Patent Publication Number: US-11034154-B2

Title: Waste ink conveying device and image forming apparatus

Description:
INCORPORATION BY REFERENCE 
     This application is based on and claims the benefit of priority from Japanese Patent application No. 2018-110977 filed on Jun. 11, 2018, and Japanese Patent application No. 2019-091551 filed on May 14, 2019, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     The present disclosure relates to a waste ink conveying device conveying a waste ink and an image forming apparatus including this waste ink conveying device. 
     Conventionally, an ink-jet type image forming apparatus ejects an ink to a recording medium, such as a sheet, by a recording head to form an image. The image forming apparatus collects a waste ink caused in the recording head to a waste ink tray, and then, conveys and contains the waste ink into a waste ink tank. 
     For example, a waste ink treating device of an ink-jet printer is configured so that, in a case where a waste ink bottle (a waste ink tank) is pushed into a waste ink bottle case from a rear part side thereof, a rear part of the waste ink bottle is lifted upper than a front part thereof. Moreover, lifting movement of the rear part is utilized for switching a cap provided an upper part at the rear part side of the waste ink bottle from a closing state to an opening state, and a waste ink ejected from an ink ejecting means is ejected from an upper side to a lower side in the waste ink bottle. 
     In an ink-jet type image forming apparatus containing a waste ink in a waste ink tank, it is feared that the waste ink is scattered and contaminates the surroundings when the waste ink tank is replaced. The above-mentioned waste ink treating device restrains scattering of the waste ink by switching the cap to the closing state when the waste ink tank is removed. However, in such a configuration, when use of the waste ink tank is repeated, it is feared that the cap is broken. If the cap is broken and cannot be switched to the closing state, the waste ink is leaked and contaminates the surroundings when the waste ink tank is taken out. Alternatively, if the cap is broken and cannot be switched to the opening state, the waste ink tank cannot be installed into a regular position. Or, even if the waste ink can be installed into the regular position, it is feared that ejecting of the waste ink to the waste ink tank is prevented by the cap of the closing state and ink clogging occurs to cause a malfunction and waste ink leakage. 
     SUMMARY 
     In accordance with the present disclosure, a waste ink conveying device includes a waste ink tank installed in a tank installed part to contain a waste ink, and a tank cover opening/closing the tank installed part. The waste ink tank includes an inflow port in which the waste ink is flowed from a side of the tank cover. The tank cover includes a nozzle, a nozzle operation part and a cover locking part. The nozzle is inserted in the inflow port to flow the waste ink in the waste ink tank. The nozzle operation part switches projecting and retracting of the nozzle in order to insert and retract the nozzle with respect to the inflow port. The cover locking part switches locking and unlocking of a closing state of the tank cover. In a case where the cover locking part is in a locking state and the nozzle is in a retracting state, the cover locking part is made capable of switching to an unlocking state. On the other hand, in a case where the cover locking part is in the locking state and the nozzle is in a projecting state, the cover locking part is made incapable of switching to the unlocking state. 
     Moreover, in accordance with the present disclosure, a waste ink conveying device includes a waste ink tank installed in a tank installed part to contain a waste ink, and a tank cover opening/closing the tank installed part. The waste ink tank includes an inflow port in which the waste ink is flowed from a side of the tank cover. The tank cover includes a nozzle, a nozzle operation part and a cover locking part. The nozzle is inserted in the inflow port to flow the waste ink in the waste ink tank. The nozzle operation part switches projecting and retracting of the nozzle in order to insert and retract the nozzle with respect to the inflow port. The cover locking part switches locking and unlocking of a closing state of the tank cover. In a case where the cover locking part is in a unlocking state and the nozzle is in a retracting state, the nozzle is made incapable of switching to a projecting state. 
     In accordance with the present disclosure, an image forming apparatus includes any one of the above-described waste ink conveying device. 
     The above and other objects, features, and advantages of the present disclosure will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present disclosure is shown by way of illustrative example. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a printer according to a first embodiment of the present disclosure. 
         FIG. 2  is a sectional view schematically showing the printer according to the first embodiment of the present disclosure. 
         FIG. 3  is a sectional view showing the inside of a left lower part of the printer according to the first embodiment of the present disclosure. 
         FIG. 4  is a front view showing the left lower part of the printer, in a condition that a tank cover is closed, according to the first embodiment of the present disclosure. 
         FIG. 5  is a front view showing the left lower part of the printer, in a condition that the tank cover is opened, according to the first embodiment of the present disclosure. 
         FIG. 6  is a perspective view showing the left lower part of the printer, in a condition that the tank cover is opened, according to the first embodiment of the present disclosure. 
         FIG. 7  is a perspective view showing the left lower part of the printer, in a condition that a locking member is attached and a cover body is omitted, according to the first embodiment of the present disclosure. 
         FIG. 8  is a front view showing a supporting plate constituting a tank installed part in the left lower part of the printer according to the first embodiment of the present disclosure. 
         FIG. 9  is a perspective view showing a waste ink tank as viewed from a left side in the printer according to the first embodiment of the present disclosure. 
         FIG. 10  is a perspective view showing the waste ink tank as viewed from a rear side in the printer according to the first embodiment of the present disclosure. 
         FIG. 11  is a front view showing the waste ink tank in the printer according to the first embodiment of the present disclosure. 
         FIG. 12  is a right side view showing the waste ink tank in the printer according to the first embodiment of the present disclosure. 
         FIG. 13  is a front view showing a part of the tank cover in the printer according to the first embodiment of the present disclosure. 
         FIG. 14  is a rear view showing a part of the tank cover in the printer according to the first embodiment of the present disclosure. 
         FIG. 15  is a perspective view showing a part of the tank cover as viewed from the rear side in the printer according to the first embodiment of the present disclosure. 
         FIG. 16  is an exploded perspective view showing a nozzle operating part and a cover locking part as viewed from the rear side in the tank cover of the printer according to the first embodiment of the present disclosure. 
         FIG. 17A  is a right side view showing a nozzle in a retracting state and the cover locking part in a locking state in the tank cover of the printer according to the first embodiment of the present disclosure. 
         FIG. 17B  is a rear view showing the nozzle in the retracting state and the cover locking part in the locking state in the tank cover of the printer according to the first embodiment of the present disclosure. 
         FIG. 18A  is a right side view showing the nozzle in a retracting state and the cover locking part in an unlocking state in the tank cover of the printer according to the first embodiment of the present disclosure. 
         FIG. 18B  is a rear view showing the nozzle in the retracting state and the cover locking part in the unlocking state in the tank cover of the printer according to the first embodiment of the present disclosure. 
         FIG. 19A  is a right side view showing the nozzle in a projecting state and the cover locking part in the locking state in the tank cover of the printer according to the first embodiment of the present disclosure. 
         FIG. 19B  is a rear view showing the nozzle in the projecting state and the cover locking part in the locking state in the tank cover of the printer according to the first embodiment of the present disclosure. 
         FIG. 20  is a perspective view showing a locking cam of the cover locking part as viewed from the rear side in the tank cover of the printer according to the first embodiment of the present disclosure. 
         FIG. 21  is a perspective view showing the locking cam of the cover locking part as viewed from a front side in the tank cover of the printer according to the first embodiment of the present disclosure. 
         FIG. 22  is a perspective view showing a pushing member, in a condition incapable of pushing with respect to the locking cam, as viewed from the front side in the tank cover of the printer according to the first embodiment of the present disclosure. 
         FIG. 23  is a perspective view showing the locking cam, in a condition incapable of rotating with respect to the pushing member, as viewed from the rear side in the tank cover of the printer according to the first embodiment of the present disclosure. 
         FIG. 24  is a perspective view showing the tank cover as viewed from the front side in the printer according to a second embodiment of the present disclosure. 
