Abstract:
To make a line head chassis detachable simply and easily in an inkjet recording apparatus, a jig for the line head chassis is provided which comprises: a first support member mounted on a table lateral to the inkjet head; a second support member mounted laterally to and lower than the first support member; a rail member mounted laterally to the first support member and having one end connected thereto; an upright support member having its lower end supported by the second support member adjustably in its height direction and its upper end connected to the other end of the rail member for supporting the rail member horizontally; a base table slidably supported on the rail member to move over a distance outward from a maintenance position; and a cradle means supported on the base table so as to be movable perpendicularly to a direction in which the base table moves for accepting the line head chassis, wherein one end of the rail member and the lower end of the upright support member are made engageable with/disengageable from the first and second support members, respectively.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Technical Field  
         [0002]     The present invention relates to an inkjet recording apparatus having an inkjet head comprising a line head chassis having a plurality of unit heads each of which has numbers of ink nozzles and which are arranged in a line in a direction of width of a printable material and a controller housing that can be moved between a printing position and a maintenance position lateral to the printing position wherein the line head chassis can be attached to and detached from the controller housing. In particular, the invention relates to a line head chassis detachably attaching jig for use in detaching and attaching such a line head chassis from and to the controller housing at the maintenance position.  
         [0003]     2. Description of the Prior Art  
         [0004]     Attaching and detaching a line head chassis from a controller housing has hitherto been effected manually by an operator. See, for example, JP H09-1789 A.  
         [0005]     In the prior art as mentioned above where the line head chassis is configured to be taken into and out of the controller housing at a fixed position in an inkjet head, the manual operation does not pose quite a problem. However, in the state that a controller housing has been moved to its maintenance position, the operation of manually detaching and attaching a line head chassis from and to the controller housing is becoming difficult as the line head chassis becomes large in weight.  
       SUMMARY OF THE INVENTION  
       [0006]     With the above taken into account, it is an object of the present invention to provide a line head chassis detachably attaching jig in an inkjet recording apparatus which enables a line head chassis to be simply and easily detached from and attached to a controller housing in an inkjet head in the state that the inkjet head has been moved to its maintenance position.  
         [0007]     In order to achieve the object mentioned above, the present invention provides, in an inkjet recording apparatus having an inkjet head comprising a controller housing that can be moved between a printing position and a maintenance position lateral to the printing position and a line head chassis that can be attached to and detached from the controller housing, a jig for the line head chassis characterized in that it comprises a first support member mounted on a table lateral to the inkjet head; a second support member mounted laterally to and lower than the first support member; a rail member mounted laterally to the first support member and having one end connected thereto; an upright support member having its lower end supported by the second support member adjustably in its height direction and its upper end connected to the other end of the rail member for supporting the rail member horizontally; a base table slidably supported on the rail member to move over a distance outward from the maintenance position; and a cradle means supported on the base table so as to be movable perpendicularly to a direction in which the base table moves for accepting the line head chassis, wherein one end of the rail member and the lower end of the upright support member are made engageable with/detachable from, the first and second support members, respectively.  
         [0008]     According to the present invention, when in an inkjet recording apparatus a line head chassis is to be detached from and attached to a controller housing in an inkjet head therein, the controller housing may be moved laterally to the inkjet head and then the line head chassis may be placed onto the cradle means which may then be moved outwards to take it out. This eliminates the need for an operator to lean his/her body forward above the apparatus body to support the line head chassis and permits the line head chassis to be attached and detached easily in a simple operation and in a short period of time while improving the workability in maintenance and inspection of the line head chassis.  
         [0009]     And, by eliminating the need for an operator to support the line head chassis and permitting the line head chassis removed to be freely moved together with the cradle means relative to the maintenance position, it is possible to prevent ink nozzle surfaces and the like of the line head chassis from suffering damages, e. g., upon contacting a part of the main body of the inkjet recording apparatus while preventing troubles from occurring in the maintenance of the integrity of the apparatus itself and the safety of the operator.  
