Ink jet recording apparatus and capping device

A capping device for an ink jet recorder is provided with a support frame of substantially L-shaped cross-section contained in a frame and supporting an ink absorbing member inside thereof, and a throttle plate in contact with the underside of the absorbing member and disposed substantially parallel to the support frame, the capping device being so disposed that the rear end edge of the throttle plate opposite to a recording head is situated vertically below the side edge surface of the recording head. The specification also discloses an ink jet recording apparatus having such capping device. (FIGS. 1 and 6-8). A flow path for directing liquid squeezed from the absorbing member has upper and lower stages, the upper stage having a sufficiently large diameter that a liquid meniscus does not form and the lower stage having a small diameter that permits a meniscus to form. (FIGS. 9 and 10).

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to an ink jet recording apparatus and a capping 
device, and more particularly to an ink jet recording apparatus in which a 
capping device is urged against the nozzle portion of an ink jet printer 
to accomplish the ink non-discharge recovery operation and to a capping 
device in such apparatus. 
2. Related Background Art 
In an ink jet printer flying liquid droplets are discharged from an orifice 
at the end of a nozzle toward recording paper by various means to thereby 
accomplish dot recording. 
In the ink jet printer of this type, the use of liquid ink causes 
occurrence of a non-discharge phenomenon such as the non-discharge of ink 
resulting from the clogging by desiccation of the ink, the clogging by 
adherence of dust, or the production of bubbles attributable to remaining 
gas. 
So, as at the beginning of recording, ink is forcibly discharged to release 
the non-discharge state. 
During such non-discharge recovery operation, ink is not discharged toward 
recording paper, but ink is discharged with the nozzle portion being 
covered with a cap. 
There are various structures of this cap, and the structure adopted most 
often is one in which an ink absorbing member comprising, for example, a 
sponge material, is provided in the cap and ink is discharged toward and 
absorbed by the absorbing member. 
In the cap of such a structure, if the ink absorbed by the absorbing member 
is not discharged by some means, the absorbing member will contain therein 
more ink than it can absorb and will thus become useless for the 
non-discharge recovery operation. 
As a method of removing ink from the ink absorbing member in such a state, 
a system for squeezing out ink by the provision of a throttle mechanism 
has been widely adopted. 
As such a throttle mechanism, there would come to mind a mechanism of a 
structure in which an ink absorbing member is contained in a frame member 
of substantially L-shaped cross-section and a throttle plate is disposed 
below the absorbing member to squeeze out ink. 
However, in the mechanism of the above-described structure, all of the 
absorbing member, the frame member supporting it and the throttle plate 
are disposed horizontally, and this has sometimes led to a problem that 
when the absorbing member is throttled by the throttle plate, ink is 
forced out forwardly of the absorbing member as well and by so throttling, 
the head side is stained by ink. 
The phenomenon that ink is forced out forwardly of the ink absorbing member 
occurs in the forward lower corner of the absorbing member and therefore, 
ink is liable to stain especially the head side. 
As another example of such a throttle mechanism, a structure is also 
conceivable in which, for example, two upper and lower throttle plates are 
provided and an ink absorbing member is sandwiched between the two 
throttle plates so that the absorbing member is pressed from above and 
below to thereby squeeze out the absorbed ink. 
However, the adoption of such a throttle mechanism has sometimes led to the 
following problem. 
That is, the ink jet printer has been made compact and the nozzle itself 
has also been made compact and therefore, the cap has also unavoidably 
been made compact correspondingly thereto, and to make the throttle 
mechanism function effectively in the compact cap, it must be contained in 
a narrow space and in such a case, squeezed ink will make a bridge between 
it and the wall surface of the case of the cap or will remain in the cap. 
If ink remains in the cap, the ink adheres to and stains recording paper or 
the like or the ink adheres to the nozzle side, and in some cases this has 
led to an inconvenience that proper discharge of ink cannot be 
accomplished. 
Also, in a structure wherein two upper and lower throttle plates are 
brouhgt close to each other to squeeze out ink, the squeezing operation is 
effected substantially in the central portion of the narrow space in the 
cap, and the throttle plates are near the upper and lower side walls of 
the cap and therefore, a bridge is created inevitably. 
