Tape winding system

Apparatus for winding a preselected, programmable amount of tape under a predetermined level of tension is described. The tape is automatically placed under the predetermined level of tension prior to actually winding the tape onto the hub. The tape is fed at a variable speed according to a look-up table, while it is wound onto a hub, and is servoloop controlled so as to maintain constant tension on the tape as the speed at which the tape is fed changes.

The present invention relates generally to systems for winding tape onto a 
hub, and more particularly to apparatus for controlling the tension on 
tape while winding a preselected amount of the tape onto a hub. 
Systems are well known for transferring magnetic recording tape of the type 
used in video or audio applications from large supply reels to smaller 
hubs commonly employed in tape cassettes and cartrides. See, for example, 
U.S. Pat. Nos. 3,499,614, 3,637,153, 3,752,415, 3,776,488, 3,893,167, 
3,997,123, 3,917,184, 4,061,286, 4,101,938 and 4,204,898. A typical 
transfer procedure comprises starting with first and second hubs connected 
by a leader tape, serving the leader tape into two portions with one 
portion being connected to a corresponding hub. The magnetic tape is then 
spliced to the end of the leader portion of one hub. A preselected amount 
of magnetic tape is then wound onto the one hub. The magnetic tape is then 
severed and the trailing end of the wound magnetic tape is spliced to the 
other leader portion of the other hub. The entire procedure can be 
accomplished on two hubs prior to mounting the two hubs and tape into a 
cassette housing. Alternatively, the entire method can be carried out with 
the hubs previously mounted in a cassette housing. 
During the winding procedure it is obvious that winding at a constant 
speed, i.e., driving the hub at a constant radial speed, results in a 
variation in the linear speed of and tension on the tape as the position 
of the tape being wound onto the hub varies from the hub center axis. This 
is often undesirable, particularly for some tapes such as those used for 
video recordings. 
Accordingly, many manufacturers of tape winding machines employ various 
techniques of maintaining a constant tension on the magnetic recording 
tape when winding the tape onto the hub. One such technique employs vacuum 
columns to control the tension of tape during the winding operation. See, 
for example, U.S. Pat. Nos. 3,499,614, 3,752,415, 3,776,488 and 3,893,167. 
The variable force vacuum column is a vacuum column in which the force on 
the tape loop varies with the position of the loop in the column. Examples 
are tapered vacuum columns, parallel wall vacuum columns with slots or 
openings at various positions through the wall of the column connected to 
atmosphere or a vacuum source, or a combination of these examples. 
Another technique for controlling the tension on a moving tape is shown in 
U.S. Pat. No. 4,101,938, wherein a slide potentiometer, controlled by the 
position of a pivotally supported lever arm, produces a voltage output 
indicative of the position of the arm and the tension of a moving tape. 
The voltage output is applied to a motor controller. The latter in turn 
controls the speed of a drive motor used for feeding the tape toward the 
lever arm so as to maintain the tension on the tape "constant" at the 
point where the tension detecting arm contacts the tape. While this system 
attempts to maintain the tape under constant tension no effect is made to 
control the speed at which the tape is wound onto a hub. 
In addition, in some prior art tape winding systems there can often be a 
great difference in the actual amount of tape would onto a hub when 
attempting to wind the predetermined amount of tape on each of a plurality 
of hubs on a mass production basis. 
It is, therefore, a general object of the present invention to overcome the 
disadvantages of the prior art systems. 
Another object of the present invention is to provide an improved system 
for automatically winding a preselected amount of tape onto a hub while 
accurately maintaining the tape under constant tension. 
And another object of the present invention is to provide an improved 
system for repeatedly winding a preselected, programmable amount of tape 
onto a hub which amount can easily be selected by the operator of the 
system. 
Still another object of the present invention is to provide an improved 
system for placing tape under a desirable tension level prior to winding 
the tape onto a hub, and winding the tape onto the hub substantially at 
that tension level. 
Yet another object of the present invention is to provide a tape winding 
system in which a tape is fed in accordance with a predetermined nonlinear 
function, and the tape is wound onto a hub such that the tension on the 
tape remains substantially constant. 
