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Патент USA US2412551

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2 Sheets-Sheet‘ l
Filed June 10. 1944
?ll-Q M ray“.
Dec» W, 1946,
Filed June 10, 1944
M j 45
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2 Sheets-Sheet 2
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Patented Dec. 10, 1946
2,412,551 >
Verneur E. Pratt and George F. Gray,
Norwalk, Conn.
Application June 10, 1944, gerial No. 539,740
'2 Claims. (Cl. 88-28)
In scanning devices, often termed reading ma
Each motor shaft supports a winding member
chines as commonly used with micro?lm, a pair
or ?lm reel ii, l5 and the reels are driven by
of winding members usually termed the delivery
‘their shafts through a suitable friction device,
such as the pad l6, pressed against the reel by
spring I‘! which is secured to the shaft so as to
rotate therewith. Spring ll may be adjusted by
\ and take-up reels are used to hold the ?lm in
the machine as it is fed past the lens system.
The ?lm is Wound oil? a delivery reel on to a take
up reel, and then rewound.
When these reels are motor driven they are
usually driven by belts and pulleys with some
mechanical shifting arrangement to shift the 10
power drive from one reel to the other, depend
ing upon whether the ,?lm is being translated,
i. e.—moved from delivery to take-up, or re
wound, i. e.--wound back on to the delivery reel.
nuts l8. Both reels have the same form of fric
tion device which is not operative to let the reel
slip‘ during normal operation of the device, but
permits slippage should abnormal tension .develop
in the ?lm.
Reel It may be considered as the delivery reel
which is ?lled with ?lm and put in the machine,
and from which the ?lm is wound oil and on to
In some cases two motors are used, one for 15 the take-up ree1 l5.
In the path of travel of the ?lm from one reel
each reel, with some provision to mechanically
to the other is located the usual light source 19
disconnect the motor not used, and thereby free
and ‘lenses 20, 2|, all as shown in Figure 2, 22
the reel from which the ?lm is being taken. In
being the ?lm. The lenses, light source, viewing
most cases, whether one or two motors are used,
some braking mechanism is necessary and is used 20 screen 23 and other parts common to readers are
not here described, as any suitable parts may be
to control the reels so that the ?lm will not un
used. The present invention is concerned only
wind too quickly from the reel from which it is
with the operation of the reels and the motor
being taken. As during such unreeling the di
ameter of the roll of ?lm continuously decreases,
uniform mechanical braking is diilicult and in 25
many devices is unsatisfactory as it results in the '
piling up of the ?lm, breakage and scratching.
drives therefor.
A current supply circuit 24 has a conductor 25
connected to motors l0, II which are connected
to run in opposite directions. These motors con
nect to a resistance or inductance 28 having a
This is particularly true with imperforate ?lm
contact arm 29 connected to conductor 30 of the
commonly used with micro?lm readers.
The present invention relates to a ?lm feed-. 30 supply circuit. The resistance 28 is of such char.
acteristics that when the arm 29 is at the mid
ing device in which the foregoing objectionable
point 3| thereon, both motors will receive equal
features are eliminated, the apparatus simpli?ed
amounts of current and therefore wi11 be oper
and smooth performance obtained with a mini
ating at substantially the same speeds and torque,
mum of parts easily constructed and assembled.
These are the objects of the invention, and 35 the latter varying slightly dependent upon the
di?erence in the load on the reels it, IS.
others will be apparent from the following speci- Y
Now, by varying the position of contact arm
?cation where three forms of the device are
29, either motor can be made to overcome the
shown. It will be understood, however, that the
other. For example, if arm 29 is'moved to the
invention may be embodied in many other forms
of apparatus once the inventive concept herein 40 point 32, the motor ll will be directly across the
current supply 23 with none of the resistance
disclosed is understood. The invention is there
28 in circuit, and all of this resistance will be
fore as de?ned in the appended claims. What is
in circuit with motor in. The result will be that
shown here is merely by way of illustration.
motor II will drive the reel I5 to take ?lm from
In the accompanying drawings:
Figure l is a diagram illustrating the invention 45 reel l4, motor 10 acting as a brake on It and
thereby keeping the ?lm tight in the lens open
as applied to the reels of a reading machine;
ing or ?lm gate 33.
