Abstract:
A gravure engraving system that capable of successively engraving each of a plurality of gravure cylinders through no intermediary of a manual operation, includes a transport device for transporting a gravure cylinder. The transport device is disposed between an engraving machine for engraving the circumferential surface of a gravure cylinder and a stock device which stores a plurality of gravure cylinders. A predetermined gravure cylinder is selected out of the gravure cylinders stared in the stock device and transported to the engraving machine by the transport device. After the transported gravure cylinder has been automatically set on the engraving machine, the gravure cylinder is engraved. Thereafter, the transport device transports the engraved gravure cylinder to the stock device where the engraved gravure cylinder is stored.

Description:
This is a division of application Ser. No. 08/682,881, filed Jul. 11, 1996. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a gravure engraving system and more particularly to a system for automatically supplying and discharging a gravure cylinder to or from a gravure cylinder engraving machine. 
     2. Description of Related Art 
     A gravure cylinder will serve as a printing plate and has a surface to be engraved by a gravure engraving machine. The gravure engraving machine is arranged such that, using a diamond bite or stylus, concave points (cells) are formed in the circumferential surface of a gravure cylinder under rotation. The basic arrangement of the gravure engraving machine is discussed for example in U.S. Pat. No. 3,964,382, U.S. Pat. No. 4,013,829 and European Unexamined Patent Publication No. 0,595,324 A1 which is a counterpart of U.S. patent application Ser. No. 08/143,552, the entire disclosure of which United States patents and application are incorporated herein by reference. 
     Conventionally, a gravure cylinder is to be mounted on a gravure engraving machine by raising the same manually or with a crane. Also, an engraved gravure cylinder is removed from the gravure engraving machine while the same is being raised manually or with a crane. 
     Accordingly, continuously engraving each of a plurality of gravure cylinders requires many hands for mounting and dismounting such a cylinder on and from a gravure engraving machine. 
     SUMMARY OF THE INVENTION 
     A gravure engraving system constructed according to the present invention comprises an engraving machine for engraving the circumferential surface of a gravure cylinder, a stock device for storing a plurality of gravure cylinders and a transport device for transporting a gravure cylinder between the engraving machine and the stock device. The engraving machine is arranged to engrave the circumferential surface of a gravure cylinder while the same is being rotated at a predetermined speed with the both ends thereof supported. 
     With the engraving system of the instant invention in operation, a predetermined gravure cylinder is selected from the gravure cylinders stored in the stock device and is transported to the engraving machine by the transport device. When the transported gravure cylinder has been automatically set in the engraving machine, the gravure cylinder is engraved. Thereafter, the engraved gravure cylinder is again transported and stored in the stock device by the transport device. Thus, gravure cylinders can continuously automatically be engraved. 
     Preferably, the transport device comprises: at least two arms for supporting a gravure cylinder from underneath; vertical drive means for vertically moving the arms for vertically moving the gravure cylinder; horizontal drive means for moving the arms in a first horizontal direction, thereby to transport the gravure cylinder between the stock device and the engraving machine; and orthogonal drive means for moving at least one of the arms in a second horizontal direction orthogonal to said first horizontal direction such that the distance between the two arms is changed. 
     Preferably, the stock device comprises: a plurality of placing stands on which gravure cylinders are placed such that the axes thereof extend substantially horizontally; and a holding mechanism for holding the plurality of placing stands in a revolving manner. According to such an arrangement, a plurality of gravure cylinders can efficiently be stored. 
     Preferably, each placing stand comprises at least two holding portions to come in contact with part of the circumferential surface of a gravure cylinder placed on the placing stand. Preferably, each placing stand is arranged such that there is defined, under the gravure cylinder as held by the holding portions, a space into which the arms of the transport device are adapted to enter. According to such an arrangement, the arms are horizontally movable can enter the space under the gravure cylinder to hold the same from underneath. Preferably, at least one of the holding portions is horizontally movable on the placing stand. With such an arrangement, any of gravure cylinders having different lengths can be held by each placing stand and can readily and securely be unloaded by the arms. 
     The engraving machine may have a pair of cone units for holding a gravure cylinder at both ends thereof. Preferably, one cone unit comprises a cone to engage with an end of a gravure cylinder and cone drive means for moving the cone toward and away from the other cone unit, and the other cone unit comprises a cone to engage with the other end of the gravure cylinder and ejecting means for ejecting the gravure cylinder engaged with the cone in such a direction in which the gravure cylinder is disengaged from the cone. 
     Preferably, the transport device is interposed between the stock device and the engraving machine; and the gravure engraving system further comprises a guide member for guiding the transport device to a retreat position where the transport device is being retracted from a position between the engraving machine and the stock device. In such an arrangement, the transport device is preferably movable between the position where the transport device is interposed between the stock device and the engraving machine for transporting a gravure cylinder, and the retreat position where the transport device is being retreated. 
     According to the arrangement above-mentioned, when the transport device is retreated or retracted from the position between the stock device and the engraving machine, the stock device, the transport device and the engraving machine are not adjacent to one another. This facilitates maintenance on any of the devices and machine. 
     The engraving machine may be disposed in a plural number and the plural engraving machines may be disposed in series. In such an arrangement, a guide member is preferably disposed in parallel with the plurality of engraving machines disposed in series. Preferably, the transport device is movable along the guide member and is capable of facing a predetermined engraving machine such that a gravure cylinder is delivered between the predetermined engraving machine and the transport device. According to such an arrangement, a plurality of engraving machines can automatically be operated to improve the productivity. Further, the transport device and the stock: device can be shared with the plurality of engraving machines. 
     The stock device may be disposed in a plural number and the plural stock devices may be disposed in series. In such an arrangement, a guide member is preferably disposed in parallel with the plurality of stock devices disposed in series. Preferably, the transport device is movable along the guide member and is capable of facing a predetermined stock device such that a gravure cylinder is delivered between the predetermined stock device and the transport device. According to the arrangement above-mentioned, since the plurality of transport devices are disposed, the automatic operation can be conducted for a long period of time. Further, while a gravure cylinder is being unloaded from one stock device by the transport device, the next gravure cylinder can be stored in another stock device or an engraved gravure cylinder can be unloaded from still another stock device. This achieves an efficient operation. 
     Accordingly, the primary object of the present invention is to provide a gravure engraving system capable of continuously engraving each of a plurality of gravure cylinders without the necessity of utilizing manual intervention. 
     Another object of the present invention is to provide transport device having means measuring the length and diameter of a gravure cylinder to be transported. 
     Still another object of the present invention is to provide a transport device capable of transporting gravure cylinders having a variety of lengths, between a stock device and an engraving machine in a gravure engraving system. 
     A further object of the present invention is to provide a transport device for transporting a gravure cylinder between a stock device and an engraving machine in a gravure engraving system. 
     A still further object of the present invention is to provide a transport device having a long transport length, yet in a compact design. 
     The foregoing objects as well as other objects and advantages of the present invention will be more fully apparent from the following detailed description set forth below when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a right side view of a gravure engraving system according to an embodiment of the present invention; 
     FIG. 2 is a plan view of the gravure engraving system according to the embodiment of the present invention; 
     FIG. 3 is a perspective view of a specific example of the arrangement of a placing stand; 
     FIG. 4 is a plan view of the transport device; 
     FIG. 5 is a side view of the left arm unit taken along the line V—V in FIG. 4; 
     FIG. 5A is a side view of another example of the left arm unit; 
     FIG. 6 is a front view of the left arm unit; 
     FIG.  7 A and FIG. 7B are schematics illustrating respectively a both-hand holding state where a gravure cylinder is held by two arm units, i.e., the right and left arm units, and a one-hand holding state where a gravure cylinder is held only by the right arm unit; 
     FIG. 8 is a plan view illustrating the relationship between the pin unit and the engagement hole of a support block; 
     FIG. 9A, FIG.  9 B and FIG. 9C are schematics illustrating the characteristic arrangement of an arm unit; 
     FIG. 10A to FIG. 10D are schematics illustrating operation of an arm unit; 
     FIG. 11A to FIG. 11D are additional schematics illustrating operation of the arm unit; 
     FIG. 12 is a schematic illustrating drive mechanisms for vertically and transversely moving the arm units in the transport device; 
     FIG. 13 is a view illustrating how the drive mechanism for vertically moving the arm units is disposed; 
     FIG. 14 is a view illustrating how the drive mechanism for the left arm unit is disposed; 
     FIG. 15 is a right side view of the transport device, illustrating the arrangement of the vertically and transversely moving mechanisms for the arm units; 
     FIG. 16A to FIG. 16D are schematics illustrating how a gravure cylinder is transported between the transport device and the engraving machine; 
     FIG. 17 is a front view of portions of the engraving machine, illustrating the arrangement of the first cone unit and its peripheries; 
     FIG. 18 is a vertical section of the engraving machine in left side elevation, chiefly illustrating the arrangement of the first cone unit; 
     FIG. 19 is a schematic plan view of the gravure engraving system according to the embodiment of the present invention, illustrating the positional relationship among the stocker, the transport device and the engraving machine, and the arrangement where the transport device is movable; 
     FIG. 20 is a section through portions of the right side of the transport device, illustrating the rails and their relevant portions; 
     FIG.  21 A and FIG. 21B are plan and side views respectively illustrating a system according to another embodiment of the present invention; 
     FIG. 22 is a block diagram of the control circuitry in the system instructed according to the present invention; 
     FIG. 23 is a flow chart illustrating the outline of the job processing of the system constructed according to the embodiment; 
     FIG. 24 is a flow chart illustrating in detail the gravure cylinder length measuring processing shown in FIG. 23; 
     FIG. 25 is a flow chart illustrating in detail the gravure cylinder unloading processing shown in FIG. 23; 
     FIG. 26 is a flow chart illustrating in detail the gravure cylinder diameter measuring processing shown in FIG. 23; 
     FIG. 27 is a flow chart illustrating in detail the gravure cylinder mounting processing shown in FIG. 23; 
     FIG. 28 is a flow chart illustrating in detail the gravure cylinder removal processing shown in FIG. 23; 
     FIG. 29 is a flow chart illustrating in detail the gravure cylinder storing processing shown in FIG. 23; and 
     FIG. 30 is a schematic illustrating cylinder length measurement according to a further embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     General Arrangement 
     Now referring more particularly to FIGS. 1 and 2, the gravure engraving system is constituted by a stocker  1 , a transport device  2  and an engraving machine  3 , of which outward shapes are individually formed by frames and which are disposed in close vicinity to one another. In the specification, the description will be made based on the premise that the stocker  1  is placed on this side and that the front view refers to a view where the system is observed from this side the stocker  1 . 