These and other objects are achieved by an improved apparatus for winding 
tape onto a hub. The tape is fed at a variable speed according to a 
look-up table, while the tape is wound onto a hub at a speed which is 
servo-controlled to maintained constant tension as the speed at which the 
tape is fed changes. Preferably, the tape is automatically placed under 
the predetermined level of tension prior to actually winding the tape onto 
the hub. 
Other objects of the invention will in part be obvious and will in part 
appear hereinafter. The invention accordingly comprises the apparatus 
possessing the construction, combination of the elements, and arrangement 
of parts which are exemplified in the following detailed disclosure, and 
the scope of the application of which will be indicated in the claims.

In the drawings, the same numerals are used to designate similar or like 
parts. 
A tape loading system 8 is shown in FIG. 1. System 8 is of a type which 
generally includes tape cutting and splicing mechanisms which are well 
known in the art and incorporates the tape winding apparatus of the 
present invention. Specifically, the system 8 includes a front panel 10 
supporting a drive spindle 12. The latter, in turn, is rotatably driven by 
a tape drive motor 13 (shown in FIGS. 2 and 4) which in turn is driven by 
the control system 15 (shown generally in FIG. 2 and in detail in FIG. 4). 
The spindle 12 rotatably supports a supply reel 14 of tape 16. Tape 16 is 
fed under roller 18, over metering wheel 20 (wheel 20 being described in 
greater detail in connection with FIG. 4) and around the roller 22 to the 
roller 24. Wheel 20 drives the encoder 23 (shown in FIG. 2) which includes 
photocells 25. The latter are adapted to provide a predetermined number of 
pulses for each revolution of wheel 20 and therefore provide an electrical 
signal representative of the actual amount of tape traveling over wheel 20 
and more particularly wound onto the hub as will be more evident 
hereinafter. Roller 22 is disposed in an arcuate slot 26 and, as shown in 
FIG. 3, is rotatably secured to an axle 28 provided on pivotal arm 30. Arm 
30 is mounted to the rear of panel 10 so that it is pivotal about pivot 
axis 32 at a location spaced from axle 28 such that roller 22 freely moves 
in arcuate slot 26 as the arm 30 pivots about axis 32. As best shown in 
FIG. 3, switches 34A and 34B, preferably in the form of magnetic switches, 
can be provided on the rear of panel 10 to (1) limit the pivotal position 
of arm 30 to positions between the two extreme positions 36 and 38 shown, 
wherein roller 22 is respectively near the opposite ends of arcuate slot 
26 and (2) sense when the arm 30 is in one of the two extreme positions. 
In this regard the positions of wheel 20 and roller 24 is such that a line 
drawn between the rotation axes of these two rollers will be to one side 
of the rotation axis of roller 22 at all times, regardless of the position 
of the arm 30. The tape 16, therefore, can only pull roller 22, and thus 
arm 30, toward position 38. The arm 30 is suitably attached to the tap of 
the potentiometer 40 so that by providing a suitable potential across the 
potentiometer, the voltage output of the potentiometer varies as a 
function of, and thus provides an indication of, the pivotal position of 
arm 30. 
Referring again to FIG. 1 the tape is fed from roller 24 through the tape 
cutting and splicing station 42 to the take up hub 44 mounted on a take up 
spindle 46. Cutting and splicing station 42 is well known and may, for 
example, be the type shown in U.S. Pat. No. 4,061,286. Station 42 
generally includes a splicing block assembly 47 for holding the leader 
tape provided on hub 24. A tape splicer assembly 49 cuts the leader tape, 
splices the leading edge of tape 16 to one piece of leader tape before the 
tape is wound onto hub 44, cuts the tape 16 after tape 16 is wound onto 
hub 44 and splices the trailing edge of tape to the remaining portion of 
the leader tape positioned on block assembly 47. As shown in FIG. 2, 
spindle 46 is driven by a take up motor 48 so that the tape is wound onto 
hub 44. The linear speed at which the tape 16 is wound onto the hub 44 is 
varied as the radial location of the tape on hub 44 increases, so that the 
tension on the tape remains substantially constant. This is accomplished 
by connecting the take up motor 48 to the output of a servo system 
contained within control system 15, which in turn receives an output from 
potentiometer 40. 
