Note: Descriptions are shown in the official language in which they were submitted.
16 Background of the Invention
17 Correction typewriters and mechanisms for feeding ribbons and
18 correction tapes on typewriters have become relatively well known in the
19 recent past. A p~imary example of such a typewriter is the IBM Correcting
SELECTRIC typewriter which embodi~s a ribbon feed mechanism and ribbon
21 cartridge substantially similar to that disclosed in U. S. patent 3,604,54922 and U. S. patent 3,731,781. The correction tape feed lS similar to that
23 disclosed in U. S. patent 3,724,633.
24 With the increased use of cartridges, due to their ease of inserting
and threading the ribbon and the cleanliness associated with handling
26 a plastic cartridge as opposed to handling a printing ribbon and adhesive
27 tape, it has become desirable to implement a system whereby the printing
28 ribbon and the correction tape are both contained within cartridges.
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1 An example of a ribbon feed and cartridge design for
accomplishing this in at least one environment is contained
in my co-pending Canadian application Serial No. 297,724,
filed February 24, 1978 and commonly assigned with this
application.
U.S. patent 4,010,839 discloses a periphery driven
moveable axis take-up spool in a ribbon cartridge for a
typewriter. U.S. patents 3,604,549 and 3,731,781, referred
to above also disclose a ribbon spool on a fixed axis which
is peripherially driven by spiked driver. The apparatus
necessary to insert the spiked driver into the cartridge to
accomplish such a driving function is relatively complex as
can be seen from U.S. patent 3,604,549, referred to above.
Disadvantages of the prior art, involving fixed loca-
tion or fixed axis take-up spools, are further compounded
when the driving mechanism required to transport the ribbon
and wind it on the take-up spool must also accommodate a
superimposed cartridge containing a correction tape.
It is desirable to drive the respective take-up spools
of the ribbon and correction tape around fixed axes to
minimize the manufacturing cost of the consumable cartridge
while at the same time accommodating the requirement for
uniform tape increment feed and uniform ribbon feed,
characteristics dictated by the nature of the ribbon and
correction tape.
LE977010 2
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1 Brief _mmary of the _v ntion
The ribbon feed mechanism is mounted to pivot on the frame of the type-
writer and to support the ribbon and correction tape cartridges thereon. The
cartridges are fabricated to have an end opening in proximity to the take-up
spool thereby permitting spring biased arms to enter into the cartridge and
engage drive wheels with periphery of the take-up spool and ribbon or tape
discs. The drive wheels are ratchet driven in response to cam follower move-
ment. The rise of the lobes on the cam control the amount of movement or
displacement of the cam follower and hence the ratchet drive thereby control-
ling the increment of feed. The same rises on the cam are utilized to control
the rocking of the ribbon cartridge support to effect raising the ribbon to
the print line and holding it in one of two different positions for printing.
A normally disengaged cam follower and linkage is connected to the correction
tape feed and mounted so that the follower will engage the correction tape
feed cam upon the rocking of the cartridge support to its extreme displaced
position thereby effecting the maximum rise of the tape cartridge and correc-
tion tape cartridge portions which span the type element to present the res-
pective ribbon and tape to the print point. The ratchet feed utilized for
- the feeding of the ribbon is constrained so that the ratchet remains in posi-
tion when the driving pawl is withdrawn and then allows the driving pawl to
re-engage the ratchet drive surface to complete the drive for a complete feed
increment upon the complete or full throw of the cam follower and connecting
linkage.
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1 In the Drawings
Fig. 1 illustrates a typewriter having a fixed print mechanism and ribbon
feed and a movable paper carriage.
Fig. 2 is a plan view of a ribbon feed/tape feed mechanism capable of
feeding ribbon and correction tape in cartridges.
Figs. 3, 4, 5, 6 and 7 are partial views of the ribbon/tape feed mechanism.
Fig. 8 is a perspective view of the underside of the ribbon/tape feed
drive and latching arrangement.
Fig. 9 is a perspective view of a second embodiment of tne ribbon/tape
drive.
Fig. 10 is a plan view of the top of the composite cam havin a feed/lift
cam and a correction tape feed cam combined.
Figs. 11 and 12 are cam rise diagrams for the cams illustrated in Fig. 10.
Detailed Description _ the Invention
During the course of this description, two embodiments will be described.
In many respects the parts are either identical or functionally identicali in
which case the same reference numeral will be used. Where there is a signifi-
cant difference in either the construction or the mode of operation separate
reference numerals or numerals printed will be assigned but will be fully
described.
