US3425303A

US3425303A - Method and apparatus of producing relief pattern

Info

Publication number: US3425303A
Application number: US583556A
Authority: US
Inventors: Lawrence G Buckley
Original assignee: Welsh Panel Co
Current assignee: Welsh Panel Co
Priority date: 1966-10-03
Filing date: 1966-10-03
Publication date: 1969-02-04
Anticipated expiration: 1986-02-04
Also published as: DE1621780A1; SE311845B; DE1621780C3; GB1159734A; DE1972835U; DE1621780B2

Description

Feb. 4, 1969 G. BUCKLEY 3,425,303

METHOD AND APPARATUS OF PRODUCING RELIEF PATTERN Filed Oct. 3, 1966 JNVE'N'T'OR BY Fl 3- W AH-bys.

Lawrence G.Buck1ey United States Patent Office 3,425,303 Patented Feb. 4, 1969 13 Claims ABSTRACT OF THE DISCLOSURE A. method of producing a design in relief as part of the surface of an embossing element comprising preparing a master design in two dimensions on a pattern surface, scanning the pattern surface with a medium sensor passed over it in successive adjacent traverses, and with signals produced by such sensor controlling the cutting of a work element with a cutting tool, whereby the work element is cut away to reproduce in the work element a design in three dimensions related to the master design appearing on the pattern surface. The third dimension of the design reproduced is the projection of such design from a background level in the work element.

This invention relates to a method and means for producing a design in relief on a work surface, through cutting away of the surface. More particularly, the invention concerns the reproduction through such cutting of a work surface of a design corresponding to a design prepared on a master pattern. The word design as used herein is used in its broadest sense, and is intended to cover within the definition thereof any plan, outline or shape.

This invention is based on the discovery of a need for apparatus and method for reproducing in a work surface a design which corresponds to a prepared design carried on a pattern surface. Procedures proposed in the past for cutting such a design generally may be characterized as being time consuming, with results dependent to a large extent upon the skill of the particular operator. With conventional procedures it has been virtually impossible to reproduce in a workpiece a design which with respect to at least some of its proportions bears a specific relationship to a design prepared on a master pattern. As a result, the duplication of a particular type of workpiece, or the modification of an already prepared workpiece according to a definite pattern, has been virtually impossible.

The invention is described hereinbelow in connection with the preparation on the cylindrical outer surface of a roll of a design corresponding to a design carried on a pattern member where the pattern member has a continuity in one direction corresponding to the continuity of a roll surface (which is continuous in a direction extending circumferentially thereabout). The pattern member, which may be an endless belt, is moved simultaneously with rotation of the roll, with preferably the belt undergoing one revolution with one rotation of the roll. A sensor sensitive to a detectable medium which portrays the design on the belt scans the belt as it revolves beside it, and a cutting tool mounting adjacent the roll surface shifts a cutting tool toward and away from the work surface moving thereunder, with such shifting being under the control of the sensor. Simultaneously with movement of the belt under the sensor, the sensor is advanced across the belt, so that a given .portion of the belt is scanned by successive traverses (produced by recurrent movement of such portion of the belt past the sensor) which are spaced apart from each other slightly (because of the movement of the sensor across the belt with rotation of the belt). Similar movement is produced in the tool mounting along the axis of the roll, with the result that the cutting tool mounting makes successive cutting passes over a given portion of the roll surface (caused by recurrent movement of such roll surface portion past the tool mounting because of rotation of the roll) spaced a slight distance apart (because of the movement of the cutting tool mounting axially of the roll). With such an organization, a design may be cut in the roll surface bearing a certain corresponding relationship to the design portrayed on the belt. The design need not be identical, since there may be some elongation of the design in a direction extending about the roll (produced if the roll surface has greater length in this direction than the length of the belt), on contraction of the design (if the reverse is true), and a distortion in a direction extending perpendicular to this direction is produceable depending upon the relationship of the speed with which the sensor travels across the belt bearing the pattern and the speed at which the cutting tool mounting moves axially along the roll.

Thus, a general object of this invention is to provide an improved method and means for reproducing, in a work surface, by cutting of the surface, a design in relief which bears a certain corresponding relationship to a design contained on a master pattern.