Further, sponge-like formed synthetic resin is widely used for the ink 
absorbing member employed in such a throttle mechanism. 
However, such an ink absorbing member has the property of swelling by 
absorbing ink. 
On the other hand, the dimensional accuracy between the ink absorbing 
member and the head is required to be considerably high in order to 
positively absorb ink. 
Accordingly, unless the absorbing member is mounted with its rate of 
swelling being accurately taken into account, the dimension thereof will 
become wrong. 
Heretofore, however, the absorbing member has been held by being adhesively 
secured to the support frame side or by a complicated structure, and this 
has sometimes led to a problem that when the absrobing member swells, the 
dimensional accuracy thereof is not obtained and accurate and positive ink 
absorption cannot take place. 
Also, there are cases where the absorbing member must be replaced with a 
new one after it has been used for a predetermined period of time, and in 
preparation for such cases, the absorbing member must be of a readily 
replaceable structure and must be held on the support frame side, but the 
absorbing member of the conventional structure has been very cumbersome to 
mount and dismount. 
The considerably complicated flow path of an ink jet printer or the like 
for supplying ink is often constituted by a tube. 
Through such a flow path, supply of ink is effected by the driving of a 
pump or a valve. 
However, in the flow path system, there is a flow path in which flow of ink 
takes place, without pressurization, in addition to the flow path in which 
flow of ink is effected by the pressure of a pump or the like. 
An example of it such as a drain tube which directs into a drain tank the 
waste ink such as the ink squeezed out from said absorbing member. 
Such a drain tube can be a thin tube simply connecting the ink collecting 
unit to the drain tank and adapted so that ink flows therethrough from 
gravity. 
Such a drain tube is widely used not only in ink jet printers but also in 
various apparatuses handling fluid. 
The use of a thin tube as such a drain tube is for the purpose of 
facilitating piping and preventing desiccation of ink or other liquid in 
the flow path system. 
The flow path structure in which flow of liquid is effected by the use of 
the thin tube as described above and in accordance with the law of gravity 
suffers from the following problem. 
Where, the diameter of the tube constituting the flows path is small, the 
influence of surface tension is great, and where liquid such as ink is not 
flowing continuously in a great deal, for example, where liquid flow 
intermittently in the form of liquid droplets (individually independent 
small volumes of liquid, i.e., small amounts of liquid), meniscus by 
surface tension is produced on the upper and lower end surfaces of the 
small amounts of liquid in the tube and these small amounts of liquid stop 
in the intermediate portion of the tube. 
When such a phenomenon occurs at a plurality of locations in the tube, the 
tube becomes closed up by these small amounts of liquid to block the 
passage of the succeeding liquid, and this has sometimes led to occurrence 
of overflow or the like. 
One means for eliminating such an inconvenience is to increase the diameter 
of the tube, whereas an increased diameter of the tube not only makes 
piping difficult, but also increases the amount of flow of air, which has 
sometimes led to desiccation of the liquid. 
SUMMARY OF THE INVENTION 
The present invention has been made in view of the above-noted problems and 
an object thereof is to provide a capping device and an ink jet recording 
apparatus in which ink absorbed by an absorbing member can be positively 
squeezed. 
Another object of the present invention is to provide a capping deivce and 
an ink jet recording apparatus in which a head and/or recording paper is 
not stained by ink absorbed by an absorbing member. 
Still another object of the present invention is to provide a capping 
device and an ink jet recording apparatus in which an absorbing member 
before swelling can be accurately mounted with the rate of swelling of the 
absorbing member taken into account and the dimensional accuracy when the 
absorbing member has become swollen can be maintained accurately. 
Yet still another object of the present invention is to provide an ink jet 
recording apparatus having a flow path structure which can prevent flow of 
air by liquid remaining in a flow path and thereby prevent desiccation of 
liquid which, when a great amount of liquid has been directed to the flow 
path side, the liquid remaining in the flow path can be expelled by the 
head pressure thereof to thereby effect flow of liquid. 