Thus, as tape 16 is wound onto hub 44, the arm 30 tends to move towards 
position 38 (the roller 22 moves to the left in FIG. 1) as the tension on 
the tape 16 increases, while arm 30 moves toward position 36 (the roller 
22 moves to the right in FIG. 1) as the tension on tape 16 decreases. The 
movement is sensed by potentiometer 40, which in turn provides the 
appropriate output to a servo system of control system 15. The latter 
provides an output to drive motor 48 so as to regulate the speed at which 
the tape 16 is wound onto the hub 44. The first movement of arm 30 is 
actually caused by tension of the tape 16 above the desired level, 
producing a force on the arm 30 so that roller 22 is moved to the left in 
FIG. 1 or the right in FIG. 2. At the desired level of tape tension the 
arm 30 remains in a neutral position and does not move. Finally, when the 
tension on tape 16 decreases below the desired level, less force is 
applied to the arm 30 and the roller 22 moves to the right in FIG. 1 and 
to the left in FIG. 2. A biasing force in the direction of arm position 36 
is utilized to negate the force produced by the running tape so as to 
maintain the arm between the two positions as the tape is being wound and 
to move the arm 30 toward position 36 when the tension on the arm falls 
below the desired level. The means for providing this negating force can 
be any suitable means, such as a simple negator spring connected to bias 
the arm 30 toward the position 36. Alternatively, and preferably as 
described in copending application U.S. Ser. No. 266,287 filed by David 
Sarser and Richard A. Berube on May 22, 1981, (assigned to the present 
assignee) the torque output of a DC motor 60 can be suitably coupled to 
the arm 30 for providing the desired bias towards the position 36. More 
particularly, as shown in FIGS. 2 and 3, the motor 60 is mounted on the 
rear of panel 10 by any suitable means such as bracket 62. The motor is 
positioned on the side of arm 30 which is opposite to the position of 
rollers 20 and 24 on the front of panel 10. The motor 60 can be any DC 
torque motor providing the desired level of torque output on its output 
shaft. The torque output of motor 60 is coupled to arm 30 through line 66. 
The latter has one end secured to the output shaft of the motor so that 
the shaft actually pulls line 66. The line 66 is secured at its other end 
to arm 30 by any suitable means such as bracket assembly 68. Bracket 
assembly 68 includes a yoke 70 and a cylinder 72 rotatably secured within 
yoke 70. The line 66 is secured to cylinder 72 by any suitable means such 
as the set screw 74 attached to cylinder 72. 
As will be more evident hereinafter, as shown in FIG. 1, means in the form 
of footage selection switches 80 are provided in the front panel 10 so 
that a preselected amount of tape 16 to be wound onto hub 44 can be 
programmed by the user. Switches are preferably BCD switches which are 
well known in the art for providing electrical signals in binary form 
indicative of the digital numbers visually selected by the operator. 
Further, a visual display of the actual number of feet of tape determined 
by encoder 23 to have been wound onto hub 44 is provided on display 82. 
Referring to the partial schematic and partial block diagram of the FIG. 4 
the system for winding tape from reel 14 onto hub 44 is shown in detail. 
