US2692554A

US2692554A - Doctor blade mechanism for intaglio printing presses

Info

Publication number: US2692554A
Application number: US235303A
Authority: US
Inventors: Arthur P Bamford
Original assignee: E G STAUDE Manufacturing Co Inc
Current assignee: E G STAUDE Manufacturing Co Inc; E G STAUDE MANUFACTURING COMPANY Inc
Priority date: 1949-06-23
Filing date: 1951-07-05
Publication date: 1954-10-26
Anticipated expiration: 1971-10-26

Description

Oct. 26, 1954 A. P. BAMFORD DOCTOR BLADE MECHANISM FOR INTAGLIO PRINTING PRESSES Original Filed June o23 1949 l2 Sheets-Sheet l ATTORNEY Oct. 26, 1954 A. P. BAMFORD DOCTOR BLADE MECHANISM FOR INTAGLIO PRINTING PRESSES l2 Sheets-Sheenl 2 Original Filed June 23 1949 NIO NIW

*9% rafa/- A1TORNEY Oct. 26, 1954 A. P. BAMFORD DOCTOR BLADE MECHANISM FOR INTAGLIO PRINTING PRESSES 12 Sheetls-Sheet 3 Original Filed June 25, 1949 O Vw. m. MR ww, uw N Nn f vim# ATTORNEY A. P. BAMFORD 2,692,554

l12 sheets-Sheet 4 l NvEN-roR ,4r/af Pamfa/z] .BYf MV nfl/ ATTORNEY Oct. 26,v 1954 DOCTOR BLADE MECHANISM FOR INTAGLIO PRINTING PRESSES original Filed June 25, 1949 0ct. 26, 1954 A. P. BAMFORD 2,592,554

DOCTOR BLADE MECHNISM FOR INTAGLIO PRINTING PRESSES Original Filed June 23, 1949 12 Sheetsrsheet 5 IIIIIIl-IIIIIIilllllllillllll@ Oct. 26, 1954 A. P. BAMFORD DOCTOR BLADE MECHANISM FOR INTAGLIO PRINTING PRESSES 12 Sheets-Sheet 6 Original Filed June 23 1949 Oct. 26, 1954 A. P. BAMFORD DOCTOR BLADE MECHANISM FOR INTAGLIO PRINTING PRESSES l2 Sheets-Sheet 7 Original Filed June 25, 1949 www mW Fmwqwwm lllllll. IIIIIIIII Oct. 26, 1954 A. P. BAMFORD DOCTOR BLADE MECHANISM FOR INTAGLIO PRINTING `PRESSES l2 Sheets-Sheet 8- Original F'iled June 25 1949 WNW ONM. AW. Im, @1v

OOM. W

A. P. BAMFORD Uct. 26, 1954 DOCTOR BLADE MECH/mism FOR INTAGLIO PRINTING PRESSES l2 Sheets-Sheet 9 Original Filed June 23 1949 INVENTOR. /vV/i//z/f PEG/77 fard BY fr Oct. 26, 1954 A. P. BAMFORD 2,692,554

DOCTOR BLADE MECHANISM FOR INTAGLIO PRINTING PRESSES Original Filed June 25, 1949 12 Sheets-Sheet l0 ATTORNEY Oct. 2 6, 1954 A. P. BAMFORD DOCTOR BLADE MECHANISM FOR INTAGLIO PRINTING PRESSES 12 Sheets-Sheet 1l Original Filed June 23, 1949 )Wi/zw" 25a/"J ATTO R N E Y Oct. 26, 1954 A. P. BAMFORD DOCTOR BLADE MECHANISM FOR INTAGLIO PRINTING PRESSES l2 Sheets-Sheet l2 Original Filed J'ue 23 1949 ATTORNEY Patented Oct. 26, 1954 STATES TENT Fries DOCTGR BLADE MECHANSM FOR INTAGLIO PRINTING PRESSES Original application June 23, 1949, Serial No. 100,894), now Patent No. 2,637,270, dated May 5, 1953. Divided and this 1951, Serial N0. 235,303

(Cl. IOL-157) 5 Claims.

This invention relates generally to intaglio printing presses and this application is a division of my co-pending application Serial No. 100,890, led June 23, 1949, and issued May 5, 1953, as

Patent No. 2,637,270. More specifically the invention relates to an intaglio printing press doctor blade and the mounting and operating mechanism therefor.

