US2819670A

US2819670A - Barrel printing apparatus

Info

Publication number: US2819670A
Application number: US390214A
Authority: US
Inventors: Benjamin R Newcomb; Laszlo M Stempel
Original assignee: JOHN WALDRON CORP
Current assignee: JOHN WALDRON Corp
Priority date: 1953-11-04
Filing date: 1953-11-04
Publication date: 1958-01-14
Anticipated expiration: 1975-01-14

Description

Jana. M, 1958 B. R. NEWCOMB ETAL fl fi BARREL PRINTING APPARATUS Filed Nov. 4, 1955 4 Sheets-Sheet 1 FIG. l.

WELALL )ATTORNEYS 1953 B. R. NEWCOMB mm. ,819,7

' BARREL PRINTING APPARATUS I Filed Nov. 4, 1955 4 Sheets-Sheet 2 BEMWN R mw fiwa C LF SZLO M- STEMPEL Fla. 2.

B. R. NEwcoMB ETAL 2,819,67fl

BARREL. PRINTING APPARATUS 4 Sheets-Sheet 4 Jan. 14, 1958 Filed Nov. 4, 1953 5 w a 5 M 5 T a o 5 a 1 Ma Ma WW R N l m 0 m M m 5 G I 9 3 If AA.- MM 5 1 2 fi 1 3 m 5 i 1 1 w 1 mmzx M- mmpw EFI C5. 6. BY 0 f QM PSTTORNEYS by suitable mechanism to permit the printing operation.

The barrel tubes are substantially cylindrical but may be somewhat irregular due to the crudeness of the bending operation forming them or damage in shipping or handling. Their ends are flared for the reception of heads and this facilitates their running on the track without any possibility of rubbing against each other except at the edges of these flanges which also keep the printed portion of the tube off of the tracks so that it is not smeared after printing. Preferably the drum tubes are cleaned and prepared by a preliminary coating of paint or the like to more readily receive the printing ink provided by the present apparatus.

Referring now to the drawings, and particularly to Figs. 1 and 2, for a better understanding of the general arrangement of the apparatus, it will be noted that the printing press is essentially composed of a blanket cylinder carrying on a portion of its periphery a resilient blanket 11 and a plurality of

plate cylinders

12, 13, 14 and 15. The number of plate cylinders is dictated by the desired number of colors in the printing and may be more or less than illustrated. These plate cylinders are distributed about the upper half of the periphery of the blanket cylinder and with it have their shafts supported in suitable bearings carried in the

side plates

16 and 17 constituting the principal frames of the machine. These plates are parallel to each other, as seen in Pig. 2, and are appropriately attached to and supported by transverse beams 18, two in number, which are themselves supported at a suitable distance above the floor level by means of corner posts or columns 19 which are in turn supported from transverse beams 20 resting on pads 21 supported from a suitable floor or the like. The columns are connected together on each side of the machine and reinforced and braced by longitudinal beam members 22 as seen in Fig. 2.

These brace beams 22 have appropriately secured to their inner flanges the centrally located vertical plates 23 for a purpose to be later described, while secured against the inner flanges of the columns 19 are the angle bars 25 extending longitudinally of the press and constituting the principal members of the drum tube feeding tracks, inclined, as shown in Fig. 1, so that the tubes supplied from the left will move by gravity toward the right under control of mechanism which will later be described. The horizontal flanges 27 of the track angles which support the ends of the tubes are seen in greater detail in Fig. 3, each mounting a tube end guide strip 23. The two guide strips are spaced apart a distance just slightly greater than the overall length of a tube which is to be printed.

Such a tube is shown on an enlarged scale in Fig. 3 at 30 and will be seen to comprise a complete tubular cylinder having the conical end flares 31 spaced apart just the proper distance to conveniently fit between the guide strips 28. The peripheries of these flares roll on the top surfaces of the flanges 27 of the tracks. It will be seen in Fig. 1 that a barrel tube may be stopped on the tracks directly beneath the lowermost point or nadir of blanket travel for printing purposes and may be held in this position until appropriately grasped by chucks, now about to be described, by having barrel tube 32 which has just been printed, held as shown by means of stop lever 33, positioned a distance substantially one and one-half times the diameter of a drum tube from a vertical line through the axis of the blanket cylinder, whereby the drum to be printed is properly positioned beneath the blanket cylinder as shown in Fig. 1.

