Abstract:
The present invention relates to an ink supplying apparatus capable of achieving labor-saving of the cleaning operation and shortening of the working time at ink replacement or the like in a printing press. This ink supplying apparatus is equipped with an ink tray provided in the interior of an ink fountain and having a bottom plate which covers upper surfaces of ink keys, and further equipped with a deflection restraining structure for supporting the bottom plate from below to restrain the deflection of the ink tray.

Description:
BACKGROUND OF THE INVENTION 
     1) Field of the Invention 
     The present invention relates to an ink supplying apparatus for use in a printing press such as a rotary press or a sheet-fed printing press, and more particularly to an ink supplying apparatus equipped with an ink tray attachable/detachable to an ink fountain. 
     2) Description of the Related Art 
     As FIGS. 16 and 17 show, a printing press such as a rotary press or a sheet-fed printing press is provided with an ink supplying apparatus  100  in which an ink fountain  102  is placed in front of an ink fountain roller  101 . The ink fountain  102  is composed of a circumferential surface of the ink fountain roller  101 , a plurality of ink keys (blades)  103  constituting a bottom section of the ink fountain  102 , and two side plates  104  (only one on the interior side is shown in FIG. 16) provided at both side surfaces of each of the ink keys  103  so that their front edges come into contact with the circumferential surface of the ink fountain roller  101  to slide thereon. In this construction, an ink lying within the ink fountain  102  is supplied through a gap between the ink fountain roller  101  and the tip portion of each of the ink keys  103  to the ink fountain roller  101  and then transferred through a non-shown ink ductor roller to a group of ink rollers lying on the downstream side. 
     The plurality of ink keys  103  are, as shown in FIG. 17, arranged in parallel with each other in a lateral direction of the apparatus so that the ink keys  103 ,  103  adjacent to each other are brought into contact with each other while both the end ink keys  103  and the side plates  104  are brought into contact with each other. In addition, the ink keys  103  are made to be driven independently of each other to rock or swing about a supporting shaft  105 , and an ink quantity control device  106  is situated under the respective ink keys  103 . 
     The ink quantity control device  106  is provided with an adjusting cam  106   b  engaging with a lower surface of the tip portion of each of the ink keys  103  and a pusher  106   a  brought into contact with the adjusting cam  106   b  to rock the adjusting cam  106   b  by its telescopic motion, namely, protruding/retracting movements. Additionally, the tip portion of each of the ink keys  103  is driven to rock in a manner that the pusher  106   a  is operated appropriately to protrude/retract for rocking the adjusting cam  106   b  so that its engaging portion of the adjusting cam  106   b  with the ink key  103  lifts/lowers, thereby controlling the gap between the ink key  103  and the ink fountain roller  101  to adjust the thickness of the ink film to be supplied. 
     Meanwhile, in the aforesaid conventional ink supplying apparatus  100 , a microscopic gap is secured between the adjacent ink keys  103 ,  103  and between both the end ink keys  103  and the side plates  104  in order to permit the mutual sliding motion. Accordingly, there is a possibility that the ink permeates through the very small gap, for example, between the ink keys  103 ,  103  by the capillary phenomenon or the like. If the ink is hardened after permeating through the gap between the ink keys  103 ,  103 , the operation of the ink keys  103  becomes unstable and the worst case reaches the difficulty of movement thereof, so that a problem exists in that the high-accuracy control of the ink film becomes impossible. 
     In addition, after the completion of printing or in the ink replacement, although there is a need to clean the interior of the ink fountain  102  by wiping off the ink remaining in the interior of the ink fountain  102  with a waste or the like, or by washing it off with a cleaning solvent, the removal of the ink is difficult because the ink shows a high viscosity. Particularly, difficulty is experienced in removing the ink permeating into the gap between the ink keys  103 ,  103  so that a severe burden falls on the cleaning worker. Still additionally, although, for improving the productivity, there is a need to shorten the preparation for the order change for enhancing the availability factor of the apparatus, if the load on the cleaning in the ink replacement is severe as mentioned above, the cleaning takes time largely. For this reason, it has been desired strongly to relieve the burden to be imposed on the worker through the labor-saving in the cleaning operation and further to enhance the availability factor of the apparatus through the shortening of the cleaning time. 
     SUMMARY OF THE INVENTION 
     The present invention has been developed in consideration of the above-mentioned problems, and it is therefore an object of the invention to provide an ink supplying apparatus which is capable of achieving the labor-saving of the cleaning operation and the shortening of the working time in ink replacement or the like of a printing press. 
