US1942592A

US1942592A - Machine for reducing printing plates to uniform thickness

Info

Publication number: US1942592A
Application number: US462884A
Authority: US
Inventors: Leslie W Claybourn
Original assignee: Individual
Current assignee: Individual
Priority date: 1930-06-21
Filing date: 1930-06-21
Publication date: 1934-01-09
Anticipated expiration: 1951-01-09

Description

Jan. 9, 1934. w CLAYBQURN 1,942,592

MACHINE FOR REDUCING PRINTING PLATES TO UNIFORM 'IIIiICKIJESSv Filed June 21, 1930 I 10 Sheets-Sheet 1 ATTORNEY.

L. W. CLAYBOU RN Jan. 9, 1934;

MACHINE FOR REDUCING PRINTING PLATES T0 UNIFORM THICKNESS 1o Sheets-Sheet 2 Filed June 21, 1950 A TTORNEY.

1934- w. CLAYBOURN MACHINE FOR mavucme PRINTING PLATES TO UNIFORM wmcxmsss Filed June 21, 1930 10 Sheets-Sheet 3 I N! 'EN TOR;

BY E

A TTORNEY.

ATTORNEY.

Jan. 9, 1934. L. w. CLAYBOURN MACHINE FOR REDUCING PRINTING PLATES TO UNIFORM THICKNESS Fi1ed June 21, 1930 10 sheets-sheet 4 em w s \\L Y L 00 Q0 |l|| Cw E m 6: A W/ Z7// ////////4 \s 3. $2 E +2 a 1. F823 m: u 53 m3 9 2m m2 O K K Jan. 9, 1934. 1,942,592

MACHINE FOR REDUCING PRINTING PLATES T0 UNIFORM THICKNESS 1.. w. CLAYBOURN Filed June 21, 1950 10 sheets-sheets I N VEN TOR A TTORNEY.

Jan. 9, 1934.

L. W. CLAYBOURN MACHINE FOR REDUCING PRINTING PLATES TO UNIFORM THICKNESS Filed June 21, 1930 10 Sheets-Sheet 6 INVENTOR. BY & I ATTORNEY.

SN IWHIHI Jan. 9, 1934. w CLAYBOURN 1,942,592

MACHINE FOR REDUCING PRINTING PLATES TO UNIFORM THICKNESS Filed June 21, 1930 10 Sheets-Sheet '7 e E:- m g 8 1| Ill W? 19 fig A T TORVE Y IN VEN TOR.

10 Sheets-Sheet 8 LN 3. H

INVENTOR:

ATTORNEY.

3 X A 8 A I I l/l/ L. w. CLAYBOURN Filed June 21, 1930 Jan. 9, 1934.

MACHINE FOR REDUCING PRINTING PLATES TO UNIFORM THICKNESS Jan. 9, 1934. w CLAYBQURN 1,942,592

MACHINE FOR REDUCING PRINTING PLATES 'IO U IFORM THICKNESS Filed June 21, 1930 10 Sheets-Sheet 9 Jan. 9, 1934. w CLAYBOURN 1,942,592

MACHINE FOR REDUCING PRINTING PLATES TO UNIFORM THICKNESS Filed June 21, 1930 10 Sheets-sheet 10 A TTOKVIJY.

Patented Jan. 9, 1934 MACHINE FOR REDUCING PRINTING PLATES TO UNIFORM THICKNESS Leslie W. Claybourn, Milwaukee, Wis.

Application June -21, 1930. Serial No. 462,884

8 Claims. 29-33) My present invention is an improvement upon the invention shown, described and claimed in Letters Patent of the United States No. 1,738,759, granted me December 10, 1929, for machine for reducing printing plates to uniform thickness.

In the present exempliiication of my invention the printing plate to be operated upon is caused to travel with relation to the cutting devices, although if desired, the cutting devices may be caused to travel with relation to the printing plate being operated on without departing from the spirit of my invention, as set forth in the accompanying claims.

In the present exemplification of my invention the printing plate is supported upon a bed which is adjustableto elevation on a reciprocating carriage, which is caused to reciprocate by fluid pressure means, and the reciprocations are controlled by means, more fully shown and described in my aforesaid patent.

It is the object of my invention to provide novel means to convey the chips produced from the back of the-printing plate.

It is the object of my invention further to provide novel rotary'cutter .means acting upon the back of the printing plate for reducing the printing plate to proximate uniform thickness;

further, to provide rotary cutter means for reducing the printing plate to proximate uniform thickness and shaving means to shavethe back of the printing plate to finished uniform thickness and conveyor means for conveying the chips produced by the rotary cutting means away from the portions of the printing plate acted on by the shaving means'before such action upon said portions by said shaving means.