Other drums

34 and 35 on the feed end of the track are pre vented from rolling further by the contact of their flange edges with the flange edges of the drum in printing position.

In order to exactly locate each drum tube in respect to the printing cylinder and to elevate the same into contact with the blanket for a printing impression, each tube in its turn is gripped between a pair of frusto-

conical chuck members

38 and 39, facing each other on opposite sides of the printing machine as seen in Fig. 2 and appro priately sized to fit within the tapered ends of the drum tubes. Such chucks may comprise dish-like castings appropriately reinforced by radical webs 49 as seen in Fig. 3 while their conical. peripheral surfaces are accurately machined to round out and properly centralize the drum tubes and thus present them as accurately as possible for the printing operation. As seen in Fig. 3, each chuck disc is mounted by means of double row, anti-friction bearings ll on a stub shaft extension 42 of a piston rod whose piston (not shown) is slidably mounted in hori- Zontally disposed

pneumatic cylinders

43, 44 in order to project the chuck for gripping or to withdraw it for releasing the drum tube as desired at the proper times in the cycle of operation of the printing press.

Each of the cylinders 43, .4 is mounted on a separate cradle 45 which is itself attached, as shown in Fig. 3, to an extension 46 on the rod 47 of a piston slidably fitted in vertical cylinder 43, 4 each of which is mounted against the inner face of plate 23 carried by column brace 22 as previously described. These plates also carry the combined guide and stroke limiting mechanisms 50' for each of the vertical cylinders, as best seen in Fig. 3. in this the extension 46 of the piston rod 47 is guided for sliding in the bushings shown. Each rod extension is fitted with a notched portion 52; operating over a fixed all) abutment 53 secured to the part 50, as shown, to limit the stroke of the piston in each direction in cylinder 48. This abutment 53 is positioned so that the lowermost position of the piston rod 46 rests the cradle 45 against the upper end of block Sit and thus positions the chuck to cooperate with a properly located drum tube resting on the track.

Thus when the drum tube is rolled down to a position determined by the stop 33 and the intervening drum tube 32 it is confronted by the two chuck heads and is at the proper level to receive them when air is let in to the outer ends of the

cylinders

43 and 44. This air under considerable pressure projects the chucks at high velocity in order to jam them tightly into the flares of the drum and bring the latter to as nearly a true round condition as possible.

As seen in Figs. 2 and 3 the piston rods 42 in

cylinders

43 and 44 extend through the outer cylinder heads and beyond are threaded to receive the adjusting nuts 55 which are split and can be tightened to lock them in position. The one shown in Fig. 2 on the left is set up to limit the inward stroke of the chuck 39 to a stop position which locates the drum tube longitudinally to exactly cooperate with the blanket 11 on the blanket cyl inder and insure full length coverage of the printing right up to the flanges on the tube. The stroke adjusting nut 55 on the right hand piston is set for full stroke for a purpose which will be later described and the action of this piston is retarded by reducing the air pressure supplied to it so that full stroke of the left hand piston is achieved before any substantial motion takes place in the right hand chuck assembly. With its reduced pressure the cylinder 43 cannot overcome the registration of the left hand chuck which has reached its stroke limit first.

After the barrel is gripped between chucks and at the proper time in the cycle of blanket rotation the drum tube and its chucks is lifted by means of pneumatic cylinders 4S and 49 into contact with the blanket as shown in Fig. 3 and rotated thereby at the same time that the printing impression is made. At the end of the impression portion of the cycle the pistons in cylinders 48 and 49 are de-energized on their lower faces and energized on the upper to immediately lower the drum tube after which it is released by the chucks and moved away on the tracks to be replaced by a fresh drum for the next printing operation. with controls arranged for operation by the blanket cyl; inder which will be later described.