         [0010]     Further, according to the makeup mentioned above, by making the rail member and the upright support member engageable with/disengageable from the first and second support members, respectively, which are provided laterally to the inkjet head, it is possible, even in an inkjet recording apparatus equipped with a plurality of inkjet heads, when the first and second support members are in advance provided laterally to each inkjet head, to use all members except both these members for attaching and detaching a line head chassis in an inkjet head and then to economically use a set of jigs for any of the inkjet heads.  
         [0011]     In the jig constructed as mentioned above, a head catch tray for accepting the line head chassis is preferably mounted on the cradle means so that the head catch tray can be engaged with and disengaged from the cradle means.  
         [0012]     By mounting a catch tray for accepting the line head chassis on the cradle means so that the former can be engaged with and disengaged from the latter in this manner, it is possible to accept the line head chassis on the cradle means, thereby to facilitate moving the line head chassis removed from the controller housing. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     In the drawings:  
         [0014]      FIG. 1  is a front view of an inkjet recording apparatus in which the present invention is implemented, seen as a whole from the side of its prime mover;  
         [0015]      FIG. 2  is an explanatory view illustrating the makeup of an inkjet head in the inkjet recording apparatus of  FIG. 1 , shown as in part cut away and decomposed;  
         [0016]      FIG. 3  is a side view illustrating a jig for attaching and detaching a line head chassis that represents one embodiment according to the present invention;  
         [0017]      FIG. 4  is a front view illustrating the line head chassis detachably attaching jig of  FIG. 3  together with a first and a second support member mounted corresponding to each inkjet head;  
         [0018]      FIG. 5  is a cross sectional view illustrating the second support member shown in  FIG. 4 ;  
         [0019]      FIG. 6  is a view taken along the line VI-VI and seen in a direction of the arrow in  FIG. 3 ;  
         [0020]      FIG. 7  is a view taken along the line VII-VII and seen in a direction of the arrow in  FIG. 3 ;  
         [0021]      FIG. 8  is a plan view illustrating a head catch tray for the line head chassis detachably attaching jig shown in  FIGS. 3 and 4 ;  
         [0022]      FIG. 9  is a front view illustrating the head catch tray of  FIGS. 3-8 ;  
         [0023]      FIG. 10  is a cross sectional view illustrating the head catch tray of  FIGS. 3-9 ;  
         [0024]      FIG. 11  is a perspective view illustrating the head catch tray of  FIGS. 3-10 ;  
         [0025]      FIG. 12  is a front view illustrating that the line head chassis detachably attaching jig shown in  FIGS. 3-11  is used; and  
         [0026]      FIG. 13  is a front view illustrating the line head chassis detachably attaching jig of  FIG. 3-11  in which the catch tray is shown in the state that it has been moved from the position shown  FIG. 12 . 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0027]      FIG. 1  is a front view of an inkjet recording apparatus in which the present invention is implemented, seen as a whole from the side of its prime mover. In  FIG. 1 , the apparatus is shown to comprise a paper feeding section  1 , a printing section  2 , a machining section  3  and a paper delivery section  4 . Paper  5  (to be printed) fed from the paper feeding section  1  is printed in the printing section  2  and after being at need dried by a drier  6  enters the machining section  3  where it is machined as necessary, and is then delivered to the paper delivery section  4 .  
         [0028]     The printing section  2  comprises a plurality of inkjet heads  2   a ,  2   b ,  2   c  and  2   d , e. g., for yellow, for magenta, for cyanogens and for black, which are arranged in the order in the travel direction of the paper  5 . And, the inkjet heads  2   a  - 2   d  are supported by frames  8  via support units  7 , respectively. Each of the support units  7  is provided with adjustment mechanisms known in the art for adjusting the vertical position of each inkjet head  2   a ,  2   b ,  2   c ,  2   d  relative to the supporting frame  8  and its posture relative to the paper  5 , etc.  
