US3705291A

US3705291A - Method and apparatus for making perforated sign templates

Info

Publication number: US3705291A
Authority: US
Inventors: Lawrence E Thompson
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-03-23
Filing date: 1971-03-23
Publication date: 1972-12-05
Anticipated expiration: 1989-12-05

Abstract

Artwork for a sign is outlined on paper or other dielectric sheet material with pencil lead or other electrically conductive marking material to form a sign pattern. A pair of spaced apart electrodes are arranged to receive the outlined sheet material between them, and they are energized for intermittent conduction between predetermined areas thereof only when said conductive marking material is interposed between said areas. The sheet material and electrodes then are moved relatively one to the other in a direction to cause small spaced apart portions of the conductive marking material to be interposed sequentially between the electrodes, whereby to cause conduction between the areas of the electrodes intercepted by the marking material and produce a plurality of spaced apart holes in the sheet material along the lines of marking material outlining the sign artwork. In one form of apparatus one of the electrodes of the pair is a single, elongated electrode and the other electrode of the pair comprises a plurality of laterally spaced electrode segments each connected sequentially to a source of intermittent electric potential to produce sequential conduction between the first named electrode and each of the electrode segments. In another form of apparatus one of the electrodes of the pair is a single, elongated, fixed electrode and the other electrode of the pair is an elongated electrode mounted spirally around an electrically non-conductive rotor. In still another form of apparatus one of the electrodes of the pair is a plate of electrically conductive metal on which the outlined sheet is supported and the other electrode of the pair is mounted on an elongated roller supported by a handle for hand manipulation over the sheet.

Description

United States Patent Thompson [54] METHOD AND APPARATUS FOR MAKING PERFORATED SIGN TEMPLATES [72] Inventor: Lawrence E. Thompson, West Linn,

Qreg. 221 Filed: March 23, 1971 21 Appl. No.: 127,172

Related US. Application Data [63] Continuation-in-part of Ser. No. 43,338, June 4, 1970, abandoned.

[52] US. Cl. ..219/384, 83/16, 83/170, 346/74 [51] Int. Cl. ..H05b 7/18 [58] Field of Search ..219/383, 384; 346/76, 74; v 83/16, 170, 171

[45] D ec. 5, 1972 Primary Examiner-- Volodymyr Y. Mayewsky A tt0rney- Oliver D. Olson [57] ABSTRACT Artwork for a sign is outlined on paper or other dielectric sheet material with pencil lead or other electrically conductive marking material to form a sign pattern. A pair of spaced apart electrodes are arranged to receive the outlined sheet material between them, and they are energized for intermittent conduc- 'tion between predetermined areas thereof only when ty of spaced apart holes in the sheet material along the lines of marking material outlining the sign artwork. In one form of apparatus one of the electrodes of the pair is a single, elongated electrode and the other electrode of the pair comprises a plurality of laterally I spaced electrode segments each connected sequentially to a source of intermittent electric potential to produce sequential conduction between the first named electrode and each of the electrode segments. In another form of apparatus one of the electrodes of the pair is a single, elongated, fixed electrode and the other electrode of the pair is an elongated electrode mounted spirally around an electrically non-conductive rotor. In still another form of apparatus one of the electrodes of the pair is a plate of electrically conductive metal on which the outlined sheet is supported and the other electrode of the pair is mounted on an elongated roller supported by a handle for hand manipulation over the sheet.

16 Claims, 11 Drawing Figures PATENTEB HEB 51912 sum 1 0F 2 w l mm vm mm 3 w M wvw WV a, m a m w fL 9m 8 v v LL mm ww N n -lfinvrm Q A s, Q \VM m g Lawren ce EZThOThPSQI'I INVENTOR v PATENIEDIIEB 5 m2 3.705291 SHEET 2 BF 2 I +11% u. 7% I98 Lawrence E.ThOmPSOn INVENTOR O =J1=Oz BY CROSS REFERENCE TO RELATEDAPPLICATION This application is a continuation-impart of my earlier application Ser. No. 43,338, filed June 4, i970 and now abandoned.