LE9-77-010 -4-
75~3 L)
n~ u iL~u h~ n ~1 ~n~Villg p.ll)CI- ('.ll-l-i.'l~'(` nll(l (I f'ixr~d l-rint ~arri~r.
itl~lnllv r~ tivol~ mi.llor m()diri~ ions, ~u ribbon fied could be adapte(i
) ;( InUVill" plint (nlrri~r. Tlle f rame 1() o~ t-hc t~pewriter i.s configured to
r(~(~e:ive rnoull~ing all(l pivot pin 12 on the end of cartridge hol.der 14.
. (`artrldgo ho.lder 14 is configured to a~commodate cartridge 16 and 18.
7 Cartridge 16 r.eceives and contairls the print ribbon 20 whil,e cartridge 18
8 contains the correction tape. ~he two cartridges 16 and 18 both are
9 configured to provide a supported entrance and exit from the major cartridge
cavities such as to span a length of ribbon 20 and tape 22 respectively
1l above and below each other. The span of ribbon 20 and tape 22 are such
l2 that they are spacially positioned between the printhead 9 of the typewriter
13 and the plat,en 11. Cartridge holder 14 is also configured to provide
14 other mounting surEaces upon which to support the other components of the ribbon drive and ribbon feed mechanism.
:L6 Holder extension 24 is either formed as a portion of the cartridge
17 holder 14 or is attached rigidly thereto as is most convenient for the
18 desired manufacturing technique, and provides a mount for pivot rod 26.
19 Pivotally supported on pivot rod 26 are two independently swingable arms
28 and 30. Arm 28 carries on its end .he ratchet feed mechanism for
21 feeding the ribbon contained within the cartridge 16. The ratchet
22 assembly to provide unidirectional feed ha.s a feed wheel 32 with apertures
2'3 34 formed in the face tllereof for engagement hy a pawl~ member 36. The
24 pawl member 36 is formed by deflecting a sn~all tab on the lever 38. Lever
38 is coaxially mounted by one of its ends on the same axis pin 40 as
26 supports the feed wheel 32.
27 To provide an input movement to ~he lever 38 push-pull link 42 is
28 connected thereto and is connected on ~he opposite end thereof to cam
29 follower 44 which is pivotally mounted on the follower pi.vot 46 for
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1 oscillatory movement. The cam follower 44 is supported on the
frame 10 of the typewriter 8 as is the feed/lift cam 48. The
feed lift cam 48 is rotatably mounted on the frame member 10
to turn in response to the drive forces exerted thereon by
gear pair 50 which includes a gear 53 mounted on the cam shaft
and a gear 51 mounted on the operational shaft 52 of the type-
writer.
A feed wheel and ratchet arrangement for arm 30, Figs. 2
and 3, has substantially identical structure and function as
that carried by arm 28 for the purpose of feeding the correc-
tion tape within the correction tape chamber of the cartridge.
To provide motive force to the tape feed wheel 60 on arm 30,
a feed arm 62 having formed into the end of it a pawl 63 is
mounted upon an axis pin 64 as seen in Fig. 8. To provide an
oscillatory or reciprocal input to the feed arm 62, feed arm
62 is connected to one end of push-pull link 66 which is
attached on its other end to a cam follower 68. In Fig. 9,
cam follower 68 is slidably mounted to shift along an axis
substantially parallel to the operational shaft 52 and to move
with holder 14 as it moves to present different segments of
ribbon and or correction tape to the print point.
In view of the fact that follower 68 is mounted on holder
14 it is moveable about the axis of rotation of the holder 14
and tab 70 of follower 68 is thus capable of being displaced
by the rocking of holder 14 to a region of engagement with
correction tape feed cam 72, 72'. In Fig. 9, the correction
tape feed cam 72 is illustrated as a face cam 72, mounted
coaxially on the operational shaft 52 and rotated thereby.
In the other figures where shown, the correction tape feed
cam 72 which is coaxially mounted and rotates with the feed
lift cam 48 is engaged by tab 70' of cam follower 68 which is
pivotally mounted upon holder 14 to thus be engaged with the
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1 cam profile only when the rear of the cartridges 16, 18 isdepressed sufficiently to rotate the holder 14 about its
axis
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1 to present the correction tape 22 to the print point. Upon
the engagement of correction tape cam follower 68 with the
feed cam 72, 72', the follower 68 will oscillate and provide
oscillatory motion to the feed arm 62 for rotation of the
correction tape feed wheel 60 upon each rotation of the
operational shaft 52 so long as holder 14 is held in the
position corresponding to the correction tape being presented
to the print point. With the correction tape feed cam 72, 72'
engaged by the correction tape feed follower 68, any otherwise
normal printing operation will result in the impacting of the
print-head 9 of the typewriter 8 onto the correction tape 22 and
forcing it against the page at the print point. Inasmuch as
the operational shaft 52 will rotate, as with any other printing
operation, the tab 70, 70' on the correction tape follower 68
engaged by the cam surface of cam 72, 72', is caused to trans-
late or oscillate, effecting the feeding of the correction tape
within the correction tape cartridge 18.