More specifically, it is an object to provide such a method and means which features the preparing of a de sign on a master pattern portrayed by detectable medium, the scanning of this master pattern with a sensor passed in successive adjacent traverses over the pattern, and while such is performed the movement of a cutting tool in successive adjacent traverses across an expanse of the work surface, with the cutting tool also being advanced toward and retracted from the surface (for changing the cutting action produced thereby), such advancement and retraction of the cutting tool being under the control of the sensor and what the same detects on scannnig the master pattern.

Contemplated among other objects of the invention is the provision of a method and means for producing a design on a work surface where such may be prepared as by drawing in two dimensions the design on a pattern, with a design similar to the design on the master pattern then being accurately reproduced on the workpiece in three dimensions.

According to a particular embodiment of the invention, the design is prepared on a light pervious or transparent web, which enables, if desired, the design to be traced from another pattern. The configuration of the design is then detected by a light-sensitive sensor, through shining a light through the web against a light responsive device.

Also an object of the invention is the provision of a novel method for producing on a work surface, in a design corresponding to a design carried on a pattern surface, variations in depth of cut, whereby the resultant design as set forth on the work surface contains gradients of depth generally enhancing the appearance and certain uses of the product. This invention contemplates a number of procedures for producing such gradients of depth, each having certain advantages. Thus, according to one procedure the sensor is adapted to produce in a transmitting medium signal fluctuations depending upon what is picked up by the sensor. These fluctuations may be utilized to produce movement of the cutting tool toward and away from the workpiece, with movement of such tool being somewhat suppressed or throttled, and not being in immediate response to the signal fluctuations. The tool, as a result, advances into the workpiece over some definite time interval as the workpiece travels past the tool, to produce a sloping cut. According to another method,

the cutting of the workpiece is done using multiple runs, with a relatively deep maximum depth level in the cuts produced in one or more runs, and with a shallower maximum depth level in the cuts produced in another run, with the cuts of the shallower maximum depth level being in areas not exactly conforming to the areas containing cuts of deeper level. Where different master patterns are used to control the cutting action in the various runs, a composite pattern is cut in relief on the :work surface which combines features of both master patterns. Alternatively, the same master pattern can be used for various runs, but the sensitivity of the sensor changed, whereby the signal fluctuations produced by the sensor are not the same in different runs. Rather than changing the sensitivity of the sensor, the response of the means employed to advance or retract the cutting tool may be changed.

Indicative of the uses to which this invention is applicable, it may 'be utilized in the preparation of an embossing roller for embossing a panel surface to produce a decorative effect thereon. In this connection it has been proposed that a grained appearance of a distinctive character can be imparted, through embossing and subsequent application of pigment, to a panel faced with a wood having no distinct natural grain. With this invention, due to the accuracy with which a roll surface may be cut to reproduce a design corresponding to a design on a master pattern, the production of multiple rollers for the production of the same or related embossment effects is generally feasible. A master pattern may even be prepared through tracing an actual grain pattern on a transparent web, which web becomes the belt controlling the movement of the cutting tool. The preparation of an embossing roll with a pattern in relief suitable for producing a book match effect in the embossed panel is made relatively easy. The above are only a few of the many advantages which are obtainable in following the concepts of the invention.

It should be also understood that :while a particular use of the product of this invention has been indicated, such is exemplary only. While certain aspects of the invention relate to the preparation of designs on cylindrical roll surfaces, it should be obvious that such rolls produced by the method and means contemplated have other uses than the one specifically indicated. -It should be further apparent that other features of the invention may have broader application than the cutting in relief of a design on a roll surface, and relate as well to the preparation of designs on surfaces of other shapes and descriptions. The invention hereinbelow will be described in connection with the preparation in relief of a three dimensional design on a cylindrical roll surface, where the roll is suited for such uses as in an embossment process, but such is for the purpose of description only, and it is not intended by so describing the invention to be limited other than as required by the definition of the invention as set forth in the claims appended hereto.

Various other objects and novel features of the invention will become more fully apparent as the following description is read in conjunction with the accompanying drawings, whereinzl FIG. 1 is a top plan view illustrating, in somewhat simplified form, apparatus according to an embodiment of the invention, such apparatus including a work station having a support for a workpiece and a mounting for a cutting tool, and adjacent such Work station a pattern scanning station, including means for supporting a master pattern and a sensor for detecting a design presented on the master pattern;

FIG. 2 is a diagrammatic view further illustrating various components shown in FIG. 1, and showing control means interconnecting such components; and

FIG. 3 is a fragmentary view, on a somewhat enlarged scale, illustrating a cutting tool mounting in the apparatus, and associated structure.

