US2491819A - Sheet delivery mechanism for stop-cylinder printing machines - Google Patents

Description

SHEET DELIVERY MECHANISM FOR STOP-CYLINDER PRINTING MACHINES Filed July 5, 1945 '7 Sheets-Sheet 1 III D 0, 1949 w. G. LAWSON ET AL 2,491,819 4 SHEET DELIVERY MECHANISM FOR STOP-CYLINDER PRINTING MACHINES Filed July 5, 1945 7 Sheets-Sheet 2 1949 w. s. LAWSON ET AL 91,819

SHEET DELIVERY MECHANISM FOR STOP-CYLINDER PRINTING MACHINES Filed July 5, 1945 7 Sheets-Sheet 5 Ja /JAE 6.

IM9 w. G. LAWSON ET AL 2,491,819

SHEET DELIVERY MECHANISM FOR STOP-CYLINDER PRINTING MACHINES Filed July 5, 1945 7 Sheets-Sheet 4 Deih 1949 w. G. LAWSON ET AL 2, 91,

SHEET DELIVERY MECHANISM FOR STOP-CYLINDER PRINTING MACHINES Filed July 5, 1945 '7 Sheets-Sheet 5 Dec. 23, 1949 W. LAWSON ET AL 2949319819 SHEET DELIVERY MECHANISM FOR STOP-CYLINDER PRINTING MACHINES Filed July 5, 1945 'TShets-Sheet 6 LAWSON ET AL SHEET DELIVERY MECHANISM FOR STOP-CYLINDER PRINTING MACHINES -Dec. 20, 1949 7 Sheets-Sheet 7 Filed July 5, 1945 Patented Dec. 20, 1949 SHE-ET DELIVERY"M'ECHANISMFOR STOP- CYLINDER PRINTING MACHINES Wilfred: George Lawson and.iFrederickStephen Ensland, ignors,.- shy mesne. assignments; to Alfred Barry .Lakeman,.

J enkins i 1- Chentsey,

London, England Application J-ulyi, 1945;.cSerialaNoie603348 42:

In iGreatBritain August 23; 19.44

,9 Claims ((1101-2761 1 Ther inyentionurelateseto improvements in the sheet delivery mechanisms-of .-a stopecylinder printing ,press, (that is, apressi-whichbase reciprocating ty-peybed andacylinderrto which a -shee't i of papen-to be printed-is ,ied 93.5 :thenylinder-is rotatingwand ris printed-duningrsuch'rotation; the cylinder being =,::stopped-wh'en-.- the mprinting; has been=completed.,-c1t is ,dmii'ngrthis stoppage 50f the iii cylinder that the sheetis removed :from the print V ingicylindermyzthe delivery mechanisms;

Oneiobject of thesinvention 'is to effectstheflif-t ing of theatailziendeof theEprintedsheetironnthe printing cylinder and to initiate the removaleoi moya'l'of thelsheet; comprisingsthefimajor :portioii of the cremovaLican iibe ieflici'ently efiected by :the stronger: nr more :positivefiaction of mechanical grippers-:: 1MO1'e0Y61,'ith6 tr3LVe1 0f the suction gers: need only he meriy short: and the liability *of a sheet being dropped by vthe i'ingers is reduced to a minimum. 1: Further; as the conveyor ean b'e provided :Wibh'i't plurality-0f sets of mechanical grippers for conveying the sheets away fromthe printing cylinder and. depositing them on a piling tablefithe travel of the sheets so conveyed can 'be prolonged and: thereby enable the sheets to dry and to prevent smearing or smudg-ing of 'the printed :matter and the necessitytfor interleaving.

Otheriobjects are to improvetheefiiciencyof th'csuction fingers in operation, to 'allow for and to :tacilitateiadju'stment ef theopera'ting' mecha- IliSHDOf the :suctionfingerssandmf that of the con veyorxito :suit thezlengthflof lsheet b'eing printed, andiipreferably to ensure that when the 'driving mechanism-.iof the-:suctiomfingers"is adjusted,"

simultaneous corresponding adjustment: of the conveyor is efiectedgethereby avoidings-thernecessity for :theiskill and time of the machinezninderf; whichiwouldzbe required'fif separate adjustments:

were required.