The system for winding tape includes the micro-controller 100 having 
supply and load inputs 102 and 104, respectively and a count output 106, 
as well known in the art. Controller 100 can be any commercially available 
microprocessing unit, such as the 8085 Microprocessor manufactured by 
Intel Corporation of California, although it will be evident that other 
microprocessors can be used. Controller 100 is preferrably programmed in 
accordance with the program attached hereto as Appendix A. For ease of 
exposition the program of Appendix A is represented by the flow charts 
shown in FIGS. 5A, 5B, and 5C. Controller 100 includes a binary output, 
shown over line 108, which is transmitted to the input of a digital to 
analog converter 110. Preferably, the output is a ten bit output 
representative of a speed at which motor 13 is to be driven. Digital to 
analog converter 110 is a type well known in the art for converting the 
ten bit output on line 108 to an analog signal whose amplitude level is a 
function of the ten bit input. Since the ten bit input to converter 110 
provides 1024 different inputs, the output of converter 110 can be at any 
one of 1024 incremental amplitude levels. The analog incremental output of 
converter 110 is connected to ramp circuit 112. The latter is of a type 
well known in the art for smoothing out the incremental analog output of 
converter 110, and for generating a ramp voltage at a rate which is a 
function to the input from the converter 110. The output of circuit 112 is 
connected to the positive input of a summing junction 114, which in turn 
has its output connected to the supply servo amplifier 116. So long as 
amplifier 116 is enabled, the output of junction 116 is processed and 
thence supplied directly to drive motor 13 for rotating supply reel 14. 
Amplifier 116 is connected to receive a disabling supply signal from 
controller 100 over line 118 so as to disable the amplifier and prevent an 
output signal from amplifier 116 to motor 13. As will be more evident 
hereinafter, at the completion of the winding of tape onto hub 44, motor 
13 is stopped by brake 120 when driven by the driver 122, which in turn 
receives a supply brake enable signal over line 124 from the controller 
100. As previously described switches 80 are provided for programming the 
select amount of footage which is desired to be wound on hub 44 from the 
reel 14. Means, preferably in the form of metering wheel 20, is provided 
for measuring the amount of tape actually provided by supply reel 14 and 
wound onto hub 44. Metering wheel 20 is rotatably driven by the tape 16 as 
the tape 16 moves over the wheels. As shown in FIG. 2, shaft encoder 23 
including photocells 25 operates to provide a pulse train output 
representative of the revolutions of the wheel as the wheel rotates. In a 
typical design the output of the encoder 23 provides 256 pulses per foot 
of tape although it is evident that this number can vary. The outputs of 
the photocells 25 of the encoder are provided to the metering wheel 
circuits 126 as shown in FIG. 4. Circuits 126 reduce the number of pulses 
provided by the photocells 25 to an acceptable level for controller 100. 
For example, one pulse per tape foot can easily be provided by dividing 
the 256 pulse per foot output by a divide by 128 circuit (not shown) and 
thence by a divide by 2 circuit (not shown) as well known in the art. By 
providing a large number of pulses per foot output from the encoder, good 
resolution with respect to measuring the amount of tape actually passing 
over wheel 20 is achieved, while circuits 126 reduce the count to an 
acceptable level for controller 100. This digital output representative of 
the footage length of tape passing over wheel 20 is transmitted from 
circuits 126 to controller 100 over line 128. Circuits 126 also includes a 
tachometer (not shown) for measuring the actual velocity of the tape over 
wheel 20. The output of the tachometer of circuits 126, the analog tape 
velocity signal, will vary proportionally with the tape reference velocity 
output of ramp circuits 112. The analog tape velocity output of circuits 
126 is transmitted to a negative input to the summing junction 114 where 
it is subtracted from the ramp output of circuits 112. 
The servosystem for controlling the take up of tape onto the hub 44 
includes the potentiometer 40. Potentiometer 40 has its output connected 
over line 132 to an input of switch 130. Limit switches 34A and 34B are 
suitably connected over lines 134 and 136, respectively, to controller 
100. Potentiometer 40 is suitably bias by a voltage potential such that 
the output (the dancer arm position signal) over line 132 to switch 130 
will be zero volts when the arm 30 is in an intermediate, neutral position 
such as shown in FIG. 4. The output will become (1) increasingly positive 
as the arm 30 moves from its neutral position toward switch 34B when the 
tension on tape 16 increases, and (2) increasingly negative as the arm 30 
moves toward the limit switch 34A when the tension decreases. Arm 30 
closes switch 34A when in position 38 generating a signal over line 134 to 
controller 100 indicating that arm 30 is in position 38. Similarly, when 
arm 30 is in extreme position 36, switch 34B closes providing a signal 
over line 136 to controller 100 indicating that arm 30 is in the position 
36. 