It is the object of my invention further to provide cutter means for the back of a printing plate, presser means for the printing plate in front of said cutter means, and novel means for protecting said presser means from chips produced by said cutter means; and, further, to provide novel means for moving said chips.

It is the object of my invention further to provide rotary cutting means acting upon the back of a printing plate, a conveyor for the chips produced by said cutting means, pressure means between said rotary cutting means and said conveyor, and a deflector between said rotary cutter means and said conveyor for directing the chips away from the printing plate and said means toward said conveyor. I

It is the object of my invention further to provide an even support for the face of the printing plate and novel presser means acting on the back pressure of the printing plate to press all portions of the printing face of the printing plate into parallelism with said even' support, and cutter means acting on the back of the printing plate while so pressed for producing a printing plate of uniform thickness.

It is the object of my invention further to provide rotary cutter means and shaving means successively actingon the back of the printing plate for reducing the same successively in thickness and a rotary spirally arranged conveyor between the rotary cutter means and the shaving means for conveying the chips taken from the back of the printing plate by the rotary cutter means away from the sphere of action of the shaving means; and, further,-to provide presser'means acting on the back of the printing plate between the conveyor and the shaving means.

i It is the object of my invention further to provide novel means in a machine of the character described for holding the printing plate toward its support to counteract buckling of the printing plate clue to end pressure upon the printing plate in the feeding operation; and, further, to provide novel means for lubricating the back of so the printing plate.

The invention'will be further readily understood from the following description and claims, and from the drawings, in which latter:

Fig. 1 is a front elevation of my improved device, showing the carriage at the beginning of its feeding movement in full lines and atthe end of its feeding movement in dotted lines.

Fig. 2 is an end elevation of the same, viewed from the infeeding end.

Fig. 3 is a plan view of the same. I v

Fig. 4 is a rear elevation of the same, partly broken away. I

Fig. 5 is a vertical longitudinal section oithe same, taken on the line 5-5 of Fig. 2.

Fig. 6 is an enlarged vertical longitudinal section, taken on the line 6-6' of Fig. 11, showing the cutting and pressing means of my improved device, and partly broken away.

Fig. 7 is an enlarged vertical section, taken on the line 6-6 of Fig. 11, showing the rotary cutter and its associated pressing means, and partly broken away.

Fig. 8 is a sectional detail view, taken on the section line 8-8 of'Fig. I0.

Fig. 9 is a rear elevation, partly broken away, showing the mounting of the stationary knife.

Fig. 10 is a bottom view of the cutting and pressing means, partly broken away, and partly in horizontal section on the line 10-'-10 01' Fig. 6.

Fig. 11 is a vertical section, taken in the plane of the line 11-11 of Fig. 6, showing the rotary cutter head.

Fig. 12 is a vertical cross-section, taken in the plane of the line 12-12 of Fig. 6, showing the chip conveying means.

Fig. 13 is a detai sectional view of onecf the roller mountings, taken on the section line 13-13 of Fig. 10.

Fig. 14 is a plan view of the cutter head laid out in plane.

Fig. 15 is a rear elevation of the hold-down means, partly in vertical section on the line 15-15 of Fig. 3.

Fig. 16 is a sectional detail view of the same, taken in the plane of the line 16-16 of Fig. 15.

Fig. 1'7 is a sectional detail view of the same, taken in the plane of the line 17-17 of Fig. 15.

Fig. 18 is a cross-sectional detail view of the handle mounting for the hold-down mechanism, taken on the line 18-18 of Fig. 10.

Fig. 19 is a cross-sectional detail view of the sectional roller mounting means, taken on the line 19-19 of Fig. 10; and,

Fig. 20 is a sectional detail view of the driving means for the conveyor, taken on the section line 20-20 of Fig. 4, and partly broken away.

In the present exemplification, the frame 21 of the machine comprises a base 22. A carriage 23 is arranged to reciprocate in the frame, the frame being provided with guideways 24 for guiding the carriage, and the carriage having complemental guideways 25. (Figs. 2, 4 and 11.)

Suitable means are provided for causing reciprocation of the carriage, this reciprocation being instanced as caused by a fluid under pressure, for instance oil, received under pressure into a cylinder 2'7 on the frame (Fig. 5), for actuating a piston 28 in the cylinder, the piston being on 'a piston-rod 29. The carriage is provided with a bracket 30 to which the piston-rod is secured.

Suitable -fluid pressure creating and control means for the oil are provided. Thus a casing 33 (Figs. 2 and 4) is fixed to the frame and contains a suitable oil reservoir and a suitable pump for placing the oil under pressure, the oil under pressure being conducted from the pump through

pipes

34, 35, communicating with the respective ends of the cylinder 2'7, these pipes being alternately employed as pressure pipes and as return pipes for return of the oil to the reservoir, depending on the direction in which it is intended to move the carriage.