The cycling of this is in accordance As seen in Figs. 1 and 2, the side frame members 16., and 17 which support the several 'c' nid'rssrtfi press are of irregular shape and each is provided withan appropriate notch 60 and cl'os ure'plate 61 for rotatably holding the eccentric bearing member 62 for main shaft. 63 of the blanket cylinder which is secured to this shaft. The eccentric members 62 are appropriately hushed as shown to journal the reduced ends of shaft 63.

In quite the same manner the respective shafts 65 of the several plate cylinders 1-2, 13, 14' and ;are journaled in hushed bearings 66similarly mounted in the side frames. These bearings 66 are also eccentric since it is the intent that adjustment in a lateral or vertical direction bepermitted for any of the plate cylinders. These cylinders as shown are closed on the ends and each is provided with a circumferential bearer 70. at each end which rests on the corresponding bearer 71 on the blanket cylinder and; insures proper cooperation between the two and determines the degree of pressure which exists between the plates on the plate cylinders and the blanket covering a portion of the periphery of the blanket cylinder. The plates may be of any desired type prepared by photoengraving, photolithography, etching or the like and their construction and manner of mounting on their respective cylinders forms no part of the present invention, but it should be pointed out that the circumferential length. of the plates is substantially the same as the circumference of the barrel or drum to. be printed.

One end of each plate cylinder shaft is provided with means for adjusting it longitudinally in order to insure proper registration between the impressions from they various plates on the respective plate cylinders. This insures location of the various color portions of a pattern tobe printed so that they are properly distributed on to the. rubber blanket and do not overlap or smear.

Such apparatus is shown in enlarged detail in Fig. 4- where the end of shaft 65 is seen to be fitted. with the extension 67 having the radial flange 68. thereon. Before being fastened to the end of the shaft by stud 69 this. extension is passed through the races for ball bearings 7i). and the opening in the smaller end of cup 71. This cup has the flange on its outer end resting on helical spring 72, surrounding the cup and bearing against the end of shaft bearing bushing 66 thereby through the ball bearing 70 urging the. shaft. 65. toward the left. This action is counteracted by the thrust disc 73. resting on the outer race of ball bearing 74 whose inner race fits against the flange 68 on the extension 67. The disc 73 is adjustable in position by means of screw 75 threaded into, the bottom of cup 76. inverted over spring 72 and having its peripheral flange bolted to bearing bushing 66 as seen in Fig. l. A lock nut 77 permits securing the screw 75 in any position in which it. is adjusted by its capstan handle 78. A smaller capstan handle 79 is provided for the lock nut. It will thus be seen that by loosening the lock nut endwise adjustment of shaft 65 and its plate cylinder is effected as desired and that the latter can be locked in position to insure it remaining as originally set.

Each of the slightly eccentric hearing bushings 66 for the plate cylinder shaft is fitted with a radial arm $0 as best seen in Fig. l and this arm is engaged on its opposite. faces by screws 81 and it; carried in a bracket mounted on the face of the frame plates. Adjustment of the two screws provides for slight rotation of the eccentric bush and adjustment of the position of the plate. cylinder. These various adjustments are provided so that all of the. plate cylinder bearers can be made to engage with equal pressure against the blanket cylinder bearers. When these adjustments are once made they remain fixed except to compensate for wear in the bearings.

The plate cylinders are each inked by a suitable ink supplying and distributing mechanism 85 and only several of these are shown in any detail. They need not be has d r ed in e e can, b at spnvcnt caal c a- FF Gfi and er e merely to. up l a ni orm. seq. asst;-

attached operating links 91 for rotating the shafts and that numbered 86 in Fig. 1. Near theopposite" of each of the inking mechanisms is a" pair of' padsf 87 adapted to rest on eccentrics 88 on shaft 89 ente'n'di between the side platesof the mechanism. These var ious shafts 89, one for each of the inking devices, each equipped with one or more crank arms 90 to which are thus the eccentrics to liftthe inking devices out of contact" with the plate cylinders whenthe press is taken off iinjpressiou.v Additional, independently actuable hand cranks are. also supplied for the convenience of the" printer.