Referring now to the drawings, the apparatus illustrated includes a work station, shown generally at 10, including a workpiece support 12 for supporting a workpiece, and a cutting tool mounting, shown at 14, for mounting a cutting tool used in producing cuts in the workpiece.

The workpiece support as shown resembles, in certain particulars, the construction of a conventional lathe. Thus, the support means includes a head stock 16 suitably mounted ordinarily in a fixed position on the frame of the device. Opposite the head stock is a steady rest 20 mounted on bedways 18 extending along the length of the frame of the apparatus. The steady rest is movable along the length of the bedways, and conventional means (not shown) is provided for securing it immobily in different positions on the bedways. Spindle 22 rotatably mounted on the head stock mounts of check 23 with jaws gripping a roll shaft portion 26a of a workpiece or cylindrical roll 26. Roll shaft portion 26b at the other end of the roll is j-ournaled in steady rest 20. Suitable power-operated means, such as a conventional motor (not shown) connected to spindle 22, is operated for the purpose of rotating the spindle under power. Roll 26, also referred to as a workpiece or work element, is mounted with its center axis aligned with the axis of spindle 22, and thus, with rotation of the spindle the workpiece or roll is rotated about its center of longitudinally extending axis.

Also mounted for movement along bedways 18 is a carriage 30. This carriage includes a central portion 30a which extends under the roll, and end portions 30b, 300 located adjacent opposite sides of the bedways 18. Movement of the carriage along the bedways, in a path which generally parallels the axis of roll 26, is produced through rotation of a lead screw, portions of which are shown at 32, which in the particular embodiment of the invention shown is located under the bedways. The carriage journals a suitable threaded nut or follower (not shown) which is screwed onto the lead screw, and on rotation of the lead screw the carriage is shifted along the bedways, with the direction of movement depending upon the direction of rotation of the lead screw. The lead screw may be operatively connected through a conventional speed box to the motor producing rotation of spindle 22, whereby shifting of the carriage along the bedways is also produced under power.

Considering further the construction of work station 10, a cross slide is shown at 34 mounted for movement along slide-ways 36 in a direction extending transversely of the axis of roll 26. The position of the cross slide is changed by turning turn-screw handle 38, which through a conventional screw and threaded follower arrangement is effective either to advance or to retract the cross slide on slideways 36. Ordinarily, during the cutting of a design on the surface of the roll, the position of the cross slide is adjusted prior to the cutting operation, and this position remains unchanged as the cutting commences. This does not mean, of course, that the position of the cross slide may not be adjusted at intervals when desired, to increase or decrease the maximum depth level of the cuts produced during the cutting of the work surface.

Referring now to both FIGS. 1 and 3, cutting tool mounting 14 is mounted on the cross slide adjacent its forward extremity. This mounting comprises a block 42 with guide flanges 42a, 42b extending along opposite sides. Guide elements 44, suitably joined to the cross slide, and having channels 44a recessed along their lengths which receive the guide flanges, slidably support block 42 with the block movable in a direction generally paralleling its longitudinal axis. A cutting tool, such as that shown at 46, terminating in cutting edge 46a, is received within an accommodating recess provided in block 42. A fastener 48 When advanced into the block serves to clamp onto an end of the cutting tool, thus to hold the cutting tool firmly on the block. With movement of the block and cutting tool to the right in FIG. 3, or upwardly in the figure in FIG. 1, the cutting tool and its cutting edge is advanced toward the workpiece, first to produce cutting contact and thence to increase the depth of cut produced, and on retraction from the block the cutting tool is backed off from the workpiece.

From this description it will be seen that with rotation of the workpiece (through rotation of the Spindle 22) simultaneously with movement of the carriage along the bedways (through operation of lead screw 32), any cutting tool such as tool 46 mounted on the mounting will be caused to be moved in successive adjacent traverses across any given portion of the surface of the roll 26. The traversing of such a surface portion is produced by the rotation of the roll, which operates periodically to move such portion into the vicinity and thence across the cutting tool, and successive traverses are spaced from each other rather than being overlapped, by reason of the advancement of the carriage.

The apparatus illustrated in FIG. 1 further includes a pattern scanning station designated generally at 50. Operation of the cutting tool mounting is controlled through this scanning station, as will now be more fully described.