         [0029]     Each of the inkjet heads  2   a  - 2   d  as shown in  FIG. 2  comprises a controller housing  9  supported by the support frame  8  via the support unit  7 , and a line head chassis  11  detachably attached via a support mechanism  10  to the controller housing  9  and provided at an under surface of the line head chassis  11  with a line head  12  having a plurality of unit heads arranged in a line.  
         [0030]     The support mechanism  10  comprises a bracket  13  movable vertically with a selected stroke length relative to the controller housing  9 , and an elevating unit  14  for vertically moving the bracket  13 . The bracket  13  has a pair of arms  13   a  and  13   b  adapted to be opposed to both widthwise side surfaces of the line head chassis  13 , respectively and is formed with horizontal keys  15  and  15  inside of the arms  13   a  and  13   b , respectively.  
         [0031]     On the other hand, the line head chassis  11  is formed in its widthwise side surfaces with a pair of grooves  16  and  16  which are adapted to mate with the keys  15  and  15 , respectively. With the keys  15  and  15  made to mate with the grooves  16  and  16 , the line head chassis  11  is engaged with and supported by the support mechanism  13 . The line head chassis  11  is also provided with a positioning pin  17 .  
         [0032]     The support frame  8  for supporting the controller housing  9  via the support unit  7  as shown in  FIGS. 2 and 3  is provided with rails  18  laid outwards towards the prime mover (at the right hand side in  FIG. 3 ) and on which rails the support unit  7  is supported so that the controller housing  9  is movable horizontally over a distance between a printing position P 1  at which it is opposite to the paper  5  and its maintenance position P 2 . The support frame  8  is also provided with a feed screw  19 , which is in mesh with the support unit  7  and is driven by a drive unit (not shown) to move the controller housing  9  from the position P 1  to the position P 2  and vise versa. In a space between the positions P 1  and P 3  there is provided a nozzle recovery unit  20  which when opposed to the line head  12  can act to purge away soil from its ink nozzles and thereby to recover their printing function.  
         [0033]     In the inkjet recording apparatus constructed as mentioned above, a jig A for detaching the line head chassis is provided in a region of the end of movement of the inkjet head  2   a , . . . ,  2   d  towards the prime mover and is in part detachable.  
         [0034]     This line head chassis detachably attaching jig A is provided in a region on the side of the prime mover from each set position of the inkjet head  2   a , . . . ,  2   d , and comprises a first support member  22  disposed on the upper surface of a auxiliary table  21  on which the nozzle recovery unit  20  is mounted, a second support member  23  mounted to an auxiliary flame  21   a  projecting outwards toward the prime mover from the an lower end portion of the auxiliary table  21 , a rail member  24  whose one end is detachably engaged with the first support member  22 , an upright support member  25  whose one end is detachably engaged with the second support member  23  and whose other end is rotatably connected to the other end of the rail member  24  and which is upright as a whole, a movable table unit  26  movably mounted on the rail member  24 , and a head catch trey  27  mounted on the movable table unit  26 .  
         [0035]     Each auxiliary table  21  corresponding to each inkjet head  2   a , . . . ,  2   d  as shown in  FIG. 4  lies parallel to the lower surface of the line head  12  of each inkjet head  2   a , . . . ,  2   d.    
         [0036]     The first support member  22  comprises a bracket  28  fastened to the auxiliary table  21  and a support bar  29  secured to the bracket  28  to lie in a direction in which the paper  5  travels and which is parallel to the auxiliary table  28 . The support bar  29  used is a round bar and is formed at two places axially with grooves  29   a  and  29   b , respectively.  
         [0037]     The second support member  23  comprises two support fittings  30   a  and  30   b  which are each vertical and positioned side by side in a direction in which the paper  5  travels. The support fittings  30   a  and  30   b  as shown in  FIG. 5  are each formed with a threaded part  31   a  in the lower end of a hole  31 , with which a bolt  32  is engaged facing upwards within the hole  31  of the support fitting  30   a ,  30   b . It is designed that changing the position of thread engagement of the bolt  32  changes the height H of its end from a flour L.  
