Measured leader length supply system

There is provided an apparatus for supplying precisely measured lengths of leader ribbon for use in the assembly of printer ribbon cartridges. The apparatus includes a supply of leader ribbon, an accumulator for retaining a length of the ribbon when it is drawn from the ribbon supply and a drive assembly for drawing a measured length into the accumulator. The drive assembly includes a fixed roller and a pivotable roller positioned on opposite sides of the ribbon path for engaging the ribbon therebetween. A stepping motor is provided for rotating the rollers a prescribed number of revolutions and thereby stuffing a measured length of the engaged ribbon into the accumulator. The apparatus also includes a cutter for severing the measured leader length from the supply ribbon.

BACKGROUND OF THE INVENTION 
The present invention relates generally to cartridges containing a 
continuous loop of ribbon, especially fabric ribbon, for use in printers 
associated with equipment such as computers and word processors. More 
particularly, the present invention relates to apparatus employed in 
loading assembled cartridges with inked printer ribbon. Still more 
particularly, the present invention relates to an apparatus for supplying 
measured lengths of leader ribbon used in the assembly and loading of 
printer ribbon cartridges. 
Present society is highly dependent on the use of microprocessors, 
minicomputers, and mainframe computers. In addition to the more 
traditional use of computers as a research tool, computers are now often 
found in the home environment and work environment of individuals who, 
until recently, never before came into contact with a computer. Computers 
are used to automate equipment in a manufacturing facility, to automate 
secretarial duties at the office and to automate a myriad of toys and 
tools around the home. 
All computers, whether mainframe computers, minicomputers or 
microcomputers, share a common requirement for some means of communication 
with users. Such means of communication may vary from a simple 
light-emitting diode (LED) to the complex cathode ray tube (CRT) terminal. 
A common means for communication of information from a computer to a user 
is a printer. Printers typically receive from a computer a stream of 
information in the form of digital electronic signals and convert the 
electronic signals to a series of symbols (letters, numbers and words) 
printed on paper. 
A first common type of printer is an impact printer, so named for the means 
by which characters are printed on paper. Each symbol which the impact 
printer is capable of generating is permanently embossed on a striking 
surface (analogous to the ball within a typewriter) within the printer. 
The printing of a particular character is accomplished by aligning the 
embossed image of that character with the paper surface onto which the 
characters are to be printed, positioning a printer ribbon having ink 
thereon between the striker and the paper, and causing the striker to 
impact the ribbon against the paper surface so as to result in an ink 
image of the embossed character on the surface of the paper. Printer 
ribbons typically are made of fabric, such as nylon, or polyester film 
coated with a carbon-type surface. 
A second common type of printer is a dot matrix printer. Such a printer 
includes a group of small-diameter wires oriented parallel to one another 
and arranged in a two-dimensional matrix. Each wire is arranged for 
independent extension from its normal matrix position to contact a printer 
ribbon, thereby printing a dot image on an adjacent paper surface. By 
selectively extending particular patterns of wires, dot images can be 
combined to form alphanumeric or other legible characters on the paper 
surface. 
In approximately 1970 there first appeared on the market a printer ribbon 
having the ends thereof adjoined to form a continuous loop. The continuous 
loop ribbons are housed within cartridges which easily may be removed from 
and inserted within the printers. Such continuous loop cartridges 
mechanically simplify the ribbon control portion of printers and thereby 
eliminate a potential source of printer failure. 
A number of companies throughout the world today are engaged in the 
business of manufacturing and/or loading printer ribbon cartridges. 
Printer ribbon cartridges are typically assembled manually, and are 
assembled before they are loaded with printer ribbon which is generally 
delivered to the cartridge manufacturer uninked or inked and spooled into 
large, narrow rolls. 
In order to subsequently load the assembled cartridge with printer ribbon, 
the cartridge may be assembled with a length of leader ribbon threaded 
through the cartridge's housing. The ends of the leader ribbon are left 
extending outside the assembled cartridge. These exposed ends of the 
leader ribbon may then be attached to inked printer ribbon and the leader 
ribbon used by the cartridge drive members or an external drive member to 
draw the appropriate length of printer ribbon into the previously 
assembled cartridge. One such apparatus particularly useful in 
automatically stuffing the assembled cartridge with inked printer ribbon 
is disclosed in U.S. Pat. No. 4,609,422, issued Sept. 2, 1986. 