     For this purpose, an ink supplying apparatus according to this invention involves the following features. 
     That is, an ink supplying apparatus according to this invention is equipped with an ink fountain roller, left- and right-hand side plates brought into sliding contact with a circumferential surface of the ink fountain roller to constitute a side wall section of an ink fountain, a plurality of ink keys arranged in parallel with each other to constitute a bottom section of the ink fountain and a supporting base for supporting the side plates and the plurality of ink keys, the ink supporting apparatus is characterized by comprising an ink tray having a bottom plate placed in the interior of the ink fountain for covering upper surfaces of the ink keys and a deflection restraining structure for supporting the bottom plate from below to restrain a deflection or bending of the ink tray. 
     In this way, since the ink tray covering the upper surfaces of the ink keys is provided in the interior of the ink fountain, the contact area of the ink keys with the ink is reducible considerably to reduce the possibility of the permeation of the ink into the gap between the ink keys, thereby stabilizing the operations of the ink keys and shortening the cleaning time of the interior of the ink fountain to improve the productivity. In addition, at the mounting of the ink tray in the ink fountain, since the deflection restraining structure supports the bottom plate from below to limit the deflection thereof, the weight reduction of the ink tray becomes feasible to provide easy handling of the ink tray, thus further improving the productivity. 
     Preferably, the aforesaid deflection restraining structure is made up of a supporting member protruding downwardly from a bottom surface of the bottom plate and a through hole made from an upper surface of the ink key to a bottom surface thereof so that, when the ink tray is mounted in the ink fountain, a lower end portion of the supporting member is brought into contact with the supporting base in a state of passing through the through hole to support the bottom plate. 
     With this construction, the deflection restraining structure can support the bottom plate from below without interfering with the ink key. 
     Alternatively, the deflection restraining structure is made up of a supporting member protruding upwardly from the supporting base and a through hole made to a location of the supporting member to extend from an upper surface of the ink key to a bottom surface thereof so that, when the ink tray is mounted in the ink fountain, a tip portion of the supporting member projecting through the through hole onto an upper surface of the ink key is brought into contact with the bottom plate of the ink tray to support the bottom plate. 
     Also with this construction, the deflection restraining structure can support the bottom plate from below without interfering with the ink key. Additionally, because the supporting member is installed on the supporting base without being required to be placed on each of ink trays, the increase in cost is suppressible. 
     Preferably, the supporting member is made to be attachable/detachable to/from the supporting base. This facilitates the replacement of the supporting member and permits the cleaning in a state removed. 
     Still alternatively, the aforesaid deflection restraining structure is made up of a first supporting member protruding downwardly from the bottom surface of the bottom plate, a second supporting member protruding upwardly from the supporting base in connection with the first supporting member and a though hole made to the location of the second supporting member to extend from a surface of the ink key to the bottom surface so that, when the ink tray is mounted in the ink fountain, a lower end portion of the first supporting member is brought into contact with a tip portion of the second supporting member to support the bottom plate. 
     Similarly, with this construction, the deflection restraining structure can support the bottom plate from below without interfering with the ink key. Additionally, owing to shortening the each of the supporting members, the possibility of bending thereof is reducible at handling. 
     Preferably, the lower end portion of the first supporting member and the tip portion of the second supporting member are brought into contact with each other in the interior of the through hole. This eliminates the troubles in the cleaning of the surface of the ink key because the second supporting member does not appear from the surface of the ink key at the removal of the ink tray. 
     Furthermore, in each of the aforesaid constructions, it is also possible that the supporting member is located to support the bottom plate at a central portion of the ink tray in its cross (width) direction. Accordingly, the supporting member supports the cross-direction central portion of the ink tray showing the largest deflection, thus restraining the deflection thereof with high efficiency. 
     Still furthermore, it is also acceptable that a plurality of supporting members are provided in a cross direction of the apparatus. This supports the bottom plate of the ink tray in the apparatus cross direction through the use of the plurality of supporting members, thus restraining the deflection with higher efficiency. 
     Yet furthermore, it is also acceptable that the through hole has an elongated slit-like configuration extending in a longitudinal (forward and backward) direction of the ink key. In this case, the interference between the supporting member and the ink key is preventable. 
