US3043215A - Priming liquid applicator for offset rotary printing machines - Google Patents

Description

July 10, 1962 A. G. R. GATES 3,043,215

PRIMING LIQUID APPLICATOR FOR OFFSET ROTARY PRINTING MACHINES Filed Jan. 27, 1961 3 Sheets-Sheet l Attorney July 10, 1962 A, e. R. GATES PRIMING LIQUID APPLICATOR FOR OFFSET ROTARY PRINTING MACHINES 5 Sheets-Sheet 2 Filed Jan. 27, 1961 w ms n 6 m k E a A July 10, 1962 A. G. R. GATES 3,043,215

PRIMING LIQUID APPLICATOR FOR OFFSET ROTARY PRINTING MACHINES Filed Jan. 27, 1961 3 Sheets-Sheet 3 Inventor ALEERT 616- 6A 755 Attorney SAM-3,215 Plsiiffiifl rronm APP ICATGR F61 EBFFSET RGTAR PRINTENG MAEHHHZS Albert George Ronald Gates, Edmonton, London, England, assignor to Gestetner Limited, London, England, a British company Filed Jan. 27, 1961, Ser. Na. 85,311 Claims priority, application Great Britain Feb. 1, 1969 21 Claims. (Cl. 1011 i3) This invention concerns oifset rotary printers which conventionally comprise a plate cylinder, a blanket cylinder, an impression cylinder, at delivery cylinder and means for applying ink and Water to the plate cylinder.

In offset rotary printers, it is necessary, before commencement of the printing operation, to apply to the plate an aqueous ink repellant solution which desensitizes the non-image areas of the plate. This operation is known as priming.

Priming of the plate is usually carried out manually by the operator of the machine wiping a dampened sponge or pad over the plate. Such a manual operation is time consuming and unpleasant for the operator.

It is known to use, for dampening a plate during th printing operation, apparatus comprising a damping liquid applicator roller engaging .the plate cylinder and supplied with damping liquid from a reservoir. It is also known to use two such applcator rollers engaging the plate cylinder at angularly spaced positions therearound and rotating with the same peripheral speed. Such known apparatus for dampening a plate during the printing operation cannot be satisfactorily used for priming the plate since it is absolutely necessary that the plate be completely covered by the priming liquid and these known apparatus do not provide a sure and effective application of liquid to all parts of the plate. For this reason, the priming liquid is up to the present time usually applied manually, although it is in some instances applied mechanically by a pad.

It is an object of this invention to provide means for effecting when required, the priming of the plate quickly, efliciently and without the operator of the machine having to handle the priming liquid.

According to this invention, I provide apparatus for use in priming the plate of the plate cylinder in an oiiset rotary printer, such apparatus being movable between a priming position and an out-of-the-way position and comprising two plate cylinder priming liquid applicator rollers engaging the plate cylinder at angularly spaced positions therearound, such apparatus being characterised in that the two rollers, when engaging the plate cylinder have different peripheral speeds.

The use of two rollers having diiierent peripheral speeds ensures a firm and even priming of the plate.

Preferably, the leading roller is arranged to be rotated at a lower speed thanthe trailing roller.

Preferably, the two rollers are coupled together so that one is automatically driven on rotation of the other and such coupling is conveniently provided by a chain engaged over sprockets on spindles on which the rollers rotate. The differential rotation of the two rollers may, with this construction, be achieved by using sprockets of different sizes and having different numbers of teeth.

When the machine is using short paper plates, e.g. for system work, and the trailing end of the paper plate is free and not secured to the plate cylinder, the faster rotation of the trailing roller causes the paper plate to buckle between the positions of the rollers, and liquid is applied by the trailing roller to the part of the cylinder which will, in use of the machine, lie beneath the trailing marite' rates ates by'the leading roller, the trailing marginal portion of the paper plate is adhered to the cylinder. Such adherence prevents the trailing end of the paper plate from flapping as the plate cylinder rotates and from being soiled, e.g. by contact with inking rollers of the machine, as occurs in conventional offset printers when used for systems work with short paper plates.