As disclosed herein the invention is shown as applied to a multi-color intaglio printing press consisting of two identical units each of which is adapted to print a diierent color on a web being fed through the press. Each unit comprises a printing cylinder, an inlring mechanism by which ink is sprayed onto the printing cylinder, a cloctor blade mechanism by which the ink is evenly spread over the cylinder, an adjustable pressure roll by which the web is held against the printing cylinder during printing and a drying and exhaust mechanism for drying the ink on the i.

web after printing.

The printing cylinder is mounted on a carriage which is sup-ported by wheels riding on a track which facilitate the removal thereof from the machine.

The doctor blade is slidably supported on and extends between the front and rear frames of the machine and is provided with manual means for vertically adjusting lthe same, with automatic reciprocating means driven by the main drive shaft for reciprocating the doctor blade, with a tilting control for varying the angular position of the doctor blade on the carriage, with adjusting means for shifting the doctor blade to or from the printing cylinder so as to position the same accurately in contact with the surface of said cylinder, and with means for adjusting the position of the blade in the holder. Means is also provided for allowing the blade to be retracted from the cylinder and to be again brought into operative position without disturbing the previous adjustments.

The doctor blade mounting and operating mechanism which constitutes the subject matter of this application is mounted between the side frames of the press along one side of the printing cylinder and comprises generally a vertically adinstable slide on which is mounted a reciprocal platform. The platform carries a tiltable frame on which is adjustably mounted a holder carrying the doctor blade. The platform is reciprocatedL by the main drive shaft of the press through suitable driving connections.

The principal object of the invention is to provide an improved doctor blade mechanism for inapplication `uly 5,

2 taglio printing presses which is of relatively simple construction, is efficient in operation and can be readily adjusted for operation with different size printing cylinders.

Another object of the invention is to provide a doctor blade mechanism or the above type by which the doctor blade can be quickly and easily moved out of and back into engagement with the printing cylinder without affecting the setting or adjustment thereof.

Other and more limited objects of the invention will be apparent from the following speci,- cation and the accompanying drawings forming a part thereof wherein:

Fig. 1 is a front elevation of a multi-color intaglio press embodying the present invention, showing two of the color units and the drive mechanism;

Fig. 2 is a top plan View of the units shown in Fig. 1 with the heating and drying mechanism of one of the units broken away;

Fig. 3 is a side elevation of a unit taken from the right side of Fig. 1 on a larger scale;

Fig. 4 is a side elevation, similar to Fig. 3, partially in section and showing the printing cylinder carriage partially removed from the press onto the dolly by which it is transported to and from the press;

Fig. 5 is a vertical section taken on the line 5 5 of Fig. 2;

Fig. 5 is a detail horizontal section taken on line E-i of Fig. 5;

Fig. 7 is a broken detail side elevation of the doctor blade and operating mechanism therefor;

Fig. 8 is a plan View or the mechanism of Fig, 7 with the press frame in section;

Figs. 9 and l0 are horizontal sections taken along the lines .-Q and Iii-lli, respectively, of Fig. 7;

Fig. 11 is a transverse vertical section taken on the line l I--i l Iof Fig. 7 showing the doctor blade in retracted position;

Fig. l2 is a View similar to Fig. ll showing the doctor blade in operative position;

Figs. 13, 14, l5 and i6 are transverse sections taken on the lines lli-13, lll-itl, lil--I and ifi- |51 respectively, of Fig. 7;

Fig. 17 is a detail vertical section taken along the line 25--25 of Fig. 7; and

Fig. 18 is an enlarged detail section showing the mechanism for clamping the doctor blade in place.

Referring to Figs. l and 2, the invention is shown as applied to an intaglio printing press composed of two units A and B each of which is adapted to print one color onto a web. Each unit includes a printing cylinder together with inking and control mechanism, a doctor blade mechanism, a web-guiding mechanism and a drying chamber. A single driving means is provided for all of the units which includes power means and drives shafts which extend in back of all of the units.

Referring to the figures more in detail, a web I is shown as fed to the unit B over guide rollers, 2, 3, 4, 5 and 6 to a pressure roll 1, thence through a drying chamber and over

guide rollers

8 and 9 and around the guide roll 2 of the unit A, thence over the correspondingly numbered rolls of the unit A from which it is discharged over a guide roll I similar to the roll 2,A thence over a roll in a pulling mechanism I2, whence it is discharged to suitable cutting or stacking mechanism or to a reeling mechanism as desired.

