Note: Descriptions are shown in the official language in which they were submitted.
~2~
WEL~ LO~DING AND FEEDING SYSTEM, RE:LATED WEB
CONSTRUCTION AND METHOD ~ND APPARATUS FOR MAKING WEB
This invention relates to web handling machines
such as plotters, recorders and sign makers wherein a web
is fed lonaitudinally of itself by a pair of sprockets co-
operating with holes in the two longitudinal side edge
~ortions of the web, and deals more particularly with a
web loading and feeding system for such a machine, includ-
ing a related web construction and a method and apparatus
for making the web, facilitating by way of visual aids the
proper loading of a web onto the machine.
The present invention may be used h~ith any one of
various types of machines wherein a web is moved by a pair
of sprocket wheels having pins, or teeth-like members, on
their peripheries cooperating with rows of holes in the
web's two side edge portions. In such machines it is usu-
ally essential to error free operation that the web be
~roperly loaded in the machine so that the sprocket pins
engage the correct web holes. This means that th'O corres-
ponding pins of the two sprockets lvcated in a common
plane passing through the sprocket drive axis should en-
gage two corresponding holes of the web located on â
commorl line extending perpendicular to ~he edges of the
web. Often, particularly when the web is very wide, it is
difficult to determine by eye which sprocket pins corres-
pond with one another and which holes on the opposite
sides of the web correspond wit:h one an~ther, and as a
res~l~t web lo~ding errors can easily o~c~r. k~reover,
sometimes whell a web loading error is made the h'~ there-
257
--2--
after nevertheless appears to feed in an apparently normal
manner so that errors introduced by the web loading may be
ascribed to other causes and not q~ickly traced back to
the faulty loading.
A general object of the invention is therefore to
provide a visual means to enable a machine operator to
easily visually determine the proper placement of a web
~hen loading it onto the feed sprockets of a machine. Al-
though, as mentioned above, this invention may be used
with various different types of web handling devices it is
particularly well suited for machines such as the sign
making machine as shown in copending Canadian patent
application serial no. 433,161-3, filed July 26, l9B3,
wherein the web is relatively wide and wherein in the
course of a day's operation many different webs may be
loaded onto the machine.
The invention also has as an object the provision
of a web construction usable with a web handling machine
to facilitate proper loading of it into the machine and
has as a related object the provision of a method and ap-
paratus for efficiently making such a web.
Other objects and advantages of the invention
will be apparent from the following detailed description
of the preferred embodiments and from the accompanying
drawings.
The invention resides in a web loading and feed-
ing system for a web handling machine with such system
including two drive sprockets each having a series of ra-
~'2(~3%5~
--3--dially outwardly extending pins uniformly spaced from one
another circumferentially of the sprocket with two corres-
ponding pins on the two sprockets - that is, two pins
located at least approximately in the same plane contain-
ing the axis of sprocket rotation - being visually distin-
guished fro~ the remaining pins, the web having similarly
uniformly spaced holes located in rows extending along
each of the side edge portions of the web with correspond-
ing holes - that is, two holes on opposite sides of the
web located in substantially the same line extending per-
pendicular to the side edges of the web - at intervals
along the length of the web being visually distinguished
from the remaining holes by means of extra holes, so that
the visually distinguished web holes may be placed on the
visually distinguished sprocket pins to assure proper web
l~ading. The distinguished pair of sprocket pins may be
so distinguished by means of extra pins engaging the extra
holes of the web, or other visual means such as color dif-
ferences may be used to provide the distinguishing fea-
tures.
The invention also resides in the construction of
the web by itself whereby in addition to a row of first
holes extending along one side edge portion of the web and
a row of second holes extending along the other side edge
portion of the web the first side edge portion includes
third holes and the other side edge portion of the web
includes fourth holes which third and fourth holes serve
to visually distinguish corresponding pairs of first and
l~Q3ZSt7
second holes to aid in properly locating the web onto a
handling machine.
The invention still further resides in a method
and apparatus for making the web construction whereby the
holes in the side edge portions of the web are made by a
simple punch, step motor drive and control apparatus.
Fig~ 1 is a perspective view of a sign making
machine having a web loading and feeding system embodying
the present invention with various portions of the machine
and of the web being broken away to reveal additional
features.
Fig. 2 is a fragmentary perspective view showing
the relationship between the drive sprockets and the web
during the loading of the web onto the machine of Fig. 1.
Fig. 3 is a side elevational view of one of the
web drive sprockets of Fig. 1.
