US3292403A - Embossing mill registration locking device - Google Patents

Description

Dec. 20, 11966 H. M. LEWIS 3,292,403

' EMBOSSING MILL REGISTRATION LOCKING DEVICE Original Filed Oct. 22, 1962 4 Sheets-Sheet 1 {6W 190 9 aid Qua ATTORNEYS Dec. 20, 1966 H. M. LEWIS 3,292,403

EMBOSSING MILL REGISTRATION LOCKING DEVICE Original Filed Oct. 22, 1962 4 Sheets-Sheet 2 NW EATOR ATTO R'YFKS Dec. 20, 1966 H. M. LEWIS 3,

EMBOSSING MILL REGISTRATION LOCKING DEVICE Original Filed Oct. 22, 1962 var- 4.

4 Sheets-Sheet 3 ATTORNEYS Dec. 20, 1966 H. M. LEWIS 3,

EMBOSSING MILL REGISTRATION LOCKING DEVICE Origihal Filed Oct. 22, 1962 4 Sheets-Sheet 4 INVENTOR BY gww 9M aw ATTORNEY United States Patent 5 Claims. (Cl. 72-81) This application is a division of my copending application Serial No. 231,975, filed Oct. 22, 1962, now abancloned, and the present invention relates to apparatus for making embossing rolls, particularly to the making of female embossing rolls by engraving a cylinder with a cylindrical mill whose axis extends parallel to the axis of the cylinder and which has an axial length a number of times less than the axial length of the cylinder being engraved thereby.

As the term is used in the .art mill refers to a small cylinder, i.e., a cylinder which is short in axial length, and usually lesser in diameter, than the cylinder onto which its pattern is imposed. The design or pattern on the cylindrical surface of the mill is in relief so as to cause the pattern which is thereby engraved onto the cylinder to be in intaglio or recess. In other words, the mill is a small male roll, and the large cylinder engraved thereby becomes a female embossing roll.

In the past, large cylinders have been embossed by small mills, by rotating the cylinder, after it has been coated with an etching resist, in contact under extremely heavy pressure with the mill, side stepping the mill one contiguous strip at a time until the full face of the cylinder has its resist removed in certain areas by the protrusions on the mill so as to leave exposed metal areas on the cylinder. The cylinder was then etched in an acid 'bath to eat away the metal of the exposed areas to a desired depth. Recoating with resist and re-running of the cylinder and mill in greater pressure contact, followed by an etching was effected the necessary number of times to obtain the desired depth of the pattern in the resultant female embossing roll.

One of the problems with the prior art procedures just described, is that a tremendous amount of pressure on the mill, during the engraving thereby of the successive circumferential strips of the cylinder, was found to be essential to maintain traction and registration, i.e., to prevent slippage of the mill relative to the cylinder, under any circumstance. This is particularly true of the prior art when a fine or shallow pattern is to be engraved onto a cylinder by a short mill or when the cylinder is initially a fully hardened tool steel roll, i.e., hardened substantially its full depth, as opposed to a metal cylinder which is substantially softer than the hardened mill. Since the mill in the prior art procedures above described has been held, as best possible, in registration with the rotating cylinder mainly because of huge pressures applied between the mill and cylinder, there was always the chance of traction not being held but slippage resulting, even when the cylinder was relatively softer than the mill.

In many instances, there are required embossing rolls that will withstand the exceptional pressures necessary between two mated embossing rolls during operation thereof to emboss metallic strips or sheets. If the metal being embossed is uneven or irregular in thickness, the embossing rolls as made in accordance with the prior art practices above described, and as described in the Sunderhauf et al. Patent 2,662,002, will not necessarily withstand the shocks or other forces produced thereon. This disadvantage is due to the lack of a sufficient hardening depth of the embossing rolls. In other words, because such procedures require engraving the potential female embossing roll while it is relatively soft, then hardening thereof afterwards can only be done to effect a case hardening, as opposed to full depth hardening, because the latter may cause undesirable warpage or distortion due to the radial expansion and contraction incident to full depth furnace hardening for example. The only afterhardening treatment found to be practical, economical, and satisfactory in the Sunderhauf et al. procedures indicated above, is the 'well known flame hardening procedure whereby the engraved female embossing roll becomes hard only in the regions of its outer surface or skin, commonly known as case hardening. Because it is desirable for many known reasons to have the mating male embossing roll to be of not only the same substantial hardness as the female embossing roll, but also of the same type of hardness and steel, the male embossing roll of the Sunderhauf process is also only a case hardened steel.