A further object of the present invention is to provide a capping device 
provided with a support frame of substantially L-shaped cross-section 
contained in a frame and supporting an ink absorbing member inside 
thereof, and a throttle plate in contact with the underside of said 
absorbing member and disposed substantially parallel to said support 
frame, said capping device being so disposed that the rear end edge of 
said throttle plate opposite to a recording head is situated vertically 
below the side edge surface of the recording head. 
Still a further object of the present invention is to provide a capping 
device having a support frame of substantially L-shaped cross-section 
contained in a frame, an upwardly and downwardly movable throttle plate 
provided under and inside said support frame, and an ink absorbing member 
disposed between said support frame and said throttle plate, characterized 
in that a ridge is provided on the underside of the upper plate of said 
support frame over the full length of said support frame, said ridge being 
adapted to stick in the upper side of said absorbing member when said 
absorbing member swells. 
Yet still a further object of the present invention is to provide a capping 
device characterized by the provision of a support frame of substantially 
L-shaped cross-section contained in a frame and supporting an ink 
absorbing member inside thereof, a throttle plate disposed in contact with 
the underside of said ink absorbing member, a bent arm member having one 
end pivotally supported on said throttle plate and the other end pivotally 
supported on one end of the arm of a shaft disposed parallel to said 
support frame, an arm member having one end fixed to said support frame 
and the other end pivotally supported coaxially with the arm member which 
is adjacent to said throttle plate, a stopper provided at a position which 
is in contact with the bent portion of the arm member which is adjacent to 
said throttle plate, and drive means for rotating said shaft in forward 
and reverse directions. 
Another object of the present invention is to provide an ink jet recording 
apparatus comprising a head element for discharging ink and effecting 
recording, a recording flow path communicating said head element with one 
end of a first ink tank, a pump side flow path communicating said first 
ink tank with said head element through a pump and constituting an ink 
circulation path with said recording flow path through said head element 
and said first ink tank, a second ink tank for supplying ink to said first 
ink tank, and a capping device provided for movement to a position in 
which it covers the front face of said head element and a position 
separate from said head element and having therein an ink absorbing member 
urged against said head element, said capping device being provided with a 
support frame of substantially L-shaped cross-section supporting said 
absorbing member inside thereof, and a throttle plate in contact with the 
underside of said absorbing member and disposed substantially parallel to 
said support frame, said capping device being so disposed that the rear 
end edge of said throttle plate opposite to a recording head is situated 
vertically below the side edge surface of the recording head. 
Still another object of the present invention is to provide a flow path 
structure characterized in that a flow path for directing liquid from 
above to below is divided into at least two upper and lower stages, said 
upper stage being of such a degree of large diameter that meniscus of 
liquid droplets does not occur, and said lower stage being of such a 
degree of small diameter that permits occurrence of meniscus of liquid 
droplets.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The present invention will hereinafter be described in detail with respect 
to an embodiment thereof shown in the drawings. 
FIG. 1 and so on illustrate an embodiment of the present invention, and the 
whole of a color ink jet printer to which the present invention is applied 
is shown in the schematic perspective views of FIG. 2 and 3. 
The embodiment illustrated adopts the bubble jet system and is shown as an 
on-demand type printer. 
Designated by 20 in FIGS. 2 and 3 is an upper unit in which a head unit is 
contained as will be described later. 
Below the upper unit 20, there is a lower unit in which a power source 
portion is contained. 
Outside the lower unit 21, a removable drain tank 22 is mounted in such a 
manner as to be visible from outside. 
On this side of the upper unit 20, a paper supply unit 24 is openably and 
closably mounted by means of a hinge 23. 
A flap 25 is removably mounted on the upper portion of the front side of 
the paper supply unit 24. 
This flap 25 is a lid covering a paper discharge port and is removed by the 
operator during the actual printing. 
An operating panel 25 is provided adjacent to the flap 25. 
Designated by 27 is a pocket in which a manual or the like is contained. 
In the lower portion of the fornt side of the paper supply unit 24, there 
is formed an opening 28 through which the amount of remaining recording 
paper may be examined. 