.Eunther objects will beiapparen't from the: following description of one example of sheet deIivJ-i' ery emechanism .accordingrto the inventions;

In the drawingsz,

2 the sheet delivery mechanismepplied, only sufiie cientparts of the presslbeing indicated toidentify themachine,.=which is well known .inthe L Figural is a reariseotional,elevationctaken on the .line II.-II,Eigure 1..

Figures. 3 and A. are, respectively, a sideielevation and iarear elevation showing .thesucker .bar, its. valve box and ,other.'-detai1s, .on .a larger scale than Figures -1'. andZ, :the-printingcylinder being indicated in dot and dash lines.

.Figuresii, 6 andfitaresside views ofsmalLlevers which. are to .be mounted oncthe sucker. ban-end areiherein-shownseparately vfor the sake of clear-.-

ness. -1- i Eigurze Z8 is -.asidelsectional elevationiof the diaphragm: motor.-. 1 or operating thesmoothersi Figurea is a side-view of oneof the suction fingers-z.

Finger-V1.0 is az-side "elevation, partly in section, showingisome iof the-parts in theirrelative =pOSi'r tions, (assumed twhen thesuction :fingers are, givingeup a sheetto the mechanical grippersonathe COIIMQQTOIZdi Figures 11 and 12 are, respectively, .a'planand a fronteview-rof ioneiendiportioneof a gripper-bar andits attachment to a chain- Eig uries 13 iandilei are side views -.show-ing.;a cam andialgripper bar Withits-actuatin'g lever-in their relative. positions 4 when the rmechanical grippers arecpenediandrclosed, respectively.

Figure 15 is a; view:-of the rearendnf the press showing then-conveyorwithfitsframe bars in section, the counter-balancing deviceioriheframe barsandrthe-piling table.

i .Referningz'firstaito Figures 'l- 'a-ndw2 the frameswonle -l-cof arstop-cylinderiprinting press supports a printing :cylinder: 2 on a shaita 3 .mountedain bearingszii. Asiris well understoodinthe:art;:the printing [cylinder :is-zarrestedat the ende-of a;pri1nt-. ing operation. The mechanism :forairiving the cylinderiandziefiectingr its arrest :are not :shown, as zthey aire well known. ':.-Simi1arly';theisheetfeede ing meehanisme is omitted, the invention only. being! concerned rwithathe sheet: deliverymechae-z nismwhichcwill now be describedzie -A tubular sucker bar 5, whichsis ;closedeat its ends, is mounted to rotate-or,-:more= strictlysoscil late about its -1ongit-udina1.axis in hearings 5 and- 'i. Theibearingxfijis screwed to the upper endzof a :Figuresti andrllaia:ogethercconstitutexaiside'eles:

bearings L92: storming; part-seer -a abrackettxifll;

which is fixed to the frame 'fihershaftosi' is co-axial with the shaft 3 of the printing cylinder 2. The lever 8 is oscillated by a cam I which is clamped on a driving shaft I I by a screw I2, as it has to be adjusted or set thereon for a purpose hereinafter explained. The shaft II is driven from the main shaft I29, through gear wheels I2I, I22 fixed, respectively, on the shafts I20 and II.

The cam I8 engages with a roller I3 on a lever I4 fulcrumed at I5 and linked by a rod I6 to a lever I? which is freely mounted to oscillate on the shaft 3'.

The lever I! has a head I8, Figure 3, for engagement with a flange I8 on the lever 8. The lever I! is not connected to the lever 8 and makes a constant oscillation. The lever I'I, however, makes contact with and thrusts the lever 8 in a direction towards the right hand, as considered with reference to Figure 1, and for convenience is hereinafter termed a contact lever.

