Since slide fasteners of
this type have a relatively increased coupling strength, they
are often employed in beltless trousers such as jeans which
are designed to tightly fit around the waist of a person who
wears them to dispense with the need for a belt. In such an
instance, severe lateral forces tending to pull the coupled
stringer tapes away from each other are exerted on the slide -
~astener. Therefore, the slider needs to be positively locked -
in its uppermost position against downward movement along the
fastener elements. To this end, the slider is provided with
a locking prong formed on the pull tab, which prong is brought
into locking engagement with the fastener elements within the
guide channel of the slider to secure the same against movement
along the fastener eléments when the pull tab lies flat against
the slider. Various slide fasteners of the discrete type are
known in which each of the fastener elements has ridges or
teeth on its inner peripheral surface for biting or gripping
engagement with the beaded tape edge so as to prevent the fas-
tener elements from being shifted out of position relative to -
and disengaged from the beaded tape edge. A common drawback of
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these conventional slide fasteners is that the slider often
fails to be positively locked and retained in place because
the fastener elements are still liable to become tilted rela-
tive to the beaded tape edge with the resultant disengagement
of the locking prong with the fastener element within the slid-
er guide channel when a severe lateral pull tending to separate
the coupled stringer tapes away from each other is applied to
the slide fastener. Another disadvantage is that even when
the fas~ener element is tilted only slightl~ with respect to
the beaded tape edge, the locking prong may go out of locking
engagement therewith because the fastener elements have a
relatively small contacting surface against which the locking
prong abuts in its locked position. A further disadvantage is
that the locking prong is susceptible to accelerated wear and
deformation because the tilted fastener elements permit the
locking prong to be forcibly disengaged therefrom when a severe
lateral pull is exerted on the sllde fastener.
It is therefore an object of ~his invention to provide
a slide fastener of the discrete type in which a series of
unformaly spaced, interengageable fastener elements are mounted
astride the longitudinal beaded edge of each of oppositely dis-
posed stringer tapes with such sufficient stability that the
fastener elements are prevented from tilting or inclining rela-
tive to the beaded tape edge even when a severe lateral pull
tending to separate the coupledstringer tapes away from each ;
other is applied to the slide fastener. :
Another object is to provide a slider fastener of the
type described in which each of the fastener elements is pro-
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vided with means cooperative with a slider for positively
locking the latter against movement along the fastener elements.
In general terms, the present invention provides
in a slide fastener including a pair of stringer tapes. .-
each having an inner longitudinal beaded edge
carrying on and along its inner longituainal beaded edge~ a
series of uniformly spaced,. interengageable fastener elements,
each of said fastener elements including.a body having a coupling
head and a pair of upper and lower legs extending rearwardly ..
from said coupling ~ead and ha~ing ~ppositely disposed inner
wall portions and opposite outer faces, each of ~aid upper and
lower ~egs also having opposi~e flat side faces lying substantially
at a right angle to saia outer ~ace and perpendicular to the plane
of the stringer tape, the improvement wherein said inner wall
15 portions being in the ~orm of an arcuate conca~e surface, which . .
portions jointly provide a continuous inner peripheral surface
of generally circular contour which is interrupted by a slot
defined by the opposed edges of said upper and lower legs, and
by said coupling head, said opposed edges being in gripping
engagement wi~h t~e stringer tape, said peripheral surface
peripherally gripping the beaded edge, said upper and lower legs
having a plurality of teeth formed integrally therewith and
projecting from the oppositely disposed inner wall portions into
said peripheral surface, the respective teeth on said upper and
~5 lower legs being disposed in registry with one anoth~r, the
teeth on ea~h leg bei~g ~paced apart along ~he length o~ the
beaded tape edge and located substantially at the center.of ..
curvature of the inner wall porti~n where the leg is the most
redu~ed in thi~kness as measured in ~e dire~tion perpendicular
to the plane of the stringer tape ~o reinforce the leg at said ::
portion thereo~, the opposi~e teeth on each i~ner wall portion :
adjacent to their opposite peripheral edges being so ~isposed .:-~
- that their.respQ~tive outer side surfaces lie subs~antially
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flush with the outer side ~aces of the leg, and each tooth
being disposed in firm biting engagement with the point of the
tooth embedded into the beaded tape edge to secure the fastener
element in po~ition against both longitudinal and rotary
displacement about the longitudinal path of the beaded tape edge.
