Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F21/00—Devices for conveying sheets through printing apparatus or machines
  • B41F21/08—Combinations of endless conveyors and grippers

Definitions

• the invention is a planetary synchronizing system for use in combination with conveyor systems of the type disclosed in Dahlgren Patent No. 3, 644 , 261, entitled "STRAIGHT FEED PRESS" and Dahlgren Patent No.
• the method and apparatus disclosed herein relates to an improved conveyor system and a planetary synchronizing system to provide register between an endless conveyor surface and a printing cylinder.
• the method of maintaining endless surfaces on two members, such as a printing cylinder and an endless sheet conveyor driven by a drive wheel associated with the printing cylinder in a precisely synchronized relationship when the drive wheel and conveyor are in rolling relation requires that the ratio of the surface speed of the endless sheet conveyor to the length of the conveyor be maintained equal to multiple of the ratio of the surface speed of the drive wheel to the circumference of the drive wheel. This relationship can be maintained by two methods , even though the dimensions and surface speeds of both the drive wheel and the sheet conveyor may change as a result of thermal expansion under normal operating conditions.
• the printing cylinder and the sheet conveyor drive vheel may be drivingly connected together through a device which permits adjustment of the surface speed of the printing cylinder relative to the surface speed of the sheet conveyor drive wheel to restore the required speed to distance relationship if the speed or dimensions or both of either the drive wheel or the sheet conveyor changes .
• either the circumference of the conveyor drive wheel or the length of the sheet conveyor can be adjusted relative to the other to restore the required speed to distance relationship.
• either the speed relationship of the printing cylinder and the drive wheel, or the distance relationship of the drive wheel relative to the sheet conveyor may be controllable adjusted to maintain a controlled non-synchronized relationship between the printing cylinder and the sheet conveyor.
• the preferred embodiment of the planetary system disclosed herein comprises a pair of endless epicyclical members, such as a conveyor drive wheel associated with a printing cylinder and a sheet conveyor, wherein the conveyor drive wheel comprises a circle which rolls around the inside or the outside of the circumference of the sheet conveyor.
• the sheet conveyor may be circular or, since it is an endless member, may be routed around a path other than a circle in a closed loop.
• the speed and distance relationship set forth above are maintained by either adjusting the relative speeds of the respective members of the relative lengths or circumferences thereof.
• the lengths or circumferences of the respective members are adjusted, it will be appreciated that at least one of the members will have a controllably variable geometry which is adjustable.
• the planetary system is disclosed herein in com bination with a sheet conveyor similar to that disclosed in the above listed United States Patents.
• a positive, infinitely variable speed drive member is mounted in the drive system for the drive wheel of the conveyor to permit adjustment of the speed of rotation of the drive wheel to correct for any change in the circumference of the drive wheel as a result of thermal expansion or contraction. If the angular velocity of the drive wheel remained unchanged while the diameter of the drive wheel increased slightly as a result of thermal expansion, the surface speed of the conveyor driven by the drive wheel would increase thereby resulting in an inaccuracy of the sheet arriving at the printing cylinder which would result in the sheet not being registered with the printing cylinder.
• the angular velocity of the drive wheel is adjusted to accommodate a change in the diameter of the drive wheel, the arrival time of the sheet to the printing cylinder can be precisely maintained.
• the angular velocity of the drive wheel may be left unchanged relative to the angular velocity of the printing cylinder if the length of the conveyor is adjusted to adjust the distance a gripper bar carrying a sheet travels during one complete revolution of the conveyor.
• a primary object of the invention is to provide a planetary system wherein epicyclic members are maintained in a registered relationship even though the circumference of one of the members varies under normal operating conditions by adjusting the ratio of the speed to the geometric dimensions of the members .
• Another object of the invention is to provide a conveyor for a sheet-fed printing press wherein the length, of the conveyor is capable of adjustment for purposes of registering the conveyor with printing cylinders to provide a sheet-fed printing press in which the sheet is continuously gripped by a single set of gifippers from the time the sheet enters the press at the feeder until it reaches the delivery station even though the dimensions of the conveyor drive wheels are variable.
• a further dbject of the invention is to provide a conveyor, the length of the conveyor being adjustable for maintaining registry between the conveyor and another member, the conveyor moving at a constant speed along a path wh ich is adjustable in length.