In order to meet the demands for harder embossing rolls, i.e., ones that will not crush or otherwise be damaged during their operation of embossing metal sheets or strips, several procedures have been effected to allow the embossing rolls to be pre-hardened to any desired depth; for example as fully described and claimed in the Nelson Patent No. 3,048,512, and the Di Leo et a1. application entitled Engraving Mills and Making Embossing Rolls Therefrom, Serial No. 206,211, filed June 29, 1962, now Patent No. 3,214,310. In the Nelson patent just referred to, the first made embossing roll can \be pre-hardened to full depth before being engraved because the master pattern roller, which causes the desired engraving of the potential female embossing roll,

is co-extensive with that roll, and can accordingly be positively driven by rotation of the roll during the engraving procedure without any problem. For example, the shafts of the coextensive master pattern roller and the female embossing roll being engraved thereby can be directly geared together so as to maintain consistent registration and traction between the pattern roller and female embossing roll to prevent any possibility of slippage therebetween. This gearing is possible because of the coextensiveness of the pattern roller and embossing roll and their respective shafts or journals, but positively rotating a mill in response to rotation of a cylinder in a situation where the mill must be side stepped a number of times in order to fully engrave the desired pattern area on the cylinder poses many problems unobvious of solution, which the present invention overcomes.

In the above mentioned Di Leo et .21. application,

positive rotation of the mill in response to rotation of the cylinder being engraved thereby, is effected by initially causing conically pointed teeth or snags to protrude from the cylindrical surfaces at each end of the mill. These cooperate with relatively soft rings that are temporarily secured to the ends of the cylinder to be engraved, making apertures whereby the mill and cylinder are effectively geared together. This type of operation is fully satisfactory for full depth pre-hardened embossing rolls, but is limited to situations Where the pattern area of the embossing roll is coextensive to the pattern area on the mill. This disadvantage is overcome by the present invention.

It is therefore a primary object of this invention to provide apparatus for engraving an embossing roll, by a mill which is a number of times shorter than the embossing roll, while effecting a positive rotational drive of the mill during rotation of the cylinder being engraved thereby, and including a flexible shaft means for driving the mill, thus allowing side stepping of the mill without 3 changing the relative angular positions of the mill and cylinder.

Another object of this invention in conjunction with theforegoing object is to effect locking of the mill drive relative to the cylinder or potential roll drive whereby traction and consistent registration therebetween during engraving of the cylinder by the mill is positively maintained.

A further object in connection with the above objects to effect said locking is the provision of gear driving the mill in synchronism with the cylinder and side setting the mill without possibility of changing the relative angular positions of the mill and cylinder.

Other objects and advantages of this application will become apparent to those of ordinary skill in the art upon, reading the appended claims and the followingdetailed description of an embodiment of the invention, in conjunction with the drawings, wherein:

' FIGURE 1 is a front elevational view of the apparatus,

FIGURE 2 is an enlarged detailed view of a portion, partially in cross-section, of the right end of the front of FIGURE 1,

FIGURE 3 is a right end view'of FIGURE 2,

FIGURE 4 is a front elevational view, partially in cross-section, of a part of the mill holder of'FIGURE 1,

FIGURE 5 is a right end elevational view of FIG- URE 4 with parts broken away, and

FIGURE 6 is a right end view of FIGURE 1.

The novel apparatus according to this invention may be appreciated generally [from the FIGURE 1 front elevat-ional view. The cylinder to be made into a female embossing roll is designated 10. Though not required, the cylinder is shown as having its shafts or journals of stepped reduced diameter, with the central reduction 12 at each end being disposed on a bearing or .pillow block 14. To accommodate different shaft diameters on different size cylinders 10, each pillow block 14 may contain a diameter adapter insert 16. It will be understood that the shafts of cylinder rest in pillow blocks 14 on inserts 16 so that the cylinder may be rotated about its longitudinal axis.

At the left end of FIGURE 1, the smallest diameter portion 18 of the shaft of cylinder 10 is grasped as by any standard type of chuck 20 the axle of which is rotatably supported in the bearing stand 22 and which further connects to the bull or driving 'gear 24. Pillow blocks 14 and stand 22 are secured to the frame 26 of the machine, which includes a motor(not shown), preferably an electrical motor, and further driving means coupled to gear 24 for rotating cylinder 10 at a desired speed. Preferably, also, there are .pushbutton switches or the like to effect start and stop, as well as jog and reverse" as desired.