To date, it has been the conventional practice to manually measure and 
sever the required lengths of leader ribbon from a supply reel or spool of 
such ribbon. Because this process of supplying measured leader lengths is 
performed manually, it is subject to operator errors both in the step of 
measuring the appropriate leader length, and in the step of cutting the 
ribbon at the appropriate location. The likelihood of errors is increased 
due to the time pressures that competitive forces place on the cartridge 
manufacturer's labor force. 
In manufacturing printer ribbon cartridges, it is critical that the 
cartridges be assembled with the proper length of leader ribbon. If the 
cartridge is assembled with a leader that is too short, the stuffer 
apparatus will not be able to load the cartridge with inked ribbon, 
requiring the operator to remove the defective cartridge, replace it with 
another and again ready the stuffing apparatus for the loading of a 
cartridge. As is evident, a cartridge having a leader that is too short 
causes costly delays in the stuffing of the assembled cartridges and in 
the ultimate production of printer ribbon cartridges. In addition, the 
defective cartridge must either be discarded, resulting in material waste, 
or reassembled, resulting in additional labor costs. 
Similarly, if a cartridge is assembled with a leader ribbon which is longer 
than that required by the stuffing apparatus, an operator is required to 
manually jog the drive motor in the stuffer apparatus in order to take up 
the excess leader length prior to initiating the stuffing cycle. Once 
again, the extra operator interaction delays the stuffing process and the 
ultimate production of finished cartridges. All such delays and output 
reductions directly affect the manufacturer's profitability. 
As is readily apparent, certain inadequacies exist in the present method 
and apparatus that are employed to supply the lengths of leader ribbon for 
use in assembling and loading printer ribbon cartridges. An apparatus 
which would accurately measure and sever the appropriate leader length 
from a ribbon supply and do so automatically with a minimum of operator 
involvement would be a welcomed addition to this art. Further, an 
apparatus which could store the severed leader length in a convenient 
position for use by the operator in assembling the cartridge would be an 
additional benefit. Ideally, the apparatus should be able to accommodate 
all types and widths of printer ribbons and would be easily adjusted so as 
to supply the varying lengths of leader ribbon needed for the different 
cartridge configurations. 
SUMMARY OF THE INVENTION 
Accordingly, there is provided herein apparatus for supplying a precisely 
measured length of leader ribbon for use in the manual or automated 
assembly of a printer ribbon cartridge and the subsequent automatic 
loading of printer ribbon into the cartridge. The apparatus of the present 
invention comprises a supply of leader ribbon, an accumulator for 
collecting a length of the leader ribbon as it is drawn from the ribbon 
supply, a mechanism for drawing a measured length of the leader ribbon 
into the accumulator, and a cutter for severing the measured length from 
the ribbon supply. 
The accumulator is generally a box-like enclosure having a ribbon path 
formed therethrough. The drawing mechanism includes a gripper for grasping 
the leading end of the supply ribbon and drawing the ribbon through the 
accumulator along the ribbon path. The drawing mechanism further includes 
a drive assembly for engaging the ribbon along the ribbon path and 
stuffing a measured length into the accumulator. 
The drive assembly includes a drive roller fixed in position on one side of 
the ribbon path and a pivotable pinch roller positioned on the opposite 
side of the ribbon path. The drive assembly further includes a pivoting 
means for pivoting the pinch roller toward and away from the ribbon path. 
The pivoting means pivots the pinch roller away from the ribbon path when 
the ribbon is drawn through the accumulator by the gripper, and, 
thereafter, pivots the pinch roller toward the ribbon path so as to engage 
the ribbon between the pinch and drive rollers. The drive assembly also 
includes a stepping motor coupled to the drive roller for rotating the 
drive and pinch rollers a precise and predetermined number of revolutions 
so as to stuff a measured length of the engaged leader ribbon into the 
accumulator. 
The cutter may include a pair of opposing blades positioned opposite one 
another on either side of the ribbon path. The cutting blades, which may 
be pneumatically actuated, cooperate to sever the measured leader length 
from the supply ribbon by the scissor action of the blades. The cutter may 
alternatively comprise a rotating cutting blade for severing the ribbon 
with or without an opposing blade. 
The present invention may further include a control system for controlling 
the operation of the drawing mechanism and cutter and may also include a 
detector in the accumulator for detecting when the accumulator is empty 
and signaling the controller to actuate the drawing mechanism and cutter. 
The invention may also include a clamping device for clamping the leader 
ribbon once the measured length has been drawn into the accumulator. The 
clamping device may include a pair of pneumatically actuated clamping 
fingers. Further, the cutter components may be attached to the clamping 
fingers such that the ribbon is clamped and the measured leader length 
severed in a single operation. 