     Arrangement of the Engraving Machine  3   
     The engraving machine  3  is arranged to engrave a gravure cylinder S and provided with a bed  4  on which disposed are a first cone unit  5  and a second cone unit  6 . The first cone unit  5  is constituted by a stationary cone  7  rotatably disposed above the bed  4 , and a drive device  8  for rotating the stationary cone  7 . The second cone unit  6  is movable above the bed  4  transversely as viewed from the front side. The second cone unit  6  is constituted by a rotatably supported and transversely movable cone  9 , and a moving device  10  for moving the movable cone  9 . 
     The gravure cylinder S is supported as held at both ends thereof by and between the stationary cone  7  and the movable cone  9 , and is to be rotated with the rotation of the stationary cone  7 . An engraving head  11  is moved at a predetermined pitch or speed from the right hand to the left hand in FIG. 2 such that concave points (cells) are successively formed in the circumferential surface of the gravure cylinder S under rotation. Mounted on the engraving machine  3  is an inspection camera  12  for monitoring the state of the cells formed in the gravure cylinder S. 
     Arrangement of the Stocker  1   
     In the stocker  1 , the rectangular parallelopiped outward shape is formed by a frame  16  of iron for example. The stocker  1  holds, in a rotary manner, a plurality of placing stands  17  on each of which a gravure cylinder S is to be placed. In this connection, the stocker  1  is provided at upper and lower portions of each of the right and left lateral sides thereof with chain gears  18  and  19 . As shown in FIG. 1, a chain  20  is installed on the chain gears  18  and  19  respectively disposed at upper and lower portions of the right lateral side. Also, a chain  20  is installed on the chain gears  18  and  19  respectively disposed at upper and lower portions of the left lateral side. For example, the chain gears  19  at the lower portions of the right and left lateral sides are coupled to each other by a shaft  21  as shown in FIG.  2 . 
     Referring to FIG. 2, the stocker  1  is provided for example at the left end thereof with a motor  22  as a drive source. The rotation force of the motor  22  is transmitted to a gear  24  coupled to the left end of the shaft  21  through a chain  23 . Therefore, when the motor  22  is rotated, the gear  24  is rotated to rotate the shaft  21 . This causes the lower left and right chain gears  19  attached to the shaft  21  to be synchronously rotated. The rotation of the lower left and right chain gears  19  circulates the chains  20  installed on the upper and lower chain gears  18  and  19  disposed at the left and right sides. 
     Disposed at each of the right and left chains  20  are a plurality of hanging pins  25  at regular spatial intervals in the lengthwise direction of each chain  20 . The hanging pins  25  at each chain project toward the other chain. The plural hanging pins  25  at the right-side chain  20  and the plural hanging pins  25  at the left-side chain  20  are disposed in the form of a plurality of pairs such that the hanging pins  25  at the right- and left-side chains  20  of each pair are opposite to each other in the horizontal direction. 
     The plural placing stands  17  are swingingly hung down by the hanging pins  25  at the right- and left-side chains  20 . 
     Arrangement of Each Placing Stand  17   
     Now referring more particularly to FIG. 3, placing stand  17  is constituted by a horizontally disposed slender pallet  30 , and two upwardly extending hanging plates  31  respectively attached to both ends of the pallet  30 . Each of the hanging plates  31  is provided at the upper end thereof with an engagement hole  32 . When hanging pins  25  are inserted in the engagement holes  32 , the placing stand  17  is swingingly hung from the chains  20 . 
     The pallet  30  is provided for example at its right end when viewed from the front-side, with a stationary holding portion  33 . Disposed at the left side with respect to the stationary holding portion  33  is a movable holding portion  34  which is movable along the pallet  30  in the lengthwise direction thereof. 
     The stationary holding portion  33  has a leg  35  of which lower end is secured to the pallet  30 , and a support stand  36  attached to the upper end of the leg  35 . The top surface of the support stand  36  serves as a support surface  37  of which center portion is downwardly concave substantially in a V shape in side elevation. The right end of the gravure cylinder S is placed on the support surface  37  as shown by a chain line. The support stand  36  is provided at the right end thereof with a regulating plate  38  for regulating the position of the right end of the gravure cylinder S to be supported. The position of the regulating plate  38  is recognized as a first reference position at the time when the gravure cylinder length is measured as will be discussed later. 
     The movable holding portion  34  is constituted by a leg  39  and a support stand  40  attached to the top of the leg  39 . Analogous to the support stand  36 , the support stand  40  has a support surface  41  of which center portion is concave substantially in a V shape in side elevation. The left end of the gravure cylinder is placed on the support surface  41 . 
     The underside of the leg  39  of the movable holding portion  34  is transversely movably attached to the top surface of the pallet  30 . More specifically, the pallet  30  is provided in the top surface thereof with a guide groove  42  extending in the lengthwise direction of the pallet  30 . The leg  39  is provided at the lower end thereof with a small projection (not shown) engaged with the guide groove  42 . By the engagement of the small projection with the guide groove  42 , the movable holding portion  34  slides transversely on the pallet  30  without coming off from the pallet  30 . 
     Further, the movable holding portion  34  has a lever  43  for switching the movable holding portion  34  between the stationary state and the movable state. For example, when the lever  43  is positioned as shown in FIG. 3, a fitting portion (not shown) of the lever  43  pushes the guide groove  42  in the pallet  30  to fix the movable holding portion  34  such that the same cannot be moved. On the other hand, when the lever  43  is rotated, pushing the guide groove  42  by the fitting portion (not shown) is released such that the movable holding portion  34  is transversely movable on the pallet  30 . Provision is made such that in use, the distance between the stationary holding portion  33  and the movable holding portion  34  is suited to the length of the gravure cylinder S. 
     In this embodiment, a scale  44  is attached to the front end surface of the pallet  30  for the convenience of usage. Further, an indication pointer  45  is disposed on the movable holding portion  34 . Thus, the distance between the stationary and movable holding portions  33  and  34  is expressed by the division that the indication pointer  45  indicates. 
     As shown in FIG. 3, when the gravure cylinder S is supported at both ends thereof by the stationary and movable holding portions  33  and  34 , the gravure cylinder S is positioned such that the axis thereof extends substantially horizontally (that is, the gravure cylinder S lies down). In this state, there is formed, under the gravure cylinder S, a space  46  into which arm units, to be described later, can be entered. Each of the legs  35  and  39  has a predetermined height, accordingly. 
     Arrangement of the Transport Device  2   
     Referring again to FIGS. 1 and 2, the transport device  2  is disposed between the stocker  1  and the engraving machine  3  for transporting a gravure cylinder S from the stocker  1  to the engraving machine  3  and for transporting gravure cylinder S to engraving machine  3  after cylinder S is engraved by machine  3 . 
     The transport device  2  is constituted by a frame  50  forming the skeletal structure thereof, a right arm unit  51  serving as a first arm and a left arm unit  52  serving as a second arm, both arm units  51  and  52  being attached to the frame  50 . Each of the right and left arm units  51  and  52  is movable in a vertical direction and in a back-and-forth direction when viewed from the front side of the system (in the transverse direction in FIG.  1 ). Further, the left arm unit  52  is movable transversely in FIG. 2 with respect to the frame  50 . 
     Arrangement of the Arm Units  51  and  52   
     Now referring more particularly to FIGS. 4-6, two-dot chain lines shown in FIG. 4 in connection with the right and left arm units  51  and  52  illustrate the movable ranges of the arm units  51  and  52  in the horizontal transport direction when a gravure cylinder S is transported. 
     Left arm unit  52  is constituted by an arm base member  53 , a slide arm member  54  and a support block  55 S. The arm base member  53  is attached to a moving frame  57  by a coupling member  56 . The moving frame  57  is movable transversely in FIG. 4 with respect to the frame  50  serving as the general skeletal structure of the transport device  2 . Accordingly, when the moving frame  57  is moved transversely in FIG. 4, the left arm unit  52  is also moved transversely. 
     On the other hand, in the right arm unit  51 , the arm base member is attached to the frame  50  by a coupling member  58 . The right arm unit  51  is different in this point from the left arm unit  52 . 