     Moreover, it is also possible that the through hole is made between the ink keys adjacent to each other. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view schematically showing a construction of an ink supplying apparatus according to a first embodiment of the present invention; 
     FIG. 2 is a perspective view showing a construction of an ink tray for the ink supplying apparatus according to the first embodiment of this invention; 
     FIG. 3 is a side elevational view showing a construction of an ink tray for the ink supplying apparatus according to the first embodiment of this invention; 
     FIG. 4 is an illustration of an engaging state between an ink tray and an ink fountain in the ink supplying apparatus according to the first embodiment of this invention, with a bracket being shown partially in a broken state; 
     FIG. 5 is a side elevational view showing a deflection restraining structure for an ink tray in the ink supplying apparatus according to the first embodiment of this invention, where the ink tray is in a mounted condition; 
     FIG. 6 is a side elevational view showing the deflection restraining structure for the ink tray in the ink supplying apparatus according to the first embodiment of this invention, where the ink tray is in a removed condition; 
     FIG. 7A is an illustration of the deflection restraining structure for the ink tray in the ink supplying apparatus according to the first embodiment of this invention, including one example of the positional relationship between a supporting member and a slit; 
     FIG. 7B is an illustration of the deflection restraining structure for the ink tray in the ink supplying apparatus according to the first embodiment of this invention, including another example of the positional relationship between a supporting member and a slit; 
     FIG. 8 is a side elevational view showing a further deflection restraining structure for an ink tray in the ink supplying apparatus according to the first embodiment of this invention, where the ink tray is in a mounted condition; 
     FIG. 9 is a side elevational view showing the further deflection restraining structure for the ink tray in the ink supplying apparatus according to the first embodiment of this invention, where the ink tray is in a detached condition; 
     FIG. 10A is an illustration of the further deflection restraining structure for the ink tray in the ink supplying apparatus according to the first embodiment of this invention, including one example of positional relationship between a supporting member and a slit; 
     FIG. 10B is an illustration of the further deflection restraining structure for the ink tray in the ink supplying apparatus according to the first embodiment of this invention, including another example of positional relationship between a supporting member and a slit; 
     FIG. 11 is a side elevational view showing a deflection restraining structure for an ink tray in an ink supplying apparatus according to a second embodiment of this invention, where the ink tray is in a mounted condition; 
     FIG. 12 is a side elevational view showing the deflection restraining structure for the ink tray in an ink supplying apparatus according to the second embodiment of this invention, where the ink tray is in a detached condition; 
     FIG. 13A is an illustration of the deflection restraining structure for the ink tray in the ink supplying apparatus according to the second embodiment of this invention, including one example of positional relationship between a supporting member and a slit; 
     FIG. 13B is an illustration of the deflection restraining structure for the ink tray in the ink supplying apparatus according to the second embodiment of this invention, including another example of positional relationship between a supporting member and a slit; 
     FIG. 14 is a side elevational view showing a deflection restraining structure for an ink tray according to a further embodiment of this invention, where the ink tray is in a mounted condition; 
     FIG. 15 is a side elevational view showing the deflection restraining structure for the ink tray according to the further embodiment of this invention, where the ink tray is in a detached condition; 
     FIG. 16 is a side elevational view illustratively showing a construction of a conventional ink supplying apparatus; and 
     FIG. 17 is a top view illustratively showing the interior of an ink fountain in the construction of the conventional ink supplying apparatus. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An ink supplying apparatus according to a first embodiment of the present invention will be described hereinbelow with reference to FIGS. 1 to  7 B. 
     The description starts at the outline of a construction of this ink supplying apparatus. As FIG. 1 shows, the ink supplying apparatus, designated generally at reference numeral  2 , is equipped with an ink fountain  23  defined by a circumferential surface of an ink fountain roller  20 , ink keys  21  and side plates  22  so that an ink is put in the ink fountain  23  and supplied to the ink fountain roller  20  in printing. A plurality of ink keys  21  are arranged in a cross (transverse) direction of the apparatus in a state of coming closely into contact with each other, and their rear end portions are supported rotatably by a supporting shaft  18  set on a supporting base  24 . The side plates  22  are fixedly secured onto the supporting base  24  in a state where the ink keys  21  are interposed therebetween, and their front end portions are brought into sliding contact with the circumferential surface of the ink fountain roller  20 . 