The direction of flow of the oil is controlled by means of suitable valves in a valve casing 37 (Figs. 2 and 4), the valves having connection with a valve operating rod 38 arranged to reciprocate in the valve casing and to be operated by an arm 39 having articulation therewith, the arm 39 being fixed to a shaft 40 journaled in bearings 41 in the base and having an operating arm 42 fixed thereto. An operating handle 43 on the operating arm is provided with suitable means for positioning the operating arm in neutral position or for travel of the carriage in either direction. (Figs. 1 and 2.)

The pump is actuated by an electric motor 45 supported on the base, the rotor of which has drive connection with a shaft 46 journaled in the base by means of a sprocket chain 47, a suitable drive chain 48 operatively connecting the shaft 46 with a shaft 50 connecting with the pump. (Fig. 4).

The means hereinbefore described, as well as the means for controlling the pressure of the oil and the feed of the carriage are the same as corresponding parts more fully shown and described in my aforesaid patent.

The adjustment between the carriage and the cutters for determining the thickness of the finished printing plate is shown accomplished by adjustment of the support for the printing plate. The printing plate. instanced at 55, is supported on a bed 56, which is adjustable up and down toward and from the cutters, between end guides 57, 58, and side guides 59, 60, on the carriage. (Figs. 5, 11 and 12.)

The bottom of the bed is provided with inclined guideways 62 coacting with inclined guideways 63 on a slide 64 guided in longitudinal guideways 65 on the carriage, and forming a wedge between the carriage and the bed, for raising or lowering the bed according to the direction of the longitudinal movement of the wedge. (Figs 5, 6 and 12) Longitudinal movement of the wedge is accomplished by means of a screw-rod 66 which is threaded in a threaded bearing 67 on the slide and is rotatable in a bearing 68 on the carriage, the screw being held endwise in said bearing, as by a gear 69 and a collar 70. The gear 69 is suitably operated by means of a handle 71 operatively connected therewith. (Figs. 1, 2, 5,11 and 12.)

The means for adjusting the elevation of the bed and for indicating such adjustments are as more fully shown and described in my aforesaid patent.

The carriage is provided with a stop 73, against which the edge f the printing plate is arranged to be placed. (Figs. 1 and 5.).

The cutting devices are exemplified as a rotary cutter-head '75 and a shaving knife 76.

. (Figs. 6' and 10.)

The rotary cutter-head is exemplified as comprising cutting teeth 77 which are arranged spirally about the cutter-head in a plurality of spiral paths which cross each other, one of which is describedop a slight helical angle about the axis of rotation of the cutter-head and the other of which is on a pronounced helical angle with relation to said axis. This is aptly illustrated in Fig. 14, which represents the cutter-head laid out inplane, and in which a represents the axis of rotation of the cutter-head, the line b represents one of said helical angles, and the line 0 represents the other of said helical angles. The cutting edges 78 of said teeth are parallel with the axis of rotation of the cutter-head, as indicated by the line 11. The cutter-head is rotated in the direction of the arrow e. The teeth comprise bodies '79 received in sockets 80 formed in the cutter-head. This cutter-head is a cylindrical body mounted on a shaft 81, to which it is connected for rotating therewith, as by a key 82. (Fig. '11.) The bodies of the teeth are provided with forward rabbets 83, which preferably extend slightly past the median lines of the teeth, and with receding outer ends 84 forming relief spaces for the teeth. The bodies of the teeth are shown round in cross-section, and are firmly secured to said head as by being firmly pressed into said sockets to prevent turning or release of said teeth. The inner walls of said sockets are prosired.

The construction and arrangements of the teeth are such that a minimum number of the teeth act simultaneously on the back of' the 15:)

cutting. i

printing plate for reducing the resistance of the The cylindrical paths of the teeth overlap each other, and-all of the teeth act upon the back of the printing plate for cutting the same for reducing the printing plate to proximate uniform thicmess by means of a large number of teeth which act separately upon the back of the printing plate for cutting the back of the printing plate with expenditure of a minimum amount of power and in separated paths for producing short plate.

chips which are readily removed in my improved device.

The forward faces 36of the teeth slant outwardly away from a radial plane 8'7 intersecting the inner ends of said faces, the slant of said forward faces being outwardly away from said radial plane so as to cause outward thrust of the chips, by centrifugal force after they have been separated from the back of the printing plate and in a path tangential to the circular path of the cutting teeth, whereby thrust of the chips from the back of the printing plate is aided.