         FIG. 25  is a perspective view showing the tank cover as viewed from the rear side in the printer according to the second embodiment of the present disclosure. 
         FIG. 26  is a perspective view showing the tank cover, in a condition that the cover body is removed, as viewed from the front side in the printer according to the second embodiment of the present disclosure. 
         FIG. 27  is a rear view showing the tank cover, in a condition that an operating part cover and an inside cover are removed, in the printer according to the second embodiment of the present disclosure. 
         FIG. 28  is a perspective view showing the tank cover, in a condition that the operating part cover and the inside cover are removed, as viewed from the rear side in the printer according to the second embodiment of the present disclosure. 
         FIG. 29  is an exploded perspective view showing the tank cover, in a condition that the cover body is removed, as viewed from the rear side in the printer according to the second embodiment of the present disclosure. 
         FIG. 30  is a perspective view showing a cylindrical wall and the periphery as viewed from the rear side in the tank cover of the printer according to the second embodiment of the present disclosure. 
         FIG. 31  is a perspective view showing the pushing member and a nozzle cam as viewed from the front side in the tank cover of the printer according to the second embodiment of the present disclosure. 
         FIG. 32  is a rear view showing the pushing member to the cylindrical wall, in a condition that the nozzle is set to the projecting state, in the tank cover of the printer according to the second embodiment of the present disclosure. 
         FIG. 33  is a rear view showing the pushing member to the cylindrical wall, in a condition that the nozzle is set to the retracting state, in the tank cover of the printer according to the second embodiment of the present disclosure. 
         FIG. 34  is a perspective view showing the pushing member projected to the front side from the cylindrical wall and the periphery as viewed from the front side in the tank cover of the printer according to the second embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     First, entire structure of a printer  1  as an ink-jet type image forming apparatus  1  according to a first embodiment of the present disclosure will be described with reference to  FIGS. 1 and 2 . Hereinafter, for convenience of description, it will be described so that the front side of the printer  1  is positioned at a near side on a paper sheet of  FIG. 1 . Arrows Fr, Rr, L, R, U and Lo in each of the drawings respectively indicate a front side, a rear side, a left side, a right side, an upper side and a lower side of the printer  1 . 
     As shown in  FIGS. 1 and 2 , the printer  1  includes a box-shape printer body  2 . In a lower part of the printer body  2 , a sheet feeding cartridge  3  storing sheets is drawably housed. 
     In a front face of the printer body  2 , an upper side cover  4  and a left lower side cover  5  are openably/closably provided. When the upper side cover  4  is opened, a sheet conveying unit  7 , a cap unit  15  and a wiper unit  16  described below become conditions capable of maintenance. Moreover, as shown in  FIG. 3 , when the left lower side cover  5  is opened, ink containers  14  and a waste ink tank  17  described below become conditions capable of replacement. 
     In a right part inside the printer body  2 , a conveyance path  6  of the sheet is arranged and, in a center part inside the printer body  2 , the sheet conveying unit  7  is ascendably/descendably arranged above the sheet feeding cartridge  3 . The conveyance path  6  is provided from the sheet feeding cartridge  3  to the sheet conveying unit  7  and, along a conveying direction of the sheet on the conveyance path  6 , a sheet feeding roller, a conveying roller and a registration roller are located in sequential order from an upstream side. 
     The sheet conveying unit  7  includes a conveying frame and an endless conveying belt and is configured to ascent/descent in upward and downward directions between a print position close to recording heads  13  described below in printing operation and an evacuation position separate from the recording heads  13  in non-printing operation. To the conveying frame, a driving roller, a following roller and a tensioning roller are rotatably arranged and the conveying belt is wound around the driving roller, the following roller and the tensioning roller so as to convey the sheet from a right side to a left side. Inside the conveying belt, an air sucking part is arranged. In the conveying belt, a lot of air intake holes are provided and the air sucking part sucks air above the conveying belt to the inside the conveying belt. 
     In a left part inside the printer body  2 , a sheet conveying part  8  is provided to continue from the left side from the sheet conveying unit  7  at the print position and, above the sheet conveying part  8 , a drying device  9  is provided. At the left side of the sheet conveying part  8 , an ejecting roller  10  is provided and, near the ejecting roller  10  and on a left face of the printer body  2 , an ejecting port  11  is provided. In addition, on the left face of the printer body  2 , an ejected sheet tray protruded from a lower side of the ejecting port  11  to the left side is provided. 
     Moreover, in a center part inside the printer body  2 , four recording heads  13  ( 13 K,  13 C,  13 M,  13 Y) are juxtaposed above the sheet conveying unit  7 . The four recording heads  13  face to an upper face of the conveying belt of the sheet conveying unit  7  in the printing operation to eject inks of black, cyan, magenta and yellow, respectively. For example, the four recording heads  13  are located in sequential order from the upstream side (the right side) in the conveying direction of the sheet. 
     In a left lower part inside the printer body  2 , four ink containers  14  ( 14 K,  14 C,  14 M,  14 Y) are juxtaposed. The four ink containers  14 K,  14 C,  14 M,  14 Y contain inks of black, cyan, magenta and yellow, respectively. For example, the four ink containers  14 K,  14 C,  14 M,  14 Y are located as shown in  FIG. 2  in sequential order from a lower side. When the left lower side cover  5  is opened, container installed parts (refer to  FIG. 3 ) of the respective ink containers  14  arranged in the left lower part inside the printer body  2  are exposed and the respective ink containers  14  become conditions attachable/detachable with respect to the respective container installed parts in the forward and backward directions. 
     Incidentally, the recording head  13  and the ink container  14  for the same color ink are connected via a sub ink tank and others. The ink contained in each ink container  14  is constantly stored in the sub ink tank, and then, supplied to each recording head  13  by a pump. 
     In a left upper part of the printer body  2 , the cap unit  15  and the wiper unit  16  are provided. The cap unit  15  and the wiper unit  16  are located at waiting positions at a left side from the sheet conveying unit  7  in the printing operation. Moreover, when the sheet conveying unit  7  is positioned at the evacuation position in the non-printing operation, the cap unit  15  and the wiper unit  16  become conditions movable in left and right directions, and then, any one of the cap unit  15  and the wiper unit  16  can move a processing position above the sheet conveying unit  7  and below the recording heads  13 . 
     The cap unit  15  includes cam members  15   a  and covers the recording heads  13  by the cam members when the cap unit  15  is moved to the processing position. The wiper unit  16  includes wiper members  16   a  and a waste ink tray  16   b , and the wiper members  16   a  and the waste ink tray  16   b  are located below the recording heads  13  when the wiper unit  16  is moved to the processing positions. At this time, purge process or cleaning process of the recording heads  13  is carried out and waste ink caused by the purge process and the cleaning process is collected to the waste ink tray  16   b.    
     Moreover, in a left lower part inside the printer body  2 , the waste ink tank  17  is arranged below the ink containers  14 . The waste ink tank  17  contains the waste ink caused by the purge process and the cleaning process. 
     In the printer body  2 , as shown in  FIGS. 2, 3 and 4 , a tank cover  22  covering the waste ink tank  17  is openably/closably provided. The tank cover  22  is arranged inside the left lower side cover  5  and exposed when the left lower side cover  5  is opened. When the tank cover  22  is opened, as shown in  FIGS. 5, 6 and 7 , a tank installed part  23  for the waste ink tank  17  arranged inside the printer body  2  is exposed and the waste ink tank  17  becomes a condition attachable/detachable with respect to the tank installed part  23  in the forward and backward directions. A right front edge part of the tank installed part  23  is composed of a supporting plate  24  provided in the printer body  2 , as shown in  FIGS. 5-8 , and, in the supporting plate  24 , a locking hole  25  engaging a locking member  52  of a cover locking part  50  described below is formed. 