Positioned adjacent the apparatus, in the vicinity of spindle 22, is a frame extension 52, ordinarily nontraveling, and which may conveniently be fixed to the main frame of the apparatus. Frame extension 52 journals a pair of laterally spaced, parallel shafts 54 56. Mounted on ends of these shafts located to one side of frame extension 52 are a pair of

drums

58, 60. The drums are employed to mount a pattern member in the form of an endless belt, such as that shown at 62, which is trained over the drums.

Means is provided producing positive driving engagement between drum 60 and the belt. Such means, in the embodiment illustrated, comprises a series of pin projections 66 equally circumferentially spaced about the drum, which are received within apertures 64 provided at regular intervals along one margin of the belt. With such a construction, a given amount of rotation in the drum produces always the same amount of movement in the belt which is trained thereover.

Spindle 22 has a sprocket 68 mounted thereon training a chain 70 which extends away from the spindle and is trained over a sprocket 72 joined to shaft 56. Such a connection results in rotation of drum 60 in timed relation to rotation of the spindle, and the workpiece or roll which is supported on the spindle. Ordinarily, the relationship is such that with one complete rotation of roll 26, belt 62 undergoes exactly one complete revolution. The drums by providing a support for belt 62 constitute what is referred to herein as a pattern support.

A distinguishing feature of this invention is that the design which is cut into the surface of the roll corresonds to an actual design portrayed on the pattern member or belt 62. As a consequence, the reproduction of the design is, in a manner of speaking, by orthographic means. The design to be reproduced is portrayed on the pattern member by a detectable medium which effects responses in a sensor to which the detectable medium is exposed.

More specifically, belt 62 may be formed from a light pervious, usually transparent web, such as a sheet of transparent plastic material. The design borne by the pattern member may be outlined with ink or other opaque material on the surface of the belt. A sensor may then be utilized which is light sensitive and relies upon the passage of light through the belt, and the obstruction of such passage by the opaque material, for its actuation. The design on the belt may be prepared by laying the belt as a sheet over a surface carrying the design and tracing it directly on the belt. In FIG. 1, a pattern is shown outlined as with black ink, on the transparent web which makes up the body of the belt 62, by the curving lines of graduated thickness collectively shown at 74.

The sensor in the embodiment of the invention disclosed comprises a light responsive device in the form of a photoelectric cell or other light sensitive means, shown schematically at 76 in FIG. 2. Such may be mounted within the confines of a cylindrical shroud or shade 78 operable to block off ambient light from the device. The top of the shroud may be provided with a small aperture, at the position shown at 80', which aperture enables a narrow beam of light to pass downwardly into the shroud and against device 76. The light receiving assembly comprising shroud and device 76 are mounted beneath the upper run of belt 62.

Supported above the upper run of belt 62 is a light emitting assembly, including an encompassing shade 82, a bulb or other light source mounted within the shade, such as the one shown diagrammatically at 84, and a lens, if desired, such as the one shown at 86 for focusing the light emanating from the bulb whereby at the vicinity of the upper reach of the belt the light from the bulb forms a narrow beam of relatively high intensity. The light emitting assembly is mounted directly over the receiving assembly, in a position whereby without any obstruction on the belt surface, light from the emitting assembly is directed against the photoelectric device to activate the sensor.

The light emitting and receiving assemblies are mounted on arms, such as those indicated by the cross sections 88 and 90 in FIG. 2, and these arms are secured through bracket structure 92 (see FIG. 1) to end portion 30b of carriage 30. As a consequence, with movement of the carriage along the length of bedways 18, the arms and light receiving and emitting assemblies are moved in the same direction, to produce travel of the light emitting and receiving assemblies in a direction extending across the width of the upper run of belt 62, with such travel being related to (actually the same as) the travel produced in the cutting tool mounting along the axis of roll 26. It should also be obvious, and considering any given region of the belt run, that the light sensor operates to scan the design borne by the region of the belt because of the sensor moving relative to the belt in successive adjacent traverses, with the movement of any one traverse being the result of belt movement produced by rotation of the drum, and successive traverses being adjacent each other rather than overlying, by reason of the movement of the light sensor in a direction extending across the width of the belt produced from movement of the carriage along the bedways.

Photoelectric device 76 is connected by conductors 94 to a power supply and amplifier unit, shown generally in FIG. 2 at 100. Assuming device 76 to be a typical photoelectric cell, such becomes conductive on receiving light from the light source and nonconductive when such light is cut off, and such periods of conductivity and nonconductivity result in voltage fluctuations in conductors 94. The power supply and amplifier unit is also connected to the light emitting assembly through conductors 102 which supply the energy for actuation of bulb 84.

