US2447090A

US2447090A - Rotary intaglio printing press

Info

Publication number: US2447090A
Application number: US518217A
Authority: US
Inventors: Willard M Pollock
Original assignee: GOSS PRINTING PRESS CO Ltd
Current assignee: GOSS PRINTING PRESS Co; GOSS PRINTING PRESS CO Ltd
Priority date: 1944-01-14
Filing date: 1944-01-14
Publication date: 1948-08-17
Anticipated expiration: 1965-08-17

Description

Aug. 17 1948. w. M. POL-LOCK ROTARY INTAGLIO PBRH'ING PRESS 4. Shoots-Shoot 1 Find Jan. 14, 1944 Aug. 17,, 18. w. M. POLLOCK. 2,447,090

ROTARY INTAGLIO PRIMING PRESS n943- w. M. POLLQCK 2,447,090

ROTARY INTAGLIO PRINTING PRESS F1104 Jan. 14, 1944 4 Sheets-Sheet 3 Aug. 17, 1948. w. M. POLLOCK 2,447,090

ROTARY INTAGLIO PRINTING IRES'S Filed Jan. 14, 1944 4 Sheets-Shut 4 ill YA/ M 241. 036% WWW W Patented Aug. 17, 1948 UNITED. STATES PATENT OFFICE 2,441,090 ROTARY INTAGLIO PRINTING PRESS Willard M. Pollock,

The Goes Printing This invention relates to new and useful improvements in inking mechanisms for rotary intaglio presses and more particularly in improvements in the operation of the doctor blade for such inking mechanisms.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means or the instrumentalities and combinations pointed out in the appended claims.

The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a part hereof, illustrate one embodiment of the invention, and together with the description, serve to explain the principles of the invention.

Of the drawings: Fig. 1 is a fragmentary vertical transverse section through a typical arrangement of doctor Glen Ellyn, IlL, assignor to Press Company, Chicago, 111., a corporation of Illinois Application January 14, 1944, Serial No. 518,217

blade and mounting in a rotary intaglio printing Fig. 3 is a detailed diagrammatic exploded view of the complete doctor blade operating mechanism according to the present invention;

Fig. 4 is a detailed sectional view of part of the operating mechanism for imparting movement to the doctor blade, as shown in Figs. 2 and 3; the

means being shown in a central or intermediate position; and

Figs. 5 and 6 are detailed sectional views of the operating means of Fig. 4 but showing the means in an extreme right and extreme left position;

respectively. I

Objects of the invention are to provide a doctor blade operating mechanism constructed and capacitated to operate reliably and efllciently under modern high speed, high quality requirements;

to provide a doctor blade operating mechanism permitting variation of the rate of reciprocation of the doctor blade; variation of the length of stroke of the doctor blade; variably timing the reciprocation of the doctor blade in direct proportion to the speed of the press; and smooth operation of the doctor blade through a preselected cycle of operation; as well as to eflect other objects which are set forth hereinafter or will be mechanism.

6 Claims. (Cl. 101-169) apparent to those skilled in the art through practicing the invention or otherwise.

To this end, in a preferred embodiment herein exemplified, various cooperating structures and principles are embodied, some of which will be briefly and generally here indicated.

A supporting and guiding means is firmly supported in flxed position upon a press frame, and on said guiding means a carriage carrying the entire doctor blade mechanism is reclprocably mounted. Various known devices for adjustably positioning the blade carrier and blade with respect to the design cylinder of the press may be provided, and these will be mounted preferably on said carriage.

In the Patent No. 2,178,069,. granted October 31, 1939, there is disclosed a doctor blade mechanism for a rotary intaglio printing press where such blade positioning and regulating means are utilized, mounted upon' the blade supporting car riage, and the present invention, consisting in providing new and improved reciprocating means for a doctor blade mechanism, may be utilized with such a doctor blade mechanism as is disclosed in said patent, although the present invention is in no way to be construed or limited to such form of doctor blademechahism.

In accordance with the present invention fluid operated means, for example, hydraulic means, are provided for reciprocating the doctor blade To this end, in the preferred embodiment, cam actuated means operated from any desired part of the press driving means and thus in a direct proportion to the speed of running of the press, are provided adapted to operate a pilot valve which is so arranged as to control the flow of fluid underpressure to one side or the other of a single piston movable in a cylinder. The blade carrier mechanism is directly connected to the piston so that reciprocating movements thereof may be obtained under control of the pilot valve.