     The waste ink tank  17  is formed, for example, as shown in  FIGS. 9, 10, 11 and 12 , in a rectangular parallelepiped shape elongated in the forward and backward directions and, in a front face of the waste ink tank  17 , an inflow port  18  for the waste ink is formed. When the waste ink tank  17  is replaced, a cap  19  is attached to the inflow port  18 , and thereby, the inflow port  18  is closed. On the other hand, when the waste ink tank  17  is installed into the tank installed part  23  and the tank cover is closed, the cap  19  is detached from the inflow port  18 , and thereby, the inflow port  18  is opened. 
     Incidentally, the waste ink tray  16   b  of the wiper unit  16  and the inflow port  18  are connected via a tube  20  (refer to  FIG. 2 ) and a nozzle  21  (refer to  FIG. 15 ), and the waste ink collected in the waste ink tray  16   b  is ejected into the waste ink tank  17  via the tube  20  by a pump. 
     Next, the printing operation (image forming operation) of the printer  1  having such a configuration will be described. When the printer  1  receives image data from an external computer or the like, the sheet stored in the sheet feeding cartridge  3  is picked up and fed to the conveying path  6  by the sheet feeding roller. The sheet fed to the conveying path  6  is conveyed to a downstream side of the conveying path  6  by the conveying roller, and then, fed from the conveying path  6  to the upper face of the conveyance belt of the sheet conveying unit  7  at the print position by the registration roller. The sheet is absorbed to the upper face of the conveyance belt by suction force of the air sucking part. 
     On the other hand, to each recording head  13 , the ink is supplied from each ink container  14 . Each recording head  13  ejects the ink to the sheet absorbed on the conveying belt on the basis of the information of the image data received from the external computer or the like. Thereby, a color ink image is formed on a surface of the sheet. The sheet having the color ink image is conveyed by the sheet conveying part  8 , the ink on the surface is dried by the drying device  9 , and then, the sheet is ejected on the ejected sheet tray  12  via the ejecting port  11  by the ejecting roller  10 . 
     In the first embodiment, the printer  1  includes a waste ink conveying device  1   a  conveying the waste ink caused in the recording head  13  to the waste ink tank  17 . The waste ink conveying device  1   a  is composed of the waste ink tray  16   b , the tube  20 , the tank installed part  23  (including the supporting plate  24 ), the tank cover  22 , the waste ink tank  17  and others. 
     Next, the tank cover  22  will be described. In the description of the tank cover  22 , front, rear, left and right indicate respective locations in a case the tank cover  22  in a closing state is a criterion. Moreover, a clockwise direction and a counterclockwise direction indicate directions as viewed from the front side. The tank cover  22  includes, as shown in  FIGS. 3, 4, 13, 14, 15  and other figures, a cover body  30 , the nozzle  21 , a nozzle operating part  40  and the cover locking part  50 . Incidentally, the nozzle  21 , the nozzle operating part  40  and the cover locking part  50  are arranged mainly at a rear side of the cover body  30  and protected by being covered with an inside cover (not shown) attached at the rear side of the cover body  30 . 
     The cover body  30  is made of a roughly plate-like member. The cover body  30  is attached to the printer body  2  with a turning shaft attached at a left end of the cover body  30 , and opened/closed by turning with respect to the printer body  2 . When the cover body  30  is closed, the tank cover  22  becomes the closing state, and the tank installed part  23  and the waste ink tank  17  is covered by the cover body  30 . On the other hand, when the cover body  30  is opened, the tank cover  22  becomes an opening state, and the tank installed part  23  and the waste ink tank  17  is exposed, and the waste ink tank  17  becomes a condition capable of replacing. 
     In the cover body  30 , a circular nozzle operating hole  31  and a circular locking operating hole  32  are opened. The locking operating hole  32  is arranged below the nozzle operating hole  31 . In a rear face of the cover body  30 , as shown in  FIGS. 14, 15  and other figures, a cylindrical wall  33  along an edge of the nozzle operating hole  31  is erected to the rear side and the cylindrical wall  33  has an inner diameter similar to the nozzle operating hole  31 . 
     In a rear end of the cylindrical wall  33 , four slits  34  extended to the front end are formed at the upper side, the lower side, the left side and the right side at regular intervals, and each slit  34  is cut out just before the edge of the nozzle operating hole  31 . Moreover, in the rear end of the cylindrical wall  33 , engaging gaps  35  are formed and each engaging gap  35  is arranged between two adjacent slits  34 . Each engaging gap  35  is composed of a first inclined face  36  inclined forwardly toward the counterclockwise direction and a roughly vertical face. Further, at a downstream side from each engaging gap  35  in the counterclockwise direction, a second inclined face  37  inclined forwardly toward the counterclockwise direction is formed. Incidentally, the first inclined face  36  is longer than the second inclined face  37 . 
     The nozzle  21  is formed so as to be bent in an L-shape and connected to the tube  20  at a proximal end of the nozzle  21 . In a distal end of the nozzle  21 , a stopper, such as a barb, is formed and, when the nozzle  21  is inserted into the inflow port  18  of the waste ink tank  17 , the nozzle  21  hardly falls out of the inflow port  18 . 
     As shown in  FIGS. 15, 16  and other figures, the nozzle operating part  40  includes a pushing member  41 , a nozzle cam  42 , a cam pushing spring  43  and an operating part cover  44 . The cover locking part  50  includes a locking lever  51 , the locking member  52  and a locking cam  53 . 
     Components (the pushing member  41 , the nozzle cam  42 , the cam pushing spring  43  and the operating part cover  44 ) of the nozzle operating part  40  will be described. 
     The pushing member  41  is formed in a cylindrical shape shorter than the cylindrical wall  33  in the forward and backward directions. The pushing member  41  has an outer diameter slightly smaller than the inner diameters of the nozzle operating hole  31  and the cylindrical wall of the cover body  30 . The pushing member  41  is a nozzle supporting part supporting the nozzle  21  and, in a left face of the pushing member  41 , a nozzle hole  41   a  allowing for insertion of the nozzle  21  is formed. A front end of the pushing member  41  is closed by a pressing face  45  and, in a rear end of the pushing member  41 , a serrated sliding face  46  is formed so as to have symmetrical inclined faces continuously. In a rear end of an outer circumference face of the pushing member  41 , a pair of first protrusions  47  (a protrusion) protruded in an outward radial direction are formed at the upper side and the lower side. 
     Each first protrusion  47  has a dimension capable of fitting in the slit  34  of the cylindrical wall  33 . The pushing member  41  is fitted in the nozzle operating hole  31  and the cylindrical wall  33  in a condition that the first protrusions  47  are respectively fitted in the upper and lower slits  34 , and then, can move along the cylindrical wall  33  in the forward and backward directions. Incidentally, each first protrusion  47  is protruded outside an outer circumference face of the cylindrical wall  33  in the outward radial direction and, when each first protrusion  47  is stopped at the edge of the nozzle operating hole  31 , the pushing member  41  is restrained from moving to the front side. 
     The nozzle cam  42  is formed in a disk shape and has an outer diameter slightly smaller than the inner diameters of the nozzle operating hole  31  and the cylindrical wall  33  of the cover body  30 , i.e. the same outer diameter as the push member  41 . In a center of the nozzle cam  42 , a nozzle hole  42   a  allowing for insertion of the nozzle  21  is formed and, in a rear face of the nozzle cam  42 , a supporting groove supporting a front end of the cam pushing spring  43  is formed around the nozzle hole  42   a . On an outer circumference face of the nozzle cam  42 , four second protrusions  48  protruded in the outward radial direction are formed at regular intervals. 