Fig. 4 is a reduced scale plan view of a portion
of the web of Fig. 1.
Fig. 5 is an enlarged scale, fragmentary section-
al view through the web taken on the line 5-5 of Fig. 4.
Fig. 6 is an enlarged scale, fragmentary plan
view of the web of Fig. 4.
Fig. 7 is a view similar to Fig. 2 but showing a
different construction of the sprockets.
Fig. 8 is a side elevational view of one of the
sprocket of Fig. 7.
Fig. 9 is a schematic view showing an apparatus
for making the web of Fig. 1.
~2~3;~i7
Fig. 10 is a fragmentary perspective view showing
another embodiment of the web.
Referring to Fig. 1, the invention is there il-
lustrated as embodied in a sign making machine 10 which is
or may be generally similar to the one shown and described
in more detail in copending Canadian application Serial
No. 433,161-3, filed July 26, 1983. The machine 10
handles and works on an associated web 12. The web is
moved longitudinally of itself, in the illustrated X-coor-
dinate direction, by a pair of drive sprockets 14, 16
forming part of the machine 10 and spaced from one another
along and supported for driven rotation in unison about a
common drive axis 18. As explained in more detail herein-
after, pins or teeth on the two sprockets 14, 16 engage
holes in the two side edge portions of the web 12 to drive
it in the X-coordinate direction. A platen or roller 17
located between the two sprockets 14 and 16, and similar
to that of a typewriter, supports that transverse portion
of the web 12 aligned with the sprockets 14, 16.
When the machine 10 is operating two web holddown
bails, one for each sprocket 14 and 16, carried by a
transverse rod 20 normally hold the web in engagement with
the sprockets. In Fig. 1 only the one holddown bail 22
associated with the sprocket 14 is shown and this bail
along with its supporting rod 20 is shown in its raised
position to give a clearer view of the sprockets.
The machine 10 also includes a tool head 24 suit-
ably supported and driven in the illustrated Y coordinate
--6--
direction relative to the web 12.
In a normal sign making mode of operation, the
tool head 24 is equipped with a knife-type cutter 26 and
the web 12 is an elongated piece of sign making stock
consisting of an upper layer of adhesive-backed plastic
material, such as vinyl, supported by a bottom layer of
release material on which the upper plastic layer is sup-
ported with its adhesive-backed face in engagement with
the release material. For example, in this case the basic
material from which the web 12 is made may be a laminated
sheet material consisting of an upper vinyl layer, three
to five mils thick, having any one of various different
colors, with a pressure-sensitive adhesive on its lower
surface, such vinyl upper layer being in turn carried by a
lower release layer in the form of a ninety-pound paper
coated with silicone. With the web 12 made of such sign
making stock and with the tool head 24 equipped with a
knife-type cutting tool 26 the web 12 and the tool 26 may
be moved relative to one another simultaneously in the X-
and Y-coordinate directions, through the operation of the
machine 10, to cut alphanumeric characters or other
indicia from the upper vinyl layer of the stock which
characters or indicia can subsequently be transferred, as
described in the aforesaid pending patent application, to
another carrier to form a finished sign.
Also, in addition to the aforedescribed cutting
or sign making mode of operation of the machine 10 it may
~Z~325~
also be operated in a plotting mode during which a pencil
or other plotting tool is placed in the work head 24 in
place of the cutting tool 26 and the web 12 is comprised
of a sheet of paper or the like. In both the sign making
mode and the plotting mode the machine 10 operates auto-
matically to cause the tool carried by the head 24 to
automatically trace characters or other indicia desired
for a sign. The purpose of the plotting mode is to allow
a proposed sign to be first plotted on paper to check the
results of the information entered into the machine before
the more expensive sign making stock is cut.
Proper operation of the machine 10 requires that
the web 12 be loaded into it - that is, onto the sprockets
14 and 16 - so that as the web is moved longitudinally of
itself by rotation of the sprockets lines extending trans-
versely of the web perpendicular to its side edges are
parallel to the sprocket axis 18. Typically, the web 12
may be relatively wide - say fifteen inches wide - and the
holes formed in each side edge portion of the web may be
relatively closely spaced to one another - say on one-half
inch centers~ With such large width of the web and small
spacing of the holes it is difficult to visua]ly properly
align the web with the sprocket pins when loading a web
onto the machine. That is, assuming the holes on one side
edge of the web are properly located relative to the pins
of its associated sprocket the holes along the other side
edge of the web may be placed on the wrong pins of the as~
sociated sprocket, and such error in the loading of the
- ~ -
web may not be readily detected in the subsequent opera-
tion of the machine even ~hough it introduces errors in
the cutting or plotting function.