As can best be seen in FIG. 1, mounted on cross slide 34, together with the cutting tool mounting, is a solenoidoperated valve assembly 106. This includes a valve 106a, and a solenoid 10612 ganged to the valve, so organized that with energizing of the solenoid the spool of the valve is adjusted in one direction and with de-energizing of the solenoid the spool of the valve returns to its original position. In FIG. 2 it will be seen that conductors 108 for the solenoid are connected to power supply and amplifier unit This unit includes the usual circuitry amplifying voltage changes between conductors 94, and shutting off current flow through conductors 108 and solenoid 106b to de-energize the solenoid during periods when the light beam is blocked off from device 76, or nonconductive periods, and to produce current flow through the conductors and solenoid during conductive periods of device 76. With the solenoid de-energized, the flow of fluid through the valve 1060 is as indicated by the parallel arrows at the left of the rectangle representing the valve in FIG. 2, which is from conduit or line 110 to conduit or line 112, and from conduit or line 114 to conduit or line 116. With the solenoid energized, the valve produces flow as indicated by the crossed arrows at the right of the rectangle representing the valve in FIG. 2, namely, to connect conduit 110 with conduit 114, and connect conduit 112 with conduit 116. Thus, in broad terms it will be seen that the sensor produces in the electric current or transmitting medium which energizes solenoid 106b signal fluctuations which are related to what is sensed by the sensor, and these signal fluctuations control adjustment of valve 106a.

Referring now more particularly to FIGS. 2 and 3, it will be noted that block 42 of the cutting tool mounting is connected to rod 120 of a fluid-operated ram or motor 122. Ram 122 further includes the usual piston 124 mounted for reciprocation within cylinder 126. The rod extends out from opposite ends of the cylinder, and stops 128 secured to these protruding ends function to limit travel of the piston in opposite directions relative tothe cylinder.

Not shown in FIG. 3 since obscured by the valve, but depicted schematically in FIG. 2, are throttle valves 132, 134 connected in

lines

112, 114, respectively, interposed between valve 106a and where these lines connect with opposite ends of ram 122. Valve 132 functions to throttle or supress the flow of fluid through conduit 112 to the right-end of the ram in FIG. 2, whereas valve 134 throttles the flow of fluid through conduit 114 to the left-end of the ram.

One use to which a roll prepared as contemplated by the invention may be put is in the embossrnent of a panel or other article. When embossing a design intended to simulate grain, on a wood surface having no distinct natural grain pattern, a pleasing natural looking elfect is produced if the lines of the design are recessed into the wood surface by the embossrnent process. A roll for producing such embossrnent, therefore, should have the lines of the design raised from the remainder of the roll surface. To produce a roll where the design portrayed by the curving lines 74 is reproduced in raised form on the surface of the roll, the cutting tool is controlled whereby with clear portions of the web traveling past the sensor the cutting tool produces cutting away of the roll surface. Such cutting takes place during most of the time that the roll is being prepared with a design as portrayed in FIG. 1 where the dark areas of lines 74 cover only a minor portion of the web. When a dark region on the web passes the sensor, the cutting tool retracts from the roll surface to decrease the cutting action, with the result that the dark region is reflected on the roll by a raised area on the roll.

By providing the throttling action which is the function of throttle valves 132, 134, and with actuation of the ram so as to retract the cutting tool from roll 26, movement is not abrupt, but takes place over a slight time interval (albeit in some instances this period may be quite short and no longer than a small fraction of a second). During the cutting of a design, the roll, of course, is rotating, so that the surface is continuously moving as the tool retracts. As as consequence, when the cutting tool backs off from the roll upon a dark region moving past the sensor (or advances when subsequently a light region moves past the sensor), such produces a cut which inclines or is of nonuniform depth over that portion of the cut made during the time interval that retraction is taking place. Further, with the solenoid actuated to provide for a momentary supply of fluid resulting in tool retraction followed immediately by a supply of fluid to produce tool advancement toward the roll, the throttling action may be such as to prevent any significant change in depth of cut from occurring, due to no significant movement occurring in the tool, or if a change in cut is produced, a raised portion on the roll may be left which covers a smaller area and projects outwardly from the roll to a less extent than if no throttling in fluid flow to the ram had taken place.