• a still further object of the invention is to provide aconveyor having a fixed length which is driven by a drive wheel having a variable diameter driven by a variable speed drive means for maintaining registry between the conveyor and another member.
• Figure 1 is a side elevational view of the printing press
• Figure 2 is a top plan view of the printing press having inkers and dampeners removed therefrom;
• Figure 3 is a diagrammatic view illustrating the relationship of the sheet conveyor to a conveyor drive wheel associated with a printing cylinder with planetary synchronization.
• Figure 4 is a diagrammatic view of a sheet conveyor which is properly registered
• Figure 5 is a diagrammatic view similar to Figure 4 in which the path of the sheet conveyor is too short;
• Figure 6 is a diagrammatic view similar to Figure 4 in which the length of the sheet conveyor is too long;
• Figure 7 is an enlarged cross-sectional view taken along line 7-7 of Figure 2;
• Figure 8 is cross-sectional view taken along line 8-8 of Figure 7;
• Figure 9 is an elevational view looking in the direction of arrows 9-9 in Figure 7. Numeral references are employed to designate like parts throughout the various figures of the drawing.
• the numeral 1 generally designates a sheet-fed, multi-color, perfecting, lithographic printing press of the type disclosed in U. S. Patent No. 3,847,079.
• a feeder mechanism 2 delivers sheets of imprinted paper from a stack. 4 to a swing gripper 6.
• the swing gripper 6 accelerates individual sheets 5 to the velocity of gripper bars 8 carried by a sheet transfer mechanism 10.
• the sheet transfer mechanism 10 comprises drive wheels 12a and 12b adjacent the feeder end of the press and idler wheels 14a and 14b adjacent the delivery end of the printing press.
• the wheels carry tapes or bands 16a and 16b, having gripper bars 8 mounted therebetween for moving individual sheets 5 through the printing press .
• a pair of printing towers 18 and 20 are provided to give the press a multi-color, perfecting printing capability. It should be appreciated that any number of printing towers may be employed for printing additonal colors or for coating sheets.
• Individual sheets 5 are gripped by a delivery mechanism 22 as they are released by gripper bars 8 to form a stack 24 of printed sheets .
• each printing tower 18 and 20 has a side frame 26 on the operator side of the press and a side frame 28 on the drive side of the press , joined by tie bars 30 , to form a strong rigid frame structure upon which various components of the press are mounted .
• Feeder 2 and delivery 22 have side frames 2a and 22a on the operator side of the press and side frames 2b and 22b en the drive side of the press , respectively.
• Tie plates 31 j oin the side frames of feeder 2, printing tower 18 , printing tower
• Each printing tower 18 and 20 is provided with an upper plate cylinder 38U and a lower plate cylinder 38L, an upper blanket cylinder 48U and a lower blanket cylinder 48L.
• the upper and lower blanket cylinders 48U and 48L serve the dual function of a printing cylinder and a back-up cylinder and engage opposite sides of sheets 5 , as best illustrated in Figure 3, carried through the printing press by gripper bars 8 extending between bands 16a and 16b.
• Each blanket cylinder 48U and 48 L has a gap 49 formed therein to permit movement of gripper bars 8 therebetween.
• each plate cylinder 38U and 38L is equipped with plate clamps to facilitate securing a printing plate thereto and that each blanket cylinder 48U and 48L is equipped with clamps for securing a blanket thereto.
• inking systems and dampening systems for applying ink and dampen printing plates are not illustrated.
• circumferential and lateral register adjustments for the various cylinders are not illustrated.
• the provision of other and further conventional components is deemed to be within the skill of a press manufacturer.
• the conveyor system is illustrated in combination ttith a lithographic printing press, the conveyor may be employed in any rotary printing system, for example , in which. an image is applied by a printing plate to a Blanket cylinder and offset onto a sheet, or , printed directly from a planographic printing plate, letter press, relief or intaglio printing plate or printing cylinder to a sheet.
• the conveyor system may be employed with a mechanism for performing operations other than printing, for example, cutting, folding, slitting, punching, reading indicaa and the like.
• the sheet transfer mechanism 10 hereinbefore crizofly described, includes drive wheels 12a and 12b connected to an axle 13 adjacent the feeder 2 of the printing press and idler wheels 14a and 14b rotatably secured about an axle 15 adjacent sheet delivery mechanism 22.
• Band 16a adjacent the operator side of the printing press, extends around wheels 12a and 14a, while band band 16b, adjacent the drive side of the press, extends about wheels 12b and 14b.
• axle 13 is driven and traction between the surfaces of wheels 12a and 12b and bands 16a and 16b, respectively, imparts motion to the bands.
• the conveyor system 10 is a mechanical device that carries the sheet 5 through the printing press 1. For proper printing to occur, the conveyor system 10 must offer mechanical repeatability of the sheet relative to each printing tower 18 and 20.