In order that this invention may more readily be understood, and further features appreciated, one embodiment of the same will now be described by way of example, with reference to the accompanying drawings, in which:

FIGURE 1 is a side elevation of apparatus according to this invention, such apparatus being shown in its damping position;

FIGURE 2 is a fragmentary plan view of the apparatus of FIGURE 1; I

FIGURE 3 is a section on the line III-I1l of FIG- URE 2;

FIGURE 4 is a side elevation of the apparatus in its out-of-the-way position; and

FIGURE 5 is a fragmentary exploded view illustrating the mounting of the priming liquid applicator rollers.

The embodiment illustrated comprises apparatus for attachment to a conventional offset rotary printer for the purpose of priming the plate on the plate cylinder 1 of such machine before commencement of the printing operation. The apparatus is mounted on a rotatable shaft 2 extending between two spaced side members 3 which are rigidly connected by cross bars i. Each of the side members 3 is carried by an arm 5 adapted to be attached to across the machine parallel to the axis of the plate cylinmoves the locking member} in a direction towards the.

ginal portion of the paper plate so that, when the buckled part of the paper plate is finally pressed on to the cylinder der. I The apparatus comprises two side plates 6 which are parallel to the side members 3 of the'apparatus and are mounted on the'rotatable shaft 2, the latter carrying at one end a handle 7 by which the shaft can be rotated to move the apparatus towards the plate cylinder 1 into a priming position as shown in FIGURES 1, 2 and 3, against the action of tension springs 8 which are connected betweeneach side plate .6 and the adjacent side member 3 and which normally. bias the apparatus to an out-of-the-way position shown in FIGURE 4.

The handle 7 carries a catch for locking the apparatus in its out-of-the-way position, such catch comprising a locking member 9 extending alongside the handle 7 and having at its outer end a finger piece 10 and at its inner end a locking peg 1-1 engaged in a slot 12 in the adjacent side member 3. The locking member 9 also has at positions intermediate the finger piece 10 and peg 11 two 1ongitudinally spaced elongated slots 13, through which pass guide pins 14 carried by a plate 15 on the side of the handle 7 opposite to the member 9, and a peg 16 projecting into a slot 17in the handle'housing a compression spring 18.

The arrangement is such that, in the priming position of the apparatus, the locking peg 11 is located at the lower end of the slot 12, the guide pins =14- are located at the forward ends of the elongated slots 13 and the peg 16 is in a position spaced from the adjacent end of 'slot 17 and compresses the spring 18. When the handle 7 is raised to move the apparatus into its out-of-the-way position, the compression spring 18 pressing on the peg 16 shaft 2 so that the locking peg 11 engages in a transverse branch of the slot 12 at the upper part thereof and locks the member 9 in this position and thereby locks the apparatusin its out-of-the-way position, To release the apparatus for downward movement into its priming position;

the member 9 has to be retracted again against the action of spring 18 by a pull exerted on the finger piece 10.

avoids undue vibration of the apparatus during operation of the machine.

Between the side plates 6" of the apparatus extend two priming liquid applicator rollers 19 and 20. mounted for rotation on parallel axes parallel, to the axis of the plate side plates 6 are connected together by a cross member 23 secured to the plates by screws 24. Removal of the screws 24 enable the side plates to, be moved apart 'to withdraw the pins 22 from the rollers for replacement of the latter or of a coveringsleeve with which one or both rollers may be provided. a I At one end of the rollers 19 and Ztleach pin 22 carries a sprocket 25 and an endlesschain 26 isengaged around the two sprockets'so that rotation of one roller causes rotation of the other. 7 r a The two rollers are arranged to rotate at difierent speeds bymaking the roller sprockets of diiferent sizes and provided with adiiferent, number of teeth. In the embodiment illustrated, the sprocket 25 associated with the leading roller 19 hasrnine teeth, whilst the sprocket 25 associated with the trailing roller 2% has eight teeth so that the leading roller l9 rotates at a lower speed than the trailing roller 20. If desired, the sprockets may be arranged to be removable and interchangeable with tray has an aperture 30 adjacent one edge and the wick 29 projects through such aperture so that, when liquid 'in the reservoir is catsuch edge, such liquidis in contact with the wick and is ledto the pad therebelow. Ifdesired,wick 29 could be dispensed with and thevpad 28 arranged so as toibe in direct communication with the liquidin the 'reservoirthrough the aperture 30. a a

