Ribbon lifting apparatus for a printing device having a print wheel and a ribbon cartridge. The lifting apparatus includes a pair of ribbon guides for supporting an exposed portion of a ribbon extending from an outlet opening of the ribbon cartridge to an inlet opening thereof. The pair of ribbon guides are supported by respective pairs of supporting levers which are swung in a plane parallel to the face plane of the print wheel. The pair of ribbon guides are lifted so that the lifting movement of the guides causes variation of a distance therebetween for keeping the path of the exposed length of ribbon substantially constant.

SUMMARY OF THE INVENTION 
This invention relates to a typewriter and more particularly to an 
ink-ribbon lifting apparatus thereof. 
In a printing device having a print wheel of a flat circular shape, an 
exposed portion of ribbon extending from an outlet opening to an inlet 
opening of a ribbon cartridge is moved up and down by a ribbon lifting 
apparatus in an extremely narrow clearance between the print wheel and a 
platen. Conventional lifting apparatuses, therefore, are not suitable for 
this type of printing device. 
The principle object of this invention is to provide an ink-ribbon lifting 
mechanism wherein the ink-ribbon is smoothly moved up and down in the 
extremely narrow clearance between the print wheel and the platen, with 
slackening and wrinkles which may occur due to the movement of the 
ink-ribbon being reduced as much as possible. 
The ribbon lifting apparatus in accordance with this invention comprises a 
drive means, an operating lever connected with the drive means and movable 
to different positions upon movement of the drive means, a pair of 
supporting means pivotally supported on a base plate and operatively 
connected with the operating lever so as to be swung to different 
positions upon different movements of the operating lever, and a pair of 
ribbon guides for supporting the ribbon in a plane parallel to a surface 
of the print wheel and defining a ribbon path of the exposed portion of 
ribbon in cooperation with the outlet opening and the inlet opening so as 
to enable the ribbon to pass between the platen and the print wheel. The 
pair of ribbon guides are each supported by the respective supporting 
means, and movable to different positions upon different pivotal movements 
of the supporting means so that the different transversely spaced, 
longitudinally extending regions of the exposed portion of ribbon are 
positioned in the plane. 
The pair of ribbon guides are preferably supported by the supporting means 
so that the different movements of the ribbon guides cause a variation in 
distance therebetween for keeping the exposed length of the ribbon 
substantially constant.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
With reference to the appended drawing a preferred embodiment will be 
described hereunder. 
A type wheel 1 or a print wheel shown in FIG. 2, is of well known 
structure, whose central portion is secured to a rotary shaft 3 of a pulse 
motor 2, and has a plurality of arms extending radially from the central 
portion. Each of the radial arms carries a type 5 facing a platen 4. 
Within a clearance formed between the print wheel 1 and a printing paper 6 
placed along the surface of the platen 4 an ink-ribbon 7 is moved 
substantially vertically in a range shown in FIG. 2 with a solid line and 
a one-dot-chain line. This ink-ribbon 7 is a carbon type of a large width, 
consisting of three longitudinally extending bands or regions transversely 
spaced across the width of the ink-ribbon 7 as can be seen in FIG. 5, and 
the greater part thereof is accommodated in a ribbon cassette or cartridge 
8 carried on a not-shown carrier together with the pulse motor 2. As 
illustrated in FIG. 4 an exposed length of the ink-ribbon 7 which is 
pulled out of the cartridge 8 from a reel 9 on the supply side by way of a 
constant tension giving member 10 and a pair of ribbon guides 11, 12 on 
both left and right sides, is wound on a reel 13 on the take-up side. The 
reel 13 is given in each printing operation a rotational force for 
advancing the ink-ribbon 7 by a distance corresponding to 1/3 of the width 
of one type or character. The reel 9 on the supply side is kept under the 
influence of a resilient force resisting to a certain extent the pulling 
force exerted from the reel 13. This resilient force cooperates with the 
constant tension giving member 10 for maintaining the tension between both 
reels 9, 13 constant. 
The ink-ribbon 7 with the three longitudinal regions is repeatedly moved up 
and down in cycle by the ribbon guides 11, 12 between the original 
position shown with a solid line in FIG. 2, where a type to be printed on 
the printing paper 6 is above and free from the ink-ribbon 7, and one of 
three lifted positions to bring a corresponding one of the three regions 
into alignment with the type to be printed (only the most-lifted or 
uppermost position is illustrated in FIG. 2 in one-dot chain line). In 
each printing operation with the ribbon advance by a distance equal to 
one-third of the type width, the ink-ribbon 7 is vertically oscillated so 
that the three longitudinal regions are alternately brought into position 
to print selected types, for example, A, B, C, D and E, in that order in 
the different regions as shown in FIG. 5. If a printing operation ceases 
for more than a predetermined time duration, this vertical movements of 
the ribbon 7 are suspended and the ribbon 7 is returned to the original 
position thereof. 