In the lower portion of the paper supply unit 24, there is provided a 
stacker formed by bending a steel wire or the like. 
Base units 30 are attached to the lower end of the lower unit 21. 
A paper supply mechanism 31 is provided inside the paper supply unit 24, 
and below it, there is provided a recording paper containing space. 
Also, the upper unit 20 provides a member for containing the head unit 
therein, and a bubble jet assembly (hereinafter referred to as BJA) 33 is 
removably mounted on the upper portion thereof. 
On this side of the BJA 33, a cap 34 is mounted for upward and downward 
movement. 
That is, the BJA 33 is assembled with a FIG. 4 
That is, the BJA 33 is assembled with a firm frame 34 as a standard and is 
removably mounted in the upper space of the upper unit 20. 
Four bubble jet units (hereinafter referred to as BJUs) 35-38 are removably 
mounted on the front face of the frame 34. 
In the case of the present embodiment, these BJUs 35-38 are arranged in the 
order of black, cyan, magenta and yellow from the top. 
Each of the BJUs 35-38 has a plurality of head elements 1, each of which 
has a number of, say, 128 nozzles (not shown). 
The head elements 1 are arranged in a staggered fashion in two stages in 
each BJU 35-38, while the nozzles are arranged so as not to vertically 
overlap one another. 
Below the BJUs 35-38, second ink tanks 12 filled with inks corresponding to 
the respective colors are removably mounted. 
These second ink tanks 12 are connected to first ink tanks 7 provided on 
the back side of the BJA 33, although not shown in FIG. 4. 
Such connection is automatically accomplished simply by mounting the second 
ink tanks 12. 
A fan 39 for supplying cooling air is mounted on each of the opposite ends 
of the frame 34 of the BJA 33. 
The BJA 33 of such a structure may be removably mounted in the upper unit 
20 by grasping the right and left handles 34a of the frame 34 and, when 
thus mounted, the BJA 33 is automatically connected to the terminal of the 
power source of the upper unit 20 side through connectors 40 provided on 
the rear end of the frame 34. 
Designated by 41 are knobs for locking and unlocking the connectors 40. 
On the other hand, denoted by 42 in FIG. 4 is a cap cover which is mounted 
to cover the BJUs 35-38. 
It is when the BJA 33 is to be mounted or dismounted that this cap cover 42 
is mounted. 
That is, the cap cover 42 is mounted by all means when the BJA 33 is 
handled, because the diameter of the nozzles formed in the head elements 1 
is so small that the nozzles may be closed if they are simply touched by 
the finger tips. 
Now, the upwardly and downwardly movable cap 34 is constructed as shown in 
FIGS. 5 and 6. 
That is, the cap 34 is assembled with a firm frame 43 as a standard and is 
provided for upward and downward movement by a driving device, not shown, 
and is movable to a position in which it covers the BJA 33 and a position 
in which it is completely downwardly separate from the BJA 33 as shown in 
FIG. 3. 
Ink absorbing members 44-47 covering the respective head elements 1 of the 
BJUs 35-38 are contained in the cap 34. 
The ink absorbing members 44-47 are contained in support frames 50 fixed to 
arms 49 pivotally supported on the frame 43 by means of a shaft 48, and a 
throttle plate 51 is disposed below each ink absorbing member 44-47 and is 
pivotally supported on the end of another arm 52 by means of a pin 52a. 
That is, the arms 49 and 52 are pivotally supported on the end of an arm 53 
extending downwardly from the shaft 48, by means of a shaft 54. 
The arms 49 and 52 are pivotally provided along the lengthwise direction of 
the support frame 50. 
A stopper 55 is provided on the frame 43 side at a position opposed to the 
bent portion of the arm 52 supporting the throttle plate 51. 
On the other hand, as is apparent from the drawings, the cross-section of 
the absorbing members 44-47 is substantially lozenge-shaped and the front 
and rear surfaces thereof are parallel to the front side of the head 
elements 1. 
The absorbing members are inclined so that the upper and lower surfaces 
thereof become lower away from the head side, and the upper and lower 
surfaces are parallel to each other. 