The present invention provides an automated apparatus for supplying an 
operator with a precisely measured length of leader ribbon for use in 
assembling printer ribbon cartridges. The apparatus can supply a desired 
length of any of a number of types and sizes of printer ribbons. The 
accurately measured and severed leader length supplied by the invention 
eliminates the time consuming and costly operator intervention in the 
automated process by which the assembled cartridge is stuffed with inked 
printer ribbon. Further, the invention eliminates the necessity of 
discarding, or dismantling and reassembling, cartridges which were 
assembled with leader ribbons that were too short. 
These and various other objects and advantages of the present invention 
will become readily apparent to those skilled in the art upon reading the 
following detailed description and claims and by referring to the 
accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, there is depicted a ribbon cartridge assembly station 
10 which includes the present invention, a measured leader length supply 
system 50. Cartridge assembly station 10 is a work station supplying a 
working surface and all the components for assembling any of a number of 
various printer ribbon cartridges. Assembly station 10 generally comprises 
a base plate 12 supported upon frame 14, base plate 12 in turn supporting 
the measured leader length supply system 50, a cartridge assembly plate 
16, a part bin support structure 28, and a ribbon turn table 32. Base 
plate 12 may further support a pneumatic press 26 for closing the ribbon 
cartridges once assembled. Base plate 12 is preferably manufactured from 
steel or aluminum, but may be made from any rigid material capable of 
supporting the various components described herein. Cartridge assembly 
plate 16 is generally centrally positioned upon base plate 12 and forms 
the working surface used by a technician to manually assemble ribbon 
cartridge components into a completed cartridge 18. An assembled ribbon 
cartridge 18 including leader ribbon length 20 is depicted in FIG. 1, 
cartridge 18 being retained upon cartridge assembly plate 16 by moveable 
cartridge positioners 22. Part bin support structure 28 is also fixed to 
base plate 12. A plurality of part bins 30 are fastened to support 
structure 28 and contain the various components used by the operator in 
assembling the ribbon cartridges 18. 
Ribbon turn table 32 is rotatably supported upon and attached to base plate 
12 and includes a spindle 33 for retaining ribbon reel 31 which is wound 
with un-inked leader ribbon 35. A ribbon guide 36 is also fixed to base 
plate 12. A ribbon tensioning post 34 is supported by a spring loaded 
pivotable arm 39 which is attached to base plate 12 arm 39 and tensions 
ribbon 35 as it is withdrawn from reel 31. Pivotable further includes a 
brake shoe assembly (not shown) biased so as to normally bear against the 
edge of turn table 32. When ribbon 35 is withdrawn from reel 31, the brake 
shoe pivots away and out of contact with turn table 32. When the force 
drawing ribbon 35 from reel 31 is disconnected, the brake assembly engages 
turn table 32 and stops its rotation, thereby preventing overrun of reel 
31. The leading end of leader ribbon 35 is manually threaded around ribbon 
tensioning post 34 and ribbon guide 36 and into measured leader length 
supply system 50. As described in more detail below, measured leader 
length supply system 50, when actuated, automatically measures and severs 
the appropriate leader ribbon length 20 from leader ribbon 35 and stores 
leader length 20 until it is needed for the assembly of a completed ribbon 
cartridge 18. 
Still referring to FIG. 1, also fixed upon base plate 12 is control panel 
40 which houses various switches and controls described below for 
operating measured leader length supply system 50 and for assembling 
ribbon cartridges 18. 
Referring now to FIG. 2, there is depicted an elevation view of the 
measured leader length supply system 50 which generally comprises a 
gripper assembly 70, a cutter and clamp assembly 130, an accumulator 
assembly 160, a drive assembly 180 and a controller 250, shown in FIG. 12. 
As described in more detail below, gripper assembly 70 grasps the leading 
end of leader ribbon 35 and draws the ribbon through both the cutter and 
clamp assembly 130 and accumulator assembly 160. Controller 250 (FIG. 12), 
then actuates drive assembly 180, which includes a stepping motor 194 
(FIG. 10), and the appropriate length of leader ribbon is drawn into the 
accumulator assembly 160 from ribbon reel 31 shown in FIG. 1. Cutter and 
clamp assembly 130 then severs the measured leader ribbon length 20 from 
leader ribbon 35 and clamps the newly formed leading end of leader ribbon 
35. Gripper assembly 70 then releases leader length 20 and returns to its 
initial position. Leader ribbon length 20 is retained within accumulator 
assembly 160 until it is needed for use in assembling a cartridge 18, at 
which time it is manually withdrawn from the accumulator by an operator. A 
ribbon detector 176 (FIG. 12) within accumulator assembly 160 then senses 
that the accumulator is empty and signals controller 250 which initiates 
the supply sequence again. 