Switch 130 remains open when no signal is provided by controller 100 over 
line 140. When a signal is provided over line 140, switch 130 closes 
providing the dancer arm position signal to the positive input of summing 
junction 138. A second switch 142 provides a slack reference input signal 
present at 146 to a positive input of summing junction 138 when enabled by 
the take up slack signal provided from controller 100 over line 144. The 
output of summing junction 138 is transmitted to the input of the take up 
servo amplifier 148, which in turn provides an output to and drives the 
take up drive motor 48 so long as amplifier 148 is enabled. Amplifier 148 
remains enabled unless a disable signal is provided by controller 100 over 
line 150. A tachometer 152 measures and provides an output signal 
indicative the speed of take up drive motor 48. The output signal of 
tachometer 150 is provided to a third positive input of summing junction 
138. 
In operation, the slack reference signal has been preset for an optimum low 
speed winding of the slack tape onto the hub 44. The user selects the 
desired footage of tape to be wound onto hub 44 by setting the footage 
switches 80. For example, a video cartridge typically is provided with 800 
feet of tape. 
As well known in the art, the tape 16 has been prewound around roller 18, 
wheel 20, roller 22, wheel 24 and secured in block assembly 47. The tape 
leader provided on hub 44 will also be secured to block assembly 47. The 
cutting and splicing mechanism 49 operates in a manner well known in the 
art by cutting the leader tape and splicing the leading edge of the tape 
16 positioned on block assembly 47 to the leader tape portion connected to 
hub 44. The tape 16 can now be wound onto hub 44. 
An initiation signal (step 200 in FIG. 5A) is now provided at the load 
input 104, which can be accomplished manually by closing an external 
switch (not shown) or automatically by providing such a signal 
responsively to the completion of the splicing operation between the 
leader tape portion connected to hub 44 and the tape 16. The winding 
operation proceeds in accordance with the flow chart in FIGS. 5A, 5B, and 
5C. With little or no tension on tape 16 prior to initiation of the 
winding operation the negating force providing by the torque output of 
motor 60 through line 66 will pull arm 30 toward limit position 36. Arm 30 
should be in limit position 36 (step 202 of FIG. 5A) so that a signal is 
provided over line 136 to controller 100. If a signal is provided over 
line 136, the system will initially provide a signal over line 124 to 
driver 122. Driver 122 in turn will provide an output to brake 120. Reel 
14 will therefore be prevented from rotating. (Step 204 in FIG. 5A). An 
energization signal is then provided over line 144 to close switch 142. 
The slack reference signal at 146 is then applied through junction 138 to 
servo amplifier 148 (step 206 of FIG. 5A). The disable signal over line 
150 is then removed (step 208 of FIG. 5A) so that the slack reference 
signal is applied to motor 48. The motor 48 pulls tape 16 moving arm 30 
against the torque output of motor 60 into the neutral position since the 
slack reference signal is at a predetermined level as a function of the 
desired level of tension for the tape 16 and the reel 14 is prevented from 
rotating. Since the limit switch 34B is now open, the servocode of FIG. 5A 
progresses to step 210. 
Next the energize signal over the take-up slack line 144 is removed so as 
to disable switch 142 (step 210 of FIG. 5A). In step 212 of FIG. 5A, a 
delay of two seconds occurs and the energize signal over line 140 is 
provided to close switch 130 and provide the dancer arm position signal to 
the summing junction 138 and thence to the input of amplifier 148. Since 
the dancer arm 30 is substantially in the neutral position the position 
signal will be zero. The disable take-up signal over line 150 is removed 
so that amplifier 148 provides an output signal to take up motor 48. 
Almost simultaneously, controller 100 next reads the desired footage count 
provided in binary code from switches 80 (step 214 of FIG. 5A). This 
desired footage count is stored in control 100 (step 216 in FIG. 5A). If 
the footage count is set at zero the operation would jump to step 242 
shown in FIG. 5C and described hereinafter. However, so long as this 
footage count is not zero (step 218), the program will continue to step 
220. Next, in accordance with step 220, the footage pulse output from the 
metering wheel circuits 126 is received by controller 100 so as to read 
the actual footage of tape which has been wound onto hub 44. This actual 
footage is shown on display 82. 