Chamfered portions 44a-47a are formed at a lower corner of the front face 
of the respective absorbing members 44-47. 
Accordingly, the lower corner of the front face of each absorbing member is 
away from the head side. 
Also, the upper surface of each support frame 50 and each throttle plate 51 
are parallel to the upper and lower surfaces of the absorbing member and 
become lower away from the head side. 
A gap 50c is formed between the rear end of each throttle plate 51 and the 
lower end of the side wall of each support frame 50. 
On the other hand, a ridge 50b is provided downwardly projectedly on the 
lower surface of the upper plate 50a of each support frame 50. 
This ridge 50b, in the case of the shown example, is of a structure in 
which a metal plate or the like of substantially L-shaped cross-section is 
fixed as by spot welding. Of course, the ridge 50b may be formed 
integrally with the upper plate 50a. 
The ridge 50b is provided on the lower surface of the upper plate 50a over 
the full length thereof. 
The mounting of the ink absorbing members 44-47 in the case where such 
ridges 50b are provided is done in the manner as shown in FIGS. 8A and 8B. 
That is, absorbing members 44-47 not containing moisture such as ink and 
relatively hard and not swollen are first prepared. 
At this time, the size of the absorbing members is determined with the 
pre-known rate of swelling thereof being taken into account. 
Accordingly, with the absorbing member being first fitted between the 
support frame 50 and the throttle plate 51, the upper end of the absorbing 
member is retracted inwardly from the end edge of the upper plate 50a as 
shown in FIG. 8A and the ridge 50b is slightly in contact with the upper 
surface of the absorbing member. 
If ink swells in this state, the absorbing member 44-47 becomes swollen as 
shown in FIG. 8B and the ridge 50b sticks in the absorbing member 44-47. 
In such swollen state, the front face of the absorbing member can protrude 
from the end edge of the upper plate 50a of the support frame 50 so as to 
be able to contact the head side. 
The then amount of protrusion is accurately dimension-controlled because 
the rate of swelling is known. 
In its swollen state, the absorbing member is only restrained by the ridge 
50b and the throttling work and the ink absorbing work can be freely 
carried out. 
Also, removal of the absorbing members during the replacement thereof is 
very easy. 
Now, the ink absorbing members 44-47, the support frames 50, the throttle 
plates 51, and the arms 49, 52 are contained in elongated spaces 
partitioned by parallel partition plates 56 provided across and inclined 
with respect to the frame 43. 
The partition plates 56 are disposed so that the absorbing member side (the 
head side) thereof is high and the opposite side thereof is low. 
A motor 57 which provides a drive source for the throttle mechanism is 
disposed in the lower portion of the frame 43. 
On the other hand, a cover 58 is fixed to this side of the frame 43, i.e., 
that side of the frame 43 which is opposite to the ink absorbing members 
44-47. 
This cover 58 is formed into the shape of a shallow disk, and a space 59 
which provides an ink path is formed between the cover 58 and the side 
surface of the frame 43. 
The space 59 is in communication with the spaces between the partition 
plates 56 in which the absorbing members and the throttle mechanism are 
contained, through openings 60. 
An inverted trapezoidal protrusion 61 is projectedly provided centrally of 
the lower portion of the frame 43. 
This protrusion 61 is formed into a hollow and is in communication with 
said space 59. 
The protrusion 61 is connected to a tube 63 through a joint 62, and the 
tube 63 in turn is connected to said drain tank 22. 
Accordingly, the throttled ink is directed from the inclined partition 
plates 56 into the space 59 through the openings 60 and further into the 
space of the protrusion 61 which is situated at the lowermost end, and 
then into the drain tank 22 through the tube 63. 
Now, as shown in FIG. 7, a lever 64 is disposed vertically on that side 
edge of the frame 43 on which the motor 57 is mounted. 
The lower end of this lever 64 is pivotally supported on the upper end of a 
pivotable lever 65 which is fixed to the output shaft side of the motor 
57, by means of a pin 66. 
One end of arms 68 is pivotally supported on the vertically disposed lever 
64 by means of pins 67 at the same pitch as the arrangement pitch of the 
absorbing members 44-47, and the other ends of the arms 68 are fixed to 
said shaft 48. 