Ms~y other ~dvantag~ and fe~tures of.~he pr~ssnt ln-
.. vant~on will becom~ ma~ifes~ to tho~e ver~ed ~n ~he art upon .
maki~g re~rence to the deta~ lea dQ~cription a~d the accomr :
`-10 panying sheet o~ drawing~ in wh~ch ~ pr~errsd structural
~mbod~m3nt in~orporat~ng the princ~ple~ of the pre~e~t ~nvea-
tlon ~B ~hown by way of exampla.
. 1 i8 a top plan vi~w og a ~llaO ~8t~Qr AC~Ord-
ing to th~ ~nv~ntlon~ showing a pA~r o~ stri~g~r t ~ e~ couple~
toge~her4
Fig. 2 i~.a per~poctlve vi~w of tho f~tene~ el ~ t .
with part ~rok~n ~way for Gl~rity o lllu~tratio~t .
Flg. 3 1B a v~rtlcal ~ro0s-sact~onal v~o~ o~ one.of ~b~
~r~ng~r t~pQs~ a~a
Flg. 4 iB a v~rti~al ~ro83-8~ctio~al ~1~ t~k~n ~lo~g .
the l~e rV-IV of Flg. 1.
F~g. 1 ~hows c ~llde ~t~r 10 comprC~lng a palr of
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oppo~ltely ~posed 8tr~g~r.tap~8 ~ ea~h h~vl~g ~ s~rl~
o~ ~n~ormly sp~cea apart~ l~t~reng~geable f~t~n~r ~em~ntg - .:
12 att~ho~ on ~n~ alo~ ~t~ longltua~ al b~a~ or r~l~for~
~d ~ago 13. The palr of ~erlo~ o~ ~as~ r ~l~m~t~ 12 ~n ,
th~ oppo~o~ ~tr~ng~r t~pes 11,11 hr~ take~ i~to ~h~ o~t o~ ; ~:
t~al ~ngagame~t by a ~ r ~not sho~n~ reclpr~c~bl~ ~lo~ .
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the fastener elements 12 to close and open the slide fastener
10 . ,'
Each of the fastener elements 12 includes a body 12a of
generally U-shaped configuration having a coupling head 14 and
S a pair of spaced apart upper and lower legs 15,16 formed inte- -
grally with and extending rearwardly from the coupling head 14
at its upper and lower portions, respectively. The coupling
~ head 14 has a coupling recess (not shown) formed in one side
; thereof and an outwardly extending coupling projection 17 on
the other side thereof. The coupling projection 17 is comple-
; mentary in shape to the coupling recess so that the coupling
projection 17 of each of the fastener elements 12 on one oF the
stringer tapes 11,11 is snugly received in the coupling recess
in its mating fastener element on the other stringer tape 11
when the slide fastener 10 is closed upon movement of the slid- ;
er along the fastener elements 12.
Each of the fastener elements 12 is attached to the
stringer tape 11 with the upper and lower legs 15,16 arranged
astride the longitudinal beaded tape edge 13 as best shown in
Fig. 3. The fastener element 12 extends longitudinally sub-
stantially at a right angle to the beaded tape edge 13 with
the coupling head 14 projecting beyond the latter. The upper
and lower legs 15,16 are mirror images of the other and hence
are disposed symmetrically with respect to the longitudinal
axis of the fastener element body 12a, as best shown in Fig. 3.
Each of the upper and lower legs 15,16 has an outer flat face -
18 lying in a plane substantially parallel to the stringer
tape 11 and opposite flat side faces 19,~0 lying substantially
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perpendicular to the stringer tape 11. The upper and lower
legs 15,16 also have a pair of oppositely disposed inner wall
portions 21,22 in the form of an arcuate, concave surface,
which portions merge into a curved portion 23 of the coupling
head 14 at their one ends to provide a continuous, smooth inner
peripheral surface 24 of generally circular contour which is
interrupted by a slot 25 defined by the opposed edges 26,27 of
the legs 15,16. The slot extends substantially centrally of
the height or thickness of the fastener element body 12a be-
tween the opposite outer flat faces 18,18.