The several links 91 have their opposite ends connected to. crank. arms on adjacent shafts 89 80 that three of the inking mechanisms may be lifted'under the action of. linkv 92 while thefourth responds to link 93. Litiks' 92 and93 areconnected respectively to two arms of a multicrank lever. having a third arm 94 connected by link 95 to. radial arm 96 on the eccentric bushing 62 for the shaft 63 of the blanket cylinder.

These eccentrics 62. have a substantial throw so that when the multi-crank lever having the arm 94 is partially rotated in one direction movement is imparted to theec' centric bearing bushings in a direction tolower the blanket cylinder and withdraw it from contact with all ofthe plate cylinders simultaneously. This happens at the same time, that the multi-crank lever actuates links 92 and93 to lift all of the inking mechanisms from contact with their plate cylinders. This operation will be'un'derstood by those acquainted with the use of offset printing presses of this general character and is for the purpose of preventing ink ridges forming between contacting rolls and/or cylinders when the press is idle.

The power'to take the press oif impression or to return it to impression comes from a small electric motor 98 shown in 'Figs. 1 and2 as resting on platforni 99 supported from the side frames at the right hand of the press. This motor through an appropriate coupling drives the worm reducer 100 whose output shaft is fitted with a crank pinned to link 101 connected to one of the arms on multi-crank lever 94. Mechanism, later to be described, limits operation of the motor so that the crank on the shaft of worm reduced 1% makes but half a revo lution for each cycling operation. One such operation serves to rock the multicrank lever to lift all of the inking mechanisms from the plate cylinders and to lower th blanket cylinder from contact with the plate cylinders, while the other half revolution restores the parts to operating condition.

The main drive for the press is shown as motor 105 mounted on a suitable platform carried by channel beams 106 which supports stub beam 107 holding the base of the motor. The motor is provided with a pinion engaging a bull gear 108 on the end of shaft 63 for the'blanket cylinder, this being outside of frame plate 1.7 and meshing individually with gears 109, one on the shaft of each of the plate cylinders. The gears 109 are each rotatably adjustable on its shaft for impression registration by means of mechanism shown at 109.. As previously. mentioned the circumferential extent of the plates onthe plate cylinders is the same as the cif cumference of the drum to be printed. The blanket covers slightly more than of the circumference of the. blanket cylinder and is of a length to insure taking the. full impression from the plates on the plate cylinders.. The gearing just described is so adjusted and timed that each plate cylinder makes its impression at the properplace for exact registration of the several colors on the surface of the plate-length blanket on the blanket cylinas as d it terat e rsvsl ltist 9. i

the plate cylinders for each drum printed and this provides them with a double inking, insuring an extremely heavy coating of ink being applied to the blanket for transfer to the drum.

The motor 105 for the main drive of the press is provided with appropriate starting and stopping control circuits actuated by the usual push buttons and provided with the desired safety mechanisms, none of which form any particular part of the present invention, but circuits for motor 93 are so interlocked with those of motor 105 that the pressing of the stop button for the main motor causes motor 98 to operate and provide one-half cycle of movement to the mechanism which takes the press ofi impression to insure against the press coming to a stop with any contact between the plate and blanket cylinders or between the plate cylinders and the inking mechanisms. As seen in Fig. 1, the worm reducer mechanism 100 is provided with a cam 110. This cooperates with switches (not shown) in the circuit of motor 98 to stop it, after each start, at the end of one-half revolution of cam 11!). Mechanism and circuits for this type of operation are old and well known, see Patent 2,464,389 for showing. The half cycle operation initiated by the stop button for motor is followed by a half cycle operation to return the press to impression, initiated by operation of the start button for motor 1115.

The shaft 63 of the blanket cylinder is provided with a pair of

cams

111 and 112 arranged to cooperate with switches (not shown). The first of these cams insures that motor 98 can only be started at a time in the cycle when the blanket cylinder is not in contact with any plate cylinder to take the press olf impression. The second cam insures that the motor 98 can be started only at a time in the press cycle when the blanket cylinder is in a position remote from contact" with any plate cylinder to put the press on impression. After each start under the control of cam 111 or cam 112, cam comes into play to limit the movement of the shaft of the worm reducer to one-half revolution.