Also, projected pieces 69 are provided on that side edge of the lever 64 
which is opposite to the arms 68, and bent portions of substantially 
L-shaped levers 71 are pivotally supported on these projected pieces 69 by 
means of pins 70. 
One end of each of these levers 71 is in contact with the lower side of 
said pin 67, and a spring 73 is extended between the other end of each of 
the levers 71 and a projected piece 72 provided below and on the opposite 
side of each projected piece 69. 
Accordingly, the levers 71 are biased for counterclockwise rotation as 
viewed in FIG. 7 and the lever 64 is normally biased upwardly. 
Designated by 74 in FIG. 5 is a cap cover used during the preservation or 
the like. 
Operation of the present embodiment constructed as described above will now 
be described. 
During the use of the printer, the paper supply unit 24 is closed and the 
cap 34 is moved downwardly. 
Accordingly, the BJA 33 is in facing relationship with recording paper. 
In this state, the head elements 1 are operated in accordance with a 
recording instruction and color recording is effected by the use of inks 
of respective colors. 
On the other hand, when the nozzles become clogged, the ink non-discharge 
recovery operation is performed, and at this time, the operator operates a 
button or the like for non-discharge recovery operation provided on the 
panel 26. 
At this time, the cap 34 is moved upwardly and covers the front face of the 
BJA 33. 
At this time, the respective ink absorbing members 44-47 are opposed to the 
head elements 1, as shown in FIG. 6. 
FIG. 6 shows the four ink absorbing members 44-47 in the operation sequence 
in accordance with the lapse of time from above, and is shown as a 
cross-sectional view for illustrating the operation. 
Before the non-discharge recovery operation is started, the motor 57 is 
stopped and the pivotable lever 65 is in its substantially vertical 
position, and the levers 71 are rotated counter-clockwise by the force of 
the springs 73 and the lever 64 is in its upper limit position by means of 
the pins 67. 
As a result, the arms 68 are in their clockwise rotational limit position 
and the shafts 48 are also in their clockwise rotational limit position, 
and the arm 53 is also in its clockwise rotational limit position, as 
shown in the first stage of FIG. 6 
At this time, the ink absorbing member 44 is not in contact with the head 
elements 1. 
When the motor 57 is operated in this state, the pivotable lever 65 begins 
to be pivotally moved and as a result, the lever 64 is pulled downwardly. 
Accordingly, the arms 68 begin to be rotated counter-clockwise and the 
shafts 48 and arms 53 also begin to be rotated in the same direction. 
As a result, the ink absorbing members move counter-clockwise while 
depicting an arcuate locus with the support frames 50 and the throttle 
plate 51, and the absorbing member designated by 45 in FIG. 6 comes into 
contact with the head elements 1. 
In this state, discharge of ink is effected and the discharged ink is 
absorbed into the absorbing member 45. 
During the above-described operation, the arms 52 adjacent to the throttle 
plates 51 flex the springs of the stoppers 55. 
When the lever 64 is further moved downwardly, the shafts 48 and arms 53 
are further rotated clockwise. 
At this time, the bent portion of the arm 52 is in contact with the stopper 
55 as indicated in the portion of the absorbing member designated by 46 in 
FIG. 6 and therefore, the arm 52 is forcibly rotated clockwise with this 
portion of contact as the fulcrum. 
As a result, the arm 49 is pushed up and the support frame 50 rotates 
clockwise while depicting an arcuate locus with the absorbing member 46 
and is thus moved upwardly. 
Then the absorbing member 46 separates from the head elements 1 while, at 
the same time, the throttle plate 51 is moved up and the absorbed ink is 
squeezed. 
The squeezed ink falls from the gap 50c between the throttle plate 51 and 
the support frame 50 onto the partition plate 56 and is directed along the 
inclined surface toward the space 59, and collects on the protrusion 61 
and is directed into the drain tank 22 through tube 63. 
This squeezing operation is effected in the upper portion of the narrow 
space between the partition plates 56 and 56 and therefore, the squeezed 
ink does not make a bridge between the partition plates 56 which form the 
bottom plates, but the squeezed ink falls positively and is directed 
toward the drain tank and thus, adherence or remaining of the ink does not 
occur. 