The shaft 81 is provided with

bearings

91, 92, 93, 94, shown as roller bearings in upwardly extending

sides

95, 96, at the respective sides of the carriage, the said sides forming part of the frame of the machine. (Fig. ll.)

The cutter-head rotates in a cross-channel 101 of a cross-housing 102 located at the upper ends of the side. walls. (Figs. 6, 7, 10 and 11.) The cross-channel has a forward wall 103 and a rear wall 104, the inner faces of which are preferably on arcs substantially concentric to the cutterhead, and surround the major portion of the cutter-head. The crossechannel has a lower opening 105 through which the cutting edges of the cutter teeth move for .coaction with the back of the printing plate. The lower ends of said walls extend to within a short distance of the back of the printing plate.

The channel is also provided with an upper cross-opening 106, through which the chips cut from the back of the printing plate by the cutterhead are projected by the rotative action of the cutter-head and the coaction of the cutter-head with its teeth and the rear wall of the crosschannel, which thrust and guide the chips between the cutter-head and said wall and through the upper cross-opening toward a cross-trough 107 in said cross-housing. This cross-trough is formed by a lower wall 108 of the cross-housing which separates the trough from the printing (Figs. 6, 7, 10 and12.) with its cutting teeth and the walls of the crosschannel form a pump for drawing the chips away from the back of the printing plate and thrusting them into the conveyor alongside the cutterhead.

There is a cross-web 109 between the trough and the cross-channel for the cutter-head, the upper face 110 of which preferably slants downwardly and forwardly from the opening 106 in the cross-channel to the opening 111'in the trough, and forms a deflector for the chips for guiding the chips toward the trough. (Figs. 6 and 7.)

The lower portion of this cross-web is formed with an upwardly extending recess 115 between the trough and cross-channel of the cutter-head.

The cross-housing is provided with a front wall 116 forming part of the wall of the crossopeninglll for the trough. There is a space 111 between the cross-opening 106 for the cross-channel of the cutter-head and the opening 111 for The cutter-head the trough 10"], forming a projecting space through which the chips are projected from the cutter-head to the trouglsi. (Fig. 6.)

A. cover 118 is provided for said space and is releaslblv secured in place on the housing by bolts 119 received through holes in the cover and threadedin threaded holes120 in the crosshousing. The bolts are provided with manually operable heads 121 for readily releasing and replacing the cover. (Figs. 6, l1 and 12.)

A conveyor 125 is rotatable in the trough (Figs. 5, 6, 10 and 12.)

It comprises a shaft 126 journaled in a bearing 127 in the cross-housing and in a bearing 128 on a cap 129 rigidly secured to the upright wall 95. A sleeve 130 is located in the side wall 95 for spanning .a hollow 131 in said side wall and forming a continuation of the trough. The outer end of said sleeve communicates with a. spout 132 into which the chips are received from the trough. The spout slopes downwardly and-outwardly away from the side wall for directing the chips away from the machine.

The shaft 125 is provided with a conveyorblade 133. This conveyor-blade is exemplified as a continuous blade arranged spirallyabout the shaft 126, although it isobvious that the conveyor blade need not be continuous, but that the conveyor may include a number of sequentially operating blades. (Figs. 6, 10 and 12.)

The conveyor rotates in the direction of the arrow ,f, (Fig. 6) and the spirals are so arranged as to push the chips toward the spout. The blade structure of the conveyor preferably extendsthroughout the length of thetrough for moving the chips through the trough, including the sleeve 130, and into the spout. The chips are conveyed in a direction crosswise of' the path of rotation of the cutter-head.

The cutter-head is driven by means of a belt 135, which may be in the form of a silent link chain, received over a pulley 136 fixed to the shaft of the cutter-head and a pulley fixed to the shaft 46. These pulleys are shown in the form of sprocket wheels coacting with the toothed chain. The pulley 136 is, located between the

bearings

91 and 92 of the cutter-head shaft. (Figs. 4, 10 and 12.) i

The conveyor shaft is driven by means of a pinion 138 fixed to the outer end of the cuttershaft, which meshes with a pinion 139 rotatable on a stud-shaft 140 secured to the cap 129, a gear 141 being fast with the last-named pinion and meshing with a gear 142 fast on the conveyor shaft 126. These gears may be covered by a gear cover 143. Figs. 11. 12 and 20.)

The shaving knife 76 is shown slantingly mounted on a supporting face 145 of a yoke 146.

The respective ends of the yoke are mountedv upper edge of the shaving lmife for adjusting the shaving :knife toward the bed. Adjusting bolts 151 are threaded in the shaving knife for adjusting the shaving knife away from the bed. Rotations of the

bolts

149, 150, adjust the shaving if to knife toward and from the plane of the bed, the knife being clamped in adjusted positions by the clamp screws 148. (Figs. 6 and 9.)