The ribbon lifting apparatus is constructed such that, for the purpose of 
up and down moving of the ink-ribbon 7 of a large width by means of the 
ribbon guides 11, 12 in the narrow clearance between the print wheel 1 and 
the printing paper 6 without touching either of the two, the ink-ribbon 7 
can be swung in a plane parallel to the print wheel 1 such that the length 
as well as the tension of the ink-ribbon 7 pulled out of the ribbon 
cartridge 8 can be maintained substantially constant during the swinging 
movement thereof. 
Both of the ribbon guides 11, 12 are supported by supporting mechanisms of 
the same structure, so only the supporting mechanism for the ribbon guide 
11 is described, leaving that for the ribbon guide 12 undescribed while 
using only reference numerals of the corresponding parts in the brackets. 
A pair of levers 18, 19 (20, 21) are pivoted, in a plane substantially 
parallel to the surface of the print wheel 1, at one end thereof about 
respective support pins 14, 15 (16, 17) on a retaining member 30 designed 
as a base plate carried by a carrier or a carriage. To the other end of 
the levers 18, 19 (20, 21) there are connected respective connecting rods 
22, 23 (24, 25) at one end thereof. The ribbon guide 11 (12) is supported 
by the other end of the connecting rods 22, 23 (24, 25) oscillatingly in a 
plane parallel to the print wheel 1. Each ribbon guide 11, 12 is 
operatively connected to a pulse motor P designed as a drive means through 
engagement of the connecting rod 23, 25 with an engaging rod 26, 27. The 
engaging rod 26, 27 is respectively connected by way of operating levers 
31 to a rotor 28 of the pulse motor P. The pulse motor P consists of the 
rotor 28 of sectorial shape and a stationary member 29 having an inner 
surface facing the sectorial periphery of the rotor 28. The operating 
lever 31 is pivotally supported via shafts 32, 33 by the carriage and 
swung by the pulse motor P causing a vertical oscillating action of the 
engaging rod 26, 27. 
The ribbon guides 11, 12 thus operationally connected to the pulse rotor P 
are oscillated as mentioned above by an amount corresponding to an amount 
of rotation of the pulse motor P such that the ink-ribbon 7 is positioned 
from the original position shown with the solid line in FIG. 2 to one of 
the three lifted positions. The vertical oscillation of the ribbon guides 
11, 12 begins from the position shown in FIG. 3 to go upwards, following 
an arcuate path in said plane causing gradual changing of the distance 
between both ribbon guides 11, 12 in response to the progress of the 
vertical oscillating movement. 
The changing of the distance is to prevent slackening of the exposed 
portion of the ribbon 7 and to maintain a constant tension thereof by 
constantly maintaining the length of the path of the exposed ink-ribbon 7 
while the ribbon guides 11, 12 are moved up and down in the plane parallel 
to the print wheel 1, because the length of the exposed ink-ribbon out of 
the ribbon cartridge 8, viz., the length of the ink-ribbon 7 from an 
outlet opening on the supply side by way of the ribbon guides 11, 12 to an 
inlet opening on the take-up side, is always constant. 
In other words, while the ink-ribbon 7 is lifted from the original position 
to the most-lifted position, the distances from the inlet opening of the 
ribbon cartridge 8 on the take-up side to the ribbon guide 11 and from the 
outlet opening on the supply side to the ribbon guide 12 decrease first 
and begin to increase immediately before the ink-ribbon 7 reaches the 
most-lifted position. The whole length of the path of the exposed portion 
of the ink-ribbon 7 is maintained constant, because the distance between 
both ribbon guides 11, 12 is so changed or varied as to absorb the 
increasing amount or the decreasing amount just mentioned. 
The ribbon lifting apparatus in accordance with this invention is capable, 
despite the unfavorable conditions that the ribbon is of large width and 
the movement thereof is in an extremely narrow clearance between the print 
wheel and the printing paper 6, of moving the ribbon up and down in the 
narrow clearance without touching either of the print wheel 1 or the 
printing paper 6 and also of maintaining the length and the tension of the 
ribbon exposed outside the ribbon cartridge 8 constant, thereby preventing 
slackening and wrinkling from taking place in the ribbon to thereby assure 
exact printing operations.