     Incidentally, the nozzle operating hole  31  and the cylindrical wall  33  of the cover body  30  is configured so that, in a case where the tank cover  22  is in the closing state, a position of the nozzle hole  42   a  of the nozzle cam  42  corresponds to a position of the inflow port  18  of the waste ink tank  17  installed in the tank installed part  23 . 
     Each second protrusion  48  has a dimension capable of fitting in the slit  34  of the cylindrical wall  33 . The nozzle cam  42  is fitted in the cylindrical wall  33  at a rear side from the pushing member  41  and, in a case where each second protrusion  48  is fitted in the slit  34 , can move along the cylindrical wall  33  in the forward and backward directions. Incidentally, each second protrusion  48  is protruded outside an inner circumference face and inside the outer circumference face of the cylindrical wall  33  in the outward radial direction. Moreover, in a case where each second protrusion  48  is engaged with each engaging gap  35  of the cylindrical wall  33 , the nozzle cam  42  is restrained from moving to the front side. 
     The pushing member  41  and the nozzle cam  42  are covered, in a condition being fitted in the cylindrical wall  33 , together with the cylindrical wall  33  by the operating part cover  44  from the rear side. Between the nozzle cam  42  and the operating part cover  44 , the cam pushing spring  43  is arranged, and the nozzle cam  42  is biased to the front side by the cam pushing spring  43 . When the nozzle cam  42  in such a condition is pushed to the rear side by the pushing member  41 , the nozzle cam  42  is slid so as to rotate in the counterclockwise direction along the serrated sliding face  46  of the pushing member  41 . Subsequently, whenever the nozzle cam  42  is pushed by the pushing member  41 , fitting of the second protrusions  48  in the slits  34  and engaging of the second protrusions  48  into the engaging gaps  35  are switched. 
     Incidentally, the nozzle  21  is inserted in the nozzle hole  41   a  of the push member  41  and the nozzle hole  42   a  of the nozzle cam  42  by using the L-shape of the nozzle  21 . Since the nozzle  21  is positioned in the forward and backward directions by the nozzle hole  41   a  of the push member  41 , the nozzle  21  is moved in the forward and backward directions as the pushing member  41  is moved in the forward and backward directions. 
     A notching mechanism of the nozzle  21  by the cover body  30  and the nozzle operating part  40  described above will be described. This presupposes that the tank cover  22  is in the closing state. 
     When the second protrusions  48  of the nozzle cam  42  are fitted in the slits  34 , as shown in  FIGS. 17A and 18A , the pushing member  41  and the nozzle cam  42  are pushed to the front side by the cam pushing spring  43 , and the nozzle  21  is positioned at a retracting position at the front side. Moreover, the pushing member  41  is protruded to the front side from a front face of the cover body  30  to indicate a retracting state of the nozzle  21 . Thus, in a case where the pushing member  41  is in a nozzle retracting state, as shown in  FIG. 22 , the first protrusions  47  of the pushing member  41  are located at the front side from the locking cam  53  of the cover locking part  50  described below. 
     When the pushing member  41  in the nozzle retracting state is pushed, as shown in  FIG. 19A , the pushing member  41  and the nozzle cam  42  are moved to the rear side, and then, the nozzle  21  is moved to a projecting position at the rear side. At this time, the nozzle  21  is inserted in the inflow port  18  of the waste ink tank  17  installed in the tank installed part  23 . Moreover, since the nozzle cam  42  is rotated and the second protrusions  48  are engaged with the engaging gaps  35 , regardless of pushing of the cam pushing spring  43 , the nozzle cam  42  is restrained from moving to the front side. The pushing member  41  is pushed into the cylindrical wall  33  without receiving a force moving to the front side to indicate a projecting state of the nozzle  21 . Thus, in a case where the pushing member  41  is in a nozzle projecting state, as shown in  FIG. 23 , the first protrusions  47  of the pushing member  41  are located at the rear side from the locking cam  53  of the cover locking part  50  described below. 
     When the pushing member  41  in the nozzle projecting state is pushed, the nozzle cam  42  is rotated and the second protrusions  48  are fitted in the slits  34  again, as shown in  FIGS. 17A and 18A , the pushing member  41  and the nozzle cam  42  are pushed by the cam pushing spring  43  and moved to the front side, and the pushing member  41  becomes the nozzle retracting state. At this time, the nozzle  21  is moved to the front side, retracted from the inflow port  18  of the waste ink tank  17  installed in the tank installed part  23 , and moved to the retracting position. 
     Components of the cover locking part  50  (the locking lever  51 , the locking member  52  and the locking cam  53 ) will be described. Incidentally, the locking cam  53  is covered together with the components of the nozzle operating part  40  by the operating part cover  44  from the rear side. Moreover, the locking lever  51  and the locking member  52  may be covered by the operating part cover  44 . 
     The locking lever  51  is formed as shown in  FIGS. 13-16  so as to have a disk-shaped supporting part  54 , a bar-shaped handle  55  and a flange  56 , and arranged to be rotatable with respect to the locking operating hole  32  of the cover body  30 . 
     The supporting part  54  has an outer diameter slightly smaller than an inner diameter of the locking operating hole  32  and is attached to be rotatable inside the locking operating hole  32 . In a rear face of the supporting part  54 , a columnar connected protrusion  57  connected to the locking member  52  is formed so as to be protruded to the rear side. The connected protrusion  57  is arranged below a center of the disk shape of the supporting part  54 . 
     The handle  55  is formed on a front face of the supporting part  54  along a center line of the disk shape of the supporting part  54 . The flange  56  is arranged in a rear end of an outer circumference face of the supporting part  54 . On a part (e.g. an upper portion) of the outer circumference face of the supporting part  54 , a gear  58  meshing with the locking cam  53  is formed. 
     The locking member  52  is formed in a plate shape elongated in the left and right directions and located at a lower side of the locking member  51 . The locking member  52  is attached to the cover body  30  so as to be movable between a locking position at the right side and an unlocking position at the left side along the rear face of the cover body  30 . In an upper portion of the locking member  52 , an elliptic connecting hole  59  elongated in the upward and downward directions is provided and, to the connecting hole  59 , the connected protrusion  57  of the supporting part  54  of the locking lever  51  is connected. When the locking lever  51  is rotated, the connected protrusion  57  is moved in the left and right directions, and accordingly, the locking member  52  having the connecting hole  59  connected to the connected protrusion  57  is moved in the left and right directions. 
     For example, in a case where the tank cover  22  is in the closing state, when the locking lever  51  is rotated in the counterclockwise direction, as shown in  FIGS. 17B and 19B , the connected protrusion  57  is moved to the right side with respect to a center of the locking lever  51 . According to this, the locking member  52  is moved to the locking position at the right side and inserted in the locking hole  25  of the supporting plate  24  of the tank installed part  23 . Thereby, the cover locking part  50  becomes a locking state and the tank cover  22  in the closing state is locked to the printer body  2 . 
     On the other hand, when the locking lever  51  is rotated in the clockwise direction, as shown in  FIG. 18B , the connected protrusion  57  is moved to the left side with respect to the center of the locking lever  51 . According to this, the locking member  52  is moved to the unlocking position at the left side and retracted from the locking hole  25 . Thereby, the cover locking part  50  becomes an unlocking state and locking of the tank cover  22  to the printer body  2  is released. 
     Incidentally, the handle  55  of the locking lever  51  may be provided so as to become parallel to the left and right directions in a case where the cover locking part is in the locking state, and to become parallel to the upward and downward directions in a case where the cover locking part is in the unlocking state. 