Presser means are. provided for bearing upon the printing plate in adjacency to the cutting means. There is furthermore a hold-down device for holding the printing plate toward the bed and preventing bending or buckling thereof when the printing plate is submitted to the endwise resistance of the cutting means and the presser devices in adjacency thereto.

This hold-down device has lubricating means in connection therewith for lubricating the back of the printing plate and aiding in reducing resistance between the presser means, the cutting devices and the printing plate. means form a wiper for wiping the back of the printing plate.

This hold-down device is also preferably 'arranged for being moved out of the way of the bed for proper positioning and manipulation of the printing plate.

The presser means include sectional pressing means arranged crosswise of the bed in advance of the respective cutting devices for pressing all portions of the printing surface of the printing plate upon the supporting surface on the bed.

The prin ing surface "155 of the printing plate may be uneven in places and for instance contain hollows 156. (Fig. 5.) The sectional pressing means are so arranged as to iron out or press all portions of the printing surface upon or parallel with the supporting surface of the printing plate in advance of the action thereon of the respective cutting devices, the cutting devices acting to produce a backing face for the printing plate which is parallel with said supporting surface in order to produce a printing plate which is of even thickness throughout its printing portions.

The hold-down device exemplified comprises a frame 161 which has bearings 162. A post 163 extends upwardly from the frame of the machine and is provided with bearings 164. A rocker-rod 165 is received through these bearings, the holddown frame being arranged to swing up and down on the pivotal connection thus formed. (Figs. 2, 3, l0 and 15.)

The axles of hold-down rollers 168 are journaled in bearing-blocks 169. The upper ends of these blocks are provided with lugs 170 received in slots 1'71 in the lower ends of the sides 172 of the holddown frame. Retaining blocks 173 are secured to the lower edges of said sides, and are received under said ears for holding said bearing blocks to the hold-down frame. (Figs. 10, 15 and 18.)

Springs 174 are received in sockets 175 in said sides above the respective bearing blocks, the'ends of said springs being respectively received against said bearing blocks and the lower ends of adjusting bolts 176 threaded in threaded holes 177 in said sides, for pressing said bearing blocks and the rollers therein toward the bed. Adjustment of the bolts adjusts the tension of the springs. (Figs. 6 and 18.)

The lugs 170 are received against the retaining blocks 173 for limiting downward movements of said rollers and normally positioning said rollers as to bear upon the back of the printing plate. The bearing blocks are pressed upwardly by the printing plate in order to exert pressure upon the printing plate. The bearing blocks reciprocate up and down between the retaining blocks and the lugs 170 reciprocate up; and down in. the

slots 1'11.

Latching means are provided between the The lubricating swinging end of the hold-down: frameand the main frame of the machine for holding therollers in position for coaction with the printing plate. (Figs. 2, 15, 16 and 17.)

A post 181 extends upwardly from the. frame and has a hollow 182 therein. A retaining pin 183 is in said hollow and has a retaining edge 184 and

inclined sides

185, 186, sloping toward said edge. The retaining pin is fixed in said arm.

A latch 191 has a latching hook 192 which coacts with the'retaining edge 184 of the retaining pin 183, which forms a catch for maintaining the hold-down bar in down position.

This latch has a bearing 193 about a rocker-pin 194, the latch being pivoted on said pin. The pin 194 has

eccentric bushings

195, 196, fixed thereto. (Fig. 16.)

The bushings are journaled respectively in'

bearings

197, 198, in a bracket 199 on the holddown frame. A manipulating handle 200 is fixed to one of said eccentric bushings for fixing the rocker-pin 194 and said handle together. (Figs. 15, 16 and 17.)

The latch is reciprocable in a socket 201 in said bracket, and is normally urged toward the catch 183, and is so held as to coact with the inclined faces 185, 186, for being automatically led, under the retaining edge 184.

A' stem 202 has a head 203 forming a shoulder 204. The sides of the pin are flattened as shown at 205 for being received in a slot 206 in the latch 191, the fiat sides of the pin coacting with the side walls of the slot for preventing turning of the pin. The head is received in a hole 207 in the inner wall of the socket 201. (Figs. 15, 16 and 17.)

The pin extends through a hole 208 in the outer wall of the socket 201 and has a handle 209 fixed to its outer end. A spring 210 is received about said stem between the outer wall of said socket and the latch 191, for normally urging the latch inwardly for positioning said latch normally in correct relation for coaction-with the inclined faces 185, 186.