Referring again to FIG. 2, the fiuid supply means for the ram is designated generally at and comprises a motor 136 driving a pump 138 which has its intake connected to a reservoir 140. The pressure side of the pump is connected through conduit 142 to valve 106a. The reservoir is also connected to valve 106a through conduit 116. A by-pass providing relief for the pump is shown at 146 including a valve 146a.

Explaining now how the apparatus described may be operated and the method of practicing the invention, it will be assumed that it is desired to reproduce on the work surface a design which is in three dimensions, but corresponds by resembling in two of its dimensions the two dimensional aspects of the design portrayed on the master pattern or belt 42. It will also be assumed that the design, such as that portrayed by the lines 74, is to be reproduced as raised regions on the roll surface. With no distortion of the design desired in a direction extending along the length of the belt, a belt is employed which has a length equaling the circumference of roll 26. As a consequence, with the machine operating, revolving of the belt causes a portion of the surface of the belt to move past the sensor at exactly the same speed as a portion of the roll surface moves past the cutting tool by reason of roll rotation. A design may be prepared on the master pattern or belt by tracing the design, using black ink or other writing medium.

The motor driving the unit is energized to produce rotation of spindle 22 and drum 60; and movement of the carriage along the bedways. The source of light is energized and made to shine light downwardly through belt 62 against device 76. With energizing of the motor driving the spindle and drum, the belt travels lengthwise past the sensor simultaneously with slow travel of the sensor across the width of the belt, so that considering any given region of the belt, the sensor traverses such region repeatedly with successive traverses being spaced laterally a slight distance apart. With the major portion of the pattern member being light pervious, for the most part passage of light through the web is permitted, solenoid 10612 is energized, and ram 122 is actuated to maintain the tool advanced into the roll to the extent permitted by stops 128. On a portion of the belt containing an opaque area moving past the sensor, the passage of light is blocked, solenoid 106b becomes de-energized, and the ram is actuated to produce retraction of the tool away from the work surface. The tool ordinarily retracts sufficiently to clear completely the work surface should be solenoid be de-energized for a period of time long enough to enable such retraction to occur. On the opaque region moving past the sensor and subsequent energizing of the solenoid, the cutting tool is caused again to advance into the work surface to the maximum depth permitted. From this is should be obvious that on successive adjacent traverses of the sensor relative to the belt over any given region of the belt, a design in relief is cut in a region of the roll surface which is in three dimensions and corresponds to the design portrayed on the belt in two dimensions. The character of the third dimensional aspect of the design may be varied by varying the responsiveness of the means producing cutting tool movement.

A design in relief may be cut on the work surface which corresponds to the design on the belt, but is distorted by having proportions extending in a circumferential direction about the roll which are different from the proportions of the design on the belt in a direction extending along the length of the belt. For example, if the belt has a length which is less than the circumference of the roll, a drawing out of the design cut in the roll results, whereas if the belt is longer than the circumference of the roll, the design cut on the work surface is compressed.

The three dimensional character of the pattern produced on a work surface can be varied by changing the throttling action provided by the valves 132, 134, or by adjusting the sensitivity of the sensor, or by other means effective to produce changes in the responsiveness of the cutting tool. Thus, with a highly sensitive sensor, and with the fastest possible response in the cutting tool, substantially all shaded areas on the belt, be they wide or small, woud be reproduced as raised regions in the relief pattern. With a decrease in the responsiveness of the cutting tool only the wider shaded areas would be reproduced.

If desired, a design may be portrayed on the belt where dark regions cover a major portion of the belt. With such an organization, a roll surface would result where the major portion of the surface comprises raised regions, and only a minor portion of the roll surface is cut away. A design such as the one portrayed on the belt in FIG. 1 may be produced with the lines appearing as recesses in the roll surfaces by changing the circuitry described, whereby the cutting tool is advanced into the work on a darkened region moving past the sensor, and retracted from the work when light passage is permitted through the belt.