While it has been found that the cams on the shafts of the worm reducer and the blanket drum provide adequate accuracy for the operations just described, it is deemed essential to provide greater accuracy in the locating of operating mechanism for determining the cycling of the gripping cylinders for the drum chucks and the elevating cylinders for the same and therefore the operating cam lugs controlling the switches for these devices are located on one head of the blanket cylinder. As shown in Fig. 1 the right head is equipped with four cam lugs, numbered respectively 115, 11 6, 117 and 118. The first two of these cooperate respectively with

switches

119 and 120 shown mounted on arm 121 at the left in Fig. 1 and supported from beam 18, while the second pair of cam lugs cooperate respectively with

switches

122 and 123 supported by arm 124 from the opposite beam 18.

Reference will now be made to Fig. 5 illustrating diagrammatically and schematically the air and electric circuits for operating the chucks for the drum tubes. In this figure the

chucks

38 and 39 are shown mounted on the piston rods of

cylinders

43 and 44 respectively. The source of air supply under relatively high pressure is illustrated at and air from this is delivered to each of the similar distributing

valves

131 and 132. respectively. The first of these controls the delivery of air to the

horizontal cylinders

43 and 44 for gripping or releasing the chucks. From the left end of distributing valve 131 air line 133 leads to the outer ends of

cylinders

43 and 44, a pressure reducing valve 135 being provided in the branch line to the outer end of cylinder 43, whereby this cylinder moves its piston more slowly than does cylinder 44 as previously described. From the opposite end of distributing valve 131 air line 136 leads directly to the inner ends of the two

cylinders

43 and 44.

The operating plunger of distributing valve 131 is under control of the two

solenoids

137 and 133. When solenoid 137 is energized the valve plunger moves to the left and distributing valve 131 supplies fluid to the outer ends of

cylinders

43 and 44, causing the chucks to advance toward each other and grip a drum tube from the tracks, operating in the manner already described to properly position this tube longitudinally in respect to the edges of the printing blanket. When the plunger of distributing valve 131 is moved toward the right under the action of solenoid 138 air is released from the outer ends of

cylinders

43 and 44 and admitted to the inner ends so that the chucks are drawn apart and the barrel released.

Solenoid 137 is under control of switch 119 which energizes it when the switch is closed by cam lug 115. As seen in Fig. 1, with counterclockwise rotation of the blanket cylinder, this lug engages switch 119 first and causes the gripping of a drum tube during the interval following the passing of the trailing edge of the blanket by the nadir so the space beneath the cylinder is free for the movement of the drum to be printed. As the leading edge of the blanket approaches the nadir cam lug 116 closes switch 120 which will be seen in Fig. 5 to move the plunger of valve 132 to the left, thereby energizing air line 140 and supplying compressed air beneath the pistons of vertical cylinders 48 and 49, simultaneously lifting the chucks and providing a resilient urging of the drum against the cushioned blanket where it is held during the half revolution necessary to complete the impression thereon. When this position is reached cam lug 117 engages and closes switch 122 drawing the plunger of distributing valve 132 to the right, charging air line 141 and releasing air from line 140. This causes the cylinders 48 and 49 to lower the chucks simultaneously, setting the drum back on its track. Almost instantly, then, cam lug 118 engages switch 123, causes movement of the plunger of distributing valve 131 to the right, energizing air line 136 and releases the chucks from engaging with the drum cylinder.

As previously mentioned, provision is made to insure against lifting of the chucks in event of absence of a drum tube between them since under these circumstances and at full inward stroke their edges might damage the blanket. The absence of a drum between the chucks is detected by measuring the over extension of the piston rod on which chuck 38 is mounted. This is achieved by providing a striker 145 thereon, which, when the chuck reaches the limit of its inward movement, engages and opens switch 146, which opens the circuit of the lift solenoid energized normally by closing of switch 120. Even though this latter switch is closed by its cam lug on the blanket cylinder the solenoid is not energized. A manual manipulation to return the chuck or its return by the release lug 118 reconditions the system for normal operation.