If it is desired to connect the hold-down frame with the main frame of the machine, the hand of the operator is arranged to be received about the inturned portion 211 of the handle 200 and the handle 209 (Fig. 1) for pulling the latch 191 outwardly and holding the eccentric support of the latch in position for lowermost positioning of the latch for ready reception of the hook thereon under the catch 183.

When the hold-down frame has been lowered, the handle 209 is released for causing full coaction between the hook 192 on the latch and the catch 183, and the handle 200 is raised for eccentric movement of the rocker pin 194 upwardly, and upward movement of the latch 191, (Fig. 16) for full engagement between the hook of the latch and the catch. The upward swinging movement of the handle 200 causes depression and locking of the hold-down frame to the main frame for positioning the hold-down rollers therein with relation to the printing plate.

Lubricating means for the printing plate are also shown mounted on the holdsdown frame. This in the present exemplification comprises an absorbent bar 215, for instance, a pad of felt, which extends crosswise of the frame and is received in a socket 216 of a bar 217 extending crosswise oi the hold-down frame and secured to said hold-down. (Figs. 6, 10 and 15.)

This lubricant bar may be termed a wiper and acts to lubricate the upper face of the printing 156 nesases 5 plate and to wipe foreign substances therefrom. Oil cups 218 are threaded in the upper threaded ends of holes 219 in the upper wall of the holddown frame and are arranged to feed oil through said holes and through coincident holes 220 in the bar 217 communicating with the slot 216 and feeding oil from said oil reservoirs to the lubricant bar 215.

The hold-down frame is provided with a bracket 221 fixed to the rocker-rod 165 and having a socket 222 in which a rod 223 is secured. (Figs. 2, 3 and 15.) A counterweight 224 has a hole 225 therethrough in which the outer end of the rod 223 is received. A set screw 226 is threaded in said counterweight, the inner end of said screw being arranged to clamp upon the rod for holding the counterweight in adjusted positions lengthwise on the rod for adjusting the counterbalance of said hold-down frame. A buffer 227, which may be a rubber block, is received in a socket 228 in the counterweight and is arranged to contact thepost 163 when the counterweight is in lowered position.

The presser means in rear of the rotary cutter-head are instanced as sectional presser shoes 231, shown arranged side by side across the bed, under a hood 232 fixed-to the infeeding end of the cross-housing 102, as in a rabbet 233 therein. The upper end of the hood is received against a shoulder 234 on the cross-frame. (Figs. 6, 7 and 10.)

A limiting bar 235 is secured to the inner side of the hood by screws and is provided with a recess 236 having a lower shoulder 237. Pivot blocks 238 have threaded shanks 239 received pivot blocks are fixed to said upper wall for positioning the pivots 240 in the pivot blocks parallel with the axis of rotation of the cutter-head. Nuts 241 are threaded over the threaded shanks and clamp the pivot blocks in place. (Figs. 6 and 7.) 1

Each of the presser shoes 231 is provided with a fork 242, the tines of which are received at the respective sides of the pivot-block, the pivotpin 240 being received through holes in said fork and in the pivot-block for pivoting the shoe to the pivot-block. (Figs. 7 and 10.) The upper face of the shoe is provided with a socket 245 and the lower face of the hood is provided with a socket 246 coincident therewith, a. spring 247 having its respective ends received ward pressures of the respective shoes upon the back of the printing plate, (Fig. 7) the shoes being in proximatesidewise arrangement extending across the entire width of the printing plate for pressing independently in closely neighboring paths crosswise of the printing plate for ironing out and smoothing the printing face of the printing plate including irregularities therepresser shoes. The front ends of the respective shoes are received in a cross-recess 249 in the rear wall 104 for positioning the presser shoes 231 close to the rotary cutter-head. (Figs. 6, 7 and 10.)

' bolt 283.

A presser roller 251 extends crosswise of the machine in front of the rotary cutter-head and is shown located in the recess 115 under the cross-web 109 of the cross-housing. The respective ends of this roller are provided with axles received respectively in hearings in bearingblocks 252 provided with lugs 253 and held to the respective sides of the cross-housing by retaining blocks 254 secured to said sides. The proximate faces between said retaining blocks and the .side walls of the recess 255 in,which said lugs 253 slide form guides for up and down movements of the bearing blocks, downward movements of the bearing blocks being limited by the lugs 253 coacting with the retaining blocks 254.

(Figs. 6, 10 and 13.)

Each of the bearing blocks is provided with an extension 256 slidable axially in a bore 257 in the side of the cross-housing, said bore having a shoulder 258 at its irmer end, from which a countersunk bore 259 extends upwardly. (Fig. 13.) A stem 260 is fixed in the bearing-block and extends into said countersunk bore for being guided by the walls of said countersunk bore. A helical spring 261 is received in the bore 257 between its shoulder 258 and the end of the extension 256. for normally pressing the bearing blockand the roller journaled therein toward the printing plate for bearing upon the printing plate and holding it close to its bed.