It is a feature of this invention that the pilot valve is so arranged as to receive flow of fluid under pressure to either side of the piston for a controllable time which can be altered to suit the desired movement to be imparted to the doctor blade.

Heretofore the doctor blade has been reciprocated by other than fluid pressure means with the result that while the desired cycle of acceleration and deceleration has been generally approached. it has never been achieved. Particularly, it is greatly desired that, at the extreme end of each stroke, a deceleration is effected, after 3 which the blade movement be quickly reversed, that is, without any lag, and prior mechanisms have been largely unable to accomplish this.

Th'e present invention attains this result completely and also accomplishes a complete .control or acceleration and deceleration, namely, permit- 7 ting a preselected cycle of movement to pertain for the doctor blade.

This is accomplished by utilizing a specific, and variable, cam contour to give a desired or preselected movement to an inner plunger which has thereon two pistons adapted to cooperate with ports arranged in an outer barrel surrounding the plunger and slidably mounted within theouter casing or body of the pilot valve. The ports of the barrel communicate at all positions of the barrel with exit ports connected through the body of the pilot valve, one of each of these ports communicating with a chamber of the cylinder previously referred to, the two chambers of which are on either side of the operating piston.

Thus, movements of the plunger under urge of the cam, result in one or the other port in the barrel being opened to a source of fluid under pressure admitted to the chamber formed by the pistons and the inner wall of barrel whereby the operating piston will be moved one way or the other to reciprocate the doctor blade.

By changing the shape of the cam it is possible to arrive at a definite cyclic acceleration and retardation of the doctor blade to suit any purpose. Thus, the cam contour positions the barrel and causes reciprocatory movements thereof, the rate of travel of the doctor blade, as well as the amount of travel, being determined by the movements of the barrel and thus being capable of preselection by choice of the contour of the cam.-

The actual flow of fluid under pressure to the piston within the cylinder is governed by movements of the barrel under influence f the rise and fall of the cam, and the rate of such rise and fall will determine the rate of flow to said cylinder.

It is desired in practice to provide for such a doctor blade a smooth even movement and the curve or contour of the cam will in practice be chosen to give a deceleration of the doctor slide as it approaches the end of each stroke, a rapid reversal, and a smooth acceleration at the beginning of each stroke.

The distance between the high point and low point of the cam will determine the length of the doctor blade stroke.

Thus, changing the cam contour gives complete variable and adjustable factors with respect to the cycle of reciprocation of the doctor blade.

Either an edge cam or a box cam can be utilized in this invention as hereinafter brought out.

It is a further feature of this present invention to vary the rate of reciprocation of the doctor blade independently of any variability of its cyclic movements.

To this end, the cam is adapted to be driven from a press driven shaft, whereby the speed of driving of the cam will always be proportional to the speed of driving of the press.

Any desired means of changing the speed of the cam may be utilized such being well known in the art and including change gears, variable gear drives, variable belt drives and the like.

It is a further feature of the present invention to provide for varying the length of the stroke of the doctor blade, irrespective of the other featured adjustments and variables given above, and accordingly the other end of the operating piston in the cylinder mentioned above has a rod extension which is linked to one end 01' a fulcrumed lever, the other end of which is linked to a shaft attached to one end of the barrel of the pilot valve.

The fulcrum is so mounted as tobe adjustable between the linked ends whereby a complete variability of the operating stroke of the operating piston is achieved since the fulcrumed lever moves under urge of the operating piston to slide the barrel of the pilot valve relatively to the pistons on the plunger and variation. of the arc of movement of the fulcrumed lever, thus caused, will alter the length of time of application of fluid under pressure to the cylinder, by movements of the barrel relative to the plunger.

Also, the linkage above described, may be variable by having the rod extension at one end of the lever and the shaft at the other end mounted for sliding movement in slots in the lever and adapted to be locked in any desired position in the slots whereby to alter the operative length of either the shaft or rod or both.

It is obvious that the barrel of the pilot valve will thus travel in the same direction as the plunger in an amount determined by the linkage and if the proportions of the linkage are changed, the travel of the operating piston and thus the doctor blade will decrease or increase accordingly.

This invention has been generally described above with respect to a unit for operating by fluid pressure means a doctor blade mechanism, this unit comprising a pilot valve and an operating piston and cylinder connected therewith, but obviously a plurality of such units will be provided for a press having a plurality of couples, and said units can each be actuated from a single source of fluid under pressure, conventionally comprising a motor, pump and manifold for multiple circuit operation with suitable cut-out valves for each unit to silence same when not needed.

