Apparatus for gapping a continuous slide fastener stringer

An apparatus for gapping a continuous slide fastener stringer comprises: a presser unit having a punch and a coacting die for pressing a group of fastener elements, in a selected portion of the stringer placed therebetween, to reduce the thickness of their leg portions, and for holding the pressed fastener elements; and a gripper unit having a pair of relatively pivotable grip members for gripping a stringer tape on the opposite sides of the stringer, the gripper unit being disposed alongside of the presser unit to grip the tape from the fastener-element side of the stringer and being movable between its normal position and its advanced position along an arcuate path for moving the gripped tape to remove the pressed and held fastener elements therefrom seriatim.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an apparatus for gapping a slide fastener 
stringer having a continuous row of fastener elements secured to a 
stringer tape along a longitudinal edge thereof. 
2. Prior Art 
Japanese Patent Publication No. 48-32222, issued Oct. 4, 1973 for a method 
of gapping a continuous slide fastener stringer, discloses the concept of 
moving a stringer tape away from a group of fastener elements to be 
removed therefrom and vice versa after those fastener elements are pressed 
at their leg portions. Although there is no concrete description for 
structural features, various figures of the Japanese Publication No. 
48-32222 indicate that a pair of grippers is disposed at the tape side of 
a stringer to grip a stringer tape from that side. With such arrangement, 
correct and easy positioning of the slide fastener stringer is difficult 
to achieve in apparatus of the type in which the stringer is to be placed 
by hand. 
SUMMARY OF THE INVENTION 
According to the present invention, a gripper unit is disposed alongside of 
a presser unit to grip a tape of a slide fastener stringer from the 
fastener-element side of the stringer. Therefore, the stringer to be 
gapped can be placed between a punch and a die of the presser unit and 
between a pair of upper and lower grip portions of the gripper unit with 
maximum ease, at which time a group of the fastener elements to be pressed 
can be positioned between the punch and the die correctly. 
Further, the gripper unit follows an arcuate path as it is moved from its 
normal position to its advanced position. With this arrangement, the 
fastener elements in a first portion of the stringer to be gapped can be 
removed seriatim, requiring only a small pulling force. 
It is an object of the present invention to provide an apparatus for 
gapping a continuous slide fastener stringer, which enables the fastener 
stringer to be placed in position with maximum ease. 
Another object of the invention is to provide an apparatus for gapping a 
continuous slide fastener stringer without injuring or breaking a stringer 
tape. 
Many other advantages, features and additional objects 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 example.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The principles of the present invention are particularly useful when 
embodied in an apparatus such as shown in FIG. 1, generally indicated by 
the numeral 10. 
The apparatus 10 generally comprises a fastener-element pressing and 
holding unit (hereinafter referred to as "presser unit") 11, a tape 
gripping and moving unit (hereinafter referred to as "gripper unit") 12, a 
presser unit (or first) drive mechanism 13 (FIG. 2), and a gripper unit 
(or second) drive mechanism 14 (FIG. 3). 
As shown in FIG. 2, the presser unit 11 includes a die 15 supported on a 
stand 16 which is mounted on a horizontal plate 17 of a frame 18 of the 
apparatus 10, and a coacting punch 19 fixed to one end of an elongate 
punch holder 20 which is pivotally supported on a bracket 21 projecting 
upwardly from the horizontal frame plate 17 by a pin 22. The punch holder 
20 is operatively connected at the other end to the first drive mechanism 
13 for pivotal movement. The punch 19 and the die 15 are aligned 
vertically with each other, and the punch 19 is movable toward and away 
from the die 15, in response to the pivotal movement of the punch holder 
20, to press or deform a group of fastener elements 23 (FIG. 7) in a first 
portion 24 of a slide fastener stringer 25 placed on the die 15, so as to 
reduce the thickness of their leg portions 26 (FIGS. 6A and 6B). The 
stringer 25 has a continuous row of fastener elements 23 secured to a 
stringer tape 27 along one longitudinal edge thereof, each of the fastener 
elements 23 being mounted astride of the tape 27. The punch 19 has a 
predetermined width which corresponds to the length l (FIG. 7) of the 
first stringer portion 24. 
The first drive mechanism 13, as best shown in FIG. 2, includes a camshaft 
28 which is connectable with a drive shaft (not shown) by means of a 
clutch (not shown) for rotation, a first cam plate 29 mounted on the 
camshaft 28, a cam follower 30, and a toggle joint 31. The cam follower 30 
is pivotally supported at one end on a vertical plate 32 of the frame 18 
by a pin 41 and has at the other end a roller 33 rotatable on a pin 42. 
The cam follower 30 is normally urged toward the cam plate 29 by a 
compression spring 34 so that the roller 33 engages with the cam plate 29 
on its peripheral cam surface. 