Gripper Assembly 70 
Referring now to FIGS. 2, 3 and 5, gripper assembly 70 generally includes 
gripper 100, horizontal drive 90, vertical drive 80 and support plate 52. 
Support plate 52 is preferably made of aluminum and is fixed 
perpendicularly to the upper surface of base plate 12 of cartridge 
assembly station 10. As explained in detail below, support plate 52 serves 
to support horizontal and vertical drives 90, 80 which, in response to 
control signals from controller 250, transport gripper 100 along the 
facing surface 55 of support plate 52. More specifically, vertical drive 
80 transports gripper 100 up and down along support plate 52 while 
horizontal drive 90 moves gripper 100 forward and back, or left and right 
respectively, as viewed in FIG. 2. 
As best shown in FIGS. 2 and 3, vertical drive 80 includes a rectangular 
slide plate 54, preferably made of aluminum, which is slidably engaged 
upon support plate 52. Vertical drive 80 also includes a pneumatic 
cylinder 82 used to raise and lower slide plate 54. Support plate 52 
includes a vertical channel 53 formed in facing surface 55. A pair of 
guide rods 56 are fixed in parallel configuration along the sides of 
channel 53 by rod supports 58. As shown in FIG. 4, fixed to the back of 
slide plate 54 are aligned bearings 60 which slidably engage guide rods 56 
and enable slide plate 54 to reciprocate vertically along guide rods 56. 
Referring again to FIG. 2, the vertical movement of slide plate 54 is 
accomplished by actuation of pneumatic cylinder 82. Cylinder 82 is a 
double action pneumatic cylinder. A cylinder manufactured by Bimba 
Manufacturing Co., Model No. BF-01-1.5-0 proved satisfactory for this 
application. Cylinder 82 is mounted vertically on support plate 52 below 
channel 53. Piston shaft 84 extends from cylinder 82 and is threaded into 
a shaft extension 86 which, in turn, is fixed to the lower end of slide 
plate 54. In this configuration, pneumatic actuation of cylinder 82 will 
cause slide plate 54 to travel upward along facing surface 55 of support 
plate 52. Piston shaft 84 will retract when the pneumatic supply to 
cylinder 82 is reversed causing slide plate 54 to move to its lower most 
position as shown in FIG. 2. A pair of magnets 109 are embedded in the 
side of slide plate 54 and, as described below, are used to signal the 
position of slide plate 54 and gripper 100 to controller 250. Magnets 109 
may be, for example, Model No. 101 MG7 8809 as manufactured by the 
Microswitch Division of Honeywell, Inc. 
Referring still to FIG. 2, rigidly attached to slide plate 54 is horizontal 
drive 90 which in the preferred embodiment is a drive unit manufactured by 
SMC Pneumatics, Inc., part number NCDYlSlOH-0750. Horizontal drive 90 
includes a double acting pneumatic cylinder 94, a pair of guide rods 96, 
end pieces 98, 99 and travelling member 120 (FIG. 3). Cylinder 94 includes 
an internal magnetic piston (not shown). Cylinder 94 and guide rods 96 are 
fixed in parallel relationship to left and right end pieces 98, 99 
respectively. Right end piece 99 is rigidly attached to slide plate 54 
such that cylinder 94 and guide rods 96 extend substantially at right 
angles from the vertical line of travel of slide plate 54. Slidably 
engaging guide rods 96 and cylinder 94 is traveling member 120. Traveling 
member 120 includes a pair of horizontal bores with sleeved bearings 
through which guide rods 96 are disposed. Traveling member 120 further 
includes a central bore 122 having a magnetic bushing (not shown) for 
slidingly engaging pneumatic cylinder 94. Due to the magnetic coupling 
between the magnetic piston of cylinder 94 and the magnetic bushing in 
travelling member 120, traveling member 120 will travel along cylinder 94 
and guide rods 96 in response to the reciprocal movement of the magnetic 
piston within pneumatic cylinder 94. 