         [0038]     The rail member  24  is as shown in  FIGS. 3 and 6 , and comprises a pair of parallel rails  24   a  and  24   b  whose respective first and second ends are interconnected by a first and a second coupling fittings  33   a  and  33   b , respectively. And, the coupling fitting  33   a  at the first end is provided below it at two places in a direction orthogonal to the rails  24   a  and  24   b  with engagement pieces  34   a  and  34   b  having at their lower ends yoke portions for engagement from the upside with the grooves  29   a  and  29   b  formed in the support bar  29  of the first support member  22 . These engagement pieces  34   a  and  34   b  have their ends provided with thrust screws  35  in a direction in which to close the yoke portions. It is designed that screwing the thrust screws  35  fastens the engagement pieces  34   a  and  34   b  engaged with the grooves  29   a  and  29   b  of the support bar  29 .  
         [0039]     The upright support members  25  are as shown in  FIGS. 3 and 4  and comprises a pair of posts  25   a  and  25   b  rotatably connected to both ends of the other coupling fitting  33   b  of the rail member  24 . These two posts  25   a  and  25   b  are spaced apart at a distance that is identical to spacing between the support fittings  30   a  and  30   b  of the second support member  23 , and adapted to have their respective lower ends releasably inserted in the holes  31  of the support fittings  30   a  and  30   b , respectively. And, the lower ends of the posts  25   a  and  25   b  are allowed to come in contact with the ends of the bolts  32  in the support fittings  30   a  and  30   b , respectively, to set up the depth of insertion, by which these posts are inserted. Thus, the depth of thread engagement of the bolt  32  can be variably adjusted to variably adjust the height H to its end from the floor L, thereby adjusting the height h 1 , h 2  from the floor L to a point where the posts  25   a  and  25   b  are connected to the coupling fitting  33   b  of the rail member  24 .  
         [0040]     It should be noted here that then, the top surface of the auxiliary table  21  which supports the first support member  22  lies parallel to the paper conveyance line along which the paper  5  travels on the underside of the corresponding inkjet head  2   a  and is not necessarily horizontal; therefore, the support bar  29  of the first support member  22  mounted thereon lies also parallel to the top surface of the auxiliary table  21  and is not horizontal, either. And, the rail member  24  whose one end portion is supported by the support bar  29  of the first support member  22  must be mounted parallel to the top surface of the auxiliary table  21 , requiring that the height h 1 , h 2  from the floor L to the tops of the two posts  25   a  and  25   b  which make up the upright support member  25  supporting the other end portion of the rail member be varied correspondingly. This height adjustment is made by the bolt  32  for the support fittings  30   a  and  30   b.    
         [0041]     The top ends of the posts  25   a  and  25   b  which make up the upright support member  25  are rotatably coupled to the other coupling fitting  33   b  of the rail member  24  and are thereby foldable. To mention further, the above coupling may be made detachable.  
         [0042]     The movable table unit  26  are as shown in  FIGS. 3, 6  and  7  and comprises a base table  36  mounted on the rail member  24  so as to be movable on its rails  24   a  and  24   b , and a cradle  37  mounted on the base table  26  so as to be movable in a direction orthogonal to the direction in which the base table  36  moves. The cradle  37  has thereon a plurality of positioning pins  38  projecting thereon. In  FIG. 6  which is a view taken along the line VI-VI and seen in a direction of the arrow in  FIG. 3 , the cradle  37  is omitted.  
         [0043]     The base table  36  is moved on the rain member  24  through bearings  39 ,  39  provided on the underside of the base table  36  to slidably fit with the rails  24   a  and  24   b . On the other hand, the cradle  37  is moved through a pair of bearings  40  and  40  provided on its underside to slidably fit with a pair of rails  41  and  41 , respectively, which are laid on the base table  36  in a direction orthogonal to the direction in which the base table  36  moves.  