At the right hand end of FIGURE 1 the smallest shaft reduction or shank 28 of the cylinder is chucked, as shown in greater detail in FIGURE 2, by the main drive chuck 30 internally of which is disposed a tapered bushing 32 secured thereto and to shaft 28 by the pressure effected by screws -34. Bushing 32 is of the split ring type, with, for example, a $5 inch saw cut or the like, so that it may be drawn tightly against shaft 28 by tightening of screws 34. These screws engage the main chuck 3 0 also,-so any rotation of shaft 28 causes chuck 30 to rotate. Chuck 30 and a drive plate 36 are interconnected by a. drive pin 38 which includes a transversely extending pin or key 40 which is slidable in a slot 42 disposed in an emboss on the main chuck 30. The tapered end of drive .pin 38 extends into a slot in the drive plate 36, which is secured as by key 44 to a spindle or rotatable shaft 46. This shaft also extends leftwardly inside a steel bushing 48 in the main chuck to effect centering of the chuck and cylinder. shoulders against bushing 48 to effect a desired spacing between chuck 30 and drive plate 36 whereby axial movement of cylinder shank 28 is prevented. In a right- Shaft 46 also Ward direction, shaft 46 is rotated on bearings 50 at one end of a bearing box 51 secured to bracket 52, and on like bearings at the other end of that box. Bracket 52 has an underneath side slot which engages the longitudinal vertically extending bar or key 54 which is fixedly secured to the main bracket 56. By virtue of bracket base 55 v 'being aflixedly slidable in way 57 (FIGURE 6) in the bed or frame 26 axially of the cylinder, bracket 56 is movable leftwardly and ri-ghtwardly (as viewed in FIG- URES 1 and 2) to allow proper mounting of chuck 30 on shank 28 and spindle 46. The vertical position of the bearing bracket 52 along key 54 may be accurately adjusted by use of adjustable screw pins 58 against abutment 60 that fixedly protrude from brackets 52. Screws 62 extend through four respective slots in bracket 52 for securing that bracket to the main bracket 56, in the correctly adjusted position.

Drive plate 36 is secured to the main spur driving gear I 64 not only by key 44, but also by four hub screws 66 disposed 90 apart around an axle or shaft 46. Accordingly, as the cylinder shaft 28 turns, so turns the main driving gear 64. This gear in turn .meshes with an idler gear 68, which meshes with an upper drive gear 70.

Briefly, as will be further appreciated from FIGURE 1, rotation of gear 70 causes long shaft 72, flexible coupling 74, short shaft 76, and meshed spur gears 77 and 79" to rotate cylindrical mill 82 against the cylindrical surface of cylinder 10, in a positive driving manner.

In more detail, as is apparent from FIGURE 2 (see also FIGURE 6), shaft 72 is splined on diametrically opposing sides to receive respective biased keys 75. As indicated, these keys are retained in a housing 76 with a pair of springs 78 for each key 75 being effective to push the key inwardly. There is just enough pressure effected and maintained by jam nuts 80 to allow shaft 72 to move longitudinally of the keys 75. In other words, the keys may slide in the splines of shaft 72 as that shaft is moved axially in a manner later described. In order to cause retainer 76, and consequently keys 75 and shaft 72 to rotate in response to rotation of gear 70, a key chuck 82 is employed in conjunction with a sleeve 84 that sur- 1 rounds shaft 72. Chuck 82 extends internally of key retainer 76 on opposite sides of keys 75 to hold the outer parts of the keys vertical, and is fixedly secured to retainer 76 by means not shown, such as by bolts. Sleeve 84, which may be seamless tubing, is caused to rotate with chuck 82 by use of clamping plugs 86 each of which includes two matingly threaded parts extending inwardly from opposite sides of the chuck with arcuate cutouts tightly engaging and clamping the sleeve to the chuck. Sleeve 84, in turn, contains a keyway as does gear 70 into which a key 88 is disposed. Accordingly, rotation of gear 70 causes sleeve 86 to rotate, and due to clamping by plugs 86, chuck 82 in turn rotates and turns the key retainer 86 and its keys 75, elfecting rotation of shaft 72, while at the same time allowing for the lengthwise adjustability of shaft 72 relative to keys 75 and sleeve 84.