In the early part of this specification stop lever 33 was mentioned, and it is illustrated in Fig. 1 in solid line position where it engages the last printed drum as it rolls down the track and holds it in the position where it will stop the following, but unprinted drum, directly beneath the bottom of the blanket cylinder ready to be engaged by the chucks prior to printing. This lever is pivoted at 151i to a pillow block on one of the standards of the press. A second arm 151 secured to the lever 33 is connected by adjustable link 152'to the piston rod of cylincier 153 which is pneumatically operated to shift the stop lever between the solid line position and the dotted line position. The mechanism for operating this cylinder comprises a pair of solenoids and a selector valve for delivering air to one end or the other of cylinder 153, the construction being exactly identical with one of the showings of Fig. 5, associated solenoids and control switches being provided in an obvious manner. Switch tripping lugs may be provided on one head of the blanket cylinder. Further illustration is not deemed necessary. The operation of lever 33 is obvious. After a drum tube is printed and released by the chucks lever 33 is lifted to dotted line position just long enough to release the drum plate tube in position 32, after which it is returnedto the stop, position toprevent further rolling of tube 3!) beyond the. position number, 32. This allows a fresh tubeto, be positioned in the. printing position.

In. some cases it may be desirable to print directly on the surface of a drum tube which has already been provided with circumferential ridges or. bilge runners, on which the barrel may be rolled, and which servesto reinforce it against distortion on impact or the like. Under these circumstances the apparatus is-provided with mechanism for spacing three parts of a blanket longitudinally along the drum to leave unblanketed areas for clearance overthese bilge runners; The plates may or may not be divided in a like manner as circumstances dictate. The peripheries of the bilge runners may be inked subsequent- 1y, or by an attachment to the above described press, or they may be left with only the initial coating thereon.

We claim:

1. Mechanism for printing on the whole cylindrical surface of a large diameter, open ended steel tube adapted to be formed into a drum comprising in combination, a blanket cylinder having substantially one half its periphery covered by a blanket, means for mounting and driving said cylinder continuously, a plate cylinder having a plate sized and positioned for transfer contact with substantially all of the blanket surface and driven in unison with the blanket cylinder, continuous inking means for the plate, means for advancing contiguous tubes one at a time beneath said blanket cylinder during each nonprinting half revolution of the blanket cylinder, power actuated means to engage and round out the tube directly beneath the cylinder, and means to subsequently pneumatically lift the last mentioned means and tube and present the latter in printing contact with the blanket, the drum and plate cylinder being of substantially the same circumference and the blanket cylinder being of twice the plate cylinder circumference.

2. The printing mechanism of claim 1 in which the said pneumatic means is timed to lift the drum for printing by means on and associated with the blanket cylinder for proper synchronization.

3. The mechanism of claim 2 in which means is provided associated with the said power actuated means to detect the absence of a drum beneath the blanket cylinder, and mechanism associating said last mentioned means and the pneumatic lifting means to prevent the energization of the latter in the absence of a drum.

4. A press for printing on the whole circumference of a cylindrical drum comprising in combination at least one plate cylinder of slightly greater diameter than the diameter of said drum and having a printing plate thereon covering substantially the full circumference thereof, means for continuously inking said plate, a blanket cylinder twice the diameter of the plate cylinder and having a blanket thereon just large enough to accept the impression from the plate, means continuously rotating said cylinders at identical peripheral speeds about horizontal axes, means to advance a line of contiguous drums in one drum steps at each passage of the unblanketed portion of the blanket cylinder below its axis, means engaging the outer peripheries of the drum ends to receive a drum beneath and spaced from said blanket cylinder, a pair of facing conical chucks spaced to clear both ends of said drum and rotatable about an axis parallel to said axes, means to simultaneously axially advance said chucks to engage said drum between them on said drum holding means, and means to subsequently elevate said advancing means and chucks to contact the drum with the blanket for rotation thereby and printing.

5. The press as defined in claim 4 wherein one of said chuck advancing means has an adjustable stroke limiting device and is advanced prior to the other to determine longitudinal registration of drum and blanket.