A spring I9 is anchored at I91 and is attached by a cable I99 to the lever 8. When the contact lever I'I recedes, it allows the lever 8 to be returned by a spring I9, Figures 3 and 4, until arrested by a stop I9I, Figure 10, which is clamped to an arcuate bracket I92 on the frame of the press. It is clamped by a screw I93 passing through an arcuate slot I94, so that it can be set in a position required to suit the length of the sheet being printed. The stop I 9| determines the initial position of the lever 8 and will be referred to later on.

The sucker bar 5 is fitted with a number of hollow suction fingers 22 having rubber sucker pads 23 for engagement with the tail end of a printed sheet on the printing cylinder each time the cylinder stops. The sucker bar 5 extends along the cylinder 2 and the suction fingers 22 are fitted at suitable intervals. Each suction finger 22 preferably has a split boss 24, Figure 9, embracing the sucker bar 5 and tightened by a screw 25 when the boss is set on the sucker bar '5, so that a hole 29 in the suction bar coincides with the passage 21 of the suction finger. Each suction finger preferably has a cock 28 for controlling the passage 21.

- In order to render the suction fingers 22 effective, air is withdrawn from the sucker bar 5 by any suitable means, such as an exhaust pump, not shown. The air passes out of the suction bar 5 through a hole 29, Figure 4, passage 30, valve box 3! and pipe 32 which is connected to the exhaust pump. The valve box 3| is fitted with a slide valve 33 having a nipple 34, Figures 3 and 4, for the pipe 32.

The slide valve 33 has two rollers 35 and 36 for engagement, respectively, with a lever 31 and a cam or stop 38, Figure 1, so that it is reciprocated to open and to cut off suction, as required, by bringing the nipple into and out of coincidence with a suction hole 34, Figures 3 and 4, in the face of the valve box.

The valve box 3| is also fitted with a flap valve 39, Figure 4, pivoted on a pin 43 and controlling an air-inlet hole 40. The flap valve 39 is closed by a spring 4|, Figure 3, surrounding a rod 42, one end of which embraces a pin 44 supported between lugs 45, 45 on the valve. The other end of the rod 42 slides in a lug 41 on the valve box. The lug 45 carries a roller 48 for engagement with a cam or stop 49, Figure 1, which is fixed on the framework of the machine. As hereinafter explained, when the roller 48 engages with the cam 49, the flap valve 39 is moved to uncover the air-inlet 48, so that air is admitted to the sucker bar 5.

A raising lever 59, Figure 3, has a split boss 5I, Figure 6, which is clamped by a screw 52 to the sucker bar 5. The raising lever 50 has a rod 52' sliding in a lug 53 and surrounded by a spring 54 which tends to thrust the lever 50 upwards and so partly'rotate the sucker bar 5 in one direction to raise the suction fingers 22. The

7 boss 5! of the lever 50 has two projection 5|,

52" for engagement with the top of the lever 8, to limit the degree of oscillation of the sucker bar 5. A lowering lever I5I has a split boss I52, Figure 5, which is clamped to the sucker bar 5 by a screw I53. The lowering lever I5I has a roller 55 for engagement with a cam 55, Figures 3 and 4. The cam 56 is adjustably secured to a slotted spur wheel 51 by a screw 58. The spur wheel 5? is free to rotate on the shaft 3, which is co-axial with the shaft 3 of the printin cylinder 2 and meshes with a spur wheel 51, Figure 1, freely rotating on a stud 88 and fixed to a sprocket 87 driven by means of a chain 86 hereinafter referred to. The function of the cam 56 is to actuate the lowering lever I5I to rotate the sucker bar '5, against the action of the spring 54, when the printing cylinder stops, so that the suction fingers 22 are moved down with their pads 23 in contact with the tail end of the sheet on the printing cylinder, and will be referred to later in the description of the general operation of the delivery mechanism.

The lowering lever I5I has a second roller 60 for engagement with a stationary cam 6|, Figures 2 and 10, mounted on the framework of the machine.