     In addition, under the ink fountain  23 , a horizontal beam  5  is installed to support components constituting the ink fountain  23 , and an ink quantity control device  25  is set on this horizontal beam  5 . The ink quantity control device  25  is made up of an adjusting cam  26  engaging with a lower surface of the tip portion of each of the ink keys  21 , and a pusher  27  made to be brought into contact with the adjusting cam  26  at its tip portion and, further, to be protruded and retracted (extensible/contractible) in the forward and backward directions in accordance with the rotations of a knob  28  or a motor  29 . Accordingly, if the pusher  27  is protruded or retracted suitably to lift or lower the adjusting cam  26  in a state where the adjusting cam  26  rocks or swings around a supporting point  26   a , then the tip portion of each of the ink keys  21  is driven to rock, thereby controlling the gap between the ink key  21  and the ink fountain roller  20  to adjust the thickness of an ink film to be supplied thereinto. Add to it that, under the tip portions of the ink keys  21 , a first ink receiver  6 A is placed to receive the ink dropping from the ink keys  21  and guides  6 C,  6 D are situated to guide the ink from the interior of the first ink receiver  6 A to a second ink receiver  6 B. 
     Still additionally, this ink supplying apparatus  2  is provided with an ink tray  30  placed detachably in the interior of the ink fountain  23 . As FIGS. 2 to  4  show, the ink tray  30  is made up of side walls  31 ,  31  formed in corresponding relation to the left- and right-hand side plates  22 ,  22  of the ink fountain  23 , and a bottom plate  32  set in a state where its tip side is tilted downwardly to the ink keys  21  constituting a bottom section of the ink fountain  23 . 
     The rear end portion of the bottom plate  32  is extended outwardly and downwardly to form a cover  34  for preventing the adhesion of the ink to the supporting base  24 . Additionally, a fin  33 , serving as a supporting member, is formed on a bottom surface of the bottom plate  32 . A detailed description of this fin  33  will be given herein later. 
     Brackets  36 ,  36  are fixedly secured onto the upper end portions of the side walls  31 ,  31  of the ink tray  30 , respectively, in a state directed outwardly. When the ink tray  30  is mounted in the ink fountain  23 , these brackets  36 ,  36  are placed on the side plates  22 ,  22 , and the ink tray  30  is put to form a bridge between the side plates  22 ,  22 . A handle  37  is set on an upper surface of each of the brackets  36 . 
     This ink tray  30  covers most of the ink keys  21  and the side plates  22  (these sections will be referred to hereinafter as coated sections) so that they do not come directly into contact with the ink within the ink fountain  23 , whereas the upper surface of the tip portion of each of the ink keys  21  and the inner surface of the tip portion of each of the side plates  22 , which slide on the ink fountain roller  20  in a state where an ink liquid film is interposed therebetween, are exposed so as to come directly into contact with the ink within the ink fountain  23  without being covered with the ink tray  30  (these sections will be referred to hereinafter as an exposed section) That is, the inner circumferetial surface of the ink fountain  23  is formed by an inner surface of the ink tray  30 , an upper surface of the exposed section (the tip portion)  21 A of each of the ink keys  21 , an exposed section  22 A of each of the side plates  22  and an outer circumferential surface of the ink fountain roller  20 . 
     The portion between the ink tray  30  and the tip portion (exposed section)  21 A of each of the ink keys  21  or the portion between the ink tray  30  and the exposed section  22 A of each of the side plates  22  constitutes a joint of the ink fountain  23 , and these portions require sealing processing. For this reason, holders  31   c  and  32   c  are set in an outer surfaces of the tip portions of the side walls  31 ,  31  and the bottom plate  32 , respectively, with a packing (sealing member)  38  having a continuous sealing surface being fitted in the holders  31   c  and  32   c.    
     In a state where the ink tray  30  is mounted in the ink fountain  23 , of the packing  38 , portions fitted in the holders  31   c  made in the outer surfaces of the tip portions of the side walls  31  are brought under pressure into contact with steps  22   a  formed on inner surfaces of the side plates  22  of the ink fountain  23 , and of the packing  38 , a portion fitted in the holder  32   c  made in the outer surface of the tip portion of the bottom plate  32  is brought under pressure into contact with a step  21   a  (see FIG. 1) formed on an upper surface of the tip portion of each of the ink keys  21 . 