     The right and left arm units  51  and  52  have support blocks  55 L and  55 S, respectively. The support blocks  55 L and  55 S are formed for placing a gravure cylinder thereon such that the gravure cylinder is transported as supported by these support blocks  55 L and  55 S. 
     Each of the support blocks  55 L and  55 S has, as a common arrangement, a mounting surface (gravure cylinder placing and supporting surface)  91  of which center portion is downwardly concave substantially in a V shape in side elevation. Thus, a gravure cylinder S is to be placed on the mounting surfaces  91 . 
     The support blocks  55 L and  55 S are structurally different in the width of mounting surface  91 . More specifically, the mounting surface  91  of the support block  55 L has a width L, while the mounting surface  91  of the support block  55 S has a width K. The widths of the mounting surfaces  91  have the following relationship: 
     
       
         L&gt;K. 
       
     
     The following will discuss the reasons why the mounting surfaces  91  are different in width. 
     Generally, a gravure cylinder S is supported by two support blocks, i.e., the support blocks  55 L and  55 S of the right and left arm units  51  and  52 , as shown in FIG.  7 A. 
     However, when the length of a gravure cylinder S is short, the gravure cylinder can be supported, with difficulty, by the two support blocks  55 L and  55 S. For example, when the length of a gravure cylinder S is short, the gravure cylinder S is held on the placing stand  17  shown in FIG. 3 with the distance between the stationary and movable holding portions  33  and  34  shortened. This narrows the width of the space  46  under the gravure cylinder S thus held. This may make it difficult to simultaneously insert both arm units  51  and  52  into the narrow space  46  at the same time. 
     Thus, provision is made such that a short gravure cylinder can be transported as held at the vicinity of the center thereof only by the support block  55 L of the right arm unit  51  as shown in FIG.  7 B. 
     Except for the foregoing difference, the right and left arm units  51  and  52  are the same in arrangement. Accordingly, the following description will be made with the left arm unit  52  taken as an example. 
     Mainly referring to FIGS. 5 and 6, the slide arm member  54  is coupled to the arm base member  53  in a manner slidable thereon in the back-and-forth direction (at the time when the whole system is viewed from the front side; in the transverse direction in FIG.  5 ). More specifically, the arm base member  53  and the slide arm member  54  are slidably coupled to each other through slide guides  59  (FIG.  6 ). The support block  55 S is coupled to the slide arm member  54  in a manner slidable in the back-and forth-direction along the top surface of the slide arm member  54 . More specifically, the slide arm member  54  and the support block  55 S are coupled to each other through a slide guide  60 . Accordingly, when viewed as a function of the arm base member  53  secured by the coupling member  56 , the slide arm member  54  is slidable on the arm base member  53 , and the support block  55 S is slidable on the slide arm member  54 . For purpose of illustration in FIG. 6, the slide arm member  54  is generally hatched and the slide guides  59  and  60  are also hatched, but in a different manner than the hatching used for arm member  54 . 
     Mainly referring to FIG. 5, the slide arm member  54  and the support block  55 S are simultaneously driven by a single motor  61  and a single chain  62 . In this connection, the following mechanism is provided. 
     Gears  63  and  64  are rotatably disposed at the front and rear ends of the arm base member  53 . The motor  61  and a drive gear  65  to be rotated by the motor  61  are disposed substantially at the center part of the arm base member  53  at its lower side. In the arm base member  53 , a tension adjust gear  66  is further disposed in the vicinity of the drive gear  65 . Gears  67  and  68  are rotatably disposed at the front and rear ends of the slide arm member  54 . It is noted that the gears  63 ,  64 ,  67 , and  68  may be disposed in the vicinity of the front and rear ends, and it is not always required that the gears  63 ,  64 ,  67 , and  68  be disposed at the front and rear ends. 
     The chain  62 , shown by a chain line for shortness&#39; sake, has one end coupled to a mounting piece  69  disposed at the support block  55 S. The chain  62  is installed on the gear  67  disposed at the slide arm member  54 , then on the gear  64  disposed at the arm base member  53 , and then on the drive gear  65 . The chain  62  is adjusted in tension by the tension adjust gear  66  and installed on the gear  63  of the arm base member  53  and on the gear  68  of the slide arm member  54 . The chain  62  has the other end coupled to the mounting piece  69  of the support block  55 S. That is, the chain  62  is so installed as to cross near the boundary between the arm base member  53  and the slide arm member  54 , such that the chain  62  is generally installed in the shape of the figure “8”. 
     This embodiment is arranged such that the slide arm member  54  and the support block  55 S are driven by the motor  61  and the chain  62 . However, a belt such as a timing belt or the like may be used instead of the chain  62 . In such a case, belt pulleys may substitute for the gears  63 ,  64 , and  65  disposed at the arm base member  53  and the gears  67  and  68  disposed at the slide arm member  54 . 
     Thus, winding wheels such as gears, pulleys or the like are disposed in the vicinity of the front and rear ends of the arm members. An endless coupling body such as a chain, a belt or the like is installed on the winding wheels in the shape of the figure “8”, and portions of the coupling body are fixed to the support block. By disposing a driving mechanism for circularly moving the coupling body, the slide arm member  54  and the support block  55 S can be driven. 
     In the embodiment described with reference to attached drawings, there has been discussed the arrangement in which the motor  61  and the drive gear  65  are disposed as associated with the arm base member  53 . However, the motor  61  and the drive gear  65  may be disposed as associated with the slide arm member  54 . 
     To regulate the operation of the slide arm member  54 , pin units  72  and  73  are disposed at or in the vicinity of the front and rear ends of the arm base member  53 . The slide arm member  54  provided in the front and rear end portions thereof with engagement holes  74  and  75  to receive respective pins  76  and  79  of the pin units  72  and  73 , respectively. In their projecting states pins  76  and  79  project above base member  53  into respective holes  74  and  75 . 
     The pin unit  72  is also constituted by an air cylinder  77  for switching the pin  76  between the projecting state and the non-projecting state, and a link  78  for transmitting the operation of the air cylinder  77  to the pin  76 . Likewise, the pin unit  73  is also constituted by an air cylinder  80 , a link  81  driven by cylinder  81  and drives pin  79  between its projecting and on-projecting (retracted) states. 
     Instead of the arrangement above-mentioned, as shown in FIG. 5A, the pin units  72 A and  73 A may be disposed at predetermined positions of the slide arm member  54  in the vicinity of the front and rear ends thereof, and the engagement holes  74 A and  75 A respectively corresponding to the pins  76 A and  79 A of the pin units  72 A and  73 A may be formed in predetermined positions of the arm base member  53  in the vicinity of the front and rear ends thereof. 
     Further, a pin unit is disposed at the support block  55 S for regulating the operation of the support block  55 S on the slide arm member  54 , and a hole for receiving a pin is formed in the slide arm member  54 . FIG. 8 shows this arrangement. 
     Referring to FIG. 8, a pin unit  82  disposed at the support block  55 S is constituted by a pin  83  which can laterally project from the support block  55 S, an air cylinder  84  for driving the pin  83 , and a link  85  for transmitting the movement of the air cylinder  84  to the pin  83 . When the support block  55 S is located in a predetermined position, an engagement hole  86  formed in the slide arm member  54  is located in a position opposite to the pin  83 . At this state, when the air cylinder  84  is driven, the pin  83  enters the engagement hole  86  to fix the support block  55 S such that the same cannot be moved with respect to the slide arm member  54 . 
     FIGS. 9A,  9 B, and  9 C are schematics illustrating the characteristic structure of the arm unit above-mentioned. The right arm unit  51  and the left arm unit  52  have the same characteristic structure. Accordingly, without making distinctions between the right arm unit  51  and the left arm unit  52 , the following description will briefly summarize the structural characteristics of an arm unit indicative of each of the right and left arm units. 
     As shown in FIG. 9A, the arm unit is divided into three blocks, i.e., the arm base member  53 , the slide arm member  54  slidable on the arm base member  53 , and the support block  55  slidable on the slide arm member  54 . The slide arm member  54  and the support block  55  are driven by a common motor and a common chain. Thus, there is disposed a mechanism that appears in FIGS. 9B and 9C. 
     That is in FIG. 9B, the arm base member  53  and the slide arm member  54  are illustrated as mounting gears  63  to  68 , and the chain  62  is illustrated as being installed on the members  53  and  54  in the shape of the figure “8”. Both the ends of the chain  62  are connected to the mounting piece  69  disposed at the support block  55 . The chain  62  is moved by the drive gear  65  driven by the motor  61 . 
     All three pins  76 ,  79 , and  83  appear in FIG.  9 C. The pins  76  and  79  are respectively disposed at the front and rear sides of the arm base member  53 , and the pin  83  is disposed at the support block  55 . Formed in the slide arm member  54  are the engagement holes  74 ,  75 ,  86 , and  87  which can receive the pins  76 ,  79 , and  83 . 
     Back-and-Forth Movement of the Arm Units  51  and  52   
     With reference to FIG. 10A to FIG.  10 D and FIG. 11A to FIG. 11D, the following description will discuss the operation of the arm units each having the arrangement above-mentioned. 