The toggle joint 31 is composed of one relatively long link 35 and four 
relatively short links 36,37,38,39. The long link 35 is pivotally 
connected at one end to said other end of the cam follower 30 by the pin 
42 and extends upwardly through an aperture 40 in the horizontal frame 
plate 17, the other end of the long link 35 being pivotally connected to 
one end of each of the two short links 36,37 by a pin 43. The other end of 
the short link 36 is pivotally connected to the bracket 21 of the 
horizontal frame plate 17 by a pin 49. The other end of the short link 37 
is pivotally connected to one end of each of the remaining two short links 
38,39 by a pin 44. The other end of the short link 38 is pivotally 
connected to a block 45 by a pin 46. The other end of the short link 39 is 
pivotally connected to said other end of the punch holder 20 by a pin 47. 
An extension spring 48 is mounted between the two pins 49,44 to normally 
urge the one end of each of the two short links 38,39 toward the pin 49, 
i.e. rightwardly in FIG. 2. The block 45 is adjustably mounted on the 
frame 18 by means of a screw 49 so that the extent of stroke of the punch 
19 can be adjusted; that is, the thickness d (FIG. 6B) of the pressed 
fastener element leg portions 26 can be adjusted. 
The die 15 has a width greater than that of the punch 19 (FIG. 1) and has a 
suitably stepped top surface 50 (FIGS. 6A-6D). Further, the die 15 has a 
pair of upwardly projecting stops 51,51 (FIGS. 2, 4 and 6A-6D) disposed 
one on each side of the punch 15, as viewed in plan, so that the group of 
fastener elements 23 to be pressed can be positioned in vertical alignment 
with the punch 15 just by placing said group of fastener elements 23 
between the stops 51,51. The die 15 is provided with a slope 52 (FIG. 6D) 
slanting down to the left from its rear end and adjoining a slope 53 (FIG. 
2) of the die stand 16, the latter slope 53 in turn leading to a chute 54 
through which the released fastener elements 23 passing over the combined 
slope 52,53 are discharged. 
As shown in FIG. 3, the gripper unit 12 is disposed alongside of the 
presser unit 11 (FIG. 1) and includes a pair of upper and lower grip 
members 60,61. The lower grip member 61 is slidably mounted on the 
horizontal frame plate 17 and is movable between its normal or retracted 
position (FIG. 3) and its advanced position (FIG. 5). The upper grip 
member 60 is pivotally supported at 62 on a bracket 63 by a pin 64, the 
bracket 63 projecting upwardly from the lower grip member 61. The lower 
grip member 61 has in its rear end a longitudinally extending guide groove 
65 in which a cam block 66 is slidably received, there being a compression 
spring 67 mounted between the cam block 66 and the lower grip member 61 so 
as to normally urge the cam block 66 rearwardly. The cam block 66 has a 
cam surface 68 against which a roller 69 rotatably mounted on the rear end 
of the upper grip member 60 is normally urged, by means of a compression 
spring 107 mounted between the upper and lower grip members 60,61. The cam 
surface 68 slopes down to the right as viewed in FIG. 3 so that, when the 
cam block 66 is pushed forward against the bias of the compression spring 
67 by a cam block pushing mechanism 92 (FIG. 1) described below, the upper 
grip member 60 pivots clockwise about the pin 64 to close a pair of grip 
portions 70,71 formed on respective front ends of the upper and lower grip 
members 60,61 (FIG. 3). When the cam block 66 is moved backward, the upper 
grip member 60 pivots counterclockwise to open the pair of grip portions 
70,71 (FIG. 3). 
The gripper unit (or second) drive mechanism 14, as best shown in FIG. 3, 
includes a second cam plate 72 mounted on the camshaft 28, a cam follower 
73 pivotally supported on the frame 18, an attachment member 74 attached 
to the lower grip member 61 on its underside by a number of bolts 85, and 
a guide lever 86 (FIG. 4) for guiding the attachment member 74 to follow 
an arcuate path. The cam follower 73 has a first roller 87 resting on a 
peripheral cam surface of the second cam plate 72 and a second roller 108 
engaging with the rear end of the attachment member 74 so that, when the 
second cam plate 72 rotates, the attachment member 74, together with the 
upper and lower grip members 60,61, is moved forwardly and backwardly 
according to the geometry of the second cam plate 72. 
The attachment member 74 has a connecting portion 88 extending through a 
slightly doglegged guide aperture 89 (FIG. 4). The attachment member 74 is 
pivotally connected at its front end to one end of the guide lever 86 by a 
pin 90, the guide lever 86 being pivotally supported on the underside of 
the horizontal frame plate 11 by a pin 91 (FIG. 4). Accordingly, the 
attachment member 74 (only the connecting portion 88 of which is shown in 
FIG. 4) is movable between the solid line position and phantom line 
position in response to pivotal movement of the guide lever 86, following 
an arcuate path; that is, the gripper unit 12 follows substantially the 
same arcuate path as it is moved between the solid line position and the 
phantom line position (FIG. 1). 
The guide lever 86, as shown in FIG. 1, is normally urged to pivot 
clockwise, as viewed in this Figure, by means of an extension spring 104 
mounted between the other end of the guide lever 86 and a pin 105 fixed to 
the frame 18. A bolt 106 serves as a stop for limiting the clockwise 
movement of the guide lever 86. 