BACKGROUND OF THE INVENTION This invention relates "to the art of sign making, and more particularly to a method and apparatus for making perforated sign templates automatically from sign patterns. v

Perforated sign templates are used fortransferring therefrom the outline of sign artwork to a surface of a member on which the sign is to be painted, or from which the sign is to be cut.

The usualprocedure for making perforated sign templates involves guiding a spikedwheel by hand along the lines outlining the'artwork on a sign pattern. This procedure is tedious and time consuming and therefore expensive. Moreover, the spiked heel produces ragged holes in the pattern sheet which results in the transfer of correspondingly ragged markings onto the surfaceto be painted or cut. Still further, the inherent instability of hand operation of the spiked wheel is reflected in the production of irregular lines of perforations due to the inability of the operator to guide the wheel precisely along the lines which outline'the artwork.

SUMMARY OF THE INVENTION In its basic concept the method and apparatus of this invention provides for the production of a perforated sign template automatically from a sheet of dielectric sign pattern material on which sign artwork is outlined by electrically conductive marking material, by providing a pair of spaced apart electrodes energized for intermittent conduction between predetermined areas thereof only when said electrically conductive marking material isinterposed between said areas, and moving the sheet material and electrodes relative one to the other in a direction tocause small spaced apart portions of the marking material to be interposed sequentially betweenthe electrodes, whereby to cause conduction between the areas of the electrodes intercepted by the portions of marking material and produce a plurality of spaced holes in the sheet material along the lines of marking material outlining the sign artwork.

It is by virtue of the foregoing basic concept that the principal objective of this invention is achieved; namely, to overcome the aforementioned disadvantages of prior methods and apparatus.

Another important object of this invention is the provision of a method and apparatus for making perforated sign templates from sign patterns automatically and with speed and precision.

A further important object of this invention is the provision of apparatus for making perforated sign templates, which apparatus is of simplified construction for economical manufacture, which is operable with speed and precision, and has a long servicelife with minimum maintenance and repair.

The foregoing and other objects and advantages of this invention will appear from the following detailed description, taken in connection with the accompanying drawings of preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view inside elevation of apparatus for making perforated sign templates and embodying the features of this invention, the housing'being'broken I away to disclose details of internal construction.

FIG. 2 is a fragmentary sectional view taken on the line 2-2 in FIG. 1. 1

FIG. 3 is a foreshortened, fragmentary plan view as viewed in the direction of arrows 3-3 in FIG. 2.

FIG. 4 is a foreshortened, fragmentary plan view as viewed in the direction of arrows 4-4 in FIG. 2.

FIG. 5-is a fragmentary plan view of a sign pattern having artwork outlined thereon preliminary to passage through the apparatus of FIG. 1.

FIG. 6 is a fragmentary plan view of the sign pattern of F IG. 5 after passage through the apparatus of FIG. 1.

FIG. 7 is a view in front elevation of a modified form of apparatus embodying the features of this invention, portions being broken away to disclose details of internal construction. I v

FIG. 8 is a sectional view taken on the line 8- 8 in FIG. 7. a i

FIG. 9 is "a fragmentary sectional 'view, on an enlarged scale, taken on the line 9,-9 in FIG. 7.

FIG. 10 is a fragmentary view in side elevation of still another modified form of apparatus embodying the features of this invention, a portion being broken away to disclose details of internal construction.

FIG. 11 is a plan view of the rotor electrode component of the apparatus shown in FIG. 10, a-portion being broken away to disclose details of internal construction.

DESCRIPTION OF THE PREFERRED EMBODIMENT The apparatus illustrated in FIG. 1 includes a hollow housing defined by bottom wall 10, top wall 12, front wall 14, rear wall 16' and side walls 18. Extending between the side walls, intermediate the bottom and top walls, are a pair of vertically spaced

guide plates

20 and 22. The infeed and outfeed ends of these guide plates terminate inwardly of the front and rear walls in alignment with vertically spaced infeed plates 24 which extend through the front wall, and vertically spaced outfeed plates 26 which extend through the rear wall.