     In addition, this packing  38  seals the portions between the tip portions of the side walls  31 ,  31  of the ink tray  30  and the side plates  22 ,  22  of the ink fountain  23  and the portions between the tip portion of the bottom plate  32  of the ink tray  30  and the upper surfaces of the ink keys  21  of the ink fountain  23  so that the ink leakage from the ink fountain  23  is preventable at the joints between the ink tray  30  and the ink keys  21  and between the ink tray  30  and the side plates  22 . 
     The fixing of the ink tray  30  to the ink fountain  23  is made by a pressing device  40  (see FIG. 1) set on the supporting base  24 . That is, by tightening a fixing screw  41  of the pressing device  40 , rear inclined surfaces  36 a (see FIG. 3) of the left- and right-hand brackets  36  are pushed toward the tip of the ink tray  30  (toward the gap between the ink keys  21  and the ink fountain roller  20 ) to fixedly secure the ink tray  30  in a state where the packing  38  of the ink tray  30  is pressed against the steps  22   a  and  21   a  (see FIGS. 1 and 4) of the ink fountain  23 . 
     Furthermore, as FIGS. 1 to  4  show, bolts  39  for positioning the ink tray  30  are set in front end portions  36   b  of the left- and right-hand brackets  36 . The mounting position of the ink tray  30  in the forward and backward directions is determined in a manner that these positioning bolts  39  are brought into contact with projecting portions  22   b  formed on upper surfaces of the side plates  22 . The position of the ink tray  30  in the forward and backward directions is adjustable by controlling the tightening quantity of the positioning bolts  39 , while the position thereof in the vertical (height) directions is adjustable by height control screws  35  set in the brackets  36 . 
     As described above, since the ink tray  30  is detachably set in the interior of the ink fountain  23 , the contact area of the ink keys  21  with the ink is considerably reducible to lower the possibility that the ink permeates into the gap between the ink keys  21 ,  21 , which not only stabilizes the operations of the ink keys  21  but also shortens the cleaning time of the interior of the ink fountain  23 , thus improving the availability factor of the apparatus and the productivity. 
     Meanwhile, although the attachment/detachment of the ink tray  30  to/from the interior of the ink fountain  23  are conducted with the left- and right-hand handles  37 ,  37  being held by the operator, if this handling constitutes a burden imposed on the operator, the aforesaid effect of the improvement of productivity is lessened accordingly. Thus, there is a need to reduce the weight of the ink tray  30  for lightening the burden thereon in handling. 
     However, for the weight reduction of the ink tray  30 , the bottom plate  32  and the side walls  31  are naturally made from thin steel products. In this case, since the ink tray  30  has an elongated configuration in the cross (width) direction of the apparatus as shown in FIG. 2, its cross-direction rigidity decreases so that a deflection occurs at the bottom plate  32  when it is put to form a bridge between the side plates  22 ,  22 . Although the tip portion of the bottom plate  32  contacts with the steps  21   a  on the tip portions of the ink keys  21  in a state where the packing  38  is interposed therebetween, if consideration is given to the facility when the remaining ink is scraped out by a knife or the like for cleaning, it is desirable that the section between the bottom plate  32  and the tip portions of the ink keys  21  has a flat configuration. However, if the deflection of the bottom plate  32  occurs, a step occurs between the vicinity of the central portion of the bottom plate  32  and the tip portions of the ink keys  21 , which throws hindrances in the way of scraping out the remaining ink by a knife or the like. What&#39;s worse, the deflection of the bottom plate  32  can create gaps at the contacting portions with the ink keys  21  or the side plates  22  to allow the ink leakage therefrom. 
     For this reason, in this ink supplying apparatus  2 , the fin  33  is formed on the bottom surface of the bottom plate  32  of the ink tray  30  as stated above, and when the ink tray  30  is mounted in the ink fountain  23 , this fin  33  supports the bottom plate  32  to restrain the deflection of the ink tray  30 . This deflection restraining structure will be described hereinbelow with reference to FIGS. 5 to  7 B. Incidentally, the ink tray  30  shown in FIGS. 5 and 6 is different in shapes of the brackets  36  and the handles  37  from that shown in FIGS. 1 to  4 . However, these illustrations are for showing another construction of this ink tray  30 , and the function thereof is substantially the same. The fin  33  is formed to have an elongated configuration in the longitudinal direction and is installed at a forward central portion of the bottom plate  32 . The height of the fin  33  is set to match the distance from the bottom plate  32  to the supporting base  24  in a state where the bottom plate  32  does not deflect. 