It will be understood that the foregoing general description and the following detailed description as well are exemplary and explanatory but are not restrictive of the invention.

Referring now in detail to the embodiment of the invention illustrated by way of example in the accompanying drawings, as shown in Figs. 1 and 2, there is provided an intaglio printing couple comprising a design cylinder l and an impression cylinder 2, which are suitably journalled in the vertical side press frames 3, the web 5 running through the impression.

The supporting structure of the doctor blade mechanism is connected with and carried by the vertical side frames 3 and also by the vertical wall 4 which is part of the ink fountain structure and extends across the press, being fixed to and carried by, the frame members 3.

The doctor blade mechanism, as here exemplifled, comprises a stationary support or base l0, supported by the wall 4 and frame members 3, and may comprise an upwardly and inwardly inclined wall which constitutes part of the fountain closure.

Guide means are suitably carried by support I! and the entire doctor blade mechanism is reciprocably mounted on the guiding and supporting means.

To this end, on the outer face of support III is formed a long horizontal supporting surface 3|. Supported upon the surface 38 and fastened thereto by any suitable means is a bevelled or undercut guide 43, having a shoulder 44 running within its upper edge, the shoulder fitting over the upper horizontal face of surface 33, whereby the guide piece 43 has hanging support on pad 33.

The carriage which supports the doctor blade mechanism and which slides reciprocabiy on guide 43 comprises a flat plate 43 having its inner surface contacting the surface of guideway 43, as at 50. The plate 43 has a forward extension 53 in sliding engagement with the upper undercut edge of guideway 43.

The doctor blade carrier 60 is mounted on the carriage 43 and is carried thereby during reciproeating movements, as hereinafter described.

Carrier 60 comprises a longitudinally extending bar having a bottom seat 66 and a rearwardly extending flange having a seat 62 upon and within which the immediate support for the doctor blade is mounted.

In the embodied form of mounting the doctor blade l and its carrier, the blade it rests upon a seat formed on a bar 12, bar 12 resting on support 6i already mentioned. Clamping fingers 13 hold the bar 72 in place and bolts I4 attach the clamping fingers l3 against the seats 0i and 62. The blade is held firmly against bar 12 by holders 80 which are clamped thereagainst by a plate BI and screw bolts 82.

If desired, a resilient sealing and backing blade 85 may be mounted in jaws 03 and 31 suitably clamped together.

Further details of this specific form of doctor blade carrier, carriage and mounting may be obtained in Patent No. 2,178,069 hereinbefore mentioned.

In accordance with the present invention, the embodied form of means for reciprocating the carrier II on the guide 43 include fluid operating means, and hydraulic means are illustrated, specifically.

A plate 90 is formed on the end of the carriage 40 and is attached thereto by screw bolts 9|. A lug 93 extends therefrom and is adapted to have attached thereto a rod 35 by a strap 04 bolted to the lug 33, as at 06, and preferably formed integrally with rod 05 or permanently attached thereto as by welding. 7

Means are provided for reciprocating rod 95 whereby to reciprocate doctor blade carriage 49 on guide 43.

To this end, a piston I00 is located within a cylinder MI and is adapted to slide therein under hydraulic pressure applied alternately through ports I02 and I03 within the cylinder.

Cylinder IN is supported within a side frame 3 of the press by, for example, anangle bracket I04 attached by bolts I05 to the cylinder and by bolts I06 to the side frame. A suitable bore I01 throughout the side frame 3 may equally serve as the means of support, if desired. Fluid under pressure, such as oil, is supplied to the ports I02 and I03 through connecting conduits I03 and I09 respectively, these conduits communicating with a pilot valve, hereinafter described, which is adapted to force the fluid under pressure alternately through the conduits I00, and I03, the return fluid being drained back to the supply source through whichever conduit is not connected to the pressure side.

Cylinder IN is also mechanically connected to the pilot valve generally indicated at I20, by suitable linkage, to which end, in the embodiment illustrated in Fig. 2, a rod Ill is connected to the side of piston I00 opposite to the rod 95 and the end of rod H3 is slip-linked at I2I to a pivoted .6 lever I22. Lever I22 is fulcrumed at I23 on a suitable bracket I24 carried by a side frame 3, and attached thereto, as by bolts I25. The other end of lever I22 is slip-linked at I26 to a shaft I21. Shaft I2? is drivingly connected with parts of valve I20 as now more clearly described.