     Referring particularly to FIG. 10A to FIG. 10D, the following description will discuss the operation of each arm unit for moving the support block  55  from the center ( 10 B) to the front or left side (FIG. 10 a ), and (to the rear or right side in FIG. 10A to FIG.  10 D). As shown in FIG. 10A, with the pin  83  withdrawn into the support block  55 , the pin  76  at the front side of the arm base member  53  is projected and entered into the front engagement hole  74  in the slide arm member  54 . 
     At this state, the motor  61  is rotated counterclockwise. As shown in FIG. 10B, only the support block  55  is moved as pulled by the movement of the chain  62 . At this time, the slide arm member  54  is fixed by the pin  76  and therefore not movable. 
     Referring to FIG. 10C, it is detected that the support block  55  has reached the rear end (the right end in FIG. 10C) of the slide arm member  54 . For example, such detection can be made by a microswitch disposed at the rear end of the slide arm member  54 . Alternatively, if the motor  61  is a step motor or a motor with an encoder, such detection can be made by counting the number of rotational pulses of the motor. 
     When this detection is made, the pin  83  of the support block  55  is inserted into the rear engagement hole  86  of the slide arm member  54  to fix the support block  55  to the rear end of the slide arm member  54 . On the other hand, the front pin  76  of the arm base member  53  is retracted such that the slide arm member  54  is movable. 
     At this state, the motor  61  is rotated clockwise. As shown in FIG. 10D, the length of the chain portion  62   x  between the mounting piece  69  of the support block  55  and the drive gear  65  is rapidly shortened and the slide arm member  54  is slid rearward. The rearward movement of the slide arm member  54  causes the support block  55  to be moved rearward with respect to arm base member  53 . 
     Likewise in the support block  55  above-mentioned, it can be detected by a switch or based on the number of pulses given to the motor  61  that the slide arm member  54  has moved up to the rear end. An example of the switch is shown in FIG.  6  and designated by a reference numeral  70 . 
     With reference to FIG. 11A to FIG. 11D, the following description will explain a situation where the support block  55  is moved from the rear end (the right end in FIG. 11A to FIG. 11D) toward the front end (the left end in FIG. 11A to FIG.  11 D). 
     First, the pin  83  of the support block  55  is retracted, causing the support block  55  to be movable with respect to the slide arm member  54 . On the other hand, the pin  79  at the rear end of the arm base member  53  is projected and entered into the forward engagement hole  74  in the slide arm member  54  to fix the same. 
     At this state, the motor  61  is rotated clockwise as shown in FIG.  11 B. Then, the length of the chain portion  62   x  between the mounting piece  69  and the drive gear  65  is rapidly shortened, causing the support block  55  to slide forwardly on the slide arm member  54 . 
     Whether or not the support block  55  has reached the front end of the slide arm member  4  as shown in FIG. 11C, is detected by a sensor such as a microswitch or the like or based on the number of rotational pulses of a motor. At this state, the pin  83  of the support block  55  is projected and entered into the forward engagement hole  87  in the slide arm member  54  to fix the support block  55 . On the other hand, the pin  79  of the arm base member  53  is retracted, causing the slide arm member  54  to be movable with respect to the arm base member  53 . 
     Now motor  61  is rotated counterclockwise as shown in FIG.  11 D. Then, the length of the chain portion  62   y  between the mounting piece  69  and the drive gear  65  is shortened rapidly, causing the slide arm member  54  to be moved forwardly on the arm base member  53 . 
     According to the arrangement above-mentioned, even in a compact design the arm unit has a long transport length. Further, using a chain and pins, the slide arm member  54  and the support block  55  can be driven by a single motor (e.g., pulse motor). 
     Provision is made such that the right arm unit  51  and the left arm unit  52  are driven individually. More specifically, each of the right arm unit  51  and the left arm unit  52  is provided with a drive motor. For synchronously driving the right arm unit  51  and the left arm unit  52  at the same time, the same pulse is entered into the drive motors. 
     However, provision is preferably made such that, in view of the possible occurrence of some change in load to produce a difference in movement between the right and left arm units  51  and  52 , such a difference is detected by a sensor or the like. Also, provision is preferably made such that the movements of the arm units  51  and  52  are changed or stopped by an output of the sensor. 
     When the whole system is viewed from the front side, the right arm unit  51  and the left arm unit  52  move not only in the back-and-forth direction, but also in the up-and-down direction as mentioned earlier. That is, when unloading a gravure cylinder S from the placing stand  17 , when placing a gravure cylinder S on the placing stand  17 , when mounting a gravure cylinder S on the engraving machine  3  or when retrieving a mounted gravure cylinder S such that the same gets out of the way, the right arm unit  51  and the left arm unit  52  are required to move vertically. 
     As above mentioned, the left arm unit  52  is transversely movable when the whole system is viewed from the front side. Thus, the distance between the left arm unit  52  and the right arm unit  51  can be optimized for holding a gravure cylinder S according to the length thereof. 
     The following description will discuss the vertical movements of the right and left arm units  51  and  52  and the transverse movement of the left arm unit  52 . 
     Vertical and Transverse Movements of the Arm Units  51  and  52  and Moving Mechanisms 
     The drive mechanisms (FIG. 12) for vertically and transversely moving the arm units  51  and  52  include internally threaded members  113  and  114 , with balls, respectively fitted to vertically disposed screw shafts  111  and  112 , and the latter are respectively fitted to the right and left arm units  51  and  52 . Accordingly, when the screw shafts  111  and  112  are rotated, the member  113  and the right arm unit  51  fitted thereto, and the member  114  and the left arm unit  52  fitted thereto, are vertically moved along the screw shafts  111  and  112 , respectively. The screw shafts  111  and  112  are respectively provided at the lower ends thereof with bevel gears  115  and  116 . 
     A horizontally extending spline shaft  117  is disposed at a lower portion of the transport device  2 . Mounted on the spline shaft  117  are bevel gears  118  and  119  meshed with the respective bevel gears  115  and  116 . Of these, the right-hand bevel gear  118  is so fixed to the spline shaft  117  as not to be transversely displaced with respect thereto. The left-hand bevel gear  119  is transversely movable along the spline shaft  117 . An L-shape gear  120  is attached to one end of the spline shaft  117 , which is connected to a motor  121  through the L-shape gear  120 . 
     According to the arrangement above-mentioned, when the motor  121  is rotated, its rotational force is transmitted to the spline shaft  117  through the L-shape gear  120 , causing the spline shaft  117  to be rotated. When the spline shaft  117  is rotated, the bevel gear  118  is also rotated. The rotational force of the bevel gear  118  is transmitted to the bevel gear  115 , causing the screw shaft  111  to be rotated. When the screw shaft  111  is rotated, the internally threaded member  113  is vertically moved along the screw shaft  111 . At the same time, the right arm unit  51  fitted to the member  113  is also vertically moved. Whether the right arm unit  51  is moved up or down, is determined by the rotational direction of the screw shaft  111 , i.e., the rotational direction of the motor  121  for rotating the spline shaft  117 . 
     When the spline shaft  117  is rotated, the left-hand bevel gear  119  is also rotated. The rotational force of the bevel gear  119  is transmitted to the bevel gear  116  meshed therewith, causing the screw shaft  112  to be rotated. When the screw shaft  112  is rotated, the internally threaded member  114  is vertically moved. Then, the left arm unit  52  fitted to the member  114  is also vertically moved together with the movement of the internal thread  114 . 
     The screw shafts  111  and  112  are rotated by the bevel gears  118  and  119  attached to the common spline shaft  117 . Accordingly, when the bevel gears  118  and  119  have in the number of teeth and pitch, the right and the same left arm units  51  and  52  can be moved vertically by the same amount at the same time. 
     To smooth the vertical movement of the right and left arm units  51  and  52 , there are disposed, in parallel with the screw shafts  111  and  112 , linear guides (not shown in FIG. 12) for guiding the vertical movement of the right and left arm units  51  and  52 . 
     The following description will discuss a drive mechanism for transversely moving the left arm unit  52 . 
     As mentioned earlier, the left arm unit  52  is attached to the moving frame  57  that has a vertically extending shaft  122 . A pinion  123  is attached to each of the upper and lower ends of the shaft  122 . Meanwhile, racks  124  engaged with the pinions  123  are secured to upper and lower portions of the frame of the transport device  2 . The upper and lower racks  124  are so disposed as to extend horizontally. Mounted on the shaft  122  is a gear  125 , to which a drive force developed by a motor  126  is applied. 
     A nut  127  movable along the spline shaft  117  is mounted thereon and coupled with the bevel gear  119 . Thus, when the nut  127  is transversely moved along the spline shaft  117 , the bevel gear  119  is also transversely moved along the spline shaft  117  with the movement of the nut  127 , and the latter is coupled with the moving frame  57 . 
     According to the arrangement above-mentioned, when the motor  126  is rotated, the rotational force causes the gear  125  to be rotated which in turn rotates shaft  122 . When the shaft  122  is rotated, the pinions  123  disposed at the upper and lower ends thereof, are meshed with the racks  124  and moved therealong. The racks  124  are stationary and the moving frame  57 , including the pinions  123 , is transversely movable. Accordingly, when the pinions  123  are rotated, the whole moving frame  57  is moved rightwards or leftwards. When the moving frame  57  is moved, the screw shaft  112  and the bevel gear  116  included in the moving frame  57  are also moved. At the same time, the bevel gear  119  and the nut  127  coupled with the moving frame  57  are also moved along the spline shaft  117 . Accordingly, the bevel gear  116  and the bevel gear  119  are transversely movable as meshed with each other. 