To maintain the proper height of shaft 72 and sleeve 84, the sleeve is mounted in bearings 90 which are re tained in a bearing box 92. As for the lower bearing box 52, the upper bearing box is'fixedly disposed on a bracket 94 which in turn is secured by screws 96 extending through respective slots into the main bracket 56, after being adjusted to the proper height along key 54 by adjusting pins 98 operating against protruding abutement 100. In order to allow for adjustability in sizes of gears that may be employed to accommodate different size mill and embossing roll diameters, and to effect the desired ratio of angular rotation therebetween to cause equal peri pheral speeds of the mill and roll, idler gear 68 is meshed to an adjustably positionable bracket 104. This bracket,

as is apparent from FIGURES 3 and 6 with its mounting slots 106 is mounted on main bracket 56 by bolts 108 in the vertically extending slots 110 of a rearward projection of the main bracket 56.

Reference is now made to FIGURES 4 and 5. In considering the coupling between shaft 76 and mill 82, it will be noted that the left end of shaft 76 has a reduced diameter portion 118 disposed internally of a bushing 112 that is secured to the gear housing 114 by lock screws .116. The reduced diameter portion 118 of shaft 76 contains a keyway, as does gear 77, with which cooperates key 120. Gears 77 and 79 are illustrated as having these gears being a 1:1 diameter ratio, and the latter is keyed, as by key 122, to the extended shaft portion 124 of the right end journal of mill 82, with bushing 126 being grippingly disposed therebetween. The larger diameter portions 128 on opposite ends of the mill shaft are disposed in slots 130 in respective end brackets 132 and 134. Bracket 132 has secured to it the previously mentioned gear housing 114, as by four bolts 136 through the respective slots in housing 114 which allow for vertical adjustment of the housing and gearing apparatus carried thereby. Spacer 138 is preferably disposed between bracket 132 and gear 77 to effect the desired horizontal disposition of the gear relative to gear 79, which may also be spaced from the bracket as by spacer 140. The right-angling, outwardly extending, upper end 142 of bracket 132 includes a vertically disposed aperture that carries a hold pin 144 which presses against the adjustable housing 114. This pin 144 has a rounded head against which cooperates the conical end of a screw threaded stud 146 for adjusting the vertical position of pin 144 and consequently of gear housing 114.

Pins 148, which extend through apertures near the lower end of each of the mill shaft brackets 132 and 134, hold the mill rotatably secured therein, hubs 150 cooperating with these brackets to prevent lateral movement of the mill 82.

Brackets 132 and 134, at their upper ends extend at right angles outwardly and engage at one side in a dovetailing manner the lower portion of a mill head holder 152, as shown in FIGURE 5 for bracket arm 142. At the other side, these bracket arms engage a retaining gib 154, which with its wedge shape cooperates via four threaded screws 156 to retain the mill brackets 132 and 134 securely in the holder 152. Head holder 152 has secured into each of its front and rear sides respective trunnions 158 on the protruding heads of which rockably rests mill head 160 via its arcuately grooved, depending arms 162. These arms are secured around trunnions 158 by lower brackets 164, which have an arcuate groove fitting the trunnion, screws 166 being utilized to hold parts 162 and 164 fixed together about trunnions 158.

However, before screws 166 are tightened, the lower plate or holder 152 is properly positioned relative to the horizontal so that mill 82 will in turn have its cylindrical surface absolutely parallel to the cylindrical surface of the cylinder being engraved thereby, by adjustment of oppositely threaded shafts 168 and 170. As shown in FIGURE 1, these shafts are respectively connected to meshed spur gears 172 and 174, the latter of which is rotatable by wheel 176. Turning of this Wheel in one direction causes lower plate 152, and accordingly mill 82, to rotate clockwise about trunnions 158, and vice versa.

Horizontally extending through base 178, which is supported on upper plate 160, is an arm 180, as may be noted in FIGURES l and 6. This arm has associated with it a mechanism 182 (FIGURE 1) by which adjustment can be made to change the position of the mill axis in a horizontal plane relative to the axis of cylinder 10. That is, in the FIGURE 1 view, the axle of mill 82 can be caused to be exactly in the same vertical plane as the axis of cylinder by adjusting the mill axis in a horizontal plane utilizing adjusting wheels 184 and 186 to cause pivoting movement in either of opposite angular directions about the vertical axis of base 178.