Each drying chamber which is disposed over the top of a printing unit comprises a heating source I6 which may comprise a steam heating unit and blower mechanism comprising a fan I1 driven by a motor I8 and discharging air through a port |9 into a zone 2B in which the air is applied to the top of the web passing through the chamber |5. The zone also communicates with chambers 2| and 22 which are disposed on the sides of the machine to apply air from the blower |1 to the webs as they advance toward and recede from the drying chamber I5. The air from the web I, containing the vapors which are picked up thereby, is removed; from the chambers 2| and 22 and from the zone 25 by means of a suction fan 23 communicating with a duct 24 which extends through and communicates with each of the drying chambers I5. The vapor-laden air from the exhaust fan 23 may be discharged to the outside or to a ventilator as desired. The exhaust fan 23 is driven by means of a motor 25 through a driving belt 26 which in turn drives a shaft 21 on which the exhaust fan is mounted.

The various units are driven by means shown as a main drive motor 28 driving a reduction gear train in a housing 29 through a multiple V-belt 35. The reduction gear in the housing 29 drives the main drive shaft 3| and a secondary drive shaft 32. The main drive shaft 3| extends along the rear of the various units and serves to drive the various printing rolls through means to be described. The secondary drive shaft 32 drives a reduction gearing mounted in a housing 33 which in turn drives a secondary drive shaft 34 which extends along the rear of the units and drives the paper feed mechanism not shown. The gear reduction mechanism in the housing 29 includes a clutch of any standard type which is actuated by a clutch lever 36 supported in suitable brackets on a pedestal 31. The lever 36 is adapted to control the operation of the main drive shaft 3| and the secondary drive shaft 34 and is mounted in a position readily accessible to the operator.

Each unit comprises a front frame 40 and a rear frame 4I on which the various elements, including the printing cylinder, are mounted. The

frames

40 and 4| are secured on longitudinal channels members 43 and 44, respectively, and are tied together at their tops by cross beams 45. A top frame comprising front and` rear members 46 and' 41 which are secured at one end to the top of the front and rear frames 4U and 4| and are supported at their other ends by uprights 48 which are also secured to the longitudinal channel members 43 and 44 is provided. The channel members 43 and 44 are tied together by spaced cross members 49 to provide a rigid unit.

A platform 5|) secured between the front and rear frames 4|) and 4| supports the printing cylinder carriage to be described. The hydraulic control mechanism for the press is mounted in a casing 5| attached to the front frame piece 4D.

The roll 2 is mounted on suitable brackets 52 carried by the channel members 43 and 44. The

rolls

3 and 4 are supported by the brackets 53 and 54 on the uprights 48. The rolls `8 and 9 are rotatably supported between the longitudinal members 46 and 41. The roll 5 is supported, in suitable bearings, between frames 40 and 4I. Guide roll 6 and pressure roll 1 are mounted on suitable slides and 6| which are supported on the front and back frames 45 and 4|, respectively, for vertical sliding movement, so that the rolls 6 and 1 are raised or lowered in unison to bring the pressure roll 1 into printing position or to retract the same from the printing cylinder. An ink reservoir generally indicated by the numeral 63 is detachably connected to the front frame 4Q. The reservoir 63 carries a suitable pump mechanism which is driven by a motor 64. The reservoir also carries a valve housing and connecting means, generally indicated at 65, by which ink is supplied to and removed from the inking mechanism.

The running register 66 through which the printing cylinder is driven from the main drive shaft 3|, is mounted in a suitable casing which is attached to the rear frame 4|. The secondary drive shaft 34 extends through this casing but is not connected to any of the mechanism there- The printing cylinder is mounted in a carriage 55 (Fig. 4) which comprises a front plate |25 and a back plate |26 joined by side plates |21. Spacer bars |28 are attached on the inside of the side plates |21 with their lower ends extending slightly below the bottoms of the side plates. The spacer bars |28 carry lower side plates |29 which extend nearly to the bottom of the end plates and are joined by a bottom plate |30. A plurality of wheels |3| are attached to the lower side plates |29 by means of studs |32. In the forms shown three wheels |3| are spaced along each side of the carriage.

The other end plate |25 of the carriage is bolted to the lower half |56 of a rectangular bearing block |51. The bearing block |51 is slidably mounted in a rectangular opening |66 in the front frame 4U and is provided with flanges |62 and |6I, by which it is positioned in the frame. The front plate |25 is provided with a rectangular ink return opening registering with an opening in the bearing block |51. The sides and bottom of the bearing block |51 may be tapered slightly to facilitate its insertion in the rectangular opening |60 in the front frame 40.