In accordance with the invention, the machine 10
and web 12 of Fig. 1 are constructed to provide a web
loading and feeding system whereby web loading errors of
the type described above can be reduced or eliminate~i
through the use of visual means facilltating proper web
loading~
10. Referring to Fig~ 2, in the web loading and sys-
tem of the invention the two sprockets 14 and 16 are both
fixed to a common drive shaft ~8 for rotation about ~he
common axis 18, The sprocket 14 has a series of radially
ou~wardly extending pins 30, 30 located in a common plane
perpendicular to the axis 18 and uniformly spaced from one
another circumferentially of the sprocket. ~he sprocket.
16 in turn has a similar series of radially outwardly ex-
tending pins 32~ 32 loca~ed in a common plane perpendicu-
lar to the axis 18 and uniformly spaced from one another
circumferentially of the sprocket 16 in a manner iden~ical
to the spacinq of the pins 30, 30 of the sprocket 14. ~he
number cf pins 30/ 30 on the sprocket 19 is therefore
equal to the number of pins 32, 32 on the sprocket 16.
This number of pins may vary from application to appli.ca--
tion, but in the illustrated case the sprocket 14 has
fourteen pins 30, 30 and the sprocket 16 likewise has
fourteen pins 32, 32. Further, the pins 30, 30 of the
sprocket 14 and the pins 32, 32 of the sprocket 16 are so
3Z~
g
relatively arranged that each pin 30 on the sprocket 14
has a correspondiny pin 32 on the sprocket 16 which two
pins are located in, or at least substantially in, a com-
mon ~lane passing through the axis 18. For example, in
Fig. 2 one such common plane is sho~n at ABCD and contains
a pair of corresponding pins 30 and 32 indicated at a and
In keeping with the invention means are provided
for visually distinguishing at least one pair of corres-
1~ ponding pins 30 and 32 from ~he remaining pins 30, 30 and
32, 32 of the sprockets 14 and 16. Such visual distin-
guishing means may take various different forms and in
Fig. 2 consists of an extra, or third, pin 34 on the
sprocket 14 and an extra, or fourth, pin 36 on the sprock-
et 16~ The pin 34 on the sprocket 14 is located between
two of the pins 30~ 30 and likewis~ the pin 36 on the
sprocket 16 is located between two of the pins 32, 32 on
the sprocket 16 with the pins 34 and 36 being located in a
common plane, such as the plane indicated at AEFD, con-
taining the axis 18. The two extra pins 34 and 36 there-
fore visually distinguish from the remaining pins 30, 30
and 32, 32 at least one corresponding pair of pins 30 and
32. In Fig. 2 such visually distinquished pair of pinC 30
and 32 may be taken to be the pins a and b located clock-
wise from the pins 34 and 36. However, the distin~uls~ed
pair of corresponding pins could also be taken ~o be the
pins c and d located counterclockwise from tr.e pins 34 and
36~ In Fig. 2 the pin 34 is located midway between two of
~Z03Z~7
--1 o--
the pins 30, 30 on the sprocket 14 and the pin 36 is lo-
cated midway between two of the pins 32, 32 on the sprock-
et 16. Such middle spacing of the pins 34 and 36 is not,
however, necessary and if desired the pin 34 may be locat-
ed closer to one of the two pins 30 between which it is
placed than it is to the other of such two pins and like-
wise the pin 36 may be located similarly closer to one of
the two pins 32 between which it is located than it is to
the other of such two pins.
The web 12, as shown in Figs. 2, 4 and 6 com-
prises an elongated piece of sheet-like material having
parallel side edges 40 and 42. In the side edge portion
of the web 12 adjacent the side edge 40 is a row of first
holes 44, 44 all located on a first line 46 spaced slight-
ly inwardly from the edge 40 and uniformly spaced from one
another by a spacing equal to the spacing between the pins
30, 30 of the sprocket 14. Likewise, fn the marginal edge
portion adjacent the edge 42 is another row of second
holes 48, 48 a:Ll located on a line 50 spac~d slightly in-
wardly from the edge 42 and unifor~ly spaced from one
another by a spacing equal to that o. the spacing of the
first holes 44, 44. Furthermore, the first holes 44, 44
are so placed relative to the second holes 48, 4B that
each first hole 44 has a corresponding second hole 48
located directly opposite from it on the other side of the
web~ That is, as indicated by the one line S2 indicated
in Fig. 4 which extends perpendicular to the side edges 40
and 42, each first hole 44 has a corresponding second hole
~Z~3257
48 with such two corresponding first and second holes be-
ing located on a common line extending perpendicular to
the web side edges and perpendicular to the lines 46 and
50 containing the rows of holes.