The reservoirhas projecting outwardly-at each side thereof two pins 31 which pass throughguide slots 32 in the adjacentside member 3 of the apparatus and which control' the movementof thereservoir whengtheappa:

ratus' is moved relatively to the side'rnembers. I 'At its lower part, the reservoir carries a roller 33 resting .onthe upperedges of the side plates 6. These upper edgeslareiso shaped that, when the apparatus :moves to its out-of-theway position, the side plates 6 exert a camming action on the reservoir and the latter moves rela- V tively to the side plates and rollers carried thereby, such movement being guided by the pins 31 engaged in the slots 32. Thearrangement is such that, in the out-of-the{ way position of the apparatus, the pad 28 below thereservoir is out of contact with the two rollers 19 and 20 and the base of :the reservoir tray 27 slopes downwardly awayfi'om the aperture 30therein and, in the damping position of the apparatus, the pad 28 engages the rollers and the reservoir is orientated so that the base of the reservoir tray slopes downwardly towards the aperture 30.

It will be appreciated that the quantity of liquid in the reservoir isarranged to be such that, when the apparatus is in itsout-of-the-way position the liquid does not extend to the aperture 30. w v As will be clearly understood from the foregoing, when the apparatus is in its out-of-the-way position, the pad 28 beneath the reservoir isoutof contactwith thepriming liquid applicator rollers H and 20 and no liquid is supplied to the pad from the reservoir, but, when the apparatus is moved downwardly by depression of the handle 7, the reservoir tilts to supply liquid to the pad 28 and the latter moves to engage the rollers which are caused to bear against the plate on the plate cylinder so as to rotate when the latter rotates and to prime the plate.

The priming liquid applicator rollers may bemade of, or have a covering of, rubber, felt, or any other suitable material and the: two rollers may be of similar or dissimilar form. The rollers, being readily removable, may be interchanged or replaced so that the apparatus may be adjustedto suit different machine operating conditions. When short paper plates are used, we have found that a convenient arrangement is to have the leading roller 19 felt covered and the trailing roller 29 formed of rubber.

Conveniently, as shown, the pins 22 carrying the trailing roller 2!; may be mounted in elongated slots 34 in the side plates 6 and be spring pressedto urge thisroller firmly into engagement with the plate on the plate cylin der. in FIGURES 1 to 4, a torsion spring 35 carried by a post 26 is used to provide this spring pressure, Alternatively, acompression spring carriedby theappropriate' side plate 6 and bearing on the appropriate pin 22 may be used.

I claim: I,

1. An oilset rotary printing machine comprising a machine frame, a plate cylinder carried by said frame for rotation about a horizontal axis, a mounting fixed relatively to said frame, a primingliquid applicator roller, support means carryingsaid roller for rotation about an axis parallel to the axis of the plate cylinder, means mounting said support means on said mounting for pivoting thereon about an axis parallel to the axes of the plate cylinder and roller between an operative position in which the said'roller engages the surface of the plate cylinder and an out-of-the-way position in which the. said roller is spaced from such surface, a reservoir for priming liquid, a base to said reservoir having an aperture along one edge thereof, wick means carried below the said reservoir base and projecting upwardly through the said aperture therein, means mounting the said reservoir on said support means so as to be'movabl'e relatively to the roller, and means on said reservoir co-operating with the said support means and said mounting and causing movement of the reservoir relatively to the rollersuch that, when the support means is in its operative position,.the said wick means engages the surface of the rollerand the base 'of the reservoir is inclined downwardly towards the aperture therein and, when thesupport means is in its out-of-theaway position, the said wick means is out of contact with the surface of the roller and the base of the reservoir is inclined 3. The offset rotaryprinting machine specified in claim 2, and including a handle by which the support means may be moved between its operative and out-of-the-way positions, a spring loaded catch carried by said handle and a locking peg on said catch co-operating with a slot in said mounting for locking the support meansin its out-ofthe-way position. a

4. In an offset rotary printing machine, "appartus for priming the plate-on the plate cylinder such apparatus comprising two priming liquid applicator rollers, means mounting said rollers for movement between an operative position in which the rollers'engage the plate cylinder at angularly spaced positions therearound and an out-ofthe-way position in which the rollers are spaced from'the ,plate cylinder, means coupling the rollers and constrainpriming liquid from the reservoir to the damping rollers in the operative position of the latter.