         [0044]     The base table  36  of the movable table unit  26  is provided on its under surface with a slotted member  42  for fitting with one rail  24   a  of the rail member  24  and a threaded handle  43  for tightening the slotted member  42  such that the movable table unit  26  can be fixed at a desired position on the rail member  24 .  
         [0045]     The cradle  37  of the movable table unit  26  is provided on its under surface with a slotted member  44  for fitting with one rail  41  of the rails  41  and  41  on the base table  36  and a threaded handle  45  for tightening the slotted member  44  such that the cradle  37  can be fixed at a desired position on the base table  36 . The cradle  37  is also provided at one side with a set screw  46  for contact with a side face of the head catch tray  27  when mounted on the cradle  37  to fix the same.  
         [0046]     The head catch tray  27  is adapted to be placed on the cradle  37  of the movable table unit  26  upon engaging with the positioning pins  38  projecting on the cradle  37  for positioning.  
         [0047]     The head catch tray  27  as shown in  FIGS. 8-11  is designed to place thereon the line head chassis  11  with the line head  12  lying at its underside and is provided at its both sides with hand holds  47   a  and  47   b . As regards these hand holds  47   a  and  47   b , it should be noted that one hand hold  47   a  lying at the upstream side ( FIG. 8 , the left hand side) in the direction in which the movable table unit  26  moves is made small so that it does not interfere with the line head chassis  11  loaded.  
         [0048]     The head catch tray  27  is provided at a plurality of places on its bottom face with cushions  48  for receiving the undersurface of the line head chassis  11 . Also, the head catch tray  27  is provided at a plurality of places circumferentially on its inner walls with guide pieces  49  for closely guiding the peripheral surfaces of the line head chassis  11  moving downwards. Also, its base plate is formed with positioning pin holes  50  and  50  to be engaged with the positioning pins  38  and  38  formed in the cradle  37 .  
         [0049]     Mention is next made of an operation of the line head chassis detachably attaching jig A constructed as mentioned above.  
         [0050]     Of those of a plurality of inkjet heads  2   a , . . . ,  2   d  as shown in  FIG. 1  as arranged along the paper conveyance line, let it be assumed that the line head chassis  11  of, say, the downstream-most inkjet head  2   d  is detached from the controller housing  9 . Then, as shown in  FIGS. 3 and 4 , the rail member  24  and the upright support member  25  of the line head chassis detachably attaching jig A are used and engaged with the first and second members  22  and  23  provided for the auxiliary table  21  and the auxiliary frame  21   a  which are positioned to correspond to the inkjet head  2   d.    
         [0051]     In this line head chassis detachably attaching jig A, first the engagement pieces  34   a  and  34   b  provided for one of the coupling fitting,  33   a , of the first rail member  24  is engaged with the grooves  29   a  and  29   b  of the support bar  29  of the first support member  22  provided for the auxiliary table  21  and are fixed fast by the thrust screws  35 , respectively, and thereby fixed to the first support member  22  there. Before or after this, the lower ends of the posts  25   a  and  25   b  of the upright support member  25  are inserted into the holes  31  of the support fittings  30   a  and  30   b  of the second support member  23 , respectively and then fixed fast there.  
         [0052]     The lower ends of the posts  25   a  and  25   b  then come into contact with the ends of the bolts  32  provided at the lower part of the support fittings  30   a  and  30   b , respectively, and thereby supported. Then, by adjusting the length of protrusion of each bolt  32  into the hole  31 , the height h 1 , h 2  from the floor L to the top end of each post  25   a ,  25   b  is adjusted so that the other coupling fitting  33   b  of the rail member  24  becomes parallel to one coupling fitting  33   a.    
         [0053]     In this state, the movable table unit  26  of the line head chassis detachably attaching jig A is supported to lie parallel to the under surface of the line head chassis  11 . Then, the base table  36  of the movable table unit  26  is positioned at an outward stroke end towards the prime mover of the inkjet head  2   d , and the cradle  37  is positioned at a stroke end away from the controller housing  9  (downstream of travel of the paper  5 ), where they are fixed fast by fastening tight the slotted members  42  and  44  with the threaded handles  43  and  45 , respectively. The head catch tray  27  is positioned by engagement of the positioning pins  38  with the positioning pin holes  50 .  