As part of the invention, the web 12 in addition
to the first holes 44, 44 and second holes 48, 48 includes
additional holes serving to visually distinguish corres-
ponding pairs of first and second holes at intervals along
the length of the web. In Figs. 2, 4 and 6 these addi-
tional holes comprise a row of third holes 54, 54 locatedon the same line 46 as the first holes 44, 44 and a row of
fourth holes 56, 56 located on the same line 50 as the
second holes 48, 48. Each third hole 54 is located be-
tween two adjacent first holes 44, 44 and each fourth hole
56 is located between two adjacent second holes 48, 48.
Further, the placement of each third hole 54 with respect
to the two first holes 44, 44 between which it is received
conforms to the placement of the third pin 34 of the
sprocket 14 between the two pins 30, 30 between which it
is received. Similarly, the placement of each fourth hole
56 with respect to the two second holes 48, 48 between
which it is received conforms to the placement of the
fourth pin 36 of the sprocket 16 with respect to the two
pins 32, 3~ between which it is received.
Also, stiil referring to Figs. 2 and 4, each
third hole 54 has a corresponding fourth hole 56 located
directly opposite from it along a common line extending
perpendicular to the side edges 40, 42 of the web and to
32~7
the lines 46 and 50, one such common line being shown for
exa~ple at 58 in Fig. 4~ It will therefore be evident
from Figs. 2 and 4 that each pair of corresponding third
and fourth holes 54 and ~6 serve to visually distinguish
at least one corresponding pair of first and second holes
44 and 48. For example, in Fig. 2 the illustrated corres-
ponding third and fourth holes 54 and 56 visually distin-
guish one pair of first and second holes indicated at e
and f. They also serve to visually distinguish another
pair of first and second holes indicated at g and h.
Since in the construction shown the third hole 54 as seen
in Fig. 2 is placed equidistantly between the holes e and
g and the fourth hole 56 is placed equidistantly between
the holes f and h the corresponding pair of first and
second holes made up of the holes e and f are visually
distinguished from the remaining first and second holes to
the same extent as are the corresponding pair made up of
the holes g and h. Therefore, the three holes e, g and 54
of Fig. 2 may be taken to be a cluster of holes which
20 cluster is itself visually distinguished from the remain-
ir.g holes 44, 44 and is placed over the corresponding
cluster of pins on the sprocket 14 made up of the pin 34
and the two pins a and c on opposite sides of it when
loading the web onto the sprocket 14, and likewise the
holes h, f and 56 may be taken to be a similar visually
distinguished cluster of holes which is placed on the
visually distinguished cluster of pins on the sprocket 16
n,ade up of the pin 36 and the two pins b and d on opposite
12~32~57
-13-
sides of it. ~lowever, if desired the hole 54 may bc
placed closer to the hole e and the hole 56 closer to the
hole f than shown in Fig. 2 to give distinctive prominence
to the corresponding first and second holes e and f and in
s~ch case the pins 34 and 36 would of course also be lo-
cated closer to the corresponding pins a and b.
As is obvious fro~ what has already been said,
the corresponding pairs of third and fou~th holes 54 and
56 distinguish corresponding pairs of first and second
holes on the web which visually aids in properly loading
the web onto the sprockets 14 and 16. That is, in a load-
ing procedure such as illustrated in Fig. 2, the sprockets
are turned to bring the third and fourth pins 34, 36 to a
web loading position at which the pins 34 and 36 extend
generally upwardly. m e web 12 is then moved over the
sprockets until a corresponding pair of third and fourth
holes 54, 56 are located generally above the sprocket pins
34, 36 and then the web is moved downwardly onto the
sprockets bringing the holes 54, 56 onto the pins 34 and
36 and bringing the visually distinguished corresponding
pair of first and second holes e and f onto the visually
distinguished corresponding pair of pins a and b and the
visually distinguished corresponding pair of holes g and h
onto the visually distinguished corresponding pair of pins
cand d, and accordingly proper movement of the web from
that point on is assured.