The carriage 55 also carries an ink sump which consists of a bottom pan |66 and the vertically adjustable side plates |66. The side plates |69 carry ink applicator' tubes |76 which extend parallel to and the full length of the printing cylinder |66. Ink is pumped from the reservoir 63 through the connector 65 and into the applicator tubes |76 which spray the ink over the surface of the printing cylinder |66 as it rotates. The excess ink falls into the sump pan |68 and drains back into the reservoir 63 through the connector 65.

In order to close the space between the ends of the printing cylinder and the front and back frames 46 and 4|, arcuate shields |75 and |76 are provided which are bolted, respectively, to end blocks 757 and H34. The shields |175 and |76 are provided with arcuate lower surfaces which are accurately machined and overlie the ends of the printing cylinder |66 and engage the peripheral surface thereof with a running fit. Of course the shields |75 and 76 are changed when different sized cylinders are used. The shields |76 and |76 cooperate with the sliding

cover plates

68 and 66 to completely enclose the printing cylinder and inking mechanism except for the limited area of the printing cylinder which is required to be exposed for contact with the web passing around the pressure roll 7. The upper edges of the cover plates 66 and 69 are shaped to engage the shields |75 and |76 which form a limiting stop and are spaced a minute distance from the peripheral surface of the printing roll.

When it is desired to change a printing cylinder the ink reservoir 63 is rst removed and then the printing cylinder carriage 55 and everything carried thereby is rolled out onto a dolly |85, as shown in Fig. 4, on which the carriage is transported to any desired place. Another carriage and cylinder is then inserted in place.

The doctor blade mechanism is driven from the main drive shaft 3i through a worm 466 which meshes with a worm gear 46| on the upper end of a vertical shaft 462. The gears 466 and 46| are enclosed in a gear case 463 bolted to the gear box 465.

Referring now to Figs. 5 and 6, the upper end of the shaft 462 is supported in a bearing 464 in the case 463 and the lower end of the shaft 462 is supported in a bearing 465 mounted in a bracket 466 bolted to the gear case 465. Above the bracket 466 the shaft 462 has keyed thereto a disc having an eccentric cam slot 466 formed therein. A reciprocating slide 476 is provided with a roller 477 which engages the cam slot 468 and is also provided with an elongated slot 472 through which the shaft 462 extends. A cover plate 473 attached to the shaft 462 holds the slide 476 in place. The slide 476 is attached to a rod 474 which drives the doctor blade mechanism to be described.

The doctor blade actuating mechanism is shown in detail in Figs. '7 tc 18 and comprises in general a slide which is adjustable vertically and carries a platform which is reciprocable axially. The platform carries a tilting frame which is tiltable and in turn supports a doctor blade carrier which is adjustable transversely and carries a doctor blade. This combination provides for adjustment of the doctor blade in all directions so as to accommodate the same to diiferent size cylinders.

Referring to Figs. '7 18 more in detail, the mechanism comprises a vertically slidable member 486 which is slidable between gibs 46| at'A tached to the front and back frames 46 and 4|. The slide 466 is provided at each end with upwardly and downwardly extending projections 462 which provide sliding surfaces and serve to hold the slide against lateral movement.

The slide 486 carries a pair of racks 463 which are disposed at each end of the slide and are engaged by gears 484 carried on a shaft 465 which is journalled in the front and back frames 46 and 4| and at one end has a worm gear 466 which is disposed in a recess 467 in the frame 46. The gear 486 meshes with a worm gear 488 carried by a shaft 486 which extends to the side of the frame 46 and carries a handle 496 by which the rack and slide 486 are vertically adjusted. A set nut 49| is provided for clamping the shaft 489 in adjusted position.

The slide 466 carries a pair of side plates 464 at each end thereof which are bolted to the slide on each side thereof and between which a platform 465 is mounted for axial reciprocation. The side plates 494 are provided with grooves 466 in which ride rollers 467 which are carried by the platform 465. The rollers 467 guide and support the platform in its axial reciprocation. At each end of the platform 465 is mounted a block 496 having parallel side surfaces 466. Rollers 566 which are mounted on the top of the side plates 464 and rotate about vertical axes engage the side surfaces 468 of the block 468 for positioning the platform 465 laterally and preventing side play as the latter is reciprocated.

