US1572710A

US1572710A - Gripper mechanism of printing presses

Info

Publication number: US1572710A
Application number: US729813A
Authority: US
Inventors: Finkhaus Oskar
Original assignee: Bohn & Herber Maschinenfabrik
Current assignee: Bohn & Herber Maschinenfabrik
Priority date: 1924-08-02
Filing date: 1924-08-02
Publication date: 1926-02-09
Anticipated expiration: 1943-02-09

Description

Feb. 9' ,'1926.

O'. FINKHUS GR'IPPER'MEcHAN-ISM F PRINTING PRESSES` 6 Sheets-Sheetl 1 `Filed August. 2' 1924 Inventur (9a/q /plw,

o@ FlNKHAus,

6 sheets-sheet s' Filed August 2 1924' I xlventor: t

"if W QM O. FfNK'HAus -GR1PPER MECH'ANISM- PRINTING PRESSES Feb., 9 1926.

' Filed Aug\1 Sl 2, 1924 6 Sheets-Sheet 4 O. FINKHAUS GRIPPER MECHANISM QF PRINTING' PRESSES Filed August 2, 1924 e sheets-sheet s.

Inventor:

Feb. 9 1926.

o. FlNKHAUs' GRIPPER MECHANISM OF PRINTING PRESSES 6 sheets-sheet e IFiled A11/gust 2, 1924 Inventor:

Patented Feb.v `9, 1926.

UNITED STATES PATENT OFFICE.

osKAn EINKHAUS, 0E WURZBURG, GERMANY, Ass-IGNOR To BoHN a Hamann, arascHINENEABnIx UND nIsENGIEssEREI, or WURZBURG, ',GERMAN'Y, A xoMMAN- nrrGnsELLscHAFT or GERMAN LAW.

'GRIHPPER -MECHANISM 0F PRINTING PRESSES.

Application vled August 2, 1924. Serial No. 729,813.

To all whom t may concer/a: p

Be it known that I, OsKAR FINKHAUS, a citizen of Deutsches Reich, and residing at 34 Petrinistreet, Wurzburg, Bavaria, Grer-A many, have invented certain new and useful Improvements in and Relating to the Gripper Mechanism of Printing Presses; and I do hereby declare that the following is a full, clear, and exact description of the same. Imprinting presses with a continuously rotating printing cylinder it frequently happens that several sheets to be printed, laid to the same laying on gages are irregularly seized bythe gripper mechanism and.I

therefore do not show an accurate register. This is undeslrable even 1f there are only slight deviations for multi-colour printing work and unfavourably affects the The inquality of the finished product. vention has for its object to eliminate the drawback in question by modifying the arrangement of the support for the sheets to be printed, whilst using without any other modification the'wellknown gripper mechanism of such machines which has proved so satisfactory and in kWhich several grippers are mounted on a spindle mounted dif rcctly in the printing cylinder-amd seize the sheet in (fo-operation with a radially and tangentially movable sheet support mounted between stops in the printing cylinder. The invention aims moreover at providing a simple and durable gripper device, easy to manipulate.

The `invention consists in the combinaspindle mounted directly in 'the' printing cylinder, a sheet support mounted in the printing cylinder in a radially and tangentially adjustable manner and rotating with the printing cylinder, means for 'rotating the gripper spindle, and means for stopping the sheet support opposite a fixed point of the machine frame when the grippers close down on the said support, and for releasing it again immediately afterwards.

The invention comprises moreover other details hereinafter more particularly described.

Two constructions according to the invention are illustrated yby way of example in the accompanying drawings in which the same reference numerals indicate the same parts.

In the said drawings: Figures 1 and 2 are respectively a crosssection and a plan of a gripper device.

Figure 3 is a section, on an enlarged scale, of the same device, in the osition immediately before the grippers c ose down.

Figure 4 is a similar section in the position immediately afterwards.

Figure 5 is a` section through an alternative construction of the gripper device according to theinvention, 1n the position immediately before the closing downof the grippers. Figure 6 a correspondin `plan.

Figure 7 isa section corresponding t0 Figure 5A in the position immediately after the closing down of the grippers.

Figure 8 a similar section in the position for putting on the cylinder blanket.