Figure 2 is a diagram of a modi?ed form of the
In Figure 2 is shown a modi?cation of the con
trol shown in Figure 1. Here the resistance or
Figure 3 is a diagram of a modi?ed form of
60 inductance is split as shown at 36, 35. Two arms
controller arm; and
'86, 31 are mounted to revolve about shaft 38 and
Figure 4 is a sectional view of one of the reels,
may be‘ individually set to e?ect the necessary op
Fig. 1.
Referring to Figure 1, the motors l0, ll, are
of any suitable type and may have gear reducers
built in or associated therewith as shown to drive 65
the reel shafts l2, It, at the desired speed.‘
erating conditions. » All connections are as shown
inFigure 1.
' >
If desired, the arms 86, 31 can be set to ef
fect some desired set di?erential control by s'e
curing them in the desired relative position to
shaft 38 as by screws 39, 40, in which event the
shaft turns with the arms. Moving either arm
.will then move the other.
In Figure 3 is shown a, further modi?cation of
the control device. Here the arms 4|, 42 are in
dependently movable about shaft 43 and are pro
vided with the lugs 44, 45 which are ?xed to the
arms but free to revolve thereon, A rod 48 passes
when used with alternating current, the mo~
tors i0, ll might be either of the shaped-pole
type or series commutating type in order that
the resistances, such as 3!, may be effective. And
itwill be understood that, instead of resistances
herein described by way of illustration, any suit
able controlling device can be used that will vary
the torque of the motors to produce the result
herein described.
It will also be observed that if the motors used
through holes in‘the lugs as shown and carries 10
have limited torque, the friction devices, such
the collars 41, 48, 49, ill which are slidable along
the rod and may be secured thereto by screws,
one of which is shown at 5!. By setting the col
lars, any desired adjustment of the differential
may be obtained in order to compensate for the
conditions due to the varying diameters of the
rolls of ?lm when being wound in either direc
as the pad l6, associated with each reel may be
omitted and ‘that instead of driving- the shafts
ii for the reels, the reels themselves may be di
rectly driven from the motor gearing or in any
other suitable manner.
What is claimed is:
1. In a ?lm feeding device having a lens, a
?lm reel, a shaft therefor, a motor connected to
For example, when translating, if arm 42 is
moved to the right to give the motor I I full torque 20 said shaft .to drive same in one direction, a sec
ond ?lm reel, a shaft therefor, a motor connect
it would ?nallyrest at 32 Figure 1, and collar 50
ed to said second shaft to drive same in the op
would be adjusted to engage lug 45 at some desired
posite direction to said ?rst reel, a ?lm connect
point in this travel to the right. This would move
ing said reels and adapted to be wound from one
rod 46 to theright, and by adjusting collar 41
thereon, arm 4| would be moved clockwise the 25 reel to the other, a friction clutch between each
desired distance to increase the resistance (or in- . reel and its associated shaft, a ?xed ?lm support
mounted on said device and ?xed in the optical
ductance) in circuit with motor ill in any desired
path of the lens thereof, a current supply circuit
relation to the decrease in resistance in circuit
connecting said motors, and means in said cir
with motor I I.
4 Conversely, by adjusting collars 48 and 49 the 30 cuit for varying the torque of said motors where
by, when one of said motors is winding said ?lm
resistance in series with motor II can be in
on one of said reels the other motor is acting as
creased, as the resistance in series with motor I0
a brake on the reel from which the ?lm is being
is diminished. Thus motor ID will have the
whereby said ?lm is tensioned across said
greater torque and motor~ ii the lesser, and ?lm
support as it traverses same.
will be wound o? ‘reel l5 and on to reel l4 while
2. In a device of the character described, a lens,
held taut in the gate 33.“ a ?lm, a ?lm gate having a movable gate mem- v
Shouldthe ?lm catch, or anything happen
ber adapted to engage and hold said ?lm in a pre
where the pull on the'?lm in either direction ex
determined relationship to said lens, a. pair of
ceeds the tension of the driving friction clutches
reels and a ?lm extending therebetween and at
(i6, i‘! on each reel) a clutch will slip and there 40 right angles to the axis of said lens, motors for
by prevent tearing the ?lm. It will be under
driving said reels connected thereto‘and adapted .