• the bands 16a and 16b have been formed with good results from a strip of steel material 3.500 inches wide and 0.042 inch thick to provide a cross-sectional area of 0.147 square inches for each band.
• the band material is preferably a 1095 carbon steel, heat treated to a hardness of Rockwell C 47 and has a modulus of elasticity of 30x10 pounds per square inch.
• Opposite ends of each of the strips of material are joined together
• a riveted aircraft-type splice joint consisting of two plates, one being 0.020 inch thick and the other being 0.035 inch thick secured by flat-head hi-shear rivets extended through countersunk holes in the band to opposite sides of the band.
• the thinner plate will deflect before the thicker plate for distributing the load and the tension in the band to the rivets in a uniform manner to enhance the fatigue life of the joint.
• wheels 12a, 12b, 14a and 14b are of substantially identical construction, each having a flange 11 secured to opposite sides thereof to form a groove into which tapes 16 extend. Flanges 11 merely prevent lateral movement of tapes 16 relative to wheels 12 and 14.
• wheels 14 at the delivery end of the printing press are freely rotatable about the non-rotatable axle 15 and have an inner hub 27 having a passage formed therethrough to receive the outer races 18 of bearings 22a and 22b.
• the inner races 21 of each of the bearings 22a and 22b are secured to axle 15 .
• Each axle 15 has a hub 15a for restraining bearings 22a and 22b against inward movement on axle 15.
• a retainer sleeve 28 extends around the outer end of axle 15 and engages the inner race 21 of the outer Bearing 22a. Sleeve 28 is captured by a lock nut 29 threadedly secured to the outer end of a journal 30 on the outer extremity of axle 15.
• Sleeve 28 extends through and is secured in an opening 32 formed in bearing block 35 which is secured by Bolts 36 to support pins 40.
• Brackets 42 and 44 have, spaced aligned apertures formed therein in which bearings 43 and 45 are secured. Opposite ends of support pins 40 are slidably secured in bearings 43 and 45 to permit movement of bearing block 35 and shaft 15. Brackets 42 and 45 are secured by bolts 46 to side frames 22a and 22b of delivery station 22.
• a bearing retainer disc 22c is secured by screws 22d to tape wheel 14b for restraining the outer race 18 of bearing 22a against outer movement.
• a grease seal 22e is urged into sealing relation with bearing disc 22c and sleeve 28 to retain lubricating oil adjacent to bearings 22a and 22b.
• the inner races 21 of bearings 22a and 22b are pre-loaded relative to out races 18 by adjusting nut 29 and the outer races are separated by spacer 18a.
• Bracket 44 has an aperture formed in a central portion thereof in which a bearing 50 is secured between lock plates 52 and 53 to prevent longitudinal movement of drive screw 55 relative to bracket 44.
• Drive screw 55 is of conventional design and has a ball screw portion 56 formed on the inner end thereof.
• a ball nut 58 is secured by screws 59 to member 60 which is in turn secured by screws 62 to bearing block 35.
• the ball screw 56 and ball nut 58 are of conventional design and are available from Saginaw Steering Gear Division of General Motors Corporation, Actuator Products Group, Saginaw, Michigan.
• the ball bearing screw is a force and motion transfer device belonging to the family of power transmission screws. It replaces the sliding friction of the conventional power screw with the rolling friction of ball bearings.
• the ball bearings circulate in hardened steel races formed by concave helical grooves in the screw and nut. All reactive loads between Screw and nut are carried by the bearing balls which provide the only physical contact between the members. As the screw and nut rotate relative to each other, the bearing balls are diverted from one end and carried by ball guide return tubes to the opposite end of the ball nut. This recirculation permits unrestricted travel of the nut in relation to the screw.
• Drive screw 55 has a 0.200 inch per revolution lead.
• Drive wheels 12a and 12b adjecent the feeder end of the printing press are rigidly secured to axle 13 which is rotatably secured to feeder side frames 2a and 2b.
• a gear 66, secured to the end of axle 13, is driven through a positive, infinitely variable speed control device 65 by line shaft 67 which drives gear trains 68 and 62 connected to plate cylinders and blanket cylinders in printing towers 18 and 20.
• Line shaft 67 is driven by one or more motors 70 connected through suitable gear trains, V-belts and sleaves, and gear boxes for transmitting the speed and driving force required for driving the printing towers and the conveyor system.
• speed ratio between printing cylinders 48 U and 48 L and drive wheels 12a and 12b can be changed by adjusting speed control device 65 which will result in changing the ratio of the angular velocity of the input from shaft 67 to control device 65 relative to the angular velocity of the output of control device 65 to axle 13 .
• each of the idler wheels 14a and 14b is equipped with a separate screw 55 to permit adjustment of the distance between the axes of wheels 12a and 14a independently of the adjustment of the distance between the axes of wheels 12b and 14b.