In the continuously rotating cylinder 1 of i `a Aprinting press (Figures 1-4 `of the drawing) is rotatably mounted the gripper spindle 2; it carries a number of grippers 3 firmly secured to it, which are distributed throughout the whole length of the cylinder, and outside the cylinder, a gripper. shoe 4 which is also Iirmly keyed to it. The gripper shoe co-operates with a c lindrical stop 6 secured tothe frame 5 of tiie machine, so that in passing the stop 6 the gripper spindle is rotated. During this rotation the gripper shoe moves between the'stops 7 and 8 which are provided outside on the end wall or cover of the printing cylinder. To the gripper spindle are also keyed, on the inside of the cylinder cover cranks 9 which are pressed upwards by means of pivoted rods 10 and pressure springs 11 mounted on the said rods. All these parts are already known for the same purpose and in the same arrangement in printing presses. Adjacent to the gripper spindle in the cylinder is mounted the sheet support 12 which is constituted by a rail or bar extending in the longitudinal direction of the cylinder. To the sheet support is secured adjacent to each endof the same a bolt 13 which can slide in rings 14; the rings' 14 are mounted so as to be freely rotatable by means of pins 15 on the inside of the cylinder cover. Between the rings 14 and the sheet support are iny close down on its upper edge.

Moreover 'on the sheet support adjacent to its ends are mounted arms 17 with which engage tension springs 18, the opposite ends l of which are secured to holders 19 screwed into ,the cover of the printing cylinder. With' the arms 17 co-operate cam discs 20 keyed to the gripper spindle 2 and each of which is providedy with a projection or boss 21. As long as the cylindrical surfaces of the cam discs 20 engage with the arms 17, they allow the sheet support to project slightly beyond the circumference of the printing cylinder 1 but when the bosses 2l come into Contactwith the arms 17 the heet support will b e forced into the cylin- At the ends of the'sheet support are provided stops 22 which engage with adjustable stops 23 secured to the inside of the cylinder cover. At the front edge of the laying-ort board or table 24 are provided elastic prongs or t tongues 25 on which the sheet 26 to be printed can be laid to the fixedlaying-on gages 27. Moreoverat both sides of the laying-on tableon the machine frame are arranged fixed and adjustable vstops 28 which co-operate with the stops 22 of the sheet support. The stops 28 are bent into al ri ht angle, thea longer branch of which is situated in the plane of the layingon table, and the shorter branch projects 'downwards near-the laying-on gages 27. 1 The shape of the gripper shoe 4 is such that the points' of the grippers 3 come down on the sheet vertically consequent upon the rotation of the cylinder. i

Shortly before the device reaches the position shown in Figures 1 and 3, the gripper shoeI 4 has engaged with the stop 6 whereby the gripper shoe is rotated and moved away from the stop 8. At the same time the spindle 2 has been rotated and with it the cam disc 20. The arms 17 have disengaged from the projection 21 of the cam discs 20 and engaged with the cylindrical surfaces of the cam discss l At the same time the sheet support 12 has been .pushed out of the printing cylinder by the springs 16, to such an extent that its stops 22 engage with the horizontal portion of the stops 28, and its upper edge engages with `the tongues 25 and the sheet 26. The printing cylinder continues to rotate in contact with the printing sheet and the tongues 25. In the positionshewn in Figures 1 and 3, the sto s 22 engage with the vertical or- `tion of t e stops 28. Immediately a terwards the grippers 3 close down on theprinting sheet 26 and therefore press at the same time against the sheet support 12.

Owing to the greater strength of the sprin 11 the sheet support 12 will be force into the printing cylinder, the springs 16 being compressed at the same time, and the gripper shoe 4 meanwhile disengagingI from the stop 6, in this way the sheet support isl finally disengaged from the stops 28, Figure 4; from the moment of the meet- `ing of the stops 22 with the vertical portion of the stops 28 to the moment of the release, the sheet support 12 cannot participate in the rotation of the printing cylinder, but remains stationary. During this period, owing to the continued rotation of the cylinder, the gripper points move at right angles tothe sheet 26 to be printed as indicated by the arrow in Fig. 5, that is to say said gripper points also do -not participate geometricallyl in the rotation of the printing cylinder. j The gripper points move relatively to the sheet 26 in a curve somewhat like the curved dotted line indicated on F 3, and said curve has some elements per enficular to the sheet support. By proper y shaping the gripper shoe 4 as indicated in Figs,

sheet 26. The sheetsupport 12 remaining stationary and the gripper points movingperpendicularly to the sheet and to the upper surface ofthe sheet support, the gripping is effected inthe same manner asit would be by a stationary gripper on' a stationary table. Only on the sheet support 12 being released by the stops 28will it continue to move with. the printing cylinder and the grippers 3 and at that moment the printing sheet 26 will be moved by thegripper device and remain in a fixed position relatively to the latter.