     In addition, to the position of the fin  33  provided on the bottom plate  32 , a through hole (slit)  21   c  elongated in the longitudinal (forward and backward) directions is formed as shown in FIGS. 7A and 7B. 
     FIG. 7A shows an example in which the fin  33  is just positioned between the ink keys  21 ,  21 , while FIG. 7B shows an example in which the fin  33  is positioned directly above the ink key  21 . The width of the slit  21   c  is set to be wider than that of the fin  33 , and the length thereof in the forward and backward directions is set to afford a margin on the rear end side in consideration of the mounting angle of the ink tray  30  with respect to the ink key  21 . 
     That is, as FIG. 6 shows, since the step  22   a  of each of the side plates  22  is set at an acute angle with respect to the ink key  21 , the mounting of the ink tray  30  from the right above the ink key  21  is difficult, and it is mounted at, at least, an acuter angle than the angle the step  22   a  makes with respect to the ink key  21 . Accordingly, if the length of the slit  21   c  does not afford a margin with respect to the length of the fin  33 , the fin  33  interferes with the ink key  21  at the attachment/detachment of the ink tray  30 . For this reason, the length of the slit  21   c  is set to have a margin on the rear end side in accordance with the mounting angle of the ink tray  30 . 
     With the construction of the ink supplying apparatus according to the first embodiment of this invention, when the ink tray  30  is mounted in the ink fountain  23 , the fin  33  formed on the bottom plate  32  comes into contact with the supporting base  24  to support the central portion of the bottom plate  32 . Accordingly, the deflection of the bottom plate  32  does not occur, and the section from the bottom plate  32  to the upper surface of the tip portion of the ink key  21  is maintained flat at all times. Additionally, a proper contacting condition is maintainable between the step  21   a  of each of the ink keys  21  and the step  22   a  of each of the side plates  22 . 
     As described above, according to this ink supplying apparatus, since the fin  33  supports the bottom plate  32  to restrain the deflection of the bottom plate  32 , the ink tray  30  is constructible with thin steel products for weight reduction. Add to it that the weight reduction facilitates the handling of the ink tray  30  so that the productivity further improves. Particularly, in the case of a printing press having a large width dimension, the width dimension of the ink tray also increases so that the ink tray tends to deflect and its weight gains; therefore, the employment of this ink supplying apparatus offers a great effect in this respect. 
     Incidentally, in addition to the above-mentioned case in which only one fin  33  is provided at the center of the bottom plate  32 , it is also appropriate that a plurality of fins  33  are provided in the cross direction. At this time, it is also possible that the method in which the slit  21   c  is formed between the ink keys  21 ,  21  to accept the fin  33  as shown in FIG.  7 A and the method in which the slit  21   c  is made in the ink key  21  to accept the fin  33  as shown in FIG. 7B are used jointly in accordance with the location of the fin  33 . In this case, because the plurality of fins  33  support the bottom plate  32 , the deflection is more suppressible. 
     Furthermore, the supporting member is not limited to the aforesaid longitudinally elongated fin  33 , but it is also appropriate to use a round-bar-like pin  50  as shown in FIGS. 8 to  10 B. Also in this case, it is also possible that, as shown in FIG. 10A, the slit  21   a  is made between the ink keys  21 ,  21  to accommodate the pin  50 , or that, as shown in FIG. 10B, the slit  21   c  is made in the ink key  21  to accommodate the pin  50 . Also in this embodiment, as shown in FIG. 8, the slit  21   c  is formed to have a sufficient margin, namely, a length passing the position of the pin  50  at the installation of the ink tray  30  so that the pin  50  does not interfere with the ink key  21  at the attachment/detachment of the ink tray  30 . 
     Secondly, a description will be made hereinbelow of an ink supplying apparatus according to a second embodiment of this invention. The ink supplying apparatus according to this embodiment differs in structure for supporting the bottom plate  32  of the ink tray  30  from the first embodiment. Referring to FIGS. 11 to  13 B, a description will be given hereinbelow of the structure for supporting the bottom plate  32  in this ink supplying apparatus. 
     As FIGS. 11 and 12 show, in this ink supplying apparatus, a column  51  is planted in the supporting base  24 . In the supporting base  24 , a vertical hole  24   a  is bored to the position of a front end central portion of the bottom plate  32  at the mounting to the ink fountain  23 , and the column  51  is fitted detachably in this vertical hole  24   a  . The height from the upper end of the column  51  to the supporting base  24  is set to match the distance from the bottom plate  32  to the supporting base  24  in the case of no occurrence of deflection of the bottom plate  32 . 