As shown in Figs. 4, 5 and 6, giving details of three positions of valve I20, oil or like fluid under pressure is adapted to be introduced to a, central part of the valve from any suitable source of supply through a conduit I28 to a port I23.

Valve I20 is provided with an inner plunger valve I3I having two piston portions I32 and I33 and terminating at one end as a shaft-like extension I34, mounted for guided movement in the valve body I36 by an end cap I35. Shaft I34 has mounted thereon at its extremity a cam follower I38 which. is preferably rotatably supported on shaft I34, by an anti-friction bearing i39. Cam follower I38 is driven by a cam which in Fig. 4 is shown as an edge cam I40, this cam being preferably driven from a drive shaft of the press and being so designed as to give a desired acceleration and deceleration of reciprocating movement to the inner plunger valve I3! for the purpose hereinafter described. When using edge cam I40. for operatively moving valve plunger I3I a spring MI is arranged at the other extremity of the plunger, this spring abutting I against the end of plunger I3I, serving to keep the cam follower I38 always in contact withcam I40. The other end of spring I4I abuts against a flange I42 of asleeve I43 surrounding plunger I3I and adapted to slide on the piston portions I32 and I33 of plunger I3I, the sleeve I43 and flange I42 forming an outer barrel for the valve I20 adapted to slide within the body I36.

Attached to the flange I42, or formed integral therewith, if desired, is a shaft I44 which extends beyond the confines of body I36 of the valve, and is mounted in a flanged end thereof I45 to reciprocate. This shaft I44 is connected by suitable linkage to the operating rod II8 of cylinder IOI and may be the shaft I21 of Fig. 2 or it may be suitably articulated thereto,

Various ports are provided in the barrel I43 for the purpose of permitting the oil under pressure, supplied through conduit I30, to be introduced into the interior of barrel I43 and to selectively flow therefrom to one side or the other of piston I00 in cylinder IOI. To this end, port I20 communicates with a port H50 in the barrel I43 and permits the oil under pressure to be contained within a chamber I5I formed by the confines of the interior walls of the barrel I43 and the pistonsI 32 and I33.

Body I36 of the valve I20 has two exit ports therein, one exit port I60 communicating withan outlet I6I through the wall of the body I36 to which outlet conduit I09 connects as by a nip =p le I62, while in the same way the other exit port I65 communicates with an outlet I66 to which is connected'conduit I08 by a nipple I61.

Barrel I43 has ports I60 and I63 communicating with exit ports I60 and I65, respectively, whereby oil under pressure from chamber I5I can be allowed to flow either through communicating ports I60 and I68 and thence through conduit I09 to port I03, 015 the cylinder IN, or through communicating ports I65 and I69 through conduits I08 to port I02 of cylinder IN, the movements of the inner plunger urge of cam I40, and particularly the position of piston parts I 63 and I 69 of the barrel, determining which of con- I32 and I33 relative to entry .ports 7 duits I08 or I09 receive fluid under pressure. The actual controlling movements of the various parts of valve I20 can be more clearly understood by reference to the relative positions of Figs. 4, 5 and 6.

In Fig. 4 barrel I43 is in its center position and both ports I68 and I89 thereof are sealed off or closed from connection with chamber I5I by the pistons I32 and I33. As the cam I40 rotates it causes cam follower I38 and thus plunger I3I to move inwardly or outwardly. In Fig. 5 the parts are shown in their extreme right hand position while in Fig. 6 the parts are shown in extreme left hand position. In Fig. 5 it will be seen that the oil under pressure from chamber I5I is flowing through the open port I68 through exit port I60 and into conduit I09 to apply pressure to piston I through port I03 and push the piston to the left of Fig. 5. Ports I69 and I65 are sealed off from pressure fluid by piston I33 but can allow drainage back of fluid through port I02, conduit I08 into a return chamber I15 from whence it can be returned to the source of supply.

Due to rod II8 being moved over to the position shown, lever I10 is placed in position H011 and shaft I44 is in position I44a thus moving the barrel I43 to follow the plunger and move over to an extreme right position.

The positions of Fig. 6 are exactly opposite to those of Fig. 5, the pressure side being on the left throughport I02, conduit I08, ports I65 and I89, with the drainage through conduit I09, the lever I10 then occupying position "Oh and lever I44 being in position I44b with the barrel in its extreme left hand position. The chamber I16 now receives drainage.