         [0054]     Then, the controller housing  9  is moved to the maintenance position P 2 . Thereafter, the movable table unit  26  upon releasing fixa-fixation of the base table  36  is moved to the maintenance position where it is fixed fast again. And, the cradle  37  upon releasing its fixation in this state is moved towards the controller housing  9 , and the catch tray  27  mounted on the cradle  37  is positioned below the line head chassis  11  where the cradle  37  is fixed fast again.  
         [0055]     Subsequently, the line head chassis  11  is disengaged from the controller housing  9 , and the elevating unit  14  is operated to move the line head chassis  11  down to place it on the catch tray  27  ( FIG. 12 ). The line head chassis  11  is then guided with the guide pieces  49  provided circumferentially on the inner wall of the head catch tray  27  and thereby seated smoothly in the catch tray  27 .  
         [0056]     In this state, the head catch tray  27  is taken out and the line head chassis  11  is removed from the bracket  13  of the controller  9   FIG. 13 ).  
         [0057]     Subsequently, the movable table unit  26  is moved outwards towards the prime mover and fixed fast again, and in this state, the set screw  46  is loosened. Then, the head catch tray  27  is carried with hands holding the handles  47   a  and  47   b  and together with the line head chassis  11  is taken out of the movable table unit  26  and moved onto a workbench (not shown). And, there the line head chassis  11  is taken out of the head catch tray  27  and maintained. Alternatively, the line head chassis  11  is replaced with a new line head chassis  11 .  
         [0058]     In loading the line head chassis  11  onto the controller housing  9 , the operations mentioned above are reversed.  
         [0059]     In the form of implementation mentioned above, the head catch tray  27  may be provided with a clamp to fasten the line head chassis  11  as mounted on the head catch tray  27 .  
         [0060]     The line head chassis detachably attaching jig A not in use may be left as it is loaded on the side of the prime mover of the inkjet head, but instead its members other than the first and second members  22  and  23  may be removed from the first and second members  22  and  23  and stored separately.  
         [0061]     The rail member  24  and the upright support member  25  when so stored are folded and can thus be stored in a limited space.  
         [0062]     In this manner, the line head chassisd detachably attaching jig A according to the present invention is mounted at the side of the prime mover of each inkjet head where its line head chassis  11  is to be maintained and, the line head chassis  11  is then detached and attached.  
         [0063]     While the inkjet heads  2   a  - 2   d  in the printing section  2  then lie individually parallel to the surface along which the paper  5  travels and the respective line head chassis bodies  11  of the heads are different from each other in the posture they take and in the height their lower surfaces have from the floor, the members of the line head chassis detachably attaching jig A according to the present invention except the first and second support members  22  and  23  can freely be used in common without the need to make any particular adjustment for the inkjet heads  2   a  - 2   d  by virtue of the fact that the posture of the rail member  24  and its height h from the floor outside can be adjusted for the second support member  23  supporting the upright support member  25  and the rail member  24  can be detached from and attached to the first support member  22  provided corresponding to each individual inkjet head  2   a , . . . ,  2   d.    
         [0064]     Also, while the support bar  29  of the first support member  22  is shown positioned parallel to the auxiliary table  21  for each individual inkjet head  2   a , . . . ,  2   d , the support bar  29  can be fastened to the bracket  28  so as to make its position adjustable while making it possible to adjust an installation error of the bracket  28  and the support bar  29  with respect to the auxiliary table  21 .  
         [0065]     Further, while the form of implementation illustrated is shown to position the catch tray  27  on the cradle  37  for engagement and disengagement and then to place the line head chassis  11  on the catch tray  27 , the line head chassis  11  may directly be placed on and engaged with the cradle  37  without using the catch tray  27 .