     As will be discussed with reference to FIG. 15, horizontally extending upper and lower linear guides  129  and  130  (not shown in FIG. 12) are disposed for smoothing the transverse movement of the moving frame  57 . 
     FIG. 13 illustrates the arrangement of the drive mechanism for vertically moving the arm units. FIG. 14 illustrates the arrangement of the drive mechanism for the left arm unit. FIG. 15 is a right side view of the transport device  2 , illustrating the arrangements of the vertically and transversely moving mechanisms of the arm units. 
     In FIGS. 13 to  15 , there are disposed linear guides  128  for directing vertical movement. There are a total of four linear guides for vertical movement  128 , i.e., front and rear there are two guides  128  for the right arm unit  51  and front and rear there are two guides  128  for the left arm unit  52 . There are also an upper linear guide  129  and a lower linear guide  130 . As mentioned earlier, these upper and lower linear guides  129  and  130  are disposed for smoothing the transverse movement of the moving frame  57 . Other component elements designated by reference numerals used in FIGS. 13 to  15 , are those already discussed. Accordingly, their shapes and layout only are shown in FIGS. 13 to  15  but detail descriptions are omitted. 
     Transport of Cylinder Between the Transport Device  2  and the Engraving Machine  3   
     The schematics of FIG. 16A to FIG. 16D are schematic views illustrating how to transport a gravure cylinder S between the transport device  2  and the engraving machine  3 . As shown in FIG. 16A, a gravure cylinder S held by the arm units  51  and  52  of the transport device  2 , is transported to a predetermined position of the engraving machine  3 . At this position, the stationary cone  7  and the movable cone  9  respectively face both the end surfaces of the gravure cylinder S. 
     As shown in FIG. 16B, the movable cone  9  is moved rightwards into contact with the left end surface of the gravure cylinder S. As the movable cone  9  moves further to the right gravure cylinder S is pushed rightwards such that the right end surface of the gravure cylinder S is engaged with the stationary cone  7 . This causes the gravure cylinder S to be supported with both its ends held by and between the cones  7  and  9 . Then, the stationary cone  7  is rotated to rotate the gravure cylinder S such that the circumferential surface thereof is engraved. In this embodiment, the movable cone  9  is rotatably held and so arranged as to be rotated following the rotation of the gravure cylinder S. However, provision may be made such that the movable cone  9  is not rotated following the rotation of a gravure cylinder, but is rotated in synchronism with the stationary cone  7 . 
     Upon completion of the engraving, the rotation of the stationary cone  7  is stopped and the gravure cylinder S is held by the arm units  51  and  52  as shown in FIG.  16 C. Then, the movable cone  9  is moved leftwards and clears the left end surface of the gravure cylinder S. 
     To separate the gravure cylinder S from the stationary cone  7 , a pushing device  140  (FIG. 16D) is used to push the right end surface of the gravure cylinder S leftwards to separate from the stationary cone  7 . At this time, since the arm units  51  and  52  are not moved, the gravure cylinder S held by the arm units  51  and  52  slides leftwards on the arm units  51  and  52 . 
     The following description will discuss in detail the For details of pushing device  140  reference is made particularly to 
     FIG. 17 which is a partial front view of the engraving machine  3 , illustrating the first or stationary cone unit  5  and its peripheral structure. FIG. 18 is a longitudinal section view in left side elevation of the engraving machine  3 , chiefly illustrating the structure in the vicinity of the first cone unit  5 . 
     First cone unit  5  is constituted by the drive device  8  including a motor, a gear mechanism and the like, and the stationary cone  7  to be rotated by the drive device  8 . The first cone unit  5  also has an air cylinder  141  secured to the drive device  8  or a frame relating thereto. The air cylinder  141  has a transversely slidable rod  142  to the left end of which a pushing piece  143  is fixed. Thus, the pushing device  140  is constituted by the air cylinder  141 , the rod  142  and the pushing piece  143 . 
     The stationary cone  7  is constituted by a truncated cone body formed by cutting the apex of a cone in a direction at a right angle to the axis thereof. The circumferential surface of the truncated cone body is arranged to be engaged with an end surface of the gravure cylinder S. 
     Gravure cylinders S, each of which is to be engaged with the stationary cone  7 , may have a variety of diameters from a diameter greater than the largest diameter of the stationary cone  7  to a diameter smaller than the largest diameter thereof. In FIG. 17, a two-dot chain line shows a gravure cylinder S having the smallest diameter as engaged with the stationary cone  7 . 
     The pushing piece  143  is disposed as downwardly extending from the rod  142  in a direction at a right angle thereto. With the slide movement of the rod  142 , the pushing piece  143  is moved leftwards to push the right end surface of the gravure cylinder S, causing the same to be separated from the stationary cone  7 . When the diameter of a gravure cylinder S is greater than the largest diameter of the stationary cone  7 , the right end surface of the gravure cylinder S can be pushed by the pushing piece  143  when it slides to the left even when provision is made such that the lower end of the pushing piece  143  does not interfere with the stationary cone  7 . However, when a gravure cylinder S of a diameter smaller than the largest diameter of the stationary cone  7  is used (as shown in FIG.  17 ), the pushing piece  143  would not interfere with the gravure cylinder S if the lower end of the pushing piece  143  did not interfere with the stationary cone  7 . Thus, the pushing piece  143  could not push the right end surface of the gravure cylinder S. In this embodiment, the lower end of the pushing piece  143  extends down to a position where the same interferes with the stationary cone  7  as shown in FIG.  17 . In such a case, however, when it is intended to move the pushing piece  143  leftwards for pushing the right end surface of the gravure cylinder S, the stationary cone  7  gets in the way to prevent the pushing piece  143  from being moved leftwards. 
     In this connection, as better shown in FIG. 18, the stationary cone  7  is provided in a part of its circumferential surface, with a notch  144  extending in the axial direction. When the stationary cone  7  is stopped such that the notch  144  is located just below pushing piece  143 , the latter can be moved leftwards after passing through the notch  144  formed in the stationary cone  7 . Thus, the pushing piece  143  can push the right end surface of a gravure cylinder S even though the same has the smallest diameter. 
     Shown in FIG. 18 are the engraving head  11  and a diamond bite  150  or stylus that is intermittently struck against the circumferential surface of the gravure cylinder S to form cells therein. 
     The inspection camera  12  is used for making sure of the state of the cells formed in the circumferential surface of the gravure cylinder S. 
     Description of the Sensors 
     The following description will discuss the sensors in the gravure engraving system according to the embodiment above-mentioned, particularly those for detecting data relating to the gravure cylinder S. 
     Referring to FIGS. 1 and 2, the stocker  1  has sensors for detecting whether or not a gravure cylinder S is being placed on a placing stand  17 . For example, two sets of photosensors are provided. More specifically, there are disposed a sensor  100  for detecting the presence or absence of a gravure cylinder S on a placing stand  17   a  stopped at a position where the gravure cylinder S can be unloaded by the transport device  2 , and a sensor  101  for detecting the presence or absence of a gravure cylinder S on a placing stand  17   b  stopped at a position that is more remote than sensor  100  from the transport device  2 . 
     The sensor  100  is constituted by a light projecting element  102  and a light receiving element  103 , and these elements  102  and  103  are fixed to the frame  16  of the stocker  1 . Provision is made such that when the placing stand  17   a  is stopped at a predetermined position where the gravure cylinder S placed thereon can be unloaded by the arm units  51  and  52  of the transport device  2 , the gravure cylinder S on the placing stand  17   a  is positioned to block the light that projects from the light projecting element  102  toward the light receiving element  103 . This means that, when the light receiving element  103  receives light from the light projecting element  102 , no gravure cylinder S is on the placing stand  17   a , and that, when the light receiving element  103  does not receive such light, a gravure cylinder S is on the placing stand  17   a.    
     The sensor  101  has an arrangement similar to that of sensor  100 . 
     Also, the stocker  1  has a passage sensor  104  for detecting the diameter of a gravure cylinder S. That is, the passage sensor  104  is arranged to detect the diameter of a gravure cylinder S which is unloaded from the stocker  1  by the arm units  51  and  52  of the transport device  2  or which is returned back to the stocker  1  by the arm units  51  and  52 . 
     For example, the passage sensor  104  is attached to the frame  16  of the stocker  1  at its side opposite to the transport device  2 , and is constituted by a light emitting element  105  disposed at an upper portion of the frame  16  and a light receiving element  106  disposed at a lower portion of the frame  16 . While a gravure cylinder S held by the arm units  51  and  52  is being moved between the stocker  1  and the transport device  2 , the gravure cylinder S intercepts the light passage from the light emitting element  105  to the light receiving element  106 . When the speed of movement of the gravure cylinder S by the arm units  51  and  52  in a back-and-forth direction (transverse direction in FIG. 1) is constant, the period of time during which the light passage from the light emitting element  105  to the light receiving element  106  is intercepted, is proportional to the diameter of the gravure cylinder S. Accordingly, by measuring the period of time between the time when the passage sensor  104  is first switched in output and the time that the passage sensor  104  is next switched in output, the diameter of the gravure cylinder S can be calculated. 
     The following description will discuss the sensors disposed in the arm units. 