6. The press of claim 5 wherein the advancing means 1-0 r pneuma c. n heon fo t e. o he chuck is. upnlil di through a pressure reducer to effect delay in advancing 7. The press of claim 6 wherein the said other chuck advancing means is equipped with an excess stroke detector, said chuck elevating means being arranged to, hereudered ineifective on actuation of said detector to prevent. damage to the blanket by the chucks.

8. The press of claim 4-v in which the chuck elevating means comprise pneumatic cylinders and pistons whereby constant contact, pressure, is effected between blanket and drum in spite of out-of-roundness of the latter.

9. The press of claim 4 in which the drum is headless and the, chucks are truncated cones, the, advancing; of said cones into the. ends .ofthe, drum, serving. to lif;1:;.it .from the receiving means insufficiently to engage the blanket and to bring it into roundness, and means to withdraw the chucks after the drum has been printed and lowered, said withdrawal means being under control of a cam on the blanket cylinder.

10. in a printing press of the type described, in combination, a blanket cylinder mounted for continuous rotation and having approximately one half its circumference covered with printing blanket, power means to drive said cylinder, means to elevate a drum and hold it against said blanket during the passage of the latter past the nadir, means to change drums during the passage of the unblanketed portion of the cylinder, a plurality of plate cylinders arranged about the upper half of the blanket cylinder and each having a plate adapted to transfer an impression to the blanket, inking means for each plate cylinder, means to drive the plate cylinders from and at the same peripheral speeds as the blanket cylinder, mechanism actuated by an operation leading to stopping of the press drive power to lower the blanket cylinder and elevate the inking means to take the press oif impression which includes an electric motor and speed reducer having an output shaft, a crank on said shaft for effecting said lowering and elevating, a control for said motor limiting its movement per initiation to one-half revolution of said crank and a cam on said crank shaft for operating said control, and means to effect such blanket cylinder lowering at a position in its cycle when the blanket is out of contact with all cylinder plates.

11. The press of claim 10 where said crank shaft mounted cam limits the shaft to one half revolution when putting the press on impression and means to limit said putting on impression to a period in the press cycle when the blanket is positioned to not be contacted by the plate cylinders.

12. The press of claim 11 wherein the means to control the period in the press cycle in which the press is put on impression is a cam on the shaft of the blanket cylinder.

13. A chuck system for gripping a cylindrical drum supported on a runway and advancing the same against a printing member for rotation thereby and printing therefrom comprising in combination, a pair of chucks fashioned to engage the opposite ends of a drum and facing each other on opposite sides of said runway, a carrying and advancing means for each of said chucks, a pneumatic cylinder, piston and rod construction supporting each chuck-carrying and advancing means, said pneumatic cylinder adapted to urge a chuck held drum resiliently into contact with the printing cylinder and means actuated in response to printing member cycle position to control the operation of said cylinder.

14. The chuck system of claim 13 in which the chuck carrying and advancing means each comprises a pneumatic cylinder, piston and piston rod, a source of compressed air connected to said cylinders, means to adjust and limit the advancing movement of one of said chuck advancing cylinders and means in the supply line of only the other chuck advancing cylinder to reduce its speed of advancement whereby the first said cylinder advances 1 1 its chuck to the adjusted limit to effect longitudinal drum location.

15. The chuck system of claim 14 in which detector means is provided for excess stroke length of the second chuck advancing cylinder, actuation of said detector serving to prevent the supply of fluid to the chuck lifting cylinders to prevent the damaging of the printing cylinder in the absence of a drum between the chucks.

References Cited in the file of this patent UNITED STATES PATENTS Onstad Mar. 1, 1921 Harrold Apr. 27, 1926 McDonough Oct. 10, 1933 Friden July 27,1937 Simonton Apr. 19, 1938 Goessling Oct. 18, 1938 Whisner Sept. 26, 1939 Gladfelter et a1 Aug. 17, 1943 Shurley Oct. 24, 1944 Gates Feb. 20, 1951 Robbins et a1. Jan. 13, 1953.v Levin July 14, 1953