5. The apparatus specified in claim 4, and comprising a sprocket associated with each of said rollers, the sprocket associated with the leading roller having a greater number of teeth than that sprocket associated with the trailing roller, and a chain engaged around the said two sprockets.

V 6. The apparatus specified in claim 4 and comprising means mounting the reservoir and wick means for movement relatively to the priming liquid applicator rollers between a position in which the wick means is in contact with the rollers when the support means is in its operative position and a position spaced from the priming liquid applicator rollers when the support means is in its out-ofthe-way position.

I 7. An ofiset rotary printing machine comprising a machine frame, a plate cylinder carried by said frame for rotation about a horizontal axis, a mounting fixed relatively to said frame, two priming liquid applicator rollers, support means carrying said rollers for rotation about axes parallel to the axis of the plate cylinder, means mounting said support means on said mounting for pivoting thereon about an axis parallel to the axes of the plate cylinder and said rollers between an operative position in which the said rollers engage the surface of the plate cylinder at angularly spaced positions therearound and an out-of-theway position in which the said rollers are spaced from such surface, a reservoir for priming liquid, a base to said reservoir having an aperture along one edge thereof, wick means carried below the said reservoir base and projecting upwardly through the said aperture therein, means mounting the said reservoir on said support means so as to be movable relatively to the said rollers, and means on said reservoir co-operating with the said support means and said mounting and causing movement of the reservoir relatively to the rollers such that, when the support means is in its operative position, the said wick means engages the surface of the rollers and the base of the reservoir is inclined downwardly towards the aperture therein and, when the support means is in its out-of-the-way position, the said wick means is out of contact with the surface of the rollers and the base of the reservoir is inclined downwardly away from the aperture therein.

8. The offset rotary printing machine specified in claim 7, and including means for locking the support means in its out-of-the-way position.

9. The offset rotary printing machine specified in claim 8, and including a handle by which the support means may be moved between its operative and out-of-the-way positions, a spring loaded catch carried by said handle and a locking peg on said catch cooperating with a slot in said mounting for locking the support means in its out-of-the-way position.

10. The offset rotary printing machine specified in claim 7, wherein the said means on said reservoir co- Operating with the said support means and said mounting comprise pegs on said reservoir engaged in slots in said mounting and a roller on said reservoir resting on a camming surface of said support means.

11. The offset rotary printing machine specified in claim 7, and comprising two spaced side plates providing said support means, a cross-member extending between said side plates, means securing said side plates readily removably to said cross-member and pins journalled in said side plates and mounting the said rollers for rotation by engaging in axial bores in the ends of the rollers.

12. An offset rotary printing machine comprising a machine frame, a plate cylinder carried by said frame, a mounting fixed relatively to said frame, two priming liquid applicator rollers, support means carrying said rollers for rotation about axes parallel to the axis of the said plate cylinder, such support means being carried by said mounting for pivoting thereon between an operative position in which the said rollers engage the surface of the plate cylinder at angularly spaced positions therearound and an out-ofthe-way position in which the said rollers are spaced from said surface, 'a reservoir for priming liquid, means mounting said reservoir on said support means so as to be movable relatively to the rollers, means on said reservoir co-operating with said mounting and said support means causing and guiding movement of the reservoir relatively to the rollers when the said support means pivots relatively to the said mounting, wick means communicating with the interior of the reservoir and contacting the surface of the rollers when said support means is in its operative position, and means coupling the said two rollers and constraining the leading roller to rotate at a lower speed than the trailing roller.

13. The oifset rotary printing machine specified in claim 12, and comprising a sprocket associated with each of said rollers, the sprocket associated with the leading roller having a greater number of teeth than that sprocket associated with the trailing roller, and a chain engaged around the said two sprockets.