The operation proceeds to step 222 (shown in FIG. 5B) where the actual 
footage count from circuits 126 is substrated from the desired footage 
count provided by switches 80. 
Since the ramp look up table provided in the program of Appendix A varies 
from 0 to 255 feet remaining, the system next determines whether the 
remaining number of feet of tape 16 to be wound onto hub 44 exceeds 255 as 
shown at step 224. If yes then the program proceeds to step 226, wherein 
the controller provides the maximum 10 bit binary output over line 108 to 
converter 110. Converter 110 will thus provide the maximum output to ramp 
circuit 212 so that the latter provides a ramping voltage output which 
increases at a maximum rate. The analog tape velocity output of the 
tachometer of metering wheel circuits 126 is subtracted from the tape 
reference velocity output of circuits 112 at junction 114, with the 
difference signal being subsequently applied to the input of servo 
amplifier 116. At step 228 amplifier 116 is enabled by insuring that the 
disabling signal is not provided over line 118, i.e., the line 118 is off, 
and similarly at step 230 the motor 13 is enabled by insuring that line 
124 is off and brake 120 removed. The system next checks to make sure that 
neither switch 34A or 34B is closed. If one of the switches 34A or 34B is 
closed, indicating that arm 30 is in one of its two limit positions, the 
system aborts as shown at step 234, shutting down the operation and 
indicating to the operator that something is wrong. 
Should both switches 34A and 34B remain open the system continues to 
operate by returning to step 222 of FIG. 5B. The system continues in the 
loop defined by steps 222, 224, 226, 228, 230 and 232 until the remaining 
number of feet of tape 16 to be wound onto hub 44 equals 255. It should be 
appreciated that until the remaining number of feet of tape equals 255, 
the ramp circuits 112 will continue to ramp at its maximum rate upwardly. 
However, as the speed of the motor 13 increases, so does the analog tape 
velocity signal output of the tachometer output of the metering wheel 
circuits 126. The latter signal is applied to the negative input of 
summing junction 114. This analog tape velocity signal at the output of 
circuits 126 is the inverse of the ramp output of the ramp circuits 112 so 
that the output of the summing junction 114 levels off at some constant 
D.C. value when motor 13 has achieved its desired speed. 
When the number of feet of tape to be wound onto hub 44 falls to 255, the 
system will proceed from step 224 to step 236. At step 236 the the ramp 
look up table shown in the program of Appendix A determines the velocity 
for this approximate incremental value of feet. The value is represented 
by a 10 bit output at 108 which is transmitted to the converter 110 
according to step 238. So long as the value is not zero, the system 
proceeds through steps 228, 230, 232, 222 and back to step 224. Since the 
feet remaining is progressing toward zero, the value of remaining feet to 
be wound onto hub 44 will now be less than 255. The system operation will 
proceed to step 236, determine the appropriate ten bit output value for 
the currently determined incremental value of the remaining number of feet 
left to be wound onto hub 44, provide the output to converter 110 in step 
238 and proceed to step 240. The system continues in the loop defined by 
steps 240, 228, 230, 232, 222, 224, 236, 238 and back to 240 so long as 
there is still an incremental amount of tape still to be wound onto hub 
44. During operation in this loop the analog voltage output of converter 
110 is proportional to the binary output on line 108 and will vary in a 
nonlinear manner with respect to the decrease in the incremental amount of 
tape remaining to be wound onto hub 44. 