Immediately in rear of the shaving. knife 76 there is a series of sectional presser rollers 265 located in close arrangement side by side across the bed for independently bearing upon the printing plate and pressing all parts ofthe sur-- faceof the printing plate toward the bed for again ironing out and straightening the printing face of the printing plate against its support in close proximity to the shaving knife, in order that, when the shaving knife acts upon the back of the printing plate thus pressed, the printing plate will receive its finishing cut for producing a finished printing plate of equal thickness throughout its printing portions. (Figs. 6, 10 and 19.)

Each of these presser rollers is joumaled on a pin 266 located in bearings in tines of a fork 267 of a bearing block 268, this bearing block being square in cross-section and provided .with a lug 269 reciprocable in a recess 270 and coacting with a shoulder 271 for limiting descent of said bearing block and the roller mounted therein. (Fig. 19.)

A cross-bar 275 is located in a rabbet 276 in the front wall of the cross-housing, being positioned by a shoulder"277. The cross-bar is secured to the cross-housing. The bearing-blocks 268 are mounted in recesses 278 in said cross-bar so as to reciprocate up and down but not to turn cal springs 284 are received'between the lower J ends of said adjusting bolts and the upper ends of the upward extensions 281 for pressing the roller blocks and the rollers thereon individually downward. I

Each of the roller blocks is provided with a .stem 285 fixed thereto received through said helical spring and guided axially in a hole in the Independent adjustment and independent movement is thereby permitted for each of the rollers 265. so as to obtain theproper pressure upon the various portions of the printing plate for holding down and flattening out the printing plate preparatory to action thereon on the back by the shaving'knife.

A presser roller 288 extends across the frame and is arranged to act upon the printing plate after action thereon by the shaving knife. (Figs. 6 and 8.) This presser roller is provided with an axle at each of its ends. Each of the axles is received in a bearing-block 289 provided with retaining lugs 290 slidable in a recess 291 in the cross-yoke for the shaving knife. A retaining block 292 is located at each side of the bearingblock and is fixed, the proximate faces of these retaining blocks and the opposite walls of the recess 291 form guiding faces for the bearingblock and its lugs, descent of the bearing-blocks being limited by the limiting lugs 290 and the retaining blocks 292.

Each of the bearing-blocks is provided with an upward extension 293 axially movable in a bore 294 in the yoke, the end of the bore forming a shoulder from which a countersunk bore 296 extends, the bores having coincident axes. A stem 29? is fixed to the bearing-block and is slidable in said countersunk bore. A helical spring 298 is received about the stem in the bore 294, the respective ends of the spring bearing against said shoulder and the upper end of said extension for pressing the bearing-block and its roller downwardly upon the back of the printing plate. The roller 288 is received in a recess 299 extending crosswise of the machine in the lower face of the yoke 146.

In operation, the printing plate is placed on the bed against the stop 73, the hold-down device having been first moved into raised position. The hold-down device is then brought into down position for coaction with the printing plate, the same being brought into latched relation with the frame by manipulation of the handle 209 and into downwardly pressed relation with the frame by swinging of the handle 200 for drawing the hold-down device toward the bed.

The operating handle 43 is then shifted for causing travel of the carriage in cutting direction. The hold-down rollers 168 press upon the printing plate for pressing the printing plate upon the bed and for preventing buckling or bending of the printing plate, and the lubricating pad 215 bears upon the back of the printing plate for lubricating said back and wiping foreign substances therefrom.

The printing plate is next caused to move intocoaction with the rotary cutter-head, the knives of which are short separated knives arranged along spiral lines of different spiralities so that a minimum number of the knives act simultaneously upon the printing plate, and the knives move in overlapping cylindrical paths for cutting short chips from the back of the printing plate, the knives moving in coincident cylindrical paths for reducing the entire surface of the back of the printing plate into the same plane.

Prior to coaction of the rotary cutter-head with the printing plate, all portions of the back of the printing plate have been pressed by the Independent presser shoes 231 so as to iron out and press all portions of the printing surface of the printing plate upon the supporting surface on the bed, in order that when the knives of the rotary cutter-head shall have performed the cutting, the printing plate will have been reduced to proximate uniform thickness throughout its printing portions.

are moved away from the back of the printing,

plate so that they may not be pressed into the planed surface of said back by the presser devices subsequently acting upon the back of the printing plate or interfere with the finishing cut given the back of the printing plate by the shaving knife.