     Moreover, out of an attaching mechanism of the locking member  52  to the cover body  2 , a rotating mechanism of the locking lever  51  and a connecting mechanism of the connected protrusion  57  and the connecting hole  59 , at least one mechanism may be configured so that movement of the locking member  52  is restricted between the locking position and the unlocking position. 
     The locking cam  53  is formed in an annular shape having a notch  60  in a part in a circumferential direction of the locking cam  53 , i.e. a C-shape, as shown in  FIGS. 14-16, 20, 21, 22 and 23 . The locking cam  53  has an inner diameter slightly larger than an outer diameter of the cylindrical wall  33  of the cover body  30  and is rotatably fitted outside the cylindrical wall  33  along an outer circumference of the cylindrical wall  33 . 
     In an outer circumference face of the locking cam  53 , a gear  61  meshing with the gear  58  of the flange  56  of the locking lever  51  is formed. Thereby, the locking cam is rotated in an opposite direction to the locking lever  51  according to rotation of the locking lever  51 . For example, in a case where the locking lever  51  is rotated in the counterclockwise direction to set the cover locking part  50  to the locking state (refer to  FIGS. 17B and 19B ), the locking cam  53  is rotated in the clockwise direction. On the other hand, in a case where the locking lever  51  is rotated in the clockwise direction to set the cover locking part  50  to the unlocking state (refer to  FIG. 18B ), the locking cam  53  is rotated in the counterclockwise direction. 
     In an inner circumference face of the locking cam  53 , a recessed portion  62  is formed in a part (the lower side) in the circumferential direction, and the notch  60  and the recessed portion  62  are provided on a center line of the locking cam  53 . The notch  60  and the recessed portion  62  compose a push allowing part allowing pushing operation of the pushing member  41  of the nozzle operating part  40 . When the cover locking part  50  is set to the locking state (refer to  FIGS. 17B and 19B ), the notch  60  and the recessed portion  62  of the locking cam  53  rotated in the clockwise direction are located at the same positions as the upper and lower slits  34  of the cylindrical wall  33  of the cover body  30  in the circumferential direction, as shown in  FIG. 23 . Therefore, since the first protrusions  47  of the pushing member  41  become movable through the slits  34  and the notch  60  and the recessed portion  62  in the forward and backward directions, movement of the pushing member  41  in the forward and backward directions is allowed, that is, pushing operation of the pushing member  41  is allowed. 
     In a rear face of the locking cam  53 , at an upstream side just before the recessed portion  62  in the counterclockwise direction, a rotation restricting part  63  protruded to the rear side is provided at the lower side on the rear face. As described above, when the cover locking part  50  is set to the locking state, the push allowing part composed of the notch  60  and the recessed portion  62  of the locking cam  53  allows pushing operation of the pushing member  41 , and thereby, the pushing member  41  can be pushed into the cylindrical wall  33  and set to the nozzle projecting state. At this time, as shown in  FIG. 23 , the first protrusions  47  of the pushing member  41  are located at the rear side from the locking cam  53 , particularly, the lower first protrusion  47  is located at the downstream side just before the rotation restricting part  63  in the counterclockwise direction. Therefore, rotation in the counterclockwise direction of the locking cam  53  is restricted by contact of the rotation restricting part  63  to the first protrusions  47 . That is, it is restricted that the locking lever  51  is rotated in the counterclockwise direction and the cover locking part  50  is set to the unlocking state. 
     Incidentally, when the pushing member  41  is set to the nozzle retracting state protruded to the front side from the front face of the cover body  30 , the first protrusions  47  of the pushing member  41  are located at the front side from the locking cam  53 . Therefore, even if the locking cam  53  is rotated, because the rotation restricting part  63  does not come into contact with the first protrusions  47 , the locking cam  53  can be rotated in the counterclockwise direction. That is, the locking lever  51  can be rotated in the clockwise direction and the cover locking part  50  can be set to the unlocking state. 
     In other words, when the cover locking part  50  is in the locking state, in a case where the pushing member  41  is in the nozzle projecting state, the cover locking part  50  cannot be set to the unlocking state, but, in a case where the pushing member  41  is in the nozzle retracting state, the cover locking part  50  can be set to the unlocking state. 
     Moreover, in a front face of the locking cam  53 , at an upstream side just before the recessed portion  62  in the counterclockwise direction, a push restricting part  64  is provided at the lower side of the front face along the outer circumference face of the cylindrical wall  33  of the cover body  30 . As described above, if the pushing member  41  is not set to the nozzle retracting state, the cover locking part  50  cannot be set to the unlocking state. When the cover locking part  50  is set to the unlocking state (refer to  FIG. 18B ), the push restricting part  64  of the locking cam  53  rotated in the counterclockwise direction is located at the same position as the lower first protrusion  47  of the pushing member  41  in the circumferential direction, as shown in  FIG. 22 . At this time, since the first protrusions  47  are located at the front side from the push restricting part  64  of the locking cam  53 , movement of the pushing member  41  to the rear side is restricted by contact of the first protrusions  47  to the push restricting part  64 , that is, pushing operation of the pushing member  41  is restricted. In other words, when the cover locking part  50  is in the unlocking state, the pushing member  41  cannot be switched from the nozzle retracting state to the nozzle projecting state. 
     In accordance with the embodiment, as described above, the waste ink conveying device  1   a  of the printer  1  includes the waste ink tank  17  installed in the tank installed part  23  to contain the waste ink, and the tank cover  22  opening/closing the tank installed part  23 . The waste ink tank  17  includes the inflow port  18  in which the waste ink is flowed from a side of the tank cover  22  in the closing state. The tank cover  22  includes the nozzle  21  being inserted in the inflow port  18  to flow the waste ink in the waste ink tank  17  when the tank cover  22  is in the closing state, the nozzle operation part  40  switching projecting and retracting of the nozzle  21  in order to insert and retract the nozzle  21  with respect to the inflow port  18 , and the cover locking part  50  switching locking and unlocking of the closing state of the tank cover  22 . Subsequently, the waste ink conveying device  1   a  makes the cover locking part  50  capable of switching to the unlocking state in a case where the cover locking part  50  is in the locking state and the nozzle  21  is in the retracting state. On the other hand, the waste ink conveying device  1   a  makes the cover locking part  50  incapable of switching to the unlocking state in a case where the cover locking part  50  is in the locking state and the nozzle  21  is in the projecting state. 
     Concretely, the nozzle operating part  40  includes the pushing member  41  as the nozzle supporting part moving between one side (the front side) where the nozzle  21  is set to the retracting state and the other side (the rear side) where the nozzle  21  is set to the projecting state. The cover locking part  50  includes the locking cam  53  rotating around the pushing member  41 . The pushing member includes the first protrusion  47  (the protrusion) located at one side from the locking cam  53  in a case where the pushing member  41  is located at one side, but located at the other side from the locking cam  53  in a case where the pushing member  41  is located at the other side. The locking cam  53  is rotated in one direction (the clockwise direction as viewed from the front side) in a case where the cover locking part  50  is switched to the locking state, but rotated in the other direction (the counterclockwise direction as viewed from the front side) in a case where the cover locking part  50  is switched to the unlocking state. The locking cam  53  includes the rotation restricting part  63  protruded to the other side at the downstream side in the other direction from the first protrusion  47 . 
     Accordingly, in a case where the nozzle  21  is in the projecting state being inserted in the waste ink tank  17 , since the tank cover  22  cannot be opened, it is restrain scattering of the waste ink from the nozzle  21  and the inflow port  21  of the waste ink tank  17 . By providing the locking cam  53 , it is possible to interlock the nozzle operating part  40  and the cover locking part  50 . Moreover, since the nozzle  21  and the inflow port  18  are not bonded, opening/closing of the tank cover  22  does not break the nozzle  21  and the inflow port  18 , and it is possible to restrain leakage of the waste ink, malfunctions of installing of the nozzle  21  and the inflow port  18 , clogging of the waste ink in the nozzle  21  and the tube  20  due to breakage of the nozzle  21  and the tube  20 . Incidentally, since it is unnecessary to put the cap  19  into an attached state for inserting and retracting of the nozzle  21 , the cap  19  is not broken and the inflow port  18  can be surely sealed by the cap  19  when the waste ink tank  17  is replaced. Therefore, it is possible to restrain waste ink contamination and malfunction due to replacement of the waste ink tank  17 . 