The connections for reciprocating the platform 465 are best shown in Figs. '7, 9 and 14. This mechanism comprises the link 474 which is pivoted to an arm 562 carried on a hub 563 which is journalled for rotating movement only in a bearing 564 mounted in a recess in the platform 56. The hub 565 has a splined opening in which the slidable end of a vertically splined shaft 565 is slidably mounted so that the shaft 565 is free to slide axially in the hub 563 but is constrained to rotate therewith. The upper end of the shaft 565 carries a hub 566 which is rotatably mounted in a bearing 567 carried by a block 566 which is bolted to the slide 466. The hub 566 carries an arm 566 which extends through a slot 576 in the side of the platform 465 and is pivoted to one end of a link 5| i, the other end of which is pivoted to the platform 465 by a vertical pin 5M.

rEhe arrangement is such that reciprocation of the rod 474 rocks the vertical shaft 565 and thereby reciprocates the platform 465.

The blocks 468 also carry pins 5 |5 which rotatably support downwardly extending ears 5|6 on the ends of a tilting frame 5|7.

At its center the platform 465 carries a pair of upwardly extending brackets 5|6 between which are positioned a pair of spaced downwardly extending legs 548 which are secured to the tilting frame 5|?. A worm gear 526 is mounted between the legs 526 and is supported on a shaft 52| which is disposed in axial alignment with the pins 5|5.

The worm gear 526 meshes with a worm 522 carried by a shaft 523 which is journalled in suitable bearings in the platform 495 and carries 7 at its outer end a hand wheel 524 by which the worm is rotated. A lock nut 525 is provided for locking the shaft 523 in adjusted position.

The worm wheel 525 is fixed to the legs |9 so that the tilting frame 5I1 is tilted about the axis of the pins 515 and shaft 52|y in response to actuation of the hand wheel 524.

A doctor blade carrier 52S slides transversely over the top surface of the tilting frame 511, and for clamping the carrier 523 in position a pair of plates 529 are slidably mounted in transversely extending T slots 535 in the tilting frame 5|1 and are secured to screws 53| which extend through the carrier 528. When the screws 53| are loosened the carrier 528 may be adjusted transversely. W hen it is properly adjusted it may be clamped by tightening the screws 53|. For accurate lateral adjustmenty of the carrier 528 a pair of feed screws 532 are provided which are journalled in the tilting frame 5H' and are provided with hand wheels 533 for manual adjustment. The screws 532 extend through feed nuts 534 having upwardly extending cylindrical legs 535 which are seated in recesses 536 formed on the upper side of carrier 528'. Set screws 531 are mounted in the carrier 528 to engage the legs 535 of the feed nuts 534 for clamping the screws 532 and thereby preventing accidental turning thereof when the carrier 528 is properly adjusted. The plate 529 and screws 53| fit somewhat loosely in the T slots 530 to permit independent adjustment of the two ends of the carrier 528 so that the carrier may be adjusted accurately to conform to the peripheral surface of the printing cylinder.

A block 545 is mounted on the top of the car- Iier 528 at each end thereof. A doctor blade holder 54| is formed with a bottom channel 542 which fits tightly over the blocks 540. The holder 54| is secured to the blocks 54D by means of screws 543. In order to remove the holder 54| from the blocks 545 after the screws 543 have been removed, a pair of jack screws 544 are provided which are threaded in bushings 545 in the holder 54| and bear against the top of the blocks 545.

A doctor blade 54S and a thin backing plate 549 are adjustably clamped to the holder 54| by means of a clamping plate 550 which is secured by bolts 55| extending through elongated slots in the doctor blade 548 and the backing plate 545. Hence the doctor blade may be positioned as desired and clamped by tightening the various clamping bolts 55|. This arrangement also permits the doctor blade to be moved outwardly to compensate for wear. The backing plate 549 is provided for strengthening purposes. An ink shield 553, having a rear depending ange 554, is secured to the underside of the clamping plate 55B by means of screws 555. The ink shield 553 is adapted to defiect downwardly into the ink pan ink which may pass over the top of the aplicator tube |10 and thereby to prevent the ink from contacting the blade carrier and actuating mechanism.