The system operation will continue in this loop until the value of input to 
converter 110 equals zero. When this occurs the system will proceed from 
step 240 to step 242 (see FIG. 5C), whereupon a signal is provided by 
controller 100 over line 124 to the driver 122 which in turn applies brake 
120 to motor 13. Almost simultaneously, in accordance with successive 
steps 244 and 246, a disable signal is applied over line 118 disabling 
servo amplifier 116, and the energize signal provided on line 140 is 
withdrawn, opening switch 130. Since the take up motor is still running 
the output of tachometer 148 will provide an output and the take up motor 
48 continues to pull tape sufficiently to move dancer arm 30 to limit 
position 38. As shown at step 248 when limit switch 34A closes indicating 
that arm 30 is in the limit position 38, the operation proceeds to step 
250 to provide a disable signal over line 150 to amplifier 148, so that no 
signal is now applied to motor 48. 
It should be appreciated that during the entire winding procedure, the 
dancer arm 30 assures that tape 16 is wound onto the hub under constant 
tension even though the tape 16 is fed at varying speeds by motor 13. This 
results because of several reasons. First, the proper tension of the tape 
is set before the winding begins as provided by the steps 202, 204, 206 
and 208 of the operation. This places the arm 30 in its neutral position 
wherein the output of potentiometer 40 is zero. When winding begins and 
during the entire winding operation should the tension on the tape start 
to increase above the desired level, the arm 30 will pivot toward switch 
34A and the output of potentiometer 40 will go negative. This decreases 
the output of summing junction 148, decreasing the input to motor 48. The 
speed of motor 48 will decrease resulting in a decrease in the tension of 
the tape. The arm will be pulled by the torque output of the DC motor 60 
back toward the arm's neutral position. This, in turn, results in a 
decrease in the negative output of the potentiometer until it is back to 
zero. In a similar but opposite manner should the tension on the tape 
decrease below the desired level during the winding operation, the arm 30 
will be pulled by motor 60 through line 66 toward switch 34B. This results 
in a positive output of potentiometer 40. The positive output is fed 
through closed switch 130, through junction 138 and amplified by the 
enabled amplifier 148 to increase the speed of the motor 48. This speeds 
up motor 48 to increase the tension on tape 16. This in turn forces arm 30 
back to its neutral position reducing the output of potentiometer 40 back 
to zero. 
Further, the nonlinear rate at which motor 13 will increase its speed from 
its start up to a point where a constant speed is achieved (assuming a 
sufficient amount of tape 16 is wound onto hub 44 to allow motor 13 to 
achieved constant speed) will be equal and opposite to the nonlinear rate 
at which motor 13 will decrease when slowing down and stopping. If 
insufficient tape is to be wound onto hub 44 to enable the motor 13 to 
achieve constant speed it will be appreciated that the nonlinear rate of 
increasing speed will still match the nonlinear rate of decreasing speed. 
It will be appreciated that providing tachometer 152 improves the stability 
of the servo loop provided by dancer arm 30 by preventing the arm from 
oscillating as a result of what is often referred to as "control jitter". 
Once the winding operation is completed the tape 16 positioned on block 
assembly 47 can be cut by assembly 49 and the trailing edge of tape 16 
spliced to the remaining leader portion provided on another hub. This 
cutting and splicing operation can be accomplished by manually initiating 
the operation or can be accomplished automatically in response to the 
completion of the winding operation. 
While the invention has been described in its preferred form it will be 
evident to those skilled in the art that modifications can be made to the 
system described in the drawing without departing from the scope of the 
invention. For example, the look up table provided in Appendix A may vary 
depending upon the type of tape being used, the performance of motor 13, 
etc. Similarly, the desired level of tension on tape 16 can be set by 
adjusting the slack reference signal at input 146 and the torque output of 
motor 60 so that during step 206 of FIG. 5A, this desired tension level 
will be provided when the arm 30 is moved into its neutral position and 
the output of potentiometer 40 is zero. Additionally, while a two second 
delay is imposed at step 212 to insure that the slack of tape 16 has been 
taken up, the same result can be achieved by, for example, sensing the 
output of potentiometer 40 so that when it equals zero, indicating the arm 
30 is in the neutral position the winding operation can begin. The 
operation can then continue in the manner previously described. 
Since certain other changes may be made in the above apparatus without 
departing from the scope of the invention herein involved, it is intended 
that all matter contained in the above description or shown in the 
accompanying drawing shall be interpreted in an illustrative and not in a 
limiting sense.