14. An offset rotary printing machine comprising a machine frame, a plate cylinder carried by said frame, a mounting fixed relatively to said frame, two priming liquid applicator rollers, support means carrying said rollers for rotation about axes parallel to the axis of said plate cylinder, such support means being carried by said mounting for pivoting thereon between an operative position in which the said rollers engage the surface of the plate cylinder at angularly spaced positions therearound and an out-of-the-way position in which the said rollers are spaced from said surface, a reservoir for priming liquid, means mounting the said reservoir on said support means so as to be movable therewith, Wick means, means mounting the latter on said support means so as to be movable relatively to the rollers between a position in which the wick means is in contact with the rollers when the support means is in its operative position and a position spaced from the rollers when the support means is in its out-of-the-way position, and means coupling the said two rollers and constraining the leading roller to rotate at a lower speed than the trailing roller.

15. The ofiset rotary printing machine specified in claim 14, and comprising a sprocket associated with each of said rollers, the sprocket associated with the leading roller having a greater number of teeth than that sprocket associated with the trailing roller, and a chain engaged around the said two sprockets.

16. An offset rotary printing machine comprising a machine frame, a plate cylinder carried by said frame for rotation about a horizontal axis, a mounting fixed relatively to said frame, two priming liquid applicator rollers, support means carrying said rollers for rotation about axes parallel to the .axis of the plate cylinder, means mounting said support means on said mounting for pivoting thereon about an axis parallel to the axes of the plate cylinder and of said rollers between an operative position in which the said rollers engage the surface of the plate cylinder at angularly spaced positions therearound and an out-of-the-way position in which the said rollers are spaced from such surface, means constraining the rollers to rotate at different peripheral speeds in the operative position of the support means, a reservoir for priming liquid, a base to said reservoir having an aperture along one edge thereof, wick means carried below the said reservoir base and pro iecting upwardly through the said aperture therein, means mounting the said reservoir on said support means so as to be movable relatively to the rollers, and means on said reservoir co-operating with the said support means and said mounting and causing movement of the reservoir relatively to the rollers such that, when the support means is in its operative position, the said wick means engages the surface of the rollers and the base of the reservoir is inclined downwardly towards the aperture therein and, when the support means is in its out of the way position, the said wick means is out of contact with the surface of the rollers and the base of the reservoir is inclined downwardly away from the aperture therein.

"l7. Theofiset rotary printing machine-specified in means may he moved between its operative and outof-thewayposi-tions, a spring loaded catch carried by said handle and a locking peg on said catch co-operating with -a slotin said mounting for locking the support means in its out-of-the-way position.

19. In an ofiset rotary printing machine, apparatus for applying a priming liquid to the plate on the plate cylinder, such apparatus comprising two priming liquid applicator rollers, means 'mounting said rollers for movement between an operative position in which the rollers engage the plate cylinder at angularly spaced positions therearound and an OUFOf-thG-WQY position in which the rollers are spaced from the plate cylinder,

' -means constraining the rollers to rotate at different peripheral speeds in the operative position of the rollers,

a reservoir for priming liquid, and wick means leading liquid from the reservoir to the rollers in the operative position ofthe latter.

20. .The apparatus specified in claim 19 and comprising means mounting the reservoir and wick means for movement relatively to the rollers between a position in which the wick means is in contact with the rollers when the latter are in said operative position and a posi-' out-of-the-Way position.

21. An otfset rotary printing machine comprising a machine frame, a platecylinder carried by, said frame, a mounting fixed relatively to said fir ame, two priming liquid applicator rollers, support means carrying said rollers for rotation about axes parallel to the axis of the" plate cylinder, such support means being carried by said mounting for pivoting thereon between an operative position in which the said rollers engagethe surface of the plate cylinder at angularly spaced positions therearound and an Out-Of-ihG-WHY position in which the said rollers are spaced from such surface, means constraining said rollers to rotate at ditferent peripheral speeds when the support means is in said operative position, a reservoir for priming liquid, means mounting the said reservoir on said support means so as to be movable relatively to the rollers, and means on said reservoir cooperating with the said support means and said mounting and causing movement of the reservoir relatively to the rollers such that, when the support means is in its operative position, the said wick means engages the'surface of therollers.

References Cited in the file of this patent UNITED STATES PATENTS

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