In order to permit the tilting frame 5l1 and the doctor blade to be tilted away from the printing cylinder when desired without disturbing the accurate adjustment and thus necessitating readjustment thereof, an adjustable stop is provided in the form of a toggle comprising a link 555 which is pivoted to a bracket 551 carried by the platform 485 and an adjustable link 558 which is pivoted to a bracket 559 carriedA by the tilting frame 511. The free ends of

thelinks

556 and 558 are connected together and the link 558 is provided with a threaded coupling 550 by which the length of said link may be adjusted. After the tilting frame has been properly adjusted to position the doctor blade against the printing cylinder the coupling 565 is adjusted to straighten the toggle and bring the

links

555 and 558 to their limiting position, Thereafter the tilting frame 511 may be retracted about its axis, causing the toggle to break into the position shown in Fig. 1.3, and in order to again position the doctor blade against the printing cylinder in its original adjusted position the tilting frame 5|1 is shifted about its axis until the movement thereof is stopped by the tightening of the toggle links 556 and 558.

From the foregoing it will be apparent to those skilled in this art that I have provided a very simple and efficient mechanism for accomplishing the objects of the invention.

It is to be understood that I am not limited to the specific construction shown and described herein as various modifications may be made therein within the scope of the appended claims.

What is claimed is:

l. A doctor blade mechanism adapted to be mounted for cooperation with the printing cylinder of an intaglio printing press and comprising a frame, an elongated horizontal vertically adjustable slide mounted in jibs on opposite sides of said frame, rack and gear means operative to move said slide up and down and hold said slide in adjusted position, an elongated horizontal platform having an upwardly extending block adjacent each end thereof; means by which said platform is reciprocally mounted on the top of said slide, said means comprising a pair of opposed spaced plates secured to slide and extending upwardly therefrom adjacent each end of said slidel longtitudinaliy extending grooves in said plates, rollers carried for rotation about horizontal axes disposed in said grooves, and rollers mounted on said plates for rotation about vertical axes engaging the sides of said blocks; drive means operable to reciprocate said platform, an elongated horizontal tiltable frame pivotally mounted on the top of said platform for rocking movement about a longitudinal axis, Worm and worm gear means operative to rock said frame back and forth and adjustable stop means settabie to hold said frame in adjusted position, an elongated horizontal doctor blade carrier slidably mounted on top of said tiltable frame for transverse movement, feed screw means operative to adjust the position of said carrier laterally on said tiltable frame, a doctor blade holder secured to said carrier and a doctor blade removably and adjustably mounted in said holder.

2. In a doctor blade mechanism as set forth in claim 1 a vertical splined shaft on said frame connected to said drive means and a coupling splined to said shaft and slidable with said slide connected to reciprocate said platform.

3. A doctor blade mechanism as set forth in claim 1 in which said adjustable stop means for the tiltable frame comprises a toggle having adjustable links and connected between said tilting frame and said platform.

4. In a doctor blade mechanism as set forth in claim 1, an ink deflector mounted on the underside of said blade holder to deflect ink from the moving parts of said assembly.

5. A doctor blade mechanism adapted to be mounted for cooperation with the printing cylinder of an intaglio printing press and comprising a frame, an elongated horizontal vertically adjustable slide mounted in jibs on opposite sides of said frame, rack and gear means operative to move said slide up and down and hold said slide in adjusted position, an elongated horizontal platform having an upwardly extending block adjacent each end thereof; means by which said platform is reciprocally mounted on the top of said slide, said means comprising a pair of opposed spaced plates secured to slide and extending upwardly therefrom adjacent each end of said slide, longitudinally extending grooves in Said plates, rollers carried for rotation about horizontal axes disposed in said grooves, and rollers mounted on said plates for rotation about vertical axes engaging the sides of said blocks; means operative to reciprocate said platform longitudinally of said slide, axially aligned trunnions carried by the blocks on said platform, an elongated horizontal tiltable frame mounted on said trunnions for rocking movement, means operative to rock said tiltable frame back and forth and to hold said frame in adjusted position, said means comprising a cooperating worm and worm gear, one of which is secured to said platform and the other of which is secured to said frame with said Worm gear in axial alignment with said trunnions, a doctor blade carrier slidably mounted on the top of said tiltable frame for transverse movement, feed screw means operative to adjust the position of said carrier on said frame, a doctor blade holder removably secured to said carrier and a doctor blade removably and adjustably mounted in said holder.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date Re. 21,212 Weiss Sept. 19, 1939 2,055,272 Weiss Sept. 22, 1936 2,115,376 Weiss Apr. 26, 1938 2,178,069 Crafts Oct. 31, 1939 2,292,344 Heller Aug. 11, 1942 2,506,011 Caulfield May 2, 1950 2,528,965 Meyer Nov. 7, 1950