The printing sheet will now travel with the printing cylinder and will be printed upon and released again when the gripper shoe 4 is again turned into its initial position. On the grippers beginning to turn again the sheet support is also released and returns to 'its normal position relatively to the stops 23.

The construction shown in Figures 5-8 of the drawing, differs from the first construction chiefly by the fact that the active part ofthe sheet support is made adjustable ort, is moved on the arc of a circle about t e gripper spindle 2. This arc is active only on its part near theI circumference 'of the cylinder 1, and said arc of the circle obviously elongates in a direction either radial or tangential with respect to the cylinder, and

when the gripper points close down on the.

printing sheet, the outer surface of the sheet support is prevented from rotating with the circumference ofthe cylinder, that is to say, its tangential movement with respect to the cylinder is what is employed by the present invention. During the next phase of operation, the grippers move the sheet support toward the center of the cylinder, which is the radial movement employed in the present invent-ion. Other movements of ,the sheet support at the same time are negligible, and do not effect the operations herein described.

The construction and the arrangement of the printing cylinder 1, gripper spindle 2, grippers 3, gripper shoe 4, cranks 9, layingon table 24, tongues 25, laying-on gages 27, stops 28 and of the corresponding parts, are substantially the same as in the construction shown in Figures 1 4.' The sheet support 29 is however mounted on the gripper spindle in a freely rotatable manner by means of two brackets 30 secured to its ends.

On the sheet support are mounted, adjacent to its ends, fingers 31 which engage with the ends of spring blades 32, the other ends of which are secured to the printing cylinder 1. The cranks 9 are provided with cams 33 which depress the spring blades 32 in the initial position of the gripper spindle 2. At the end of the sheet support are provided stops 38. On a spindle-34arranged parallel to the gripper spindle, are mounted a number of brackets 35 which carrybuffers 36 forced outwards by springs 37, The buffers 36 engage from the inside against the sheet support andpress it outwards. The spindle 34, in addition to the brackets 35, carries also S-shaped springs 39 intended to secure the cylinder blanket 40.' The spindle 34 can be rotated by means of a hand lever 41 which is bifurcated at the end and secured outside to the end wall ofthe printing cylinder. .At the same place is pivoted a clamp 42 which can be turned into the gap between the bifurcated ends of the lever 41 and secured there by'screwing down a handle 43.

The operation of the device ,is as follows The gripper spindle together with the shoe, grippers, cams 33 and spring blades 32 are first in the position shown in vFigure 8.- The tail of the gripper shoe engages with the stop 8. The other parts in the cylinder being in position indicated in Fig. 7, the sheet. support 29 is pressed outwards by the buffers 36 until the fingers 31 engage with the spring blades 32; the outer edge of the sheet support is during that period still-in the interior of the printing cylinder. During the rotation of the printing cylinder before the position shewn in Figure 5 is reached, the gripper shoe 4 will strike the cylindrical stop 6 secured to the l frame and will thus be turnedl say to an angle of 135. The cams 33 of the cranks 9, previously depressing the spring blades 32, will be brought into the' position shown in Figure 5 so that the sheet support 29 will be moved by the buffers 36 outwards beyond the casing of the printing cylinder. During the rotation of the printing cylinder, the sheet support will travel for a short distance along the tongues 25; finally its stops 38 will strike, in the position shewnl i in Figure 5, lthe vertical lportions of the stops 28. At that moment the upper edge of the sheet support. will be therefore pre-` vented from continuing its rotation about the axis of rotation of the printing cylinder.

Almost simultaneously, the grippers 3 will close down on the printing sheet. 26 and the sheet support 29, the said grippcrs moving then at right angles to the sheet.`

As the printing cylinder continues to rotate without an interruption, the sheet support 29 will slide o' from the stops 28, its upper edge moving 'in respect to the frame of the machine in the radial direction of the cylinder. The movement is facilitated by the arrangement of the gripper' spindle 2, about which the sheet support 29 turns, obliquely below thexedge of the stop 28. The centre of rotation of the movement of the sheet support relatively to the frame of the machine is situated in the point of intersection of the radius o f the printing cylinder, drawfn through the centre of the grip per spindle 2, with a line drawn through its lower corner point at right angles to the vertical arm of the stop 28.