     Moreover, in the first embodiment, the waste ink conveying device  1   a  of the printer  1  having such a configuration as described above makes the nozzle  21  incapable of switching to the projecting state in a case where the cover locking part  50  is in the unlocking state and the nozzle  21  is in the retracting state. 
     Concretely, the locking cam  53  of the cover locking part  50  includes the recessed part  62  located at the same position as the first protrusion  47  in the circumferential direction in a case where the locking cam  53  is rotated in one direction, and the push restricting part  64  located at the same position as the first protrusion  47  in the circumferential direction in a case where the locking cam  53  is rotated in the other direction. 
     Thereby, in a condition that the tank cover  22  is opened, since the nozzle  21  cannot be set to the projecting state, it is possible to restrain misoperation of the nozzle  21  and restrain waste ink contamination due to contact to the projected nozzle  21 . 
     Incidentally, structure of the nozzle operating part  40  is not limited by an example described about the tank cover  22  of the waste ink conveying device  1   a  according to the above-described first embodiment. Next, the tank cover  22  of the waste ink conveying device  1   a  according to a second embodiment will be described with reference to  FIGS. 24-34 . 
       FIG. 24  is a front perspective view of the tank cover  22  and  FIG. 25  is a rear perspective view of the tank cover  22 .  FIG. 26  is a front perspective view of the tank cover  22  in a condition that the cover body  30  is removed, and  FIGS. 27 and 28  are a rear view and a rear perspective view of the tank cover  22  in a condition that the operating part cover  44  of the nozzle operating part  40  and an inside cover  30  of the cover body  30  are removed.  FIG. 29  is an exploded rear perspective view of the tank cover  22  in a condition that the cover body  30 .  FIG. 30  is a rear perspective view of a cylindrical wall  70  and the periphery of the cover body  30 .  FIG. 31  is a front perspective view of a pushing member  80  and a nozzle cam  90  of the nozzle operating part  40 .  FIG. 32  is a rear view of the pushing member  80  to the cylindrical wall  70  in a condition that the pushing member  80  is pushed into the cylindrical wall  70  and the nozzle  21  is set to the projecting state, and  FIG. 33  is a rear view of the pushing member  80  to the cylindrical wall  70  in a condition that the pushing member  80  is protruded to the front side from the cylindrical wall  70  and the nozzle  21  is set to the retracting state.  FIG. 34  is a front perspective view of the pushing member  80  projected to the front side from the cylindrical wall  70  and the periphery. 
     The tank cover  22  of the second embodiment has almost the same configuration as the first embodiment. Thereupon, hereinafter, the different structure from the first embodiment will be mainly described and description of the same structure as the first embodiment is omitted. The tank cover  22  of the second embodiment includes the nozzle  21 , the nozzle operating part  40  and the cover locking part  50  similar to the first embodiment, the cover body  30 , as shown in  FIGS. 24, 25, 26, 27, 28 and 29 , but the nozzle operating part  40  and the cover locking part  50  have the different structure from the first embodiment. 
     For example, in the second embodiment, the cover body  30  includes the cylindrical wall  70  corresponding to the cylindrical wall  33  of the first embodiment, and the nozzle operating part  40  includes the pushing member  80  and the nozzle cam  90  corresponding to the pushing member and the nozzle cam  42  of the first embodiment. Incidentally, the nozzle  21 , the nozzle operating part  40  and the cover locking part  50  are provided at the rear side of the cover main body  30  mainly and, shown in  FIGS. 25 and 26 , covered by the inside cover  30   a  attached to the rear side of the cover body  30  and protected by the inside cover  30   a.    
     The cylindrical wall  70  of the cover body  30  has an inner diameter larger than the nozzle operating hole  31  as shown in  FIGS. 27, 28, 29 and 30  and is erected to the rear side from the circumference over the nozzle operating hole  31 . Incidentally, although  FIGS. 24 and 34  illustrate an example that the cylindrical wall  70  is formed so as to penetrate the cover body  30  in the forward and backward directions and an annular bottom face having the nozzle operating hole  31  is formed at a front end of the cylindrical wall  70 , the cylindrical wall  70  is not limited by this example. In another example, the cylindrical wall  70  may be formed so as to be extended to the rear side from the rear face of the cover body  30  having the nozzle operating hole  31  and, in this case, a part (a circumferential portion over the nozzle operating hole  31 ) of the cover body  30  constitutes the bottom at the front end of the cylindrical wall  70 . 
     In a rear part of the cylindrical wall  70 , two slits  71  extended from a rear end of the cylindrical wall  70  to the front end are formed at the upper side and the lower side, and each slit  71  is cut out just before a rear end of the cover body  30 . At the left side in the cylindrical wall  70 , an opening  72  in which the proximal end of the nozzle  21  is located is provided and the proximal end of the nozzle  21  can be moved in the forward and backward direction inside the opening  72 . Incidentally,  FIGS. 25, 27 and 28  illustrate a stopper  21   a  at the distal end of the nozzle  21 , but, in  FIG. 29 , the stopper  21   a  is omitted from the nozzle  21 . 
     On an inner circumference face of the cylindrical wall  70 , as shown in  FIGS. 30, 32 and 33 , a plurality of ribs  73  are provided at intervals in the circumferential direction. Each rib  73  is formed from the inner circumference face of the cylindrical wall  70  to the edge of the nozzle operating hole  31  in a radial direction, in other words, an inner diameter composed of the plurality of ribs  73  is equal to the inner diameter of the nozzle operating hole  31 . In addition, each rib  73  is formed so as to be extended backwardly from a front face of the cylindrical wall  70  to the vicinity of a center of the cylindrical wall  70  in the forward and backward directions. 
     The pushing member  80  of the nozzle operating part is formed in a cylindrical shape shorter than the cylindrical wall  70  in the forward and backward directions, as shown in  FIGS. 29, 31 and 34 . The pushing member  80  has an outer diameter slightly smaller than the inner diameter of the nozzle operating hole  31  of the cover body  30  and the inner diameter composed of the plurality of ribs  73  of the cylindrical wall  70 , is fitted in the nozzle operating hole  31  and the cylindrical wall  70 , and can be moved along the plurality of ribs  73  in the forward and backward directions. Incidentally, the pushing member  80  is pushed to the front side by the nozzle cam  90  biased to the front side with the cam pushing spring  43 , as described below. 
     Moreover, the pushing member  80  is rotatable in the clockwise direction and the counterclockwise direction as viewed from the front side around a rotation axis extended in the forward and backward directions inside the nozzle operating hole  31  and the cylindrical wall  70 . The pushing member  80  is rotated according to operation of a user. For example, in an activation condition of the printer  1 , as shown in  FIGS. 24, 26 and 32 , the pushing member  80  is rotated to a predetermined activation position at a side in the counterclockwise direction. But, in a non-activation condition of the printer  1 , as shown in  FIGS. 33 and 34 , the pushing member  80  is rotated to a predetermined non-activation position at a side in the clockwise direction. 
     In a front end of the cylindrical pushing member  80 , a bottom face (a front face) having an operation lever protruded to the front side is provided and the operation lever  81  is formed along a center line of a circle shape of the bottom face of the pushing member  80 . Incidentally, the operation lever  81  may be provided so as to become parallel to the upward and downward directions in a case where the pushing member  80  is in the activation position, and to become parallel to the left and right directions in a case where the pushing member  80  is in the non-activation position. 