Gripper 100, which in the preferred embodiment is a Mini Hand IMH 20-C by 
Tomita U.S.A., Inc., is attached to travelling member 120 by L-shaped 
mounting bracket 102, best shown in FIGS. 2 and 3. As depicted, one leg of 
mounting bracket 102 is fixed to travelling member 120 while the second 
leg is fixed to gripper 100. Gripper 100 includes a pair of downwardly 
extending, pneumatically actuated jaws 104 which are used to grip leader 
ribbon 35 and draw it into the accumulator assembly 160. Gripper 100 
further includes a pair of pneumatic tube connectors 118 for connecting 
pneumatic lines 119 to gripper 100 which, in the preferred embodiment, 
extend through bores formed in gripper mounting bracket 102. Gripper 100 
is attached to travelling member 120 which includes a magnet 111 embedded 
in the lower face of travelling member 120 as shown in FIG. 2. As 
explained below, magnet 111 is employed to signal the horizontal position 
of gripper 100 to controller 250. 
By operation of the drive apparatus thus described, gripper 100 may be 
moved forward and backward along support plate 52 by actuation of 
horizontal drive 90, and may be raised and lowered by vertical drive 80. 
To limit the travel of gripper 100 in both the horizontal and vertical 
directions, the measured leader length supply system 50 includes four Hall 
effect sensors 108, 110, 112, 114 positioned about support plate 52 and 
electrically connected to controller 250. As best shown in FIG. 2, Hall 
effect sensors 108 and 110 are attached to facing surface 55 of support 
plate 52 in a line parallel and adjacent to the line of travel of magnets 
109 in slide plate 54. In the preferred embodiment, sensors 108, 110, 112, 
114 are Model No. D-F76 as manufactured by SMC Pneumatics, Inc. Sensors 
108, 110 detect the proximity of magnets 109 and signal controller 250 
that gripper 100 has reached its uppermost or lower most position 
respectively. Hall effect sensors 112, 114 similarly signal the horizontal 
position of gripper 100 to controller 250. A sensor mounting channel 116 
is attached to the bottom of end pieces 98, 99 of horizontal drive 90 
parallel to pneumatic cylinder 94. Sensors 112 and 114 are mounted near 
the left and right ends of mounting channel 116 as viewed in FIG. 2 and, 
by detecting the proximity of magnet 111, signal controller 250 when 
gripper 100 has reached the forward and back position respectively. 
Cutter and Clamp Assembly 130 
The cutter and clamp assembly 130 is best shown in FIGS. 2, 6 and 7A and 
generally includes an elongate base 132 supporting a pair of clamping 
fingers 148, 150 and a pair of cutting blades 140, 146. Upon actuation by 
controller 250, cutter and clamp assembly 130 clamps leader ribbon 35 
between fingers 148 and 150 and then severs a measured length 20 of ribbon 
35 by means of blades 140, 146. A ribbon track 37 having a generally 
U-shaped cross section is mounted on base plate 12 by stand-offs 38 and 
supports leader ribbon 35 as it is drawn from ribbon reel 31 around 
tensioning post 34 and ribbon guide 36 and into cutter and clamp assembly 
130. 
Referring to FIG. 6, base 132 is fastened to base plate 12 and includes a 
longitudinal bore 134 formed parallel to the path of ribbon 35. Disposed 
within bore 134 is a pivotable shaft 138. Rigidly attached to one end of 
shaft 138 are pivotable clamping finger 148 and pivotable cutting blade 
140. Attached to base 132 opposite pivotable clamping finger 148 is an 
upwardly extending fixed clamping finger 150. Fixed cutting blade 146 is 
attached to fixed clamping finger 150 opposite pivotable cutting blade 
140. 
Referring still to FIG. 6, pivotable clamping finger 148 includes a lower 
extension 149 which extends through an aperture in base plate 12. A double 
acting pneumatic cylinder 152 is attached beneath base plate 12 and 
includes a piston rod 154 which is threaded to a clevis 156, clevis 156 
being rotatably fixed to lower extension 149 of pivotable clamping finger 
148 by pin 158. The reciprocal action of piston rod 154 within pneumatic 
cylinder 152 causes shaft 138 to pivot within base 132, thereby also 
pivoting clamping finger 148 and blade 140. As can be seen in FIG. 6, as 
shaft 138 rotates in the clockwise direction, pivotable clamping finger 
148 will engage fixed clamping finger 150 thereby securing leader ribbon 
35 therebetween. As best shown in FIG. 7A, after leader ribbon 35 is 
clamped, leader ribbon 35 is cut by the scissor action of pivotable blade 
140 against fixed blade 146. 
An alternative embodiment of the cutter mechanism is shown in FIG. 7B. As 
shown, a rotatable cutting blade 141 is rotatably secured to pivoting 
clamping finger 148 and is driven by motor 143 by a shaft (not shown) 
extending through clamping finger 148. Rotatable cutting blade 141 
includes a toothless blade having a tapered edge 145. Blade 141 is 
positioned along guide track 143 that is formed on clamping finger 148 
parallel to the clamp face. A pneumatic cylinder or other operating 
mechanism known to those skilled in the art (not shown) is connected to 
the cutter mechanism to permit the mechanism to traverse guide track 143 
such that the ribbon 35 will be severed by blade 141 after it has been 
clamped between fingers 148, 150. 