As shown in FIGURE 6, arm 180 extends both forwardly and rearwardly of its support 178. At its rear side, it curves downwardly and is pivoted about shaft 188, which pivot is secured in an upstanding shaft 190, the lower portion of which rests on a way or bed of frame 26, and has an integrally downwardly extending arm member 192 including a nut secured to a feed screw 194. The downwardly extending arm 192 also connects with a forwardly protruding arm 196 that rests and slides on a front way or bed of frame 26. To this forwardly extending arm 196 is pivotally secured a lever 198 lengthwise on which is adjustably positioned a variable weight 200. Lever 198 is coupled to the outwardly extending arm 180 at the top of the mill head by a turnbuckle 202 by which the distance between the lever and arm may be properly adjusted.

For purposes of adjusting the main bracket 56 properly in a forward and a rearward direction, use may be made of screws 204 and 206, thereby to align chuck properly with cylinder shaft 28.

As shown in FIGURE 1, mill 82 is there disposed toward the left end of cylinder 10. As previously indicated, it is desirable to side set or step this mill one circumferential strip at a time during the engraving of the complete face or axial length of the desired cylindrical surface pattern area of cylinder 10. Use may be made of two different registration systems to effect this function, one of these being the conically pointed, protruding registration pins 208, 210 and 212 (FIGURE 4) shown on mill 82 at its opposite peripheral ends inside of the pattern area 214 in which the desired design is engraved in relief. Pins 208 and 210 are circumferentially disposed and are utilized to aid accurate registration in a circumferential direction when the mill is stepped from one strip to the next contiguous one on cylinder 10. On the other hand, registration pin 212, which is preferably in line horizontally with pin 208 is employed to aid accurate registration in an axial direction whenever the mill is side stepped one strip; that is, in side stepping, pin 208 is disposed in the indentation made by pin 212 during the preceding circumferential strip.

The other registration system, which generally may not be as accurate as that effected by pins 208, 210 and 212, but which is mainly utilized for a coarse adjustment, involves feed screw 194. This feed screw is supported in bearings 214 (FIGURE 1) and extends at one end to be secured as by key 216 (FIGURE 6) to a large spur gear 218. This gear in turn meshes with pinion 220 which is rotatively fixed to an intermediate size spur gear 222. These latter two gears are disposed on a shaft which may be adjustable in position to accommodate different size gears, by supporting lever 224, which in turn is adjustably secured in the slotted adjustment bracket 226. For purposes of indexing mill 82 longitudinally of cylinder 10, a spring biased keeper or marker 228 may be secured to bracket 226 for engaging the teeth of gear 222. Rotation of this gear causes feed screw 194 to rotate, thereby moving nut 192 and accordingly the complete mill and head mechanism, lengthwise of cylinder 10, in either direction, according to the direction of rotation of gear 222. Correspondence of the number of teeth passing by finger 228 per revolution of gear 222 to the length of movement of mill 82 may be predetermined so that the mill can be side stepped without any problems of indexing.

In order to effect side stepping at all, it is necessary to raise mill 82 off the surface of cylinder 10. This can be readily effected by lifting the outer end of lever 198, thereby raising turnbuckle 202 and pivoting arm about shaft 188, bringing head 178 and mill 82 up off the surface of cylinder 10. Since mill 82 is coupled, however, to shafts 76 and 72, the latter of which is slidable along the keys in key retainer 76 and through the sleeve and housing 82, there must be some give in a vertical direction to the shaft coupling. This, in certain circumstances, may be efficiently effected by the resiliency of shaft 72 itself, thereby eliminating any need for a flexible coupling 74, in which case shaft 72 would be itself secured directly to the upper spur gear 77 as is shown for shaft 76. However, according to the degree of flexibility desired as well as the type of material from which shaft 72 is preferably made, it may be desirable to use flexible coupling 74. Since it may be necessary to be able to raise mill 82 at any point in its arcuate movement without losing the angular relation that then exists between the mill and cylinder, coupling 74 must be flexible in all directions without shafts 72 and 76 being rotatable one relative to the other. Any desired flexible coupling of this nature may be employed, and for exemplary purposes reference may be had to the couplings described relative to FIGURES 54 to 57 on pages 895 and 896 of Mechanical Engineers Handbook by Lional S. Marks (Fifth edition, Fourth printing, 1954), McGraw-Hill Book Company.