The pushing mechanism 92 for the cam block 66, as shown in FIG. 1, includes 
a rod 93 extending parallel to the lower grip member 61 and slidably 
supported by a pair of stationary front and rear guide blocks 94,95, an 
arm 96 mounted on the rod 93, a push rod 97 slidably supported on a free 
end of the arm 96 for pushing the cam block 66, a lever 98 pivotally 
supported on the frame 18 for moving the rod 93 in the axial direction, 
and a cam plate (not shown) mounted on the camshaft 28. Assuming that the 
lever 98 pivots so as to push the rod 93 forwardly, i.e. downwardly as 
viewed in FIG. 1, through the medium of a roller 100 mounted on the rod 
93, the arm 96 is moved forwardly against the bias of an extension spring 
101 mounted between the rear guide block 94 and the arm 96. This movement 
causes the push rod 97, through the medium of a compression spring 102, to 
move forwardly to push the cam block 66 against the bias of the 
compression spring 67, as shown in FIG. 5. As a result, the pair of grip 
portions 70,71 are closed to grip the stringer tape 27 as aforementioned. 
The front guide block 94 has a horizontally projecting stop 103 (FIGS. 1, 
3 and 5) for limiting the forward movement of the cam block 66. 
The apparatus 10 thus operates in the following manner. The slide fastener 
stringer 25 is placed by hand between the punch 19 and the die 15 and 
between the pair of grip portions 70,71 such that the group of fastener 
elements 23 to be removed is positioned away from the operator and in 
vertical alignment with the punch 19, and with other fastener elements 23 
disposed to the rear of the grip portions 70,71. Thereafter, the camshaft 
28 is connected to the drive shaft (not shown) for rotation by actuating 
the clutch (not shown) by a suitable means (not shown), whereupon the 
punch 19 is lowered to press or deform the group of fastener elements 23 
to reduce the thickness of their leg portions 26 (FIG. 6B), thereby 
forming forwardly facing shoulders for engaging rearwardly facing 
shoulders on the punch 19 and the die 15. The punch is slightly raised to 
provide a clearance as shown in FIG. 6C, whereby the punch shoulder, under 
the influence of the illustrated spring, remains in contact with the upper 
shoulders of the fastener elements. Such clearance enables the leg 
portions to be deflected apart as shown in FIG. 6D. Simultaneously with 
the lowering of the punch 19, the grip portion 70 of the upper grip member 
60 is lowered to grip the opposite sides of the stringer tape 27 at a 
second portion 109 (FIG. 7) of the stringer 25, from the fastener element 
side thereof. Subsequently, the gripper unit 12 is advanced from the solid 
line position to the phantom line position (FIG. 1), thereby moving the 
tape 27 from the solid line position to the phantom line position (FIG. 7) 
while the pressed fastener elements 23 are held in position by the punch 
19 and the die 15 (FIG. 6C). At that time, the gripper unit 12 follows an 
arcuate path. This path causes the group of fastener elements 23 in the 
first portion 24 of the stringer 25 to be removed seriatim (FIG. 6D) from 
the tape 27. Thus, a gap s (FIG. 7) devoid of the fastener elements 23 has 
been formed in the stringer 25. Then, the grip portions 70,71 are opened 
so that the stringer 25 can be taken out. The presser unit 11 and the 
gripper unit 12 and their associated parts are then returned to respective 
original or retracted positions shown in FIGS. 2 and 3. 
FIG. 8 shows a pair of slide fastener stringers 25,25 each having an 
element-free gap s formed by the apparatus 10 according to the present 
invention. 
According to the apparatus 10 thus constructed, the gripper unit 12 is 
disposed alongside of the presser unit 11 to grip the stringer tape 27 
from the fastener-element side of the stringer 25. In other words, there 
is no part located at the tape side (right side as viewed in FIGS. 2 and 
3) of the stringer 25. Therefore, the stringer 25 to be gapped can be 
placed between the punch 19 and the die 15 and between the upper and lower 
grip portions 70,71 with maximum ease, at which time the group of fastener 
elements 23 to be pressed can be positioned between the punch 19 and the 
die 15 correctly. 
Moreover, because the gripper unit 12 follows an arcuate path as it is 
moved from its normal position to its advanced position (FIG. 7), the 
fastener elements 23 in the first portion 24 of the stringer 25 can be 
removed seriatim, requiring only a small pulling force. This processing 
does not injure or break the tape 27 during gapping operation. Further, 
since the upper and lower grip portions 70,71 are opened to release the 
tape 27 as they are in the advanced position indicated in phantom in FIG. 
7, the gapped stringer 25 can be taken out with ease. 
Although various minor modifications may be suggested by those versed in 
the art, it should be understood that I wish to embody within the scope of 
the patent warranted hereon all such embodiments as reasonably and 
properly come within the scope of my contribution to the art.