Accumulator Assembly 160 
Referring to FIGS. 3 and 8, accumulator assembly 160 includes a generally 
box-like enclosure 161 in which a measured length of leader ribbon 35 is 
stuffed by drive assembly 180 and stored until needed for the assembly of 
a ribbon cartridge 18. 
Accumulator enclosure 161 includes base 162 supported above base plate 12 
by stand offs 164. Supported upon and fixed to accumulator base 162 are 
left and right side members 166, 168 and a pair of strippers 220, 221. A 
pair of spaced-apart plastic accumulator covers 172, 174 rest upon side 
members 166, 168. Together these components form an interior chamber 175 
generally formed by the inner surfaces of accumulator base 162, covers 
172, 174, side members 166, 168 and strippers 220, 221. 
Left and right side members 166, 168 are positioned upon and attached to 
accumulator base 162 opposite and substantially parallel to one another 
such that a gap 169 is formed there between. Strippers 220, 221 are 
attached to accumulator base 162 generally perpendicularly to the ends of 
left and right side members 166, 168 such that a gap 225, formed between 
the ends of strippers 220, 221, is aligned with gap 169. The separation 
between accumulator covers 172, 174 is directly above and aligned with 
gaps 169, 225 so as to form a path for gripper jaws 104 to transport 
leader ribbon 35 through accumulator enclosure 161 as gripper 100 is 
driven from right to left as viewed in FIG. 3 by horizontal drive 90. 
Referring still to FIGS. 3 and 8, left side member 166 includes a beveled 
face 171. Rigidly attached to beveled face 171 is tension clip 170. 
Tension clip 170 is made of a thin flexible metal and extends diagonally 
across gap 169. As gripper 100 transports leader ribbon 35 through 
accumulator enclosure 161, gripper jaws 104 engage tension clip 170 
causing tension clip 170 to flex toward left side member 166, allowing 
gripper jaws 104 and ribbon 35 to pass through gap 169. After gripper 100 
has passed tension clip 170, tension clip 170 springs back to its unflexed 
position extending diagonally into gap 169. After a length of leader 
ribbon 35 has been drawn into accumulator enclosure 161 and a leader 
length 20 has been severed by cutter and clamp assembly 130, tension clip 
170 tensions leader length 20 as it is pulled from enclosure 161 by the 
cartridge assembly technician. 
The accumulator assembly 160 also includes a ribbon detector 176 for 
detecting the presence or absence of ribbon within accumulator enclosure 
161. In the preferred embodiment, the ribbon detector 176 comprises an 
optical sensor. One such sensor that has been found satisfactory is Model 
No. EX-D200E manufactured by Sunx Corp. As shown in FIG. 8, ribbon 
detector 176 is mounted in bore 178 in left side member 166 facing the 
inner surface of right side member 168. Grooves 179 are formed on the 
inner surface of right side member 168. Grooves 179 are coated with 
optical black serving to prevent operation of the optical sensor 
indiscriminately. Without blackened grooves 179, the light may tend to 
"bounce back" to the sensor and indicate falsely that a length of leader 
ribbon 35 is in accumulator 160. 
Accumulator Drive Assembly 180 
Referring now to FIGS. 8-10, accumulator drive assembly 180 generally 
comprises drive roller 182, pinch roller 196 and stepping motor 194. As 
detailed below, stepping motor 194 actuates drive roller 182 and, through 
the cooperation of pinch roller 196, stuffs a measured length of leader 
ribbon 35 into accumulator enclosure 161. Drive roller 182 is mounted 
adjacent to left stripper 220. Drive roller 182 includes roller shaft 184 
which is rotatably supported within an aperture in accumulator base 162. 
Stepping motor 194, mounted to the underside of base plate 12 by motor 
stand offs 190, includes motor shaft 192 which is coaxially aligned with 
and coupled to roller shaft 184 by coupling 186. In the preferred 
embodiment, stepping motor 194 is Model No. VEXTAPX 244-03AA manufactured 
by Oriental Motors U.S.A. Corp. The motor shaft 192 rotates 1.8 degrees 
for each stepping pulse generated by controller 250. 