The cam 9| is shaped to ensure that the suction fingers 22 will be held in the correct position when presenting the sheet to the mechanical grippers of a conveyor hereinafter referred to. It is secured to the stationary part I92 by a screw I95 passing through a slot I96 in the cam, so as to allow for adjustment of the cam.

When smoothers are provided to engage with the printed sheet on the printing cylinder, it is desirable that they be rendered inoperative while the sheet is being removed from the cylinder. The smoothers 93, Figures 2 and 4, are carried by a shaft 94 (Figures 2, 4 and 8), mounted to oscillate in lugs 95 on collars 95' clamped to the sucker bar 5. A lever 95, clamped on the shaft 94, is pivotally connected to a rod 9! which is secured to a diaphragm 98, Figure 8, in a chamber 99. The part of the chamber above the diaphragm is in communication with the interior of the sucker bar 5 through passages I09, MI and holes I92, I03. The part of the chamber 99 below the diaphragm 98 is open to the atmosphere through hole I95.

A spring I94 presses on the upper side of the diaphragm 98 and, when the interior of the sucker bar 5 is filled with air, the spring I94 holds the diaphragm down, so that the smoothers are pressed on to the sheet on the printing cylinder.

When the air is sucked out of the sucker bar 5, the pressure of the atmosphere on the underside of the diaphragm 98 overcomes the force of the spring I94, so that the rod 91 is pulled up and rocks the lever 96, to rotate the shaft 94, so that the smoothers 93 are raised to leave the sheet free to be removed from the printing cylinder 2 by the sucker fingers 22.

A stop disc I95 prevents the rod 9'! rising too far.

The conveyor for taking the sheets from the suction fingers and for conveying them to the end of the printing machine remote from the printeffect engagement with which have just arrived to receive it. As the 5 contact lever ll away from the lever 8,so that the '-lever' B is returned to its initial position'by its spring l9, and the suction fingers 22 are in position to move down on to the next sheet as the printing cylinder 2 completes its rotation and is stopped.

It will be appreciated that the travel of the suction fingers, while carrying a sheet to the mechanical grippers of the conveyor, is very short relatively to the travel of the sheet in the mechanical grippers on the conveyor.

The long travel on the conveyor gives ample time for the printing ink on the sheets to dry suificiently, so that smudging of the printed ink is avoided.

Moreover once the sheet has been gripped by the relatively more powerful or positive mechanical grippers, it can be pulled suificiently oir the printing cylinder.

' stop-cylinder printing press, having suction devices for engaging with the tail end of a printed sheet on the printing cylinder of the press when said suction devices are in initial position and for initiating the removal ofthe sheet from the printing cylinder, a conveyor having mechanical grippers for taking the sheet from the suction devices when the printing cycle has been completed and completing its removal from the printing cylinder and conveying it away therefrom, means for carrying the suction devices from their initial position to the conveyor and back to their initial position, and means for arresting said carrying means with their suction devices in their initial position, said arresting means being adjustable to regulate the initial position of the suction devices in accordance to the length of the sheet to be printed, whereby to 0 regulate the movement of said suction device to the tail end of the printed sheet.

2. A sheet delivery mechanism for a stop-cylinder printing press, comprising suction fingers for engaging with the tail end of a printed sheet on the printing cylinder of the press and initiating the removal of the sheet therefrom, a sucker-bar carrying said suction fingers, a lever supporting said sucker-bar, said sucker-bar being mounted to oscillate on the lever and said lever being pivotally mounted on the shaft co-axial with that of the printing cylinder, a conveyor having mechanical grippers, means for oscillating said sucker-bar relatively to its supporting lever for the purpose of moving the suction fingers into and out of their operative positions, and means 'for moving the supporting lever towards the said conveyor to move the suction fingers towards the conveyor to allow the mechanical grippers ther of to take the sheet from the suction fingers to complete the removal of the sheet from the printing cylinder after the printing cycle has been completed, and means for arresting said lever in its initial position, said arresting means beingadjustable to determine said initial position to suit the length of sheet to be printed, whereby to effect engagement with the tail end of the printed sheet.