Thus, by this valve arrangement, a relatively small movement of the shaft I34 from cam follower I38 coupled with following movements of the barrel I43 give a maximum controlled movement of piston I00 in cylinder I0 I.

The cam shown in Figs, and 6 is a box cam I11, so that the spring I4I may be dispensed with in such a modification of cam form.

In order to prevent build up of pressure against the flange I42 of barrel I43 and to permit feeding back into drainage chamber I18, holes I18 in said flange may be drilled, as shown.

The pistons I 32 and I33 may be of cylindrical form but in such event, as the ports I88 or I69 are cleared by the pistons I32 or I33 and thus are placed in communication with pressure chamber I5I an immediate flow of fluid under the full pressure will take place and will remain at the same pressure until the opened port is closed again. In use, the barrel I43 closely follows movement of the inner plunger BI, and in order to provide for adequate flow through the various .ports of the fluid under pressure, the pistons I32 and I33 will be preferably formed as clearly.

shown in Figs. 4, 5 and 6 with both advance and return edges tapered.

In Fig. 3 an exploded view of the whole apparatus for operating the doctor blade mechanism is shown. Motor I80 drives pump I 8I and the oil thus under pressure is passed through conduit I82 to a manifold I83. A suitable pressure guage I84 is associated with manifold I83. Conduit I85 leads the fluid under pressure to the valve I20, a suitable cut-off valve I88 for silencing the unit when desired, being provided in the line, More than one doctor blade reciprocating unit may be operated fromthe one source of supply of fluid under pressure, and therefore a branch line I81 is shown from manifold I83 each of which may be identical with the unit illustrated comprising valve I20, cylinder IN, and operating connections. Return or drainage oil from the chembers I15 and I16 may be taken into the sump I81 of pump I8I through conduit I88, the drainage from other units being also passed thereto by conduit I89.

In Fig. 3, cam follower I38 is shown in contact with edge cam I40 which is driven from the press at an adjustable speed.

To this end, cam I40 may be pivotally mounted in a bracket I on a shaft I9I, on which shaft a pair of pulleys I92 each with an inclined face are splined and are spring urged toward each other. A V shaped belt I93 is driven from a pulley I94 and is adapted to simultaneously contact both pulleys on the inclined faces thereof in such way that, as the belt is tightened about the pulleys, the two pulleys move away from each other and the belt contacts a different peripheral portion, whereby the relative speed of driving cam I40 is changed.

An idler I95 mountedto be adjusted by a screw I98 against a spring I91 rides on the upper face of belt I93 and by adjusting the idler I95. the position of belt I93 with respect to the inclined faces of pulleys I92 is altered, to vary the driving speed, at will.

Driving pulley I94 is driven from any suitable moving shaft of the press by a belt I98 and a pulley I99 mounted on shaft 200 in a bracket MI.

The linkage between the operating piston I00 and the barrel shaft I44 in Fig. 3 is of somewhat modified form. Rod H8 is mounted in a bearing block 20I for support and is linked at 202 to an extension arm 203, the link 202 being pivotal. Arm 203 is slip-linked in a groove 204 in one arm of a fulcrumed lever 205, slip-link 206 being adapted. to be adjusted and clamped in place longitudinally of lever 205.

In the same manner, shaft I44 is supported by a bearing block 208 and is linked at 209 to an extension 2I0 which is slip-linked at 2 II in a groove 2I2 in the other arm of lever 205.

Furthermore, fulcrum 2I3 of lever 205 is mounted in a block 2I4, the block being vertically slidable on a guide 2I5. Adjustments of the fulcrum point 2I3 may be made by screw 2 I6 which is carried by an extension 2I1 of said slide, a lock screw 2i 8 being provided for preventing accidental movement of the fulcrum.

By altering the position of the fulcrum the length of stroke of the doctor blade can be varied and by altering the angular attachment of the slip-

links

206 and 2 further adjustment of the length of the operative thrust exerted on the blade carrier can be made.

Thus, there is provided by the present invention, new and improved actuatingmeans for reciprocating the doctor blade mechanism, such means providing smooth, economical operation and being hydraulic actuated or actuated by equivalent fluid pressure means with additional features of control and adjustability including means for varying the rate of reciprocation of the doctor blade; means tovary the length of stroke of the doctor blade; and means for timing the reciprocation to vary in direct proportion with the speed of the press.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom vention and without sacrificing its chief advantages.