Referring again to FIGS. 8 and 9, there is shown pinch roller swing arm 200 
pivotably supported between accumulator base 162 and base plate 12 by 
shaft 202. Pinch roller swing arm 200 supports fixed pinch roller shaft 
198. Rotatably supported on pinch roller shaft 198 is pinch roller 196. 
Fixed to the upper surface of base plate 12 beneath accumulator base 162 
is double acting pneumatic cylinder 212. Extending from cylinder 212, 
which in the preferred embodiment is Model No. 007-.5 DXP manufactured by 
Bimba Manufacturing Co., is piston rod 214 which is connected to shoulder 
portion 204 of pinch roller swing arm 200 by clevis 206 and pin 208. With 
piston rod 214 extended as shown in FIG. 9, pinch roller 196 is positioned 
away from drive roller 182 and into the position shown in FIG. 8 so as to 
allow gripper jaws 104 to pass through gap 225 and into accumulator 
chamber 175. When pneumatic cylinder 212 is actuated such that piston rod 
214 is retracted, pinch roller 196 is drawn toward drive roller 182 such 
that leader ribbon 35 is engaged between rollers 196 and 182. Upon the 
subsequent actuation of stepping motor 194 which causes drive roller to 
rotate in a clockwise direction as viewed in FIGS. 3 and 8, a measured 
length 20 of leader ribbon 35 will be drawn into interior chamber 175 of 
accumulator enclosure 161. 
As best shown in FIG. 8, strippers 220, 221 include body portions 222 and a 
plurality of curved fingers 24 extending therefrom. As also shown in FIG. 
8, drive and pinch rollers 182, 196 include a plurality of projecting 
roller surfaces 195 for engaging leader ribbon 35. Roller surfaces 195 are 
manufactured from or coated with a rubber or elastomeric material so as to 
engage leader ribbon 35 without damaging the ribbon as it is drawn into 
accumulator enclosure 161. Rollers 182, 196 and strippers 220, 221 are 
positioned such that curved fingers 224 are disposed between the 
projecting roller surfaces 195 of rollers 182 and 196, fingers 224 serving 
to prevent leader ribbon 35 from being drawn around rollers 182 and 196 
rather than being drawn between them and into accumulator enclosure 161 as 
desired. 
Controller 250 
FIG. 12 shows a block diagram disclosing the basic organization of the 
control system for the measured leader length supply system 50. The 
control system is centered around controller 250 which may comprise, for 
example, a digital control circuit designed in accordance with principals 
well known in the art to effect the operation of the controller 250 a 
described herein. Controller 250 is supported by base plate 12 and, in the 
preferred embodiment, is housed beneath part bin support structure 28 
shown in FIG. 1. Power supply 252 is electrically connected to controller 
250 and supplies the power necessary for the control of measured leader 
length supply apparatus 50. 
The control system comprises a plurality of control inputs 260 and a 
plurality of control outputs 270. Inputs 260 comprise switches and sensors 
located throughout the measured leader length supply system 50. To the 
extent that such switches and sensors have been previously described and 
shown, common reference characters are used herein and reference is made 
to those figures wherein such switches or sensors are depicted. 
As shown in FIG. 12, control inputs 260 include a start switch 262 which 
signals controller 250 to initiate the operation of supplying measured 
leader lengths 20. Ribbon detector 176 mounted in accumulator 160 supplies 
an input to controller 250 indicating the presence or absence of ribbon 35 
within accumulator chamber 175. As previously described, Hall effect 
sensors 108, 110, 112, 114 signal controller 250 that gripper 100 has 
reached certain desired positions about support plate 52. More 
specifically, sensor 110 signals controller 250 when gripper 100 is in the 
down position and sensor 108 signals controller 250 when gripper 100 is in 
its raised position. Hall effect sensors 112 and 114 signal controller 250 
that gripper 100 has reached its forward and back position respectively. 
Control inputs 260 further include ribbon length switch 264 for selecting 
the desired length of leader ribbon to be supplied. Preferably, ribbon 
length switch 264 comprises a thumbwheel rotary switch providing a digital 
indicator for the length of leader selected. Unit selection switch 266 
indicates to controller 250 whether the length selected by ribbon length 
switch 264 is to be measured in centimeters or inches. 
Control outputs 270 include an output to stepping motor 194 for driving 
stepping motor 194 to rotate the appropriate number of revolutions 
necessary to stuff the desired length of leader ribbon 35 into accumulator 
enclosure 161. The remaining control outputs 270 from controller 250 
comprise outputs to solenoid valves 272, 274, 276 and to solenoids 278 and 
280 which operate a single pneumatic valve (not shown) as described below. 