     In addition, to match the position of the column  51  installed on the supporting base  24 , a through hole  21   d  is made as shown in FIGS. 13A and 13B. FIG. 13A illustrates an example in which the column  51  is positioned just between the ink keys  21 ,  21 , while FIG. 13B illustrates an example in which the ink key  21  is positioned above the column  51 . The diameter of the through hole  21   d  is set to be larger than, at least, the diameter of the column  51 , and is formed to have a configuration extending toward the front end side of the ink key  21  with respect to the column  51 . This is for preventing the interference between the through hole  21   d  and the column  51  which will occur when the ink key  21  is rotated around the supporting shaft  18  at cleaning, maintenance or the like. 
     Since the ink supplying apparatus according to the second embodiment of this invention is constructed thus, when the ink tray  30  is set in the ink fountain  23 , the column  51  placed on the supporting base  24  comes into contact with the bottom plate  32  of the ink tray  30  to support the central portion of the bottom plate  32 . Accordingly, the bottom plate  32  is prevented from its deflection, and the section from the bottom plate  32  to the upper surface of the tip portion of the ink key  21  is maintained in a flat condition at all times. Additionally, the contacting condition between the step  21   a  of the ink key  21  and the step  22   a  of the side plate  22  is kept properly. 
     As described above, according to this ink supplying apparatus, since the column  51  can support the bottom plate  32  to restrain the deflection of the bottom plate  32 , as well as the first embodiment, the ink tray  30  can be made from thin steel products for the weight reduction and the handling of the ink tray  30  becomes easy, thus improving the productivity. 
     In addition, because a plurality of ink trays  30  are required for one ink supplying apparatus, although the first embodiment requires the fin  33  for each of the ink trays  30 , this embodiment requires only the column  51  placed on the supporting base  24 ; therefore, the increase in cost is suppressible. Still additionally, in the case in which the fin  33  is provided for each of the ink trays  30 , in many cases, the difference in precision there among exists. On the other hand, in this embodiment, since the positioning of the bottom plate  32  is accomplished by the column  51  placed on the supporting base  24 , a higher accuracy is easily attainable. 
     Moreover, since the column  51  is attachable/detachable to/from the supporting base  24 , the replacement thereof is easy and the cleaning thereof is possible in a state detached therefrom. 
     Incidentally, in addition to the above-mentioned case in which only one column  51  is provided to the center, it is also appropriate that a plurality of columns  51  are provided in the cross direction. At this time, it is also possible that the method in which, as shown in FIG. 13A, the through hole  21   d  is made between the ink keys  21 ,  21  so that the column  51  is inserted thereinto and the method in which, as shown in FIG. 13B, the through hole  21   d  is made in the ink key  21  so that the column  51  is inserted thereinto are used jointly in accordance with the location of the column  51 . In this case, because the plurality of columns  51  support the bottom plate  32 , the deflection is more suppressible. 
     In addition, the column  51  is not limited to the aforesaid detachable structure, but it is also acceptable to fixedly secure it to the supporting base  24 . Still additionally, the supporting member is not limited to the aforesaid column  51  having a circular-bar-like configuration, it is also possible that it has a fin-like configuration as well as the first embodiment. 
     Although the two embodiments related to the ink supplying apparatus according to this invention have been described above, it should be understood that this invention is not limited to the above-described embodiments, and that it is intended to cover all changes of the embodiments in the range which does not constitute departures from the spirit of the invention. For example, it is also possible to employ a combination of the above-described two embodiments. That is, as FIGS. 14 and 15 indicate, a pin (first supporting member)  52  is provided on the bottom plate  33  of the ink tray  30  and a column (second supporting member)  53  is vertically set on the supporting base  24  to match the position of a pin  51 so that the column  53  supports the pin  52 , thereby preventing the occurrence of the deflection of the bottom plate  32 . 
     At this time, if the pin  52  and the column  53  are, as shown in FIG. 14, made to come into contact with each other in the interior of a through hole  21   e , when the ink tray  30  is detached therefrom, they do not appear from the surface of the ink key  21 , which makes it possible to eliminate the hindrance at the cleaning of the surface of the ink key  21 . Still additionally, since it is possible to shorten the length of the pin  52  set on the ink tray  30 , the possibility of bending thereof decreases, thus improving the precision at the mounting thereof.