What I claim is:

1. A rotary intaglio inking mechanism including in combination a guide, a doctor blade carrier mounted for reciprocation thereon, and fluid pressure means for reciprocating said doctor blade carrier including a pilot valve having an innner plunger and a barrel surrounding same and mounted for relative sliding movement therewith, ports in said barrel communicating with exit ports through the body of said pilot valve, means for conducting fluid under pressure to the interior of said pilot valve, means to move said barrel and plunger to periodically permit flow of said fluid under pressure through first one and then the other of said exit ports, a piston within a cylinder, ports on either side of said piston, means to connect said exit ports with said cylinder ports, whereby said piston is reciprocated under flow of pressure from said pilot valve, 2. driving rod from said piston to said blade carrier, and a connection between the other side of the piston and the barrel of said pilot valve whereby movements of said barrel relative to said plunger may be effected.

2. A rotary intaglio inking mechanism including in combination a guide, a doctor blade carrier mounted for reciprocation thereon, and fluid pressure means for reciprocating said doctor blade carrier including a pilot valve having an inner plunger and a barrel surrounding same and mounted for relative sliding movement therewith, ports in said barrel communicating with exit ports through the body of said pilot valve, means for conducting fluid under pressure to the interior of said pilot valve, means to move said barrel and plunger to periodically permit flow of said fluid under pressure through first one and then the other of said exit ports, a piston within a cylinder, ports on either side of said piston, means to connect said exit ports with said cylinder ports, whereby said piston is reciprocated under flow of pressure from said pilot valve, a driving rod from said piston to said blade carrier, and a connection between the other side of the piston and the barrel of said pilot valve whereby movements of said barrel relative to said plunger may be effected, said connection being a linkage including a fulcrumed lever, the fulcrum of which can be varied relative to the piston and the barrel to vary the length of stroke of the blade carrier.

3. A rotary intaglio inking mechanism including in combination a guide, a doctor blade carrier reciprocably mounted thereon, a hydraulically operated piston attached to said carrier adapted to receive fluid under pressure on one side or the other to reciprocate said carrier, a pilot valve having two internal moving parts, cam means to move one part relative to the other,

means to move the other part under urge of said rier reciproeably mounted thereon, a hydraulically operated piston attached to said carrier adapted to receive fluid under pressure on one side or the other to reciprocate said carrier, a pilot valve having two internal moving parts, cam means to move one part relative to the other in predetermined variable amounts, means to move the other part in predetermined variable amounts under urge of said piston to follow the first part, and means to apply fluid under pressure in predetermined variable amounts to said piston from said pilot valve under control of the relative movements of said parts.

5. A rotary intaglio inking mechanism including in combination a guide, a doctor blade carrier mounted for reciprocation thereon, fluid pressure means for reciprocating said carrier, a pilot valve governing the application of fluid pressure to said reciprocating means, and mechanical means acting to operate said pilot valve to determine the rate of flow of fluid under pressure to said reciprocating means in a continuous accelerating and decelerating cycle, whereby the cycle of movement of said carrier follows a predetermined acceleration-deceleration pattern,

said mechanical means including a cam operating on a moving part of said pilot valve, and linkage between another moving part of said pilot valve connected to said reciprocating means to cause said other moving part of the pilot valve to follow the stroke of said reciprocating means in a predetermined proportion.

6. A rotary intaglio inking mechanism including in combination a guide, a doctor blade carrier mounted for reciprocation thereon, fluid pressure means for reciprocating said carrier, a pilot valve governing the application of fluid pressure to said reciprocating means, and mechanical means acting to operate said pilot valve to determine the rate of flow of fluid under pressure to said reciprocating means in a continuous accelerating and decelerating cycle, whereby the cycle of movement of said carrier follows a predetermined accelerationdeceleration pattern,

said mechanical means including a cam operating on a moving part of said pilot valve, and linkage between another moving part of said pilot valve connected to said reciprocating means to cause said other moving part of the pilot valve to follow the stroke of said reciprocating means in a predetermined proportion, said linkage being adjustable to alter the proportion of following of the stroke of the reciprocating means assumed by said other moving part of the pilot valve, whereby the length of travel of said carrier can be adjusted independently of the amount of fluid pressure supplied.

' WILLARD M. POLLOCK.

REFERENCES CITED The following references are of record in the file of this patent:

FOREIGN PATENTS Number Country Date 753,303 France Aug. '7, 1933 512,135 Germany Feb. 26, 1932