3. A sheet delivery mechanism for a stop-cylinder printing press according to claim 2, including a spring for returning the sucker-barlever to its initial position after each operation, an adjustable stop for arresting the lever in its initial position on its return to suit the length of the sheet being printed, a contact lever for engaging with the sucker-bar lever and thrusting it against the action of the spring towards the conveyor, means including a cam for oscillating the contact lever, a shaft for the cam and means i for adjustably fixing the cam on its shaft for the purpose of setting it on the shaft to suit the length of the sheet being printed. I

4. A sheet delivery mechanism for a stop-cylinder printing press according to claim 2, including a spring for returning the sucker-bar lever to its initial position after each operation, an adjustable stop for arresting the lever in its initial position on its return to suit the length of the sheet being printed, a contact lever for engaging with the sucker-bar lever and thrusting it against the action of the spring towards the conveyor,

means including a cam for oscillating the contact lever, a shaft for the cam, means for adjustably fiXing the cam on its shaft for the purpose of setting it on its shaft to suit the length of sheet being printed, and a sprocket for driving the conveyor, said sprocket being fixed to the cam for the purpose of ensuring simultaneous adjustment of the cam and the sprocket.

5. A sheet delivery mechanism for a stop-cylinder printing press according to claim 2, said means for oscillating the sucker-bar relatively to the lever supporting it, for the purpose of lowering the suction fingers on to a sheet and of raising them to lift the sheet, comprising a wheel freely mounted on a shaft co-axial with the shaft of the printing cylinder, a cam adjustably secured to said wheel, means for rotating said wheel, a follower lever carried by the sucker-bar and having a roller engaging with said cam, and a raising lever on the sucker shaft and a return spring for actuating said raising lever.

6. A sheet delivery mechanism for a stop-cylinder printing press according to claim 2, said means for oscillating the sucker-bar relatively to the lever supporting it, for the purpose of lowering the suction fingers on to a sheet and of raising them to lift a sheet, comprising a wheel freely mounted on a shaft co-aXial with the shaft of the printing cylinder, a cam adjustably secured to said wheel, means for rotating said wheel, a lowering lever carried by the sucker-bar and having a roller for engagement with said cam, and a raising lever on the sucker-bar and a return spring for actuating said raising lever, said lowering lever having means for controlling the suction fingers when presenting a sheet to the mechanical grippers of the conveyor, said controlling means consisting of a second roller on the aforesaid lowering lever, and a stationary cam for engagement with the second roller when the sucker-bar supporting lever is moved towards the conveyor.

7. A sheet delivery mechanism for a stop-cylinder printing press according to claim 2, said sucker-bar being provided with a suction valve and an air inlet valve, means being providedto open the suction valve and to close the air inlet valve when the suction fingers are to engage with a sheet and to close the suction valve and open the air inlet valve when the suction fingers are to release a sheet.

8. A sheet delivery mechanism for a stop-cylinder printing press comprising suction fingers for engaging with the tail endof a printed sheet on the printing cylinder of the press and initiating the removal of the sheet therefrom, a suckerbar carrying said suction fingers, an endless chain conveyor having mechanical grippers, means for moving said suction fingers relatively to the printing cylinder to engage with a sheet thereon, means for moving said sucker-bar, when the suction fingers are in engagement with a sheet, towards the conveyor to enable the suction fingers to present the sheet to the mechanical grippers thereof, and means for returning said sucker-bar and its suction fingers to their initial positions, a

valve box on the sucker-bar having a suction.

valve and an air inlet valve, the suction valve consisting of a plate pivoted on the face of the box to control the suction opening and carrying a suction pipe nipple, means for moving said plate in one direction touncover the suction opening and bring the nipple coincident there- 2 with and means for closing the air valve when REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 305,798 Cottrell Sept. 30, 1884 1,141,277 Smith June 1, 1915 1,907,452 Spless May 9, 1933 2,250,657 Seybold et al July 29, 1941

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