     On an outer circumference face of a rear part of the pushing member  80 , a flange  82  is provided and the flange  82  is formed to have an outer diameter larger than the inner diameter composed of the plurality of ribs  73  of the cylindrical wall  70  and slightly smaller than an inner diameter of the cylindrical wall  70 . The flange  82  has a plurality of flange gaps  83  and a plurality of locking recessed portions  84 . Moreover, on an outer circumference face of a rear end of the pushing member  80 , a restricted rib  85  is provided at the rear side from the flange  82 . 
     The plurality of flange gaps  83  are arranged at the same intervals as the plurality of ribs  73  of the cylindrical wall  70  in the circumferential direction. When the flange  82  is located at the rear side from the plurality of ribs  73  in a condition that the pushing member  80  is located inside the cylindrical wall  70 , the pushing member  80  becomes rotatable because each rib  73  is not interfered with each flange gap  83 . 
     When the pushing member  80  is located at the non-activation position, all of the plurality of flange gaps  83  are respectively located so as to correspond to the plurality of ribs  73  (located at the same positions as the plurality of ribs  73  in the circumferential direction) and the pushing member  80  becomes movable to the front side. At this time, the pushing member  80  is moved to the front side by receiving biasing force of the cam pushing spring  43  and each rib  73  is fitted in each flange gap  83 , and the pushing member  80  is moved to the front side along the nozzle operating hole  31  and the plurality of ribs  73  until the flange  82  comes into contact with the bottom face of the cylindrical wall  70 . 
     Incidentally, the pushing member  80  at the non-activation position is restricted from rotating by fitting of each rib  73  and each flange gap  83 . When the pushing member  80  at the non-activation position is pushed to the rear side against the biasing force of the cam pushing spring  43 , since the flange  82  is located at the rear side from the plurality of ribs  73 , and fitting of each rib  73  and each flange gap  83  is released, the pushing member  80  becomes rotatable. 
     The plurality of locking recessed portions  84  are provided at intervals in the circumferential direction and recessed in a front face of the flange  82 . When the pushing member  80  is located at the activation position, each locking recessed portion  84  is located so as to correspond to any one of the plurality of ribs  73  (located at the same position as any one of the ribs  73  in the circumferential direction). At this time, the pushing member  80  receives the biasing force of the cam pushing spring  43 , but any one of the ribs  73  is fitted in each locking recessed portion  84  and locked, and thereby, the pushing member  80  is restricted from moving to the front side. 
     Incidentally, the pushing member  80  at the activation position is restricted from rotating because any one of the ribs  73  is fitted in each locking recessed portion  84  and the other rib  73  is fitted in the flange gap  83 . When the pushing member  80  at the activation position is pushed to the rear side against the biasing force of the cam pushing spring  43 , since the flange  82  is located at the rear side from the plurality of ribs  73 , and fitting of the rib  73  and the locking recessed portion  84  or the flange gap  83  is released, the pushing member  80  becomes rotatable. 
     The restricted rib  85  is locked by a first restricting rib  94  of the nozzle cam  90  as described below when the pushing member  80  is rotated to the activation position in the counterclockwise direction, and then, restricts rotation over the activation position of the pushing member  80 . Moreover, the restricted rib  85  is locked by a second restricting rib  95  of the nozzle cam  90  as described below when the pushing member  80  is rotated to the non-activation position in the clockwise direction, and then, restricts rotation over the non-activation position of the pushing member  80 . 
     The nozzle cam  90  of the nozzle operating part  40  is the nozzle supporting part, instead of the pushing member  41  of the first embodiment, moving between one side (the front side) where the nozzle  21  is set to the retracting state and the other side (the rear side) where the nozzle  21  is set to the projecting state. The nozzle cam  90  includes a lower protrusion  93  (the protrusion) located at one side from the locking cam  53  in a case where the nozzle cam  90  is located at one side, but located at the other side from the locking cam  53  in a case where the nozzle cam  90  is located at the other side. 
     The nozzle cam  90  is formed in a cylindrical shape shorter than the cylindrical wall  70  in the forward and backward directions, as shown in  FIGS. 29 and 31 . The nozzle cam  90  is fitted in the cylindrical wall  70  at the rear side from the pushing member  80  and provided movable in the forward and backward directions. The nozzle cam  90  may have ribs on an outer circumference face thereof in order to reduce sliding resistance to  70  inner circumference face of the cylindrical wall  70  and to restrain rotation. On an outer circumference face of a rear end of the nozzle cam  90 , a flange  91  is provided, and the flange  91  is formed to have an outer diameter lager than the inner diameter composed of the plurality of ribs  73  of the cylindrical wall  70  and slightly smaller than the inner diameter of the cylindrical wall  70 . When the flange  91  is locked by rear ends of the plurality of ribs  73 , the nozzle cam  90  is restricted from moving to the front side. 
     A front end of the nozzle cam  90  has an outer diameter slightly smaller than an inner diameter of the pushing member  80  and is fitted in a rear end of the pushing member  80 . Thereby, the pushing member  80  is connected to the nozzle cam  90  and becomes rotatable with respect to the nozzle cam  90 . The pushing member  80  and the nozzle cam  90  in a mutually connected state are fitted in the cylindrical wall  70 . 
     In the second embodiment, the nozzle cam  90  is the nozzle supporting part supporting the nozzle  21 , a nozzle hole  90   a  allowing for insertion of the proximal end of the nozzle  21  is formed in a left face of the nozzle cam  90 , and a nozzle hole  90   b  allowing for insertion of the distal end of the nozzle  21  is formed in a center of a rear face of the nozzle cam  90 . Moreover, in the rear face of the nozzle cam  90 , a supporting groove supporting the front end of the cam pushing spring  43  is formed around the nozzle hole  90   b , and the nozzle cam  90  is biased to the front side by the cam pushing spring  43  as described below. 
     Incidentally, the nozzle  21  is inserted in the nozzle hole  90   a  and the nozzle hole  90   b  of the nozzle cam  90  by using the L-shape of the nozzle  21 , and thereby, supported by the nozzle cam  90 . Since the nozzle  21  is positioned in the forward and backward directions by the nozzle hole  90   a  of the nozzle cam  90 , the nozzle  21  is moved in the forward and backward directions as the nozzle cam  90  is moved in the forward and backward directions. 
     In the second embodiment, the nozzle operating hole  31  and the cylindrical wall  70  of the cover body  30  is configured so that, in a case where the tank cover  22  is in the closing state, a position of the nozzle hole  90   b  of the nozzle cam  90  corresponds to a position of the inflow port  18  of the waste ink tank  17  installed in the tank installed part  23 . 
     The nozzle cam  90  includes an upper protrusion  92  and the lower protrusion  93  (the protrusion), as shown in  FIG. 28 . The upper protrusion  92  is formed so as to be protruded from the upper side of a rear end of an outer circumference face of the nozzle cam  90  in the outward radial direction, and the lower protrusion  93  is formed so as to be protruded from the lower side of the flange  91  of the nozzle cam  90  in the outward radial direction. Moreover, on the outer circumference face of the nozzle cam  90 , the first restricting rib  94  and the second restricting rib  95  protruded in the outward radial direction are provided. 
     The upper protrusion  92  and the lower protrusion  93  have dimensions capable of fitting in the upper and lower slits  71  of the cylindrical wall  70 . The nozzle cam  90  is fitted in the cylindrical wall  70  in a condition that the upper protrusion  92  and the lower protrusion  93  are fitted in the upper and lower slits  71 , and become movable along the cylindrical wall  70  in the forward and backward directions. By fitting the upper protrusion  92  and the lower protrusion  93  into the respective slits  71 , the nozzle cam  90  is restricted from rotating. Incidentally, the upper protrusion  92  and the lower protrusion  93  may be protruded outside an outer circumference face of the cylindrical wall  70  in the outward radial direction. 