In Fig. 9, a load lever 80 is illustrated as pivotally
supported on the frame 10 at pivot point 82. On one end of
load lever 80, is located an appendage 84. To retract the
ribbon feed wheel 32 and arm 28 together with the tape feed
wheel 60 carried on arm 30 from the interior of the ribbon
and tape cartridges respectively, load lever 80 may be rotated
around its pivot point 82 in a counterclockwise direction thus
engaging projection 86 with appendage 84 on arm 28 and a
corresponding projection on arm 30. Projection 86 and its
counterpart on arm 30 will then be forced in a clockwise
direction around their pivot rod 26 effectively retracting
the ribbon feed wheel 32 and tape feed wheel 60 from the inside
of cartridges 16 and 18. To release arms 28 and 30 for re-entry
into the cartridges inner chambers, the load lever 80 may then
be moved in a clockwise direction relieving the forces against
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1 projection 86 and its counterpart. When relieved, bias spring
88 and 90 will urge arms 28 and 30 respec-tively in a counter-
clockwise direction to present the
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1 feed wheels 32 ~nd 60 to the periphery o~ the ribbon and
correction tape take-up spools.
A comparable action is accomplished by the mechanism
illustrated in Fig. 2, wherein pull links 100 and 102 are
attached by means of axis pins 40 and 64 to the ribbon and tape
feed ratchets 32, 60 and arms 28, 30 respectively. The pull
links 100, 102 are provided with apertures 104 and 106, both
of which are simultaneously engaged by bellcrank arm 108.
Bellcrank arm 108 is rotated about horizontal axis 110 and
controlled by link 112. Link 112 is attached to control lever
114 which may conveniently be positioned to extend outward from
the exterior of the typewriter.
Cartridge holder 14 is controlled during operation by the
typewriter to present the ribbon at two different levels rela-
tive to the print point. The control of the level is accom-
plished through cam follower 92 engaging feed lift cam 48.
Referring to Fig. 10, the configuration of feed lift cam 48 is
illustrated with four lobes, two of a high rise 49 and two of
an intermediate rise 47. The rises on the cam may preferably
be designed such tnat the rise from low dwell 45 to high dwell
of the largest loke 49 is approximately equal to twice the net
rise from low dwell 45 to the high dwell of the smaller inter-
mediate lokes 47. This will cause the holder 14, through cam
follower 92 to be rotated twice as much on the high dwell lobe
49 as for the low dwell lobe 47 thus moving the ribbon twice
as far along its arcuate path. Should it be desired that some
other relationship be maintained so that the ribbon is more
fully recessed during non-printing, the low dwell 45 of the
cam may be reduced even more so. The actual dimensioning of
the rises of the cam is, of course, determined by the dimen-
sional requirements of the particular ribbon feed into which
it is incorporated.
LE9-77-010 -8-
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1 The other significant relationship with respect to the
dwells of the cam 48 is that cam follower 44, Fig. 6, push
pull link 42, lever 38 and
LE9-77-010 -8a-
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1 feed wheel 32 are all dimensioned such that the rise of the
cam 48 from its lowest dwell 45 to the highest rise 49 results
in one complete ribbon feed increment. The relationship
between the lowest dwell 45 and the rise on lobe 47 is not
that critical, since the smaller rise will provide a partial
increment of feed and due to the engagement of the pawl 36
on lever 38 with the apertures 34 in feed wheel 32. As seen
in Fig. 4 the partial increment of feed will be accomplished
during the low rise with the pawl 36 re-engaging the same
aperture 34 on the next successive high rise 49 and not initiat-
ing feed until such time as the rise of the cam 49 has reachedthe equivalent of the preceeding low rise 47. At that point,
the lever 38 will then have been displaced sufficiently far to
engage the pawl 36 with the leading edge of apertures 34 and
again feed the feed wheel 32 the remainder of the feed incre-
ment~
Fig. 11, illustrates a typical cam rise pattern for the
lift feed cam 48. Fig. 12 illustrates the typical cam rise
pattern for the correction tape feed cam 72.