With the novel apparatus thus described, a method of this invention may be set forth in detail making reference to the apparatus as it is employed when necessary to effect certain steps of the method. It will be recalled that the primary object of this invention is to hold theposition of the mill relative to the cylinder being engraved thereby, with positive'traction and consistent registration, even if the cylinder is exceptionally hard, or the pattern quite shallow. As previously indicated, by this invention it is possible to fully harden cylinder 10 :before it is engraved by the mill, yet no slippage between the mill and the cylinder is to be expected since the mill is positively driven via gearing in response to rotation of the cylinder itself.

As a first step, after cylinder 10 is disposed in its pillow blocks 14 and properly chucked at both ends, mill 82 is caused to be disposed adjacent one end of cylinder 10. This may be accomplished by lifting lever 198 of FIGURE 6 while gear 222 is rotated until suchtime as mill 82 is at the desired end peripheral strip of cylinder 10, for example as shown in FIGURE 1.

Then, an acid etching resist, for example, an asphalt base wax as Well known in the art, is applied on the section of cylinder 10 just underlying the mill. After this is done, a relatively light Weight 200 is placed on lever 198 so that the pressure of the mill on the resist is can respondingly light. Cylinder 10 is then rotated, and via shaft 28, chuck 30, gears 64, 68, '70, shafts 72 and 76 with flexible coupling 74, and gears 77 and 79, mill 82 is positively rotated under pressure against the resist underlying it on the cylinder. When the cylinder has made one revolution, rotation thereof is stopped, and a close inspection is made of the cylinder to make' sure that no doubles exist and that the marks made in the resist by the conically pointed pins 208, 210 and 212 on the mill are sharp and well defined. As soon as this is all fully assured, a heavier weight 200 is applied to lever 198 and the cylinder is rotated one or more revolutions with the mill operating into the resist under the greater pressure. As the mill turns, any resist gathered thereon is continually wiped olf. The furthest protruding parts of the registration pins and relief design on the mill remove the resist and expose areas of metal on the cylinder clearly and in a well defined manner. When this is accomplished, lever 198 is lifted to raise the mill above the coated cylinder surface, and the mill is then side stepped, by rotation of gear 222, one circumferential strip, making sure that the mill registration pins are properly interaligned with their impression in the previous strip. The cylinder and mill are again rotated with the same amount of pressure between them during the engraving of the second circumferential strip, the inspection and resist wiping steps above-mentioned being effected during the engraving of this strip also.

Successive circumferential strips of cylinder 10 are engraved by the mill in a like manner, until the desired full 8 axial pattern length on the cylinder face is so engraved. Then, a trough (not shown) or the like, which is filled with a metal etching liquid such as a combination of nitric and acetic acids, is disposed underneath cylinder 10 and the cylinder rotated therein to effect an etching of the exposed metal areas in the cylindrical surface thereof to a depth desired for the first etching step. If this depth is not suflicient for the desired pattern, then the cylinder is engraved across its complete face, step,

by step, with mill 82 again, in the same manner as above discussed, but under heavier contact pressure so as to allow a second etching in an acid bath to effect a greater design depth.

When the cylinder is completely engraved, its pattern is in recess whereby the cylinder is a female embossing roll. Though designs can be embossed by the use of just the female embossing roll, it is generally more preferable to emboss from both sides using mated embossing rolls. A male embossing roll may be made from the female embossing roll in the same manner as fully described in the Sunderhauf et al. Patent 2,662,002, and it will be appreciated that the male embossing roll, like the female embossing roll made in accordance with this invention, is also pre-hardened to substantially full depth, or to any desired depth, in the same degree and manner. as for the female roll.

Theoretically, there is no need of any contact pressure between the mill and resist coated cylinder since the mill is positively driven, but in practice it is preferred to use some amount of weight 200. The amount of weight utilized, however, is nominal, and much, much less than the huge pressures heretofore required, for example as required with the above-mentioned Sunderhauf et al. apparatus. The invention eliminates any need for huge registration pressures while at the same time preventing any possible slippage between the mill and cylinder but maintaining full traction and consistent registration at all times during the engraving of the full cylinder face one circumferential strip after another.