The chips produced by the rotary cutter-head are projected out of the housing in which the rotary cutter-head rotates through the opening 106 therein, and through the passage 117 between said opening and the'cross-trough 107, the chips being projected into said cross-trough and deflected thereinto by the lower wall 110 slanting toward said trough and the upper wall 118 and end wall 116 of said passage. The chips 'are thus brought into coaction with the conveyor 125 having the spiral blades 133, which are rotated and convey the chips laterally across the machine into the delivery spout 132.

A presser roller acts upon the printing plate between the rotary cutter and the conveyor for holding the printing plate to its bed during coaction of the printing plate with the shaving knife.

The short presser rollers 265 act upon the printing plate immediately in rear of the shaving knife '76, for pressing allportions of the printing surface of the printing plate into the same plane, in

order that after the printing plate shall have received its finishing cut by means of the shaving knife, the printing plate will have been reduced to uniform finished thickness throughout its printing portions.

After coaction of the shaving knife upon the printing plate, the printing plate is acted on by the presser roller 288 for holding the printing its printing portions at one passage between the printing plate and the cutting agencies, prevents bending or buckling of the printing plate, insures removal of the chips made by the rotary cutterhead away from the back of the printing plate, so that the subsequent operations upon the back of the printing plate in the machine will be free from interference by said chips, and provides simple andconvenient means for adjusting and manipulating the parts.

Having thus fully described my invention,

what I claim as new, and desire to secure by Letters Patent, is:

1. In a machine of the character described, the combination of a rotary cutter-head for cutting the back of a printing plate, a rotary conveyor alongside said rotary cutter-head, coacting walls for said rotary cutter-head and said rotary conveyor respectively, aponnecting web between said walls, said walls and said connecting web. forming a downwardly opening recess extending lengthwise of said cutter-head between said walls, and presser meansfor'the printing plate in said recess. I i a 2. In a machine of the character described, the combination of a bed for supporting a printing plate, a rotary cutter-head, a shaving knife and presser'means complemental to said rotary cutter-head and said shaving knife, a hold-down frame, hold-down rollers therein, means for movably mounting said hold-down frame relatively to said bed, and latching means for said hold-down frame.

3. In a machine of the character described, the combination of a bed for supporting a printing plate, a frame, plate cutting means mounted in said frame complemental to said bed, a holddown frame, pivotal connection between one end of said hold-down frame and said first-named frame, and latching means between the other end of said hold-down frame and said firstnamed frame, said latching means comprising a handle and eccentric means operated by said handle for drawing said hold-down'frame toward said first-named frame.

4. In a machine of the character described, the combination of a frame, a bed for supporting a printing plate, plate cutting means on said frame complemental to said bed, a hold-down frame, hold-dawn rollers therein, a lubricating wiping pad on said hold-down frame, pivoting means between one end of said hold-down frame and said first-named frame, latching means between the other end of said hold-down frame and said first-named frame, said latching means comprising a latching arm on one of said frames and a coacting catch therefor on the other of said frames, and a handle and eccentric means for one of said coacting latching parts having operative connection with said handle for drawing said hold-down frame toward said firstnamed frame.

5. In a machine of the character described, the combination of a frame, a bedv for supporting a printing plate, cutting means in said frame complemental to said bed, a hold-down frame, hold-down rollers therein, a lubricating wiper in said hold-down frame, pivoting means between one end of said hold-down frame and said first-named frame, a latching arm on the other end of said hold-down frame, a coacting catch therefor on said first-named frame, an eccentric means for said latching arm, a handle for 6. In a machine of the character described,

the combination of a bed for a printing plate, a rotary cutter-head complemental thereto, and presser means for said printing plate in rear of said cutter-head comprising pressure shoes arranged side by side, independent pivot means for said shoes arranged side by side, independent spring pressure means for said respective shoes arranged side by side, and means for limiting movements of said shoes toward said bed. 7. In a device of the character described, the combination of a support for a printing plate, a rotary cutter-head coacting therewith, an arcuate wall about the rear of said rotary cutterhead, a hood extending rearwardly from said wall, a series of presser shoes located side by side along the length of said rotary cutter-head in rear of said arcuate wall under said hood, pivot means under said hood between said hood and the rear portions of said shoes, and springs between said hood and said shoes for pressing said shoes independently toward said support. 8. In a device of the character described, the combination of a support for a printing plate, a rotary cutter-head coacting therewith, an arcuate wall about the rear of said rotary cutterhead, a hood extending rearwardly from said wall, a series of presser shoes located side by side along the length of said rotary cutter-head in rear of said arcuate wall under said hood, pivot means between said hood and the rear portions of said shoes, said arcuate wall providedwith recesses for receiving the front ends of said shoes, and springs acting on said shoes to press said shoes independently toward said support. LESLIE W. CLAYBOURN.