Operation of the Invention
To insert the cartridges 16 and 18 into the ribbon feed
mechanism, the pull lever 114 in Fig. 2, or the load lever 80
in Fig. 9, are pivoted about their respective axis to retract
arm 28 and arm 30. The cartridges 16, 18 are then placed into
the holder 14 in their appropriate position. After the place-
ment of the cartridges 16, 18, the control lever 114 or load
lever 80 are then returned to their disengaged position thus
allowing arms 28 and 30 to enter the apertures formed in the
end of the cartridges 16 and 18 and allow the feed wheel on
each of the arms 28 and 30 to engage the periphery of the
take-up spool or ribbon disc or tape disc~ if ribbon or tape
is already partially wound upon their respective spool~. At
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1 this point the loading sequence is completed and the type-
writer 8 is otherwise ready for operation. As each letter
is typed,
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1 the operational shaft 52 is rotated one complete revolution by
a drive mechanism which cyclically operates this shaft. ~s
the shaft operates, gear pair 50, comprising gear 53 and 51
are respectively rotated about their axis. As gear 51 is
rotated, it turns the superimposed feed/lift cam 48 and correc-
tion tape feed cam 72 in Figs. 7 and 8 or only the feed/lift
- cam 48 is Fig. 9. The ribbon feed cam follower 44 is then
oscillated by the rise and fall of cam 48 and acts through
push/pull link 42 to move lever 38 about the axis pin 40 and
engage pawl 36 with the apertures 34 in feed wheel 32 thus
causing feed wheel 32 to rotate a partial increment as best
can be observed in Figs. 4 and 8. On the next succeeding
character the next cam lobe of feed/lift cam 48 is presented
to the cam follower 44 and the sequence of operation repeated
with only a variance in the amount of arc through which lever
38 is moved. Thus on every other cycle, the feed wheel is
incremented through a completed ribbon feed increment~
To condition the typewriter 8 and particularly the ribbon
feed mechanism to ~he correction mode, the rear of the cart-
ridge 18 is depressed manually to cause the cartridges 16 and18 and holder 14 to rotate about the axis of rotation of
holder 14. The cartridges 16, 18 may be held in this dis-
placed position or may be latched in the displaced position
by a latch 120, 122. As holder 14 is tilted or partially
rotated about its axis, the correction tape feed cam 72' is
engaged by the tab 70' on the follower 68. As the machine
then operates in the next print cycle, the push/pull link 66
is translated along with follower 68 to effect movement of
the feed arm 62 about its axis pin 64 and thereby rotate tape
feed wheel 60 a partial revolution corresponding to a complete
correction tape feed increment. If holder 14 is latched in
its displaced position, thus presenting the correction tape
LE9-77-010 10-
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1 to the print point after the typehead has impacted thecorrection tape against the printed page, the latch may be
L~9-77-010 -lOa-
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;it(~ 1Y ~ V op~ ;lt~ ;Ir)~ r:l7l~ Ir` ty~ wri~(~r ~
` (~ollvellien~lv ~ o(l ne;lrby. A! ;U~ m~ , illustrates a l~tc~l
3 ~lrl~ace 120 depen(ling from holder ]4. ~ngageab]c witll the latch ~surLace
' l20 i~s lat~h member 122 which is spring biased by spring 124 about pivot
126, attached to frame 10. Latch member 122 is provided with cam follower
6 arm 128 which terminates in cam follower surface 130. Surface 130 will
7 pivot clockwise to engage a face cam surface 132 on operational shaft
8 52, when holder 14 is pivoted and moves latch surface 120 forward. The
9 ~ovement of surface 120 permits latch member l22 to pivot behind latch
sllrface 120 and hold it in its displaced position until the use of face
Il cam 132 causes counterclock~ise movement o~ latch member 122, thereby
L2 unlatching surface 120 and holder 14 for restoration. As the latch 120
13 is released, holder 14 will then return to its normal, at rest position,14 prepared to be elevated in the next machine cycle to its position corres-
ponding to a printing position.
16 After the correction tape 22 or the ribbon 20 are exhausted from
17 their respective cartridges 18 and 16, the cartridge of the exhausted
1~ supply i9 removed and replaced w]~l~ a new c:3rtrLdge. '~e removal procedure
1'3 is substantially that described e~rlier witll respect to the installation,
'0 of retracting the arms 28~ 30 carrying the feed wheels 32, 60 while the
21 cartridges 16, 18 are lifted from the holder 14.
22 This ribbon feed mechanism together with its operation provides the23 substantive advantages of being able to use a cartridge which has a fixed
24 axis take-up spool together with a direct peripheral drive for uniform feed
increments.
26 While the invention has been particularly shu~m and described with
27 reference to two embodiments thereof, it will be understood by those
28 skilled in the art that the foregoing and other changes in form and
29 details may be made therein without departing from the spirit and scope
of the invention.
LE9-77-010