It is therefore apparent that there has been provided.

by this invention an apparatus which accomplishes all of the objects, features, and advantages herein mentioned. It will be apparent, however, to those of ordinary skill in the art, after reading this disclosure, that other objects, features, advantages, and different embodiments of the invention may be effected, but it will be appreciated that the foregoing description is not intended to be limitative but only exemplary, the invention being defined by the appended claims. a

I claim:

1. Apparatus for making a first cylinder into an embossing roll by engraving that cylinder with a second cylinder of axial pattern length an integral number of times less than the desired axial pattern length for the first cylinder, comprising:

means for rotatively supporting said first cylinder,

means for rotating said first cylinder, and

means coupled to the said first cylinder rotating means for drivingly' rotating the said second cylinder in locked synchronism with rotation of the first cylinder with cylinder axes parallel,

said second cylinder-- driving means including flexible shaft means for carrying said second cylinder and for allowing separation of the axes of said cylinders for disengaging the said cylinders and means for allowing during said separation relative movement between said cylinders in an axial direction while maintaining circumferential registration between said cylinders.

2. Apparatus as in claim 1 wherein the flexible shaft means for driving said second cylinder includes a flexible coupling together with a driven shaft coupled thereto and extending parallale to the cylinder axes,

and a gear for rotating said driven shaft and thereby said second cylinder, the means for allowing relative axial movement between said cylinders including means for allowing such movement between said gear and shaft. 3. Apparatus as in claim 2 wherein said shaft is lengthwise slidably keyed to said gear.

4. Apparatus for making a female embossing roll from a journalled first cylinder of given diameter and axial face dimension, comprising:

a cylindrical mill that has a diameter which is related to the diameter of said cylinder substantially by a whole number and which has a pattern in relief on its cylindrical surface,

one axial end of said pattern including a plurality of conically pointed circumferential disposed registration pins and the other such end including at least one conically pointed registration pin aligned axially with one of the said circumferential pins,

the axial length of said mill being approximately 1/ Nth the axial length of said cylinder,

means for rotatively supporting said cylinder by its journals,

means for rotating said cylinder via one of its journals,

shaft means coupled at one end to said mill to effect rotation thereof when the shaft means is rotated,

gear means coupled between said shaft means and the other journal of said cylinder for causing said mill to be rotated in locked synchronism with said cylinder a whole number of times per revolution of said cylinder,

said gear and shaft means being relatively slidable so that the shaft means can be moved axially the length of the desired pattern area on the cylinder, means in said shaft means adjacent said one end thereof for allowing flexibility of said shaft means so that said mill can be separated from the cylinder without possibility of changing or loosing any of the relative angular relationships between the gear means, shaft means, mill and cylinder,

means for so separating said mill and cylinder a predetermined amount,

and means for axially moving said mill said 1/Nth distance parallel to the cylinder axis while the mill and cylinder are so separated during which time said shaft means moves relative to said gear means in the same direction.

5. Apparatus as in claim 4 wherein said shaft means includes a shaft having a spline from near said flexibility allowing means to the other end of said shaft, there being a biased key fixed to rotate with said gear means and slidably coupled to said spline.

References Cited by the Examiner UNITED STATES PATENTS 250,209 11/1881 Crane 72 s5 398,243 2/ 1889 Ferguson 72-85 2,661,526 12/1953 Bruegger 72--84 2,662,002 12/ 1953 Sunderhauf 76-107 FOREIGN PATENTS 203,165 10/ 1908 Germany.

CHARLES W. LANHAM, Primary Examiner.

H. D. HOINKES, Assistant Examiner.

Claims (1)

1. APPARATUS FOR MAKING A FIRST CYLINDER INTO AN EMBOSSING ROLL BY ENGRAVING THAT CYLINDER WITH A SECOND CYLINDER OF AXIAL PATTERN LENGTH AN INTEGRAL NUMBER OF TIMES LESS THAN THE DESIRED AXIAL PATTERN LENGTH FOR THE FIRST CYLINDER, COMPRISING: MEANS FOR ROTATIVELY SUPPORTING SAID FIRST CYLINDER, MEANS FOR ROTATING SAID FIRST CYLINDER, AND MEANS COUPLED TO THE SAID FIRST CYLINDER ROTATING MEANS FOR DRIVINGLY ROTATING THE SAID SECOND CYLINDER IN LOCKED SYNCHRONISM WITH ROTATION OF THE FIRST CYLINDER WITH CYLINDER AXES PARALLEL,

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