     Referring to FIGS. 5,  6 , and  8 , two sensors are disposed in the support block  55 S. One sensor is disposed for detecting whether or not a gravure cylinder S is being mounted on the support block  55 S, and the other for detecting whether or not the left arm unit  52  has contacted with an end surface of the gravure cylinder S when the whole left arm unit  52  including the support block  55 S has moved rightwards in FIG.  4 . 
     As shown in FIGS. 6 and 8, the support block  55 S is provided in the center of the mounting surface  91  with a recessed groove  92  extending in the back-and-forth direction. A light projecting sensor element  93  and a light receiving sensor element  94  are disposed in the recessed groove  92  such that these elements  93  and  94  do not protrude from the mounting surface  91 . 
     While a gravure cylinder S is mounted on the support block  55 S, light from the light projecting sensor element  93  to the light receiving sensor element  94  is intercepted by the gravure cylinder S as shown in FIG.  5 . Accordingly, the presence or absence of gravure cylinder S can be detected by judging whether or not the light receiving sensor element  94  receives the light from the light projecting sensor element  93 . 
     Referring to FIG. 6, an actuator  95  is disposed at the right end of the support block  55 S in the left arm unit  52  and projects rightwards from the support block  55 S. As shown in FIG. 8, the actuator  95  has a predetermined length in the back-and-forth direction (in the transverse direction in FIG.  8 ). The actuator  95  swings around a fulcrum  96  when an article comes in contact with the lower end of the actuator  95 . By this swing, a light shade plate  97  integrated with the actuator  95  intercepts light which passes through a sensor  98 . 
     In the foregoing, the description has been made of the gravure cylinder detecting sensors. In addition, there are disposed, as necessary, microsensors or the like for detecting, for example, whether or not the arm units  51  and  52  properly operate. However, since these sensors do not particularly take part in the features of the present invention, the description thereof is here omitted. 
     Arrangement of the Whole System 
     FIG. 19 is a schematic plan view of the system, illustrating the positional relationship between stocker  1 , the transport device  2  and the engraving machine  3  in an arrangement where the transport device  2  is movable. As shown in FIG.  19  and FIG. 2 that has been described earlier herein, the stocker  1 , the transport device  2  and the engraving machine  3  are disposed in this order from the front side to the rear side. Accordingly, in such an arrangement, the transport device  2  and the engraving machine  3  are to be maintained with difficulty and a gravure cylinder cannot manually be set on the engraving machine  3 . 
     In this connection, the embodiment in FIG. 19 is arranged such that the whole transport device  2  can be slid leftwards. That is, two rails  151  are disposed under the transport device  2  such that the same is transversely movable thereon. 
     FIG. 20 is a section view of portions of the right side of the transport device  2 , illustrating the structure relating to the rails  151 . As shown in FIG. 20, the two rails  151  are installed on a stand plate  153  on a floor surface  152 . Legs  154  project downwardly from the frame  50  of the transport device  2 , and the lower ends of the legs  154  are slidably engaged with the rails  151 . 
     Engagement pieces  155  are fixed to the stand plate  153  at respective positions corresponding to the transport and retreat positions of the transport device  2 . That is, the engagement pieces  155  are arranged to fix (hold) the transport device  2  at the transport position shown by solid lines in FIG. 19 when the same has been moved thereto, and at the retreat position shown by broken lines in FIG. 19 when the same has been moved thereto. Meanwhile, the frame  50  of the transport device  2  has a pin  156  downwardly projecting from the frame  50 , and a pedal  157  coupled with the pin  156  for vertically moving the same. The pedal  157  is biased by a spring  158  such that the operating portion thereof is normally turned up. As a result, the pin  156  coupled with the pedal  157  normally projects under the frame  50 . 
     When the transport device  2  is moved along the rails  151  to the predetermined transport or retreat position, the pin  156  is engaged with one of the engagement pieces  155 , causing the transport device  2  to be fixed at the transport or retreat position such that the same cannot be moved. For moving the transport device  2 , the pedal  157  may be pushed down to disengage the pin  156  from the engagement piece  155  and the transport device  2  may be pushed transversely. 
     Preferably, the transport device  2  transversely movable along the rails  151  is provided at both moving ends thereof with shock absorbers  159  each formed by a rubber pad or the like. The shock absorbers  159  are arranged to absorb a shock exerted on the transport device  2  when the transverse terminal ends thereof come into collision with stop pieces, walls or the like in the transverse movement of the transport device  2 . 
     General Arrangement of Systems of Other Embodiments 
     FIG. 21 shows the arrangement of a system according to another embodiment of the present invention. FIG. 21A is a plan view of a gravure engraving system where a plurality of stockers  1   a  and  1   b , a single transport device  2 , and a plurality of engraving machines  3   a  and  3   b  are disposed. 
     The transport device  2  is transversely movable on rails  151  installed thereunder. While the transport device  2  is stopped for example between the stocker  1   a  and the engraving machine  3   a , a gravure cylinder can be transported between the stocker  1   a  and the transport device  2  and between the engraving machine  3   a  and the transport device  2 . Likewise, while the transport device  2  is stopped between the stocker  1   b  and the engraving machine  3   b , a gravure cylinder can be transported between the stocker  1   b  and the transport device  2  and between the engraving machine  3   b  and the transport device  2 . Accordingly, it is possible for example that the transport device  2  is stopped at a position opposite to the stocker  1   a , a gravure cylinder stored in the stocker  1   a  is unloaded, and the gravure cylinder thus unloaded is then set to the engraving machine  3   a . Or, it is also possible that the transport device  2  which is holding a gravure cylinder unloaded from the stocker  1   a , is moved along the rails  151  and then stopped at a position opposite to the engraving machine  3   b , and the gravure cylinder held by the transport device  2  is set to the engraving machine  3   b.    
     Thus, in the embodiment shown in FIG. 21, a gravure cylinder can be transported by the single transport device  2  between any of a plurality of stockers and any of a plurality of engraving machines. 
     FIG. 21B shows an example of a moving mechanism for moving the transport device  2  along the rails  151 . As shown in FIG. 21B, a screw shaft  160  is disposed in parallel with the rails  151 . An internally threaded member  161  with balls is fitted to the screw shaft  160  and the outer casing of member  161  is fixed to the transport device  2 . The screw shaft  160  is rotated by a drive device such as a motor  162  or the like. Thus, the transport device  2  can be transversely smoothly moved and the moving amount thereof can be controlled by the rotation of the motor  162 . 
     In the embodiment above-mentioned, a plurality of stockers  1  and a plurality of engraving machines  3  are disposed. However, provision may be made such that a single stocker  1  is disposed and a gravure cylinder is transported from the single stocker  1  to any of a plurality of engraving machines  3  by a common transport device  2 . 
     The number of each of stockers  1  and engraving machines  3  to be disposed may suitably be changed according to requirements of the user factory or the like that employs the gravure engraving system of the present invention. 
     Operation of the System 
     The following description will discuss in detail the job operation and control operation of the gravure engraving system according to the embodiment of the present invention. 
     FIG. 22 is a block diagram of a control circuitry in the gravure engraving system in FIGS. 1 and 2. The control circuitry is constituted by a data input unit  170  and a data output unit  171 . The data input unit  170  is a device for entering image data, character data and the like and is constituted by a keyboard, a display, a scanner, a mouse and the like. The data output unit  171  is a device for forming gravure engraving data by editing and arranging data entered from the data input unit  170 . The data output unit  171  is connected, through a bus  172 , to an operation unit  173  of the stocker  1  and the transport device  2 . The operation unit  173  is provided with a processing device including microcomputer. The processing device contains an automatic operation program  200  in a suitable storage medium. The automatic operation program  200  is arranged to be invoked according to data supplied from the data output unit  171 . According to this program  200 , the stocker  1  and the transport device  2  are driven. Further, the data output unit  171  is connected to the engraving machine  3  through the bus  172 . The engraving machine  3  is arranged to execute a predetermined engraving processing according to engraving data supplied from the data output unit  171 . 
     FIG. 23 is a flow chart illustrating the job processing of the gravure engraving system according to this embodiment. It is noted that data required for the job are previously entered from the data input unit  170  and edited and arranged by the data output unit  171 . When the job starts, job contents are read by the operation unit  173  through the bus  172  (Step S 1 ). In reading the job contents, one of a plurality of job contents previously designated is read out. The job contents include a variety of engraving conditions such as the number of the placing stand  17  on which a gravure cylinder to be used is being placed (See FIG.  1 ), the file name of data to be used for engraving, the number of lines to be engraved, cell shape (elongate, compressed, etc.) and the like. 
     Upon completion of reading the job contents, the length of the gravure cylinder to be used is measured (Step S 2 ). This measurement processing is conducted by moving the left arm unit  52  (See FIG. 4) but its detail will be discussed later. 
     Then, the gravure cylinder is unloaded (Step S 3 ). That is, the gravure cylinder is delivered from the stocker  1  to the transport device  2 , and then transported. In the course of such delivery, the diameter of the gravure cylinder is measured as mentioned earlier (Step S 9 ). 
     Then, the gravure cylinder is supplied from the transport device  2  to the engraving machine  3  and attached to a predetermined portion thereof (Step S 4 ). 
     Then, predetermined engraving is applied onto the circumferential surface of the gravure cylinder by the engraving machine  3  (Step S 5 ). 