According to the invention, each of the upper and lowerlegs 15,16 has a pair of teeth 28,28 formed integrally there-
with and projecting from the inner wall portion 21(22) toward
the opposed leg. Each of the fastener elements 12 is clamped ~:
on and around the beaded tape edge 13 with the continuous peri~
pheral surface 24 peripherally embracing the beaded edge and
with the pair of teeth 28,28 on each inner wall portion 21(22)
disposed in biting or gripping engagement with the beaded edge
13, as best shown in Fig. 3, to eliminate the possibility of
the fàstener elements 12 becoming tilted relative thereto or
disengaged therefrom. In this condition, the opposed edges
26,27 are also held in gripping engagement with the stringer
tape 11 closely adjacent to the beaded tape edge 13. Each of .
the teeth 28 terminates short of the plane of the stringer : ~
tape 11. :
The fastener element 12 has the upper and lower legs
15,16 initially flared outwardly prior to attachment to the ;
beaded tape edge 13, and the legs 15,16 are deformed ox press-
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ed toward each other from the outwardly-flared configuration
into a compressed configuration as shown in the drawings to
bring the legs 15,16 into clamping or gripping engagement with
the beaded tape edge 13 with the teeth 28 on the legs held in
firm biting engagement therewith.
The pair of teeth 28,28 on the inner wall portion 21 are
disposed in registry with the other pair of teeth 28,28 on the
inner wall portion 22, and the teeth 28,28 on each inner wall
portion is spaced apart from each other along the length of the
beaded tape edge. Each of the teeth 28 is located substantial- ;
ly at the center of curvature of the arcuate inner wall portion
21(22). In other words, the two pairs of teeth 28 on the inner
wall portions 21,22 are located at the thinnestportions 29,29
of the legs 15,16 in diametricall~ opposed relationship when
viewed in the direction of the length of the beaded tape edge
13. Thus, the pair of teeth 28,28 on each leg 15(16) serve to
increase its mechanical strength at its weakest portion 29.
This prevents the upper and lower legs 15,16 from being deform-
ed away from each otherin a direction perpendicular to the
stringer tape 11 when the slide fastener 10 is subjected to
severe external stresses, thereby ensuring that the legs 15,16
can be positively held in firm gripping engagement with the `-
beadéd tape edge 13.
Each of the teeth 28 is of wedge-shaped configuration
having a pair of opposite parallel, flat side surfaces 30,30
and a pair of inclined surfaces 31,31 converging outwardly
toward its distal or outer edge.
Each side surface 30 has a substantially triangular
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shape as best shown in Fig. 3. Preferably, the pair of teeth
28,28 on each leg 15(16) are so disposed that their respective
outer side surfaces 30,30 lie flush with the side flat faces
19,20, respectively, as best shown in Figs. 2 and 4. Alter- - -
natively, each pair of teeth 28,28 may be disposed closely
adjacent to the opposite peripheral edges of ~he inner peri-
pheral surface 24 so that the outer side surfaces 30,30 are
disposed slightly inwardly of the side ~aces 19,20. As mention-
ed previously, each tooth 28 bites into the beaded tape edge 13
so that it deforms the tape edge 13 immediately adjacent to the
outer side surface 30 to provide a depressed region 32 as shown -;
in Fig. 4. The slider is provided with a locking prong 33 at -
one end as indicated in dotted lines in Fig. 4 which prong is
selectively brought into locking engagement with one of the
fastener elements 12 within the guide channel of the slider to ;`
thereby secure the slider against movement along the fastener -~
elements when the pull tab lies flat against the slider. More
specifically, in the locked position of the slider, the lock-
ing prong 33 has its distal end portion disposed in the depress-
ed region 32 in close contact relation to the outer side face
19 and outer side surface 30 as shown in Fig. 4. Thus, the
area of contact of the fastener element 12 with the locking prong
33 is increased by virture of the provision of the tooth 28.
This ensures that the locking prong 33 can positively be held
in locking engagement with the fastener element in the locked
position of the slider even when a severe lateral pull is ex-
erted on the coupled stringer tapes 11,11. i
Although various minor modifications may be suggested by
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~ o~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.
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