stood that at all other times the clutches main
to drive said reels in opposite directions and con
tain a positive drive between the motors and
stituting the sole means for moving said ?lm in
the reels, and play no part in the normal brak .45 both directions, a circuit connected to said mo
ing operation, unlike many clutches in the prior
tors to simultaneously operate the same, means
art. Here, the braking action as described is
in said circuit for varying the torque of said mo
entirely due to the difference in torque of the two
tors whereby when one motor is moving said ?lm
motors, both of which operate simultaneously in
across the axis of said lens the other motor is act
opposite directions to maintain the ?lm at the 50 ing as a brake to tension said ?lm between said
desired degree of tension between the reels.
reels, and means in said circuit and operable with
When one motor is operating to wind, the other.
said motors therein for automatically releasing
acts as a brake on the ?lm.
said gate member to release the ?lm held thereby.
While for the sake of illustration the inven
3. In a ?lm feeding machine, winding mem
tion is disclosed as applied to a ?lm winding ap 55 bers, separate independent motor means for si
paratus, it will be apparent to those skilled in
multaneously operating said members to wind in
the art that it can be advantageously applied
opposite directions, a ?lm between said members
to many devices wherein it is desired to wind we'bs
to be moved thereby, means including a movable
while holding same under tension. ‘
‘ ?lm gate engaging said ?lm between said reels,
In Figure 2 is disclosed an arrangement which 60 means for utilizing one of said motor means as a
can be used with the circuits herein described
brake on the movement of said ?lm, a circuit in
to lift the ?lm gate 5| or any other device in
cluding a source of current connected to said
contact with the web or ?lm between the reels.
motors, and means included in said circuit and
Here when the switch 52 in the current supply
operable bycurrent ?owing therein for releasing
mains 24 is operated, as for example when the v65 said movable ?lm gate while either of said motor
circuit through the motors l0, ii is closed, the
means is in operation in either direction.
electromagnet 53 operates to attract armature
4. In a ?lm feeding device of the class de
44 attached to the movable member of the, ?lm
scribed, a ?lm and rotatable means for moving
gate 52 which is opened, thereby relieving the
same, a pair of motors connected to said moving
?lm when same is in movement in either direc 70 means and adapted to move same in either di
tion, The magnet 53 may be “quick”, opening
rection, a circuit common to said motors, means
and slow closing to give the ?lm opportunity to
connected to said circuit for simultaneously vary
stop moving before 5| closes. Magnet 53 can be
ing the torque of said motors whereby the torque
bridged across conductors 25 and 30 instead of
of one may exceed the other to tension said ?lm
being in series with 25, as shown.
75 being moved thereby, and means for gripping said
?lm when same is at rest, and for releasing same '
whenever said motors are moving same in ei
ther direction, said means including an electro
magnet connected to said circuit,
5. In a ?lm feeding device having a lens, a pair
of shafts supported on said device, a ?xed ?lm
gate in the optical path of said lens system and
supported on said device in ?xed relation to said
shafts, individual motors supported on said de
vice and separately connected to said shafts to
supported on said device in ?xed relation to said
shafts, individual motors supported on said de
vice and separately connected to said shafts to
drive same in opposite directions, means includ
ing detachable ?lm reels driven by said shafts for
winding a ?lm from one location on said device
to another location thereon with said ?lm gate
therebetween, ‘and means varying the tordue of
said motors when both are rotating whereby‘ a
?lm passing through said gate may be 'wound by
one of said motors and tensioned by the other
motor while said gate remains ?xed in the op
tical path of said lens.
7. The combination as claimed in claim 8
varying the torque of said motors when both are 15 wherein each of said reels is connected to its ro
tating shaft by an independently adjustable
rotating, whereby a ?lm passing through said
clutch,‘ whereby each reel may be independently
gate may be wound by one of said motors and
drive same in opposite directions, means driven
by said shafts for winding a ?lm from one loca
tion on said device to another location thereon
with said ?lm gate therebetween, and means for
tensioned by the other motor while said gate
remains ?xed in the optical path of said lens.
‘adjusted to permit slippage when the tension on
a ?lm extending between said reels exceeds a pre
6. In a ?lm feeding device having a lens, a pair 20 determined limit.
_of shafts supported on said device, a ?xed ?lm
gate in the optical path of said lens system and
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