     The gravure cylinder is removed from the engraving machine  3  and transported by the transport device  2  (Step S 6 ). The engraved gravure cylinder is transported from the transport device  2  to a vacant placing stand  17  of the stocker  1  (Step S 7 ). 
     At the operation unit  173 , it is judged whether or not there is an engraving job to be subsequently executed (Step S 8 ). In the affirmative, the operations from Step S 1  are repeated. In the negative, the job processing is then finished. 
     FIG. 24 is a flow chart illustrating in detail the processing of measuring the length of a gravure cylinder, which is executed at the step S 2  in FIG.  23 . 
     First, the positions of the placing stands  17  in the stocker  1  are determined (Step S 21 ). More specifically, as shown in FIG. 1, the placing stand  17   a  on which the gravure cylinder S intended to be used is being placed, is located in a predetermined unloading position (shown by A in FIG.  1 ). 
     Then, the arm units  51  and  52  are vertically moved and stopped at a measurable position (Step S 22 ). The measurable position in the vertical direction refers to a position having a height such that the actuator  95  of the left arm unit  52  shown in FIG. 6 can come in contact with the end surface of the gravure cylinder S on the placing stand  17   a  in FIG.  1 . The gravure cylinder S on the placing stand  17   a  is different in diameter dependent on the type. Accordingly, based on the position of the positioned placing stand  17   a , the heightwise measurement position is determined such that the actuator  95  can come in contact with the end surface of the gravure cylinder S even though the diameter thereof is small. 
     At this time, the arm units are located in the original point in both the transverse direction and the back-and-forth direction. The original point refers to the position where the arm units are not being slid in the back-and-forth direction and are located in the state shown in FIG. 10A, and where the left arm unit  52  is located in the leftmost position, the second reference position, as shown in FIG.  4 . 
     As shown in FIG. 4 for example, the left arm unit  52  is then slid (forwardly) toward the stocker  1  (Step S 23 ). As mentioned earlier, each of the right arm unit  51  and the left arm unit  52  has a motor for horizontally moving the same. Accordingly, the right arm unit  51  and the left arm unit  52  can be operated individually in a slide movement in the horizontal back-and-forth direction. At the step S 23 , only the left arm unit  52  is horizontally slid toward the stocker  1 . As a result, the left arm unit  52  is brought to the state shown in FIG.  1 D. Setting is previously made such that, at this state, the center of the support block  55 S is opposite to the center of the left end surface of the gravure cylinder S placed on the placing stand  17   a  of the stocker  1  in FIG. 1 
     Then, the left arm unit  52  is horizontally moved rightwards as shown in FIG. 14 (Step S 24 ). When the left arm unit  52  is continuously moved rightwards in FIG. 14, the actuator  95  of the left arm unit  52  (See FIG. 6) is then displaced as coming in contact with the left end surface of the gravure cylinder S placed on the placing stand  17   a  (See FIG.  1 ). Then, the sensor  98  in FIG. 8 is turned on (Step S 25 ) to top the horizontal rightward movement of the left arm unit  52  and measure the length of the gravure cylinder S (Step S 26 ). To this end, the automatic operation program  200  in the operation unit  173  recognizes, as the first reference position, the position where the right end surface is regulated by the regulating plate  38 . The automatic operation program  200  has previously set the above-mentioned second reference position, and controls the motor  126  so that the initial position of the left arm unit  52  is the second reference position. 
     The length of a gravure cylinder S can be obtained in the following manner. In FIG. 4 for example, the left arm unit  52  starts moving rightwards from the leftmost position, the second reference position, and stops when the left arm unit  52  comes in contact with the left end surface of the gravure cylinder. The amount of movement of the left arm unit  52  can be obtained, for example, by counting the number of pulses given to the motor  126  (See FIG. 12) for moving the left arm unit  52 . As shown in FIG. 3, each gravure cylinder S is placed in the stocker  1  such that the right end surface of the gravure cylinder S comes in contact with the regulating plate  38 . In other words, each gravure cylinder S is disposed such that the right end thereof is located along the predetermined first reference position. Accordingly, the length of the gravure cylinder S can be calculated by subtracting, from the distance between the predetermined first reference position and the second reference position, the distance by which the left arm unit  52  has moved. 
     Then, the left arm unit  52  is moved slightly leftwards such that the actuator  95  (See FIG. 6) does not come in contact with the left end surface of the gravure cylinder (Step S 27 ). 
     Then, the left arm unit  52  is slid in the back-and-forth direction with the transverse position maintained as it is, such that the slide arm member  54  is returned to the original point in the back-and-forth direction (See FIG. 10A) (Step S 28 ). 
     In the embodiment above-mentioned, the second reference position is defined as the position where the left arm unit  52  is located in the leftmost position. However, the second reference position may be a position separated, from the first reference position, by a predetermined distance toward the other end of the gravure cylinder. Further, the sensor  98  disposed at the left arm unit  52  has the mechanically operated actuator  95  (See FIG.  6 ). Instead of the mechanical type, the sensor  98  may be of the optical type having for example a light projecting element and a light receiving element and arranged such that light from the light projecting element is reflected from the circumferential surface of the gravure cylinder and received by the light receiving element. When such an optical sensor is used, the other end surface of the gravure cylinder can be detected even though the left arm unit  52  does not come in contact with the end surface of the gravure cylinder. Further, when such an optical sensor is used, the second reference position can be set at a predetermined position separated, from the first reference position, by a distance shorter than the length of the gravure cylinder. That is, since the sensor actuator is not required to come in contact with the gravure cylinder, an end surface of the gravure cylinder can be detected without the gravure cylinder and the left arm unit  52  physically interfering with each other. 
     FIG. 25 is a flow chart illustrating in detail the gravure cylinder unloading processing at step S 3  in FIG.  23 . 
     In the gravure cylinder unloading processing, it is first judged whether or not the length of the gravure cylinder measured at the step S 2  in FIG. 23 is equal to or less than a predetermined value (Step S 30 ). As mentioned earlier, such a judgment is required to determine whether the gravure cylinder is to be held by two arm units, i.e., both the right arm unit  51  and the left arm unit  52  (referred to as “both-hand holding” hereinafter), or only by the right arm unit  51  (referred to as “one-hand holding” hereinafter). 
     When the gravure cylinder length is greater than the predetermined value, the gravure cylinder is transported in a so-called both-hand holding mode using the two arm units  51  and  52  (Step S 31  to S 35 ). 
     Here, the left arm unit  52  is first moved by a predetermined amount rightwards in FIG. 2 for example. When the measurement of the gravure cylinder length is finished, the left arm unit  52  is located in a position slightly leftwards with respect to the left end surface of the gravure cylinder when transversely viewed from the front side. Accordingly, the left arm unit  52  is moved rightwards to a position where the left arm unit  52  can hold the gravure cylinder. The amount of movement is adjusted based on the calculated gravure cylinder length. 
     Then, the arm units  51  and  52  are downwardly moved by a predetermined amount. As discussed with reference to FIGS. 12 and 13, such downward movements are synchronously conducted at the same time. The arm units  51  and  52  are stopped at preparatory unloading positions opposite to the space  46  of the placing stand  17  on which the gravure cylinder to be unloaded is being placed (See FIG.  3 ). 
     Then, the arm units  51  and  52  are horizontally forwardly slid toward the stocker  1  (Step S 33 ). Therefore, the support blocks  55 L and  55 S (See FIG. 4) of the arm units  51  and  52  are entered into the space  46  (See FIG. 3) and located under the gravure cylinder S to be unloaded. 
     Then, the arm units  51  and  52  are moved upward, causing the support blocks  55 L and  55 S to support the gravure cylinder S (Step S 34 ). This unloading position is slightly above the position where the gravure cylinder S is held by the stationary holding portion  33  and the movable holding portion  34  in FIG.  3 . 
     Then, the arm units  51  and  52  are rearwardly slid under the velocity control thereof and returned to the original point (Step S 35 ). 
     When returned to the original point at the step S 35 , the gravure cylinder S is measured in diameter (Step S 9 ). How to measure the diameter will be discussed later. 
     On the other hand, when the gravure cylinder length is not greater than the predetermined value, a so-called one-hand holding mode is carried out. The operations in this mode is the same as the operations in the both-hand holding mode above-mentioned except that the left arm unit  52  is not moved in the back-and-forth direction and in the transverse direction. As mentioned earlier, the vertical movements of the arm units  51  and  52  are cooperatively conducted by the single motor  121  (See FIG.  12 ). Accordingly, even in the one-hand holding mode, the left arm unit  52  is vertically moved. 
     In the one-hand holding mode, an operation corresponding to the step S 31  is omitted, and there are executed operations at steps S 36 , S 37 , S 38 , and S 39  respectively corresponding to the steps S 32 , S 33 , S 34 , and S 35 . Thereafter, the gravure cylinder is measured in diameter likewise in the both-hand holding mode (Step S 9 ). 
     FIG. 26 is a flow chart of the gravure cylinder diameter measurement processing at the step S 9  in FIGS. 23 and 25. 
     As discussed with reference to FIGS. 1 and 2, the diameter of a gravure cylinder is measured using the passage sensor  104 . First, it is judged whether or not the passage sensor  104  (See FIG. 1) is turned on (Step S 91 ). As shown in FIG. 1, there is formed, in the passage sensor  104 , a light passage (detection line) from the light emitting element  105  to the light receiving element  106 . When this light passage is blocked, the passage sensor  104  is turned on. As shown in FIG. 2, the movements of the arm units  51  and  52  in the back-and-forth direction do not intercept the light passage. However, when a gravure cylinder is being placed on the arm units  51  and  52 , the movement of the placed gravure cylinder in the back-and-forth direction intercepts the light passage of the passage sensor  104 . 