Now, during the above-described squeezing operation, the ink oozes in the 
lower corner of the front face of each absorbing member, but if a 
chamfered portion is formed in this portion, the ink will not adhere to 
and stain the head even if it oozes. 
The oozing ink falls onto the partition plates 56 from gravity. 
When the squeezing operation is terminated in this manner, the motor 57 
revolves in the reverse direction and the lever 64 is moved upwardly. 
Therefore, the arms 68 are rotated clockwise and the shafts 48 and arms 53 
are also rotated clockwise and thus, the arms 49 and 52 restore their 
original positions and, as shown in the lowermost stage of FIG. 6, the ink 
absorbing member restores its original position. 
In this manner, one cycle of squeezing operation is effected and the entire 
cap 34 is moved downwardly and separates from the BJA 33, thus assuming 
its standby position. 
The ink absorbed into the absorbing member in this manner is positively 
throttled and does not adhere to the cap and thus, does not stain the head 
nor remain on the head side to stain the recording paper. 
In the above-described embodiment, a number of ink absorbing members and 
throttling mechanisms corresponding to the number of colors of inks are 
provided because the apparatus is a color printer, but only a set of ink 
absorbing member and throttling mechanism may be provided where the ink 
may be of one color. 
Also, the ridge provided on the underside of the upper plate 50a of each 
support frame has been shown as being projected vertically downwardly, 
whereas the direction of projection may be any direction in which the 
absorbing member can be hooked, and the ridge need not always be provided 
on a streight line, but may be bent. 
Also, depending on the material of the absorbing members, the ridge may be 
provided on the throttle plate 51 side. 
As is apparent from the foregoing description, according to the present 
invention, a structure is adopted in which the ink absorbing members are 
substantially lozenge-shaped and the front and rear surfaces of the 
absorbing members are parallel to the head side and the upper and lower 
surfaces of the absorbing members are parallel to each other and become 
lower away from the head side and the upper surface of the support frames 
and the throttle plates are along the upper and lower surfaces of the 
absorbing members and a gap is provided between the rear end of each 
throttle plate and the lower end of the side wall of each support frame 
and therefore, the absorbed ink falls naturally from the gap between each 
throttle plate and each support frame and even during the squeezing 
operation, the ink is throttled out of this gap and the amount of ink 
forced out toward the head is small. 
Also, a chamfered portion is formed at the lower corner of the front face 
of each absorbing member and therefore, even if ink is forced out into the 
lower corner of the front face during squeezing, ink will not adhere to 
and stain the head because said lower corner is far away from the head 
side. 
Further, according to the present invention, a structure is adopted in 
which a ridge is provided on the underside of the upper plate of each 
support frame and the swollen state of the ink absorbing members is 
maintained by this ridge and therefore, the absorbing members before they 
are swollen can be accurately mounted with the rate of swelling of the 
absorbing members taken into account, and the dimensional accuracy when 
the absorbing members become swollen can also be accurately maintained. 
Also, even when the absorbing members become swollen, the ridges only stick 
in the absorbing members and cannot restrain the absorbing members and 
therefore, the squeezing operation and the absorbing operation can be 
effected freely and the removal of the absorbing members is also easy and 
even the swollen state, the dimensional accuracy can be maintained very 
high. 
In addition, according to the present invention, a structure is adopted in 
which arms supporting the support frames of the ink absorbing members and 
arms supporting the throttle plates disposed below the absorbing members 
are pivotally supported on the shafts rotated by the lever moved up and 
down by the motor, through projected arms, and the arms supporting the 
throttle plates have the pivotal movement of their bent portions 
controlled by a stopper and therefore, by the pivotal movement of the 
absorbing members which accompanies the pivotal movement of each arm, the 
absorbing operation by the contact of the absorbing members with the head 
and the squeezing operation in the portion separate from the head and 
above the space of the cap can be effected as a series of operations. 