     The first restricting rib  94  and the second restricting rib  95  are provided at intervals (e.g. an interval of 90 degrees) in the circumferential direction, and lock the restricted rib  85  of the pushing member  80  to restrict rotation of the pushing member  80 . 
     The pushing member  80  and the nozzle cam  90  in a condition fitted in the cylindrical wall  70  are covered together with the cylindrical wall  70  by the operating part cover  44  from the rear side. Between the nozzle cam  90  and the operating part cover  44 , the cam pushing spring  43  is arranged, and the nozzle cam  90  is biased to the front side by the cam pushing spring  43 . Thereby, the nozzle cam  90  is restricted from displacing to the rear side from the cylindrical wall  70 . 
     Inserting and retracting operation of the nozzle  21  with respect to the waste ink tank  17  by the cover body and the nozzle operation part  40  of the second embodiment will be described. This presupposes that the tank cover  22  is in the closing state. 
     For example, as shown in  FIG. 33 , when the pushing member  80  is rotated to the non-activation position, all of the plurality of flange gaps  83  of the pushing member  80  are respectively located so as to correspond to the plurality of ribs  73  of the cylindrical wall  70 , and then, movement of the pushing member  80  to the front side is allowed. Incidentally, by fitting the plurality of ribs  73  into the plurality of flange gaps  83 , rotation of the pushing member  80  is restricted. 
     Subsequently, the pushing member  80  and the nozzle cam  90  are moved to the front side by receiving the biasing force of the cam pushing spring  43 . As the nozzle cam  90  is moved, the nozzle  21  supported by the nozzle cam  90  is moved to the front side, retracted from the inflow port  18  of the waste ink tank  17  installed in the tank installed part  23 , and then, located at the retracting position at the front side. When the nozzle  21  is retracted from the waste ink tank  17 , it is possible to turn off a power source of the printer  1  and to set the printer  1  to the non-activation condition. 
     As described above, when the nozzle cam  90  sets the nozzle  21  to the retracting state, as shown in  FIG. 34 , the pushing member  80  is protruded to the front side from the nozzle operating hole  31  (the cover body  30 ) and the operation lever  81  becomes parallel to the left and right directions to indicate the retracting state of the nozzle  21 . At this time, the nozzle cam  90  is supported at the nozzle retracting state at the front side by the biasing force of the cam pushing spring  43 . 
     In a case where the pushing member  80  and the nozzle cam  90  are in the nozzle retracting state, the lower protrusion  93  of the nozzle cam  90  is located at the front side from the locking cam  53  of the cover locking part  50 . Here, if the locking cam  53  is rotated, since the rotation restricting part  63  of the locking cam  53  does not come into contact with the lower protrusion  93 , the locking cam  53  can be rotated in the counterclockwise direction. That is, the locking lever  51  can be rotated in the clockwise direction and the cover locking part  50  can be set to the unlocking state. 
     Next, when the pushing member  80  in the nozzle retracting state is pushed to the rear side against the biasing force of the cam pushing spring  43 , the nozzle cam  90  is moved to the rear side. As the nozzle cam  90  is moved, the nozzle  21  supported by the nozzle cam  90  is moved to the rear side, inserted in the inflow port  18  of the waste ink tank  17  installed in the tank installed part  23 , and then, located at the projecting position at the rear side. When the nozzle  21  is inserted in the waste ink tank  17 , it is possible to turn on the power source of the printer  1  and to set the printer  1  to the activation condition. 
     At this time, the plurality of flange gaps  83  of the pushing member  80  are moved to the rear side from the plurality of ribs  73  of the cylindrical wall  70 , and then, rotation of the pushing member  80  is allowed. Here, as shown in  FIG. 32 , when the push member  80  is rotated to the activation position, each of the plurality of locking recessed portions  84  of the pushing member  80  is located so as to correspond to the rib  73  of the cylindrical wall  70 , and then, the pushing member  80  is restricted from moving to the front side regardless of the biasing force of the cam pushing spring  43 . 
     As described above, when the nozzle cam  90  sets the nozzle  21  to the projecting state, as shown in  FIG. 24 , the pushing member  80  is housed in the cylindrical wall  70  and is retracted to the rear side from the nozzle operating hole  31  (the cover body  30 ) and the operation lever  81  becomes parallel to the upward and downward directions to indicate the projecting state of the nozzle  21 . At this time, the nozzle cam  90  is supported at the nozzle projecting state at the rear side by the pushing member  80  restricted from moving to the front side. 
     In a case where the pushing member  80  and the nozzle cam  90  are in the nozzle projecting state, the lower protrusion  93  of the nozzle cam  90  is located at the rear side from the locking cam  53  of the cover locking part  50 . Here, the lower protrusion  93  is located at downstream side just before the rotation restricting part  63  of the locking cam  53  in the counterclockwise direction, and then, rotation of the locking cam  53  in the counterclockwise direction is restricted by contact of the rotation restricting part  63  to the lower protrusion  93 . That is, the locking lever  51  is restricted from rotating in the clockwise direction and the cover locking part  50  is restricted from setting to the unlocking state. 
     Incidentally, in the second embodiment, the cover locking part  50  is configured similar to the first embodiment, and the locking cam  53  of the cover locking part  50  has the inner diameter slightly larger than an outer diameter of the cylindrical wall  70  and is rotatably fitted outside the cylindrical wall  70  along an outer circumference of the cylindrical wall  70 . Therefore, the notch  60  and the recessed portion  62  of the locking cam  53  compose the push allowing part allowing pushing operation of the pushing member  80  of the nozzle operating part  40 . 
     That is, when the cover locking part  50  is set to the locking state and the locking cam  53  is rotated in the clockwise direction, the notch  60  and the recessed portion are located at the same positions as the upper and lower slits  71  of the cylindrical wall  70  of the cover body  30 . Subsequently, since the upper protrusion  92  and the lower protrusion  93  of the nozzle cam  90  become movable through the slits  71  and the notch  60  and the recessed portion  62  in the forward and backward directions, movement of the pushing member  80  and the nozzle cam  90  in the forward and backward directions is allowed, that is, pushing operation of the pushing member  80  is allowed. 
     In other words, when the cover locking part  50  is in the locking state, in a case where the pushing member  80  is in the nozzle projecting state, the cover locking part  50  cannot be set to the unlocking state, but, in a case where the pushing member  80  is in the nozzle retracting state, the cover locking part  50  can be set to the unlocking state. 
     When the cover locking part  50  is set to the unlocking state, the push restricting part  64  of the locking cam  53  is located at the same position as the lower protrusion  93  of the pushing member  80 . At this time, since the lower protrusion  93  is located at the front side from the push restricting part  64  of the locking cam  53 , movement of the pushing member  80  and the nozzle cam  90  to the rear side is restricted by contact of the lower protrusion  93  to the push restricting part  64 , that is, pushing operation of the pushing member  80  is restricted. In other words, when the cover locking part  50  is in the unlocking state, the pushing member  80  cannot be switched from the nozzle retracting state to the nozzle projecting state. 
     Although the embodiments was described as example about a case applying the configuration of the present disclosure to the printer  1 , the disclosure is not limited by this example, and the disclosure may be applied to, for example, another image forming apparatus, such as a copying machine, a facsimile or a multifunction peripheral. 
     While the present disclosure has been described with reference to the particular illustrative embodiments, it is not to be limited by the embodiments. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present disclosure.