     When it is judged that the passage sensor  104  is being turned on (YES at Step S 91 ), time counting starts (Step S 92 ). Thereafter, when the gravure cylinder is moved such that the light passage of the passage sensor  104  is cleared, and it is judged that the passage sensor  104  is being turned off (YES at Step S 93 ), time counting is finished (Step S 94 ). 
     Based on the time thus counted, the diameter of the gravure cylinder is operated (Step S 95 ). The operation can be conducted for example by multiplying the counting time by the back-and-forth transport speed. 
     FIG. 27 is a flow chart of the cylinder mounting processing for setting a gravure cylinder to the engraving machine  3 , shown at the step S 4  in FIG.  23 . 
     In the cylinder mounting processing, the arm units  51  and  52  are normally downwardly moved to a preparatory mounting position (Step S 41 ). The preparatory mounting position is not the position, as shown in FIG. 16A, where the axis of the gravure cylinder S held by the arm units  51  and  52  is identical in height with the axes of the cones  7  and  9 , but refers to a position where the axis of the gravure cylinder S is located in a position lower than the axes of the cones  7  and  9 . After the arm units  51  and  52  are lowered to the preparatory mounting position, the arm units  51  and  52  are rearwardly slid to the engraving machine position shown in FIG. 10D (Step S 42 ). In the one-hand holding mode, only the right arm unit  51  is driven. 
     Then, the arm units  51  and  52  are upwardly moved, according to the diameter of the gravure cylinder held thereby, to the mounting position where the axis of the held gravure cylinder S is identical in height with the axes of the cones  7  and  9  as shown in FIG. 16A (Step S 43 ). 
     Then, the movable cone  9  is moved rightwards as shown in FIG. 16A, and then the gravure cylinder S is held at both its ends by and between the stationary cone  7  and the movable cone  9  (Step S 44 ). 
     Then, the arm units  51  and  52  are moved down to the preparatory mounting position (Step S 45 ), then horizontally slidably moved and returned to the original point (Step S 46 ). 
     In the cylinder mounting processing, the preparatory mounting position discussed in connection with the steps S 41  and S 45  is set for the following reasons. 
     Firstly, by setting such a preparatory mounting position, it is the single passage that a gravure cylinder passes through when it is transported between the transport device  2  and the engraving machine  3 . This presents structural advantages such as a reduction in the number of transport detection sensors or the like. 
     Secondly, when removing a gravure cylinder from the engraving machine  3 , if the gravure cylinder as caught by a cone is moved in the unloading direction (horizontal forward direction), this may be dangerous. That is, there is a possibility of the relatively heavy gravure cylinder falling down. Accordingly, from a safety viewpoint it is preferable to have the gravure cylinder lowered before removal. Thus, the preparatory mounting position is provided. Whether or not the gravure cylinder to be removed is being caught by a cone, when such an arrangement is adopted, the preparatory mounting position may be omitted. 
     FIG. 28 is a flow chart of the gravure cylinder removal processing at the step S 6  in FIG.  23 . In this processing too, operations to be executed vary with the gravure cylinder length measured at the step S 2  in FIG.  23 . More specifically, there is executed a both-hand holding processing, using the arm units  51  and  52 , when the gravure cylinder length is greater than a predetermined value, and there is executed a one-hand holding processing, using only the arm unit  51 , when the gravure cylinder length is not greater than the predetermined value. 
     More specifically, it is judged whether or not the length of a gravure cylinder to be removed is equal to or less than a predetermined value (Step S 60 ). When the length is greater than the predetermined value, the left arm unit  52  is moved in the transverse direction (in FIG. 16C for example) according to the length of the gravure cylinder (Step S 61 ). Then, the arm units  51  and  52  are vertically moved to the preparatory mounting position (Step S 62 ). 
     Thereafter, the arm units  51  and  52  are horizontally rearwardly slidably moved to the engraving machine position after which Step S 63  arm units  51  and  52  are moved upwardly, according to the diameter of the gravure cylinder, to the mounting position where the gravure cylinder S can be held (Step S 64 ). 
     Then, the movable cone  9  is retracted leftwards as shown in FIG. 16C (Step S 65 ) followed by gravure cylinder S being separated from the stationary cone  7  by the pushing device  140  as shown in FIG. 16D (Step S 66 ). 
     Then, the arm units  51  and  52  are downwardly moved to the preparatory mounting position (Step S 67 ) after which arm units  51  and  52  are horizontally forwardly slidably moved and returned to the original point (Step S 68 ). 
     In the one-hand holding mode, the left arm unit  52  is not horizontally transversely moved, but other operations are similarly to operations in the both-hand mode. That is, only the operation at the step S 61  is not executed, but the operations corresponding to the operations from the step S 62  to the step S 68  are executed. However, it is noted that, at each of steps S 63 ′ and S 68 ′, only the right arm unit  51  is operated without the left arm unit  52  being operated. 
     FIG. 29 is a flow chart illustrating in detail the gravure cylinder storing processing at the step S 7  in FIG.  23 . 
     In the gravure cylinder storing processing, the positions of the placing stands  17  in the stocker  1  (See FIG. 1) are determined. More specifically, in FIG. 1, the chain  20  is circulated such that a vacant placing stand (on which a gravure cylinder to be stored has been placed before being engraved) is located in the position where a gravure cylinder can be unloaded or stored by the transport device  2  (the position where the placing stand  17   a  is located in FIG. 1) (Step S 71 ). 
     Then, the arm units  51  and  52  are moved vertically such that the arm units  51  and  52  reach the unloading position (Step S 72 ). 
     Then, the arm units  51  and  52  are forwardly slidably moved toward the stocker  1  (Step S 73 ). In the so-called one-hand holding mode, the left arm unit  52  is not driven but only the right arm unit  51  is driven at the step S 73 . 
     Thereafter, the arm units  51  and  52  are downwardly moved to the preparatory mounting position (step S 74 ). This causes the gravure cylinder supported by the arm units  51  and  52  to be transported to the placing stand  17   a  and supported by the holding portions  33  and  34  thereof (See FIG.  3 ). 
     Then, the arm units  51  and  52  are rearwardly slidably moved to the original point (Step S 75 ). In the so-called one-hand holding mode, only the right arm unit  51  is driven at the step S 75 . This is because, at the step S 73 , the left arm unit  52  has not been moved but remained at the original point. 
     Then, the arm units  51  and  52  are vertically moved and returned to the original point. It is noted that the original point in the vertical direction may be optional and the operation at the step S 76  may be omitted. 
     Then, the left arm unit  52  is moved leftwards (leftwards in FIG. 4 for example) up to the leftmost position serving as the original point (Step S 77 ). 
     Other Embodiments 
     In the embodiment above-mentioned, the length of a gravure cylinder S is calculated based on the distance by which the left arm unit  52  has been moved from the second reference position. However, the length of a gravure cylinder S may be obtained by reading, with a linear scale or the like, the absolute value of the position where the left arm unit  52  has stopped. 
     This is schematically shown in FIG.  30 . That is, FIG. 30 is a schematic plan view of an arrangement in which the length of a gravure cylinder is measured using a linear scale  180 . In FIG. 30, the linear scale  180  is disposed in parallel with the transverse direction in which the left arm unit  52  is to be moved, and is arranged to measure the stop position of the left arm unit  52 . More specifically , the left arm unit  52  has a reading device  181  for reading a division of the linear scale  180 . This reading device  181  is arranged to read the absolute value of the stop position of the left arm unit  52  based on the first reference position. Here, the stop position of the left arm unit  52  refers to the position of the actuator  95  which comes in contact with the left end surface of the gravure cylinder S. In the embodiment in FIG. 30, the original point of the linear scale  180  is set to the first reference position which is the position of the regulating plate  38 . Accordingly, the absolute value read by the reading device  181  is equal to the length of the gravure cylinder S. However, the original point of the linear scale is not necessarily set to the first reference position, and the length of the gravure cylinder S may be calculated based on a difference between the arm stop position and the first reference position. 
     In each of the embodiments above-mentioned, a transport device for a gravure cylinder has been discussed. However, there may be used, for transporting not only a gravure cylinder but also another article, the transport device of the present invention having the arrangement which is discussed particularly with reference to FIGS. 5,  6 ,  8 ,  9 ,  10 , and  11 , and which more specifically is constituted by the arm base members  53 , the slide arm members  54  slidable on the arm base members  53 , the support blocks  55  slidable on the slide arm members  54 , and the motors  61  and the chains  62  for sliding the slide arm members  54  and the support blocks  55 . For example, by matching the shape of the placing surface of each support block  55  with an article to be transported, the transport device may be applied not only to a gravure cylinder, but also to a printing plate, a material block to be machined, a mechanical unit or the like. 
     The foregoing has discussed in detail embodiments of the present invention. However, the foregoing embodiments are mere illustrative examples for disclosing the technical nature of the present invention, and the present invention should not be interpreted in a narrow sense by limiting same to these practical examples only. Hence, the true spirit and scope of the present invention should be limited only by the accompanying claims.