• the length of bands 16a and 16b are independently adjustable. It should be appreciated that the length of bands 16a and 16b may be adjusted by moving third and/or forth wheels 14 ' , 14 " positioned either above or below one of the flights of bands 16a or 16b, as shown in dashed outline in Figure 4. Initial band tension has been chosen to be
• the length of band driven by each drive wheel 12a and 12b during one revolution is 48. 000 inches times ⁇ . This figure is approximately 150.7963 inches.
• the design ratio of the diameter of the conveyor drive wheels 12a and 12b to the diameter of the sixteen inch printing cylinders 38U and 38 L was 3 : 1 while the ratio of the drive wheel to a 24 gripper bar system is 8 : 1. Multiplying 150. 7963 by 8 gives 1206. 3705 inches for the nominal final length, of the band.
• the manufactured length of the band to achieve a 1, 800 pound pre-load on the band was 25.1227 times 48 which equals 1205. 8883 or a total of 0.4922 inches shorter than the installed length of the band.
• axle 13 at the 'feeder end of the press is driven, as hereinbefore described and axle 13 is secured to maintain axle 15 in an established position. This is desirable because swing grippers 16 must register with the conveyor 10 for feeding sheets to the sheet conveyor. Thus, By maintaining driven axle 13 in a fixed position, register can be established and maintained between feeder 2 and conveyor 10. Further, since opposite ends of axle 15 can be moved independently by screws 55, axle 15 will not necessarily be maintained in a precisely aligned parallel relationship to driven axle 13.
• Drive wheels 12a and 12b are rigidly secured to drive axle 13 to maintain the timing of band 16a relative to band 16b.
• the timing of the idler wheels 14a and 14b relative to each other is a variable that is unpredictable. Therefore, in the illustrated embodiment, the two idler wheels 14a and 14b are allowed to rotate freely and independently of each other since their speed of revolution will vary according to the actual diameter of the respective wheels.
• the main function of the conveyor system is to afford repeatability of the sheet relative to each printing tower 18 and 20.
• Mechanical repeat of conveyor bands 16a and 16b relative to drive wheels 12a and 12b occurs every eight revolutions of the drive wheels. Therefore, the length, of the Band is 8 times the theroretical circumference of drive wheels 12a and 12b.
• the error repeat of the band and the drive wheel will be .002 inches.
• An initial position error could also exist with the band mounting on the wheel.
• the band could be initially misplaced relative to the wheel 12 a or 12b even though the distance between axes of axles 13 and 15 is proper. In this instance , the error should not accumulate with each revolution of the drive wheel but would remain constant.
• conveyor bands 16A and 16C are flexible and are routed around drive wheels 12 and idler wheels 16 to form a closed loop.
• bands 16 have been illustrated in dashed outline as a ring or circular loop 16' having a smooth surface in rolling relation with the smooth surface of drive wheel 12'.
• Drive wheel 12' rotates about axis 13' to impart rotation to band 16'.
• band 16' and printing cylinder 48' can be moved in synchronized relationship even though the diameter of drive wheel 12' has been changed.
• 16' can be moved in synchronized relation with printing cylinder 48' by changing the circumference of the band
• the error in the registration of this sheet carried by the gripper bars 8 relative to printing cylinder 48U and 48L can be monitored in a variety of ways including visually inspecting the sheets at the delivery end of the printing press. If the drive wheel 12 has changed in diameter as the result of thermal expansion which has resulted in the conveyor bands 16 moving at the improper speed relative to printing cylinders 48U and 48L, the error will accumulate and increase with each revolution of the printing press.
• the pressman may either adjust the surface speed of drive wheels 12A and 12B by adjusting the speed control device 65 to cause conveyor belts to be driven at the proper surface speed, or drive screw 55 may be rotated for adjusting the length of bands 16 relative to the circumference of drive wheel 12 to register sheets carried by the conveyor relative to the printing cylinder.

Landscapes

• Delivering By Means Of Belts And Rollers (AREA)
• Separation, Sorting, Adjustment, Or Bending Of Sheets To Be Conveyed (AREA)

Applications Claiming Priority (1)

Publications (2)

Family

ID=22154551

Family Applications (1)

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• 1980
  • 1980-09-12 WO PCT/US1980/001212 patent/WO1982000976A1/en not_active Application Discontinuation
  • 1980-09-12 EP EP19810901355 patent/EP0059714A4/de not_active Withdrawn
  • 1980-09-12 JP JP81501820A patent/JPS57501367A/ja active Pending
• 1981
  • 1981-09-10 SE SE8105390A patent/SE8105390L/ not_active Application Discontinuation
  • 1981-09-11 IT IT49275/81A patent/IT1142800B/it active
  • 1981-09-11 BR BR8105835A patent/BR8105835A/pt unknown
  • 1981-09-11 GB GB8127529A patent/GB2083449A/en not_active Withdrawn
  • 1981-09-11 FR FR8117254A patent/FR2491895A1/fr not_active Withdrawn
  • 1981-09-14 DD DD81233273A patent/DD201865A5/de unknown

Non-Patent Citations (1)

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