Accordingly, during the squeezing operation, the distance between the 
absorbing members and the bottom of the cap is maximum and therefore, no 
bridge of ink is formed and the squeezed ink is reliably collected into 
the drain tank and thus, does not stain the head side and accordingly the 
recording paper. 
The flow path structure of the present invention will now be described with 
reference to the schematic illustrations of the flow path structures of 
the present invention shown in FIGS. 9 and 10. 
Referring to FIG. 9 which illustrates a preferred embodiment of the flow 
path structure of the present invention, reference numeral 91 designates a 
storage tank in which liquid such as ink is temporarily stored. One end of 
a tube 93 of large diameter is connected to the lowermost portion of the 
storage tank 91 through a joint 92. 
The other end of the tube 93 of large diameter is connected to the upper 
end of a tube 96 of small diameter through an intermediate joint 95 fixed 
to the partition plate 94 of the apparatus. 
The lower end of the tube 96 of small diameter is connected to a drain tank 
97. 
If the structure as described above is adopted, the flow path is divided 
into two upper and lower stages, and the upper stage is provided by the 
tube of large diameter and the lower stage is provided by the tube of 
small diameter and therefore, the following phenomenon occurs. 
That is, if the diameter of the tube 93 of large diameter is selected to 
such a degree of diameter that meniscus of liquid droplets does not occur, 
for example, a diameter of 8 mm or more, no meniscus will occur in the 
droplets which pass through this portion, and a small amount of liquid 
which will close the path will not remain but will flow toward the tube 96 
small diameter. 
On the other hand, meniscus of liquid will occur in the tube 96 of small 
diameter and a small amount of liquid will remain therein. 
By such remaining of the liquid, the flow of air between the storage tank 
91 and the drain tank 97 has been blocked and thus, desiccation of the 
liquid in the flow path has not occurred. 
On the other hand, when the amount of liquid flowing to the tube 93 large 
diameter becomes great, the head pressure thereof is applied to the small 
amount of liquid remaining in the tube 96 of small diameter and thus, the 
small amount of liquid can no longer remain and has been collected into 
the drain tank 97 with the great amount of liquid. 
If the structure as described above is adopted, occurrence of overflow can 
be prevented simply by providing the tube 93 of large diameter over a 
slight length and desiccation of the liquid can be prevented by the liquid 
droplets remaining in the tube 96 of small diameter. 
Also, the tube 93 of large diameter may be provided only over a slight 
distance and therefore, piping is not difficult and does not occupy so 
large a space. 
In FIG. 10 which illustrates another embodiment of the flow path structure 
of the present invention, portions identical to those in FIG. 9 are given 
identical reference numerals and need not be described. 
In the present embodiment, the tube 93 of large diameter and the tube 96 of 
small diameter are not connected together through the intermediate joint 
95, but they are formed integrally with each other. 
Adoption of such a structure has resulted in obtainment of an effect 
similar to that of the above-described embodiment. 
In the above-described embodiments, the tube constituting the flow path is 
divided into two upper and lower stages, and the upper stage is provided 
by a tube of large diameter and the lower stage is provided by a tube of 
small diameter, but alternatively, tubes of large diameter and small 
diameter, respectively, may be provided in a plurality of stages from 
above. 
Further, in the above-described embodiments, the flow path has been shown 
as being provided by tubes, but of course, the flow path may be formed 
integrally with the wall surface or the like. 
As is apparent from the foregoing description, the flow path structure of 
the present invention adopts a structure in which the flow path for 
directing liquid by the utilization of gravity is divided into at least 
two upper and lower stages and the upper stage is of such a degree of 
large diameter that meniscus of liquid droplets does not occur and the 
lower stage is of such a degree of small diameter that permits occurrence 
of meniscus of liquid droplets and therefore, by the liquid droplets 
remaining in the flow path of small diameter, flow of air can be prevented 
to thereby prevent desiccation of liquid, and when a great amount of 
liquid is directed to the flow path of large diameter, the liquid droplets 
remaining in the flow path of small diameter can be expelled by the head 
pressure thereof to thereby effect flow of liquid. 
Also, the flow path has a portion of large diameter only in a portion 
thereof and therefore, piping is very easy.