Solenoids 278 and 280 are employed to actuate a pneumatic valve that 
controls horizontal drive 90 of gripper assembly 70, only one of solenoids 
278, 280 being actuated at a time. Upon actuation of solenoid 278 by 
controller 250, gripper 100 is driven to the left as viewed in FIG. 2 by 
operation of horizontal cylinder 94. Similarly, the actuation of solenoid 
280 drives gripper 100 to the right. Solenoid valve 274 is employed to 
actuate vertical drive 80 of gripper assembly 70. Solenoid valve 276 
actuates cylinder 212 and pinch roller swing arm 200. Solenoid valve 272 
actuates cutter and clamp assembly 130 as well as gripper 100 such that 
gripper 100 is closed when cutter and clamp assembly 130 is open, and vice 
versa. In the preferred embodiment, solenoids 272-280 are housed within 
control panel 40 shown in FIG. 1, but they may alternatively be situated 
below or upon base plate 12 in any convenient location. 
Operation of Measured Leader Length Supply System 50 
Referring to FIGS. 1 and 2, ribbon supply reel 31 is first positioned upon 
ribbon turn table 32. The leading end of leader ribbon 35 is then manually 
threaded around ribbon tensioning post 34 and ribbon guide 36 and through 
ribbon tract 37 into position between gripper jaws 104 of gripper 100. 
Ribbon length switch 264 is set for the desired length of leader ribbon 
and unit selection switch 266 is set for the desired units of measure, 
either centimeters or inches. 
With the power supply 252 turned on to controller 250 and the pneumatic 
pressure of 60 psi available to the system, start button 262 is depressed. 
With accumulator 160 empty, ribbon detector 176 will signal controller 250 
to initiate the supply cycle. Controller 250 first actuates cutter/gripper 
solenoid valve 272 causing gripper 100 to close gripper jaws 104 about 
leader ribbon 35 and, simultaneously, causing pivoting clamping finger 148 
and blade 140 to pivot away from fixed clamping finger 150 and fixed blade 
146. After gripper jaws 104 have grasped leader ribbon 35 and cutter and 
clamp assembly 130 has opened, controller 250 will actuate solenoid 278, 
thereby opening the pneumatic valve controlling horizontal drive 90 of 
gripper assembly 70. Horizontal cylinder 94 is thus actuated and the 
leading end of leader ribbon 35 is drawn into and through accumulator 160. 
When gripper 100 reaches the position shown in FIG. 11A, Hall effect 
sensor 112 signals controller 250 which actuates solenoid valve 276. The 
actuation of solenoid valve 276 in turn actuates cylinder 212 to retract 
piston rod 214 causing pinch and drive rollers 196 and 182 to engage 
leader ribbon 35. Controller 250 next actuates stepping motor 194 which 
rotates drive roller 182 clockwise as shown in FIG. 11B a predetermined 
number of revolutions, thereby stuffing the desired leader length into 
accumulator enclosure 161. The cutter/gripper solenoid valve 272 is then 
actuated by controller 250 such that gripper 100 releases the leading end 
of leader ribbon 35 while cutter and clamp assembly 130 clamps leader 
ribbon 35 and severs a measured length 20, the ends of measured leader 
length 20 extending from accumulator enclosure 161. 
To recycle gripper 100 to its initial starting position, controller 250 
first actuates solenoid valve 274 thereby causing vertical drive 80 of 
gripper assembly 70 to raise gripper 100. When gripper 100 is raised above 
accumulator 160, Hall effect sensor 108 signals controller 250. Upon 
receipt of this control signal, controller 250 responds by actuating 
solenoid 280 which, in turn, actuates horizontal drive 90 of gripper 
assembly 70 such that gripper 100 is moved to the right as viewed in FIG. 
2. When gripper 100 reaches the position directly above its initial 
position, Hall effect sensor 114 signals controller 250 which actuates 
solenoid valve 274 to lower gripper 100. When gripper 100 reaches its 
lower most position, Hall effect sensor 110 signals controller 250. At 
this point in the supply cycle, gripper 100 and measured leader length 
supply system 50 are again positioned as shown in FIG. 2; however, a 
measured leader length 20 is now retained within accumulator enclosure 
161. When the cartridge assembly technician grasps the leading end and 
removes measured leader length 20 from accumulator 160, ribbon detector 
176 signals controller 250 that accumulator 160 is now empty, at which 
point controller 250 then initiates another supply cycle. 
While a preferred embodiment of the invention has been shown and described, 
modifications thereof can be made by one skilled in the art without 
departing from the spirit of the invention.