With reference to Fig. 4, the third holes 54, 54
are spaced uniformly from one another along the length of
~'Z6~132~7
-14-
the web by a distance S which distance S is equal to Nd,
where d is the spacing between the first holes 40, 40 and
is the spacing between the second holes 48, 48, and where
N is the number of first pins 30, 30 on the sprocket 14
the number of second pins 32, 32 on the sprocket 16. In
the illustrated case the number of pins 30, 30 and 32, 32
is fourteen and therefore S equals 14d - that is, a third
hole 54 occurs after every fo~rteenth hole 44 and likewise
a fourth hole 56 occurs after every fourteenth hole 48.
As a result of this each time the sprockets 14 and 16
undergo one revolution the third and fourth pins 34 and 36
will enter a new pair of third and fourth holes 54 and 56.
As indicated previously the web 12 may take vari-
ous different forms depending on the type of machine with
which the invention is used, and in the illustrated case
may be either a length of sign making stock from which
signs are cut or may be a length of paper or the like on
which a sign is drawn as a test or checking procedure
prior to its being cut from sign making stock material.
In Fig. 5 the web 12 is shown to comprise a piece of sign
making stock such as the material previously mentioned.
As such it consists of an upper layer 60 made of a thermo-
plastic material such as vinyl on the order of three to
five mil thickness and having an adhesive backing or coat-
ing 62. This upper layer is supported on a release layer
64, to which it is releasably held by the adhesive backing
62, which release layer may consist for example of a
ninety-pound paper coated or impregnated with silicone
~2~325~
-15-
to give it its release property.
Fig. 10 illustrates another embodiment of the web
12 which is si~ilar to the embodiment of Fig. 2, but in-
cludes a row of fifth holes 9o located along the same line
46 as the first holes 44 and a row of sixth holes 92
located along the same line 50 as the second holes 48.
Each pair of holes 90, 92 is associated with the same
holes 44, 48 as a corresponding pair of holes 54, 56, so
that the visually distinguished sets of holes 44, 48 are
readily identifiable upon visual observation~
In the embodiment of Fig. 10, however, the holes
54 are not positioned equidistant between the holes 44,
but instead, are offset and placed closer to the visually
distinguished holes 44 which serve as the keyholes for
placing the web on the sprockets. Similarly, the fourth
holes 56 are offset and positioned closer to the second
holes 48 that are transversely aligned along the perpen-
dicular line 94 with the visually identified holes 44 at
the opposite side of the web. The pins on the sprockets
engaged by the web, of course, would include visually
distinguished pins having the same offset as the holes 54,
56.
With uneven spacing between the holes 54, 56 and
the adjacent holes 44, 48, the web 12, in the absence of
the holes 90, 92 can only be loaded into the machine 10
with one orier.tation, that is, the holes 44 must always be
engaged with a particular sprocket at one end of the drive
shaft 28 and the holes 48 must be engaged with the sprock-
1;2~32~7
-16-
et at the opposite end of the drive shaft. Any reversal
of the holes 44, 48 and the sprocke~s would result ir the
offset pins on the sprockets engaging the locations of the
web on the side of the perpendicular line 94 opposite from
the holes 54, 56. ~he rows of fifth holes 90 and sixth
holes 92 are provided for this reason.
It should be understood that the set of fifth
holes 90 and the set of sixth holes 92 need not be trans-
versely aligned with one another provided that the holes
lO 54, 56 have the same misalignment. The fifth holes 9o
must be offset from the disting~ished hole 44 by the same
amount that the fourth hole is offset from the distin-
guished hole 98, but on the opposite side of the line 94.
Correspondinqly, the sixth hole 92 must be offset from the
second hole 48 by the same amount that the third hole 54
is offset from the visually distinguished hole 44 but on
the opposite side of the line 94. ~ith both sets of holes
54, 56 and 90, 92 the web 12 may be loaded into the ma-
chine without regard to its orientation or association of
20 the holes at one longitudinal edge of the ~eb with one or
the other of the drive sprockets.
Referring to Figs. 7 and 8, these figures show
another embodiment of the invention in which the sprockets
14' and 16' do not include any extra pins and wherein
other means are provided for visually distinguishing a
pair of first and second pins from the remaining ones of
such pins. In particular, the sprocket 14' includes a
series of uniformly spaced first pins 66, 66 and the
lZ~3257
-17-
sprocket 16' similarly includes a corresponding series of
uniformly spaced second pins 68, 68. On the sprocket 14'
one of the first pins 66, 66 is visually distinguished
from the others by having an appearance different from
that of the others, such visually distinguished pin being
indicated at G. Similarly on the sprocket 16' one of the
second pins 68, 68, as indicated at H, has a visual ap-
pearance distinguishing it from the others. This differ-
ence in visual appearance of the pins G and H from that of
10 the other pins 66, 66 and 68, 68 may be achieved in vari-
ous ways, but preferably and as illustrated, it is accom-
plished by ~aking the pins G and H of a color distinctly
different from the color of the pins 66, 66 and of the
pins 68, 68. Such a color difference may be achieved for
example by painting the pins G and H and the pins 66, 66
and 68, 68 different colors or by making them of differ-
ently colored materials.