The movement of the sheet support is independent of the'movement of the gripper shoe 4. The forces of acceleration produced are taken up, on the one hand, by the stops 28, and on the other hand, by the bearings of the gripper spindle 2 in the printing cylinder. The gripper shoe 4' is given such a shape that the grippers 3 follow the movement of the sheet support in the same time ratio. t

From themoment of striking the vertical edge of the stops 28 to the moment of its release therefrom, the position shown in Figure 3, the upper edge of the sheet supradial direction of t-he cylinder. Conseq'uently during that interval the printing sheet is seized in the same manner as by stationary grippers on a stationary sup- .port 29 executes only a movement in the the springs 39 will first engage with the' inder without being able to move relatively to the cylinder; it Will be then printed upon and' when the gripper shoe 4 returns to its initial position again released. l

The cylinder blanket 40 is put on in the following mannerz- The handle 4l is released and turned in the anti-clockwise direction, Figure 8. The buifers' will then also beturned downwards. The sheet support 29' will follow them and finally the springs 39 will be released and pass into the space 'ust left .free by the sheet support; the end o the cylinder blanket can then be conveniently put on. If the handle 41 and with it the rod 34 are then t'urned back in the clockwise direction,

cylinder blanket, then they will bc cocked, Whilst at the same time the buffers 36 vand with them the sheet support 29 will be raised again. The handle 41 will then be llocked again by means of the clamp 42 operated by the handle 43.

The'invention described oii'ers the following advantages In spite'of the movement of the cylinder,

the printing sheet is seized as accurately asu by stationary grippers and a stationary sheet support; it can therefore engage Wit xed laying-on gages and will not move at the moment of seizing. Each sheet will he therefore locked on the cylinder in the same position as the others. During the rotation of the printing cylinder, the edge of the printing sheet will not slide on thev casing of the lprinting cylinder and there-l fore will not be damaged. The Whole device is extremely simple and utilizes the Well known gripper device which has proved so satisfactory in such machines. The second construction has this advantage over the first one, that the rsheet support will be driven direct by the gripper spindle 2 during the renewed acceleration after striking the stops 28, so that the grippers 3, the gripper shoe 4 and the stop Gare relieved from the forces which these parts have to resist`rin the firs-t construction for the acceleration of thesheet support.

Having now particularly described and ascertained the nature of my said invention and in What manner the same is to be performed I declare th at what I claim is 1. In a printing press comprising a frame, a rotary printing cylinder supported in said frame, a gripper spindle rotatably supported within and rotating With said printing cylinder, grippers mounted on said gripper spindle, a printing sheet support mounted Within and rotating with said printing cylinder, a fixed stop outside of and a ]acent t. said printing cylinder,

means on said spindle for engaging said fixed stop.. and actuatlng said gripper spin- -port is adjustable oblique with respect to the outer cylindrical surface of the printing cylinder.

3. Ina printing press such asset forth in claim 1, in which said printing sheet support rotates With said cylinder until it engages said stopping means. l

In a printing press such as set'forthin claim 1, 1n which the-means on the spindle engaging the fixed stop is a cam surface of such configuration or curvature as to actuate the grippers on the spindle in such a manner that the engaging ends of said grippers close down on the printing sheet support perpendicularly or normally to the printing sheet.

5. In a printing press such as set forth in claim 1, in which is rovided means for actuating the printing s eet support so that said support is moved out of the printing cylinderl before its engagement with the stopping means.

6. In a printin' press such as set forth in claim 1, in Whic the means on the spindle engaging the fixed stop is a cam surface of such 'configuration or curvature as to depress the sheet support back into the printing cylinder after said grippers have reached sald sheet support. y

7. In a printing press such as set forth in claim 1, in which the printing sheet support is pivoted and rotatable on the gripper spindle.

8. In a printing press such as set forth f in claim 1, in which the printing sheet support is spindle, a cam on the gripper spindle, said cam engaging said sheet support in such a manner as to allow said support to swing out- Wards from the printing cylinder during 'the advance-of the grippers but hold said OSKAR FINKHAUS.

pivoted and rotatablelon the gripper