The invention also permits the producing of a design which is a composite of designs cut by successive runs. By way of example, and using the pattern member shown in FIG. 1, cutting of the roll may first be done using a relatively shallow maximum depth level for the cutting tool, and with relatively slow response in the cutting tool. This would produce on the roll a design with uncut portions forming ridges, and with such ridges appearing in areas corresponding to regions on the belt carrying only relatively wide portions of lines 74. The same mas ter pattern may be then utilized in a succeeding run, with an adjustment made to increase the level of cut, and to increase the rapidity of response in the cutting tool. This would result in the cutting tool further cutting away portions of the already cut away regions of the roll surface, with the tool retracting to stop cutting in areas corresponding to regions of the belt containing not only wide but also narrow portions of lines 74. The tool, in other Words, is prevented from cutting in expanses of the roll surface having greater area than the expanses where cutting took place in the first run. Further illustrating the production of a composite design, instead of using the same master pattern two different patterns may be employed of complementing design, with the making of one or more runs using one pattern and one or more runs using the other pattern, and with different depths of cut resulting from the use of the two patterns.

The apparatus and method permits the manufacture of a roll which is the exact duplicate of another roll by employing for such roll the same master pattern used to prepare the other roll. Further, should there by some fault in the design cut on a roll by virtue of tool wear or failure, whereby not enough material is cut away, such can be removed by going over the faulty area, using the same master pattern for controlling cutting as initially used, with cuts then being produced removing this excess material.

If a master pattern has been used in preparing a design on a roll, and if for some reason it is desired to recut the design on the roll, such may be done through the steps of removing the first cut design by cutting away the roll to form a substantially smooth cylinder. With a roll of relatively large diameter this cutting away of the roll will result in only a slight reduction in the diameter and circumference of the roll. The design of the master pattern may then be recut in the roll using the method outlined. With the recutting of the design, the design produced will be somewhat compressed in a direction extending about the circumference of the roll, due to the shorter roll circumference in the second cutting. However, the amount of this compression is only slight with only a slight reduction in the roll circumference.

By practicing the method using a transparent web for the pattern member and an opaque substance portraying the design on the web, one preparing the master pattern may have a relatively accurate visual conception of the embossed pattern produceable with the roll by viewing the master pattern. In a manner of speaking, the design which is prepared on the master pattern is a full scale duplicate, although in two dimensions, of the design to be expected in the embossment process. This has a decided advantage, as one knows with fair certainty before cutting the roll the type of results to be obtained upon embossing with the roll.

With the apparatus and method of the invention, no special skills are required during the various manufacturing phases which are gone through to produce the final roll. For instance, as already indicated, tracing procedures may be employed in producing the pattern member, and operation of the apparatus to produce roll cutting is relatively uncomplicated.

It should be obvious that other variations and changes are possible. Other means may be devised, for instance, to change the response in the cutting tool and producing changes in the three dimensional aspects of the pattern cut in relief. Further, details of the construction of the pattern scanning station and the work station may be modified.

With the understanding that modifications and variations are possible in the invention without departing therefrom, it is desired by the appended claims to cover all forms of the invention as would be apparent to one skilled in the art.

It is claimed and desired to secure by Letters Patent:

1. A method of producing a design in relief in three dimensions as the surface of a work element comprising preparing a master design in two dimensions on a pattern surface with the design portrayed by a detectable medium,

scanning the pattern surface with a medium sensor passed over the pattern surface in successive adjacent traverses, and with such sensor producing in a transmitting medium signal fluctuations related to what is sensed by the medium sensor,

passing a cutting tool in successive adjacent traverses across an expanse of the work element, such tool moving continuously across the expanse of the work element during each of such traverses,

moving the cutting tool toward and away from said work element to increase and decrease the cutting action thereof, respectively, such movement of the tool progressing over a time interval and taking place while the cutting tool is passing in a traverse across the expanse of the work element whereby the cutting tool during such time interval produces a cut of nonuniform depth,

controlling such movement with the signal fluctuations produced by the medium sensor, and by so controlling such movements producing a design cut in the work element in relief which design is related to the design portrayed on the pattern surface.

2. A method of producing a design in relief in three dimensions as the surface of a work element comprising preparing a first design cut in relief on an expanse of the work element, and superimposing over such first design another design cut in relief on said expanse of the work element, said other design being produced through the steps of preparing a master design in two dimensions on a pattern surface with the design portrayed by a detectable medium, scanning the pattern surface with a medium sensor passed over the pattern surface in successive adjacent traverses and with such sensor producing in a transmitting medium signal fluctuations related to what is sensed by the medium sensor, passing a cutting tool in successive adjacent traverses over the expanse of the work element, moving the cutting tool toward and away from said work element to increase and decrease the cutting action thereof, respectively, controlling such movement with the signal fluctuations produced by the medium sensor, and by so controlling such movement producing said other design cut in relief in the work element with such other design related to the design portrayed on the pattern surface.