The web 12 used with the sprockets 14' and 16' of
Figs. 7 and 8 may be identical to that described above in
connection with Figs. 2 to 6 and is so illustrated in Fig.
7.
Again, as illustrated in Fig. 7, each pair of
third and fourth holes 54, 56 of the web serve to visually
distinguish two corresponding pairs of first and second
holes from the remaining ones of such first and second
holes of the web. One such pair of distinguished holes is
the pair indicated at e and f and the other such pair is
the pair indicated at g and h. Therefore, to achieve
JL~ U ~3f~ ~
-18-
proper loading of the web onto the sprockets either one of
such visually distinguished pair of holes - that is, the
pair _ and f or the pair ~ and h ~ may be placed onto the
visually distinguished pins G and H and thereafter the web
will be driven properly by the sprockets as the machine
operates.
In the embodiment of Fig. 7 the holes 54, 54 do
not receive any corresponding pins of the sprockets 14'
and 16' and therefore it is not essential that the spacing
of the third holes 54, 54 from one another along the
length of the web, or the corresponding spacing of the
fourth holes 56, 56 from one another along the length of
the web be related to the number of teeth on the sprock-
ets. That is, in the equation S = Nd given above, for the
embodiment of Fig. 7 it is not necessary that N be equal
to the number of first or second pins on the sprockets but
instead it is sufficient that N be some integer other than
one.
In accordance with the broader aspects of the
invention it is not essential that the first holes 44, 44
of the web all be located exactly on a common line such as
the line 46 or that the second holes 48, 48 be located on
a common line such as the line 50. Instead, for example,
alternate ones of the first holes 44, 44 could be located
on opposite sides of the line 46 and alternate ones of the
second holes 48, 48 could be located on opposite sides of
the line 50, and in conformity with this the first pins
30, 30 of the sprocket 15 could be alternately located on
325~
opposite sides of a plane perpendicular to the axis 18 and
alternate ones of the second pins 32, 32 could be located
on opposite sides of another plane perpendicular to the
axis 18 to cause the pattern of the pins 30, 30 and of the
pines 32, 32 to match the pattern of the holes 44, 44 and
of the holes 48, 48. However, to locate the holes on com-
mon lines such as the line 46 and the line 50 does have
certain advantages and among other things allows a web 12
to be made from a previously unperforated length of sheet
material by a simple punching method and apparatus.
The simple punching method and apparatus referred
to in the preceding paragraph is illustrated by Fig. 9.
As shown in this figure, the apparatus comprises a supply
roll 70 for supplying a quantity of unperforated web mate-
rial 72, and a take-up roll 74 for rerolling such material
after it is punched. Between the supply roll 70 and the
take-up roll 74 are two punches 76 and 78 located directly
opposite from one another along opposite edges of the web
72 for punching the holes in the opposite side edge por-
2Q tions of the web. Each punch 76 and 78 is of a type which
punches one hole in the web 72 during each cycle of opera~
tion. Between the punches 76, 78 and the take-up roll 74
are a pair of sprockets 80 and 82, driven in unison by a
step motor 84 which engage the holes 44, 94 and 48, 48
formed in the web 72 by the punches to move the web past
the punches 76 and 78. The operation of the stepping
motor 84 and of the punches 76 and 78 is controlled by a
controller 86. In operation the controller 86 commands
~Z~32~
-20-
the stepping motor 84 to move the web a proper distance
for the punching of the next pair of corresponding holes
by the punches 76 and 78. The motor is then stopped and
the punches 76, 78 are then commanded to operate simultan-
eously to punch two corresponding holes in the opposite
sides of the web, and the same cycle is then repeated.
The distance the stepping motor moves the web between each
punching operation is readily controlled by the controller
86, through preprogramming of it, to achieve proper spac-
ing of the holes 44r 44 and 54, 54 along the one side edge
of the web and correspondingly similar spacing of the
holes 48, 48 and 56, 56 along the other side edge of ~he
web.