3. The method of claim 2, wherein said first and said other designs are cut to different maximum depth levels in the expanse of the work element with the production of a composite design displayed in relief at different depth levels on the work element.

4. The method of claim 2, wherein said first design is prepared according to the method of claim 2, and different master designs are employed in producing said first and said other designs on the work element, whereby the composite design finally produced in the work element reflects the differences in the two master designs.

5. The method of claim 2, wherein said first design is prepared according to the method of claim 2 and substantially the same master design is employed in producing said first and said other designs on the work element, the two designs are cut to different maximum depth levels on the work element, and certain of the cuts made during preparation of one of the designs cut in relief are not repeated during preparation of the other design cut in relief.

6. A method of producing a design in raised relief in three dimensions as the surface of a work element where such design includes as its third dimension its raised projection from a background level in the element, comprising preparing a master design in two dimensions on a pattern surface with the design portrayed by a detectable medium, scanning the pattern surface with a medium sensor passed over the pattern surface in successive adjacent traverses, with said sensor producing in a transmitting medium signal fluctuations with one type of signal resulting upon the sensor passing background in the pattern surface and another type of signal resulting on the sensor passing over the design portrayed on the pattern surface, passing a cutting tool in successive adjacent traverses across an expanse of the work element, moving the cutting tool into and outwardly from the work element to form progressively as traversing of the expense of the work elements is continued a background at one level in said element and the design in raised outward projection from the level of said background, such movement being controlled by signals in said transmitting medium with the type of signal resulting when the sensor passes over background in the pattern surface producing movement of the cutting tool into said work element and with the type of signal resulting with the sensor passing over the design portrayed on said pattern surface producing movement of the cutting tool outwardly from said work element.

7. The method of claim 6, wherein the design produced on the work element is superimposed over another design cut in relief on the work element to produce a final design which is a composite of both designs.

8. The method of claim 6, wherein the pattern surface on which the master design is prepared is the surface of a light pervious web, the design is portrayed with an opaque substance on said surface, and scanning is performed by directing a beam of light against a portion of such web.

9. The method of claim 8, wherein the light pervious web comprises a continuous belt, the work element comprises a roll, and the belt is moved past the beam of light during scanning with movement in timed relation to rotation of the roll, whereby one revolution of the belt accompanies one revolution of the roll.

10. The method of claim 8, wherein the master design is prepared by laying a transparent web on a surface presenting a visually discernible design, and tracing at least a portion of this design on the web.

11. The method of claim 10, wherein the web after tracing of the design is made into a continuous belt, the work element comprises a roll, and scanning is performed by moving the belt past a light source with movement in timed relation to rotation of the roll, whereby one revolution of the belt accompanies one revolution of the roll.

12. Apparatus for preparing a pattern in relief on a workpiece comprising, a work station including a workpiece support adapted to support a workpiece and a cutting tool mounting adapted to mount a cutting tool; the mounting and support being mounted relative to each other whereby any tool mounted on the mounting is movable in successive adjacent traverses across the surface of any workpiece supported on the workpiece support; a pattern scanning station comprising a pattern support adapted to support a pattern and a sensor; said pattern support comprising means for mounting a belt with the belt revolvable in the pattern support; said sensor being mounted for movement relative to the pattern support whereby the sensor moves across any belt mounted on the pattern support; revolving of such belt in said pattern support producing traversing of the sensor over surface portions of the belt along the length thereof and movement of the sensor relative to the pattern support whereby the sensor moves across the belt producing axial spacing of adjacent traverses; power-operated means for producing such movement of the cutting tool mounting relative to the workpiece support and such movement of the sensor relative to the pattern support; cutting tool actuating means operatively connected to the cutting tool mounting for producing advancement and retraction of the mounting toward and away from the surface of a workpiece mounted on the workpiece support; and control means operatively interconnecting the cutting tool actuating means and sensor whereby operation of the actuating means is controlled by the sensor.

13. The apparatus of claim 12, wherein the sensor comprises a source of light and a light-responsive device, and such are positioned on either side of a run of a belt mounted in the pattern support, with the source of light operable to direct light through such belt run and against the light-responsive device.

References Cited UNITED STATES PATENTS 1,695,617 12/1928 Teissere 8214.2 2,681,595 6/1954 Compte 13.9 2,911,868 11/1959 Thomson 8214 GERALD A. DOST, Primary Examiner.

US. Cl. X.R.