Interposed between the infeed plates 24 and the adjacent ends of the

guide plates

20, 22 are a pair of in- .

feed rolls

28 and 30 mounted on

shafts

32 and 34,

respectively, extending between the side plates of the housing. Intermediate the outfeed plates 26 and the adjacent ends of the guide plates are a pair of

outfeed rolls

36 and 38 mounted on

shafts

40 and 42, respec- I the embodiment of FIG. 1 one of the electrodes 52 is formed of a single elongated strip of electrically conductive material mounted on an insulating base 54 (FIGS. 2 and 3) secured to the upper guide plate in such manner that the electrode extends transversely substantially the full width of the guide plate. The other electrode of the pair comprises a plurality of laterally spaced electrode segments 56 (FIG. 4) supported on a transversely elongated insulating base 58 secured to the lower guide plate 22. These electrode segments are disposed parallel to each other and are arranged angularly in the longitudinal direction of the plates so that each segment overlaps the next adjacent segment in the longitudinal direction of movement of sign pattern sheet material through the apparatus.

The electrodes may be formed in any desired manner. For example, they may be of-thin metal sheet embedded in or otherwise secured to the insulating base, or they may ,be. formed by printed circuit technique.

It is apparent that the upper electrode 52 is common to all of the lower electrode segments 56 constituting the second electrode of the pair and that the electrode 52 forms with the segments 56 a plurality of laterally spaced pairs of vertically spaced electrodes. The upper electrode may be formed as a plurality of laterally spaced electrode segments each registeringwith one of the lower electrode segments. However, the single electrode construction illustrated is preferred for its simplicity. I

In accordance with this invention, means is provided for energizing the pair of electrodes for intermittent conduction between predetermined areas thereof only when areas of the-electrically conductive outline marking material on a sheet is interposed between said areas. In the embodiment of FIG. 1 such means is provided for connecting the pairs of electrodes sequentially to asource of electric potential. Thus, each of the lower electrode segments 56 is connected through an electrical conductor 60 to a separate terminal 62 of a fixed member 64 of a multiple terminal rotary switch. The rotary member 66 of the switch is mounted for rotation on a shaft 68 supportedby a frame 70 secured to the bottom wall of a housing. The rotary member is driven from the output shaft 72 of an electric motor 74 through the belt 76 and pulleys 7.8. The electric motor preferably is of the variable speed type to accommodate adjustment of the speed of rotation of the rotary member of the switch.

The rotary member 66 of the switch carries an electrically conductive arm 80 which extends radially outward for engagement with each of the terminals 62 of the fixed member 64. The arm is in electrical engagement with an electrical engagement with an electrically conductive collector ring 82 on the rotary member. A brush contact 84 carried by a frame 70 slidably engages the collector ring and is connected through the electrical conductor86 to one terminal of the secondary winding of astep-up transformer 88 mounted in the housing. The other terminal of the secondary winding is connected through the electrical conductor 90 to the upper electrode 52, as illustrated. Preferably, the

conductors

86 and 90 are connected to the transformer secondary through a rectifier R, as illustrated in FIG. 10, to provide direct current to the electrodes.

The terminals of the primary winding of the transformer are connected, preferably through a voltage divider 92 such as a potentiometer or rheostat, to a terminal plug 94- for connection to a source of electric potential. Conveniently, this source of electric potential may be conventional house current of '1 10 V., cycles, and the transformer secondary winding may be chosen, for example, to provide a variable output of up to about 1,000 volts.

Accordingly, as the rotary arm is rotated by motor 74 successively into contact with each terminal 62, each electrode segment 56 is energized sequentially for possible conduction relative to electrode 52, as explained hereinafter.

The operation of the apparatus described hereinbefore is as follows: A sheet of sign pattern paper or other dielectric material is provided with desired artwork for a sign by outlining the artwork with a lead pencil or otherelectrically conductive marking material 102. Such outlined artwork is illustrated in FIG. 5 by the letter L. With the

electric motors

46 and 74 energized and the transformer 88 connected to the house current through the terminal plug 94, this sheet of sign pattern material is fed through the infeed plates 24 to the infeed rolls 28, 30. These rolls move the sheet material forward between the

guide plates

20, 22 toward the outfeed end of the housing.

The sheet material thus passes between the laterally spaced pairs of

electrodes

52, 56. The voltage divider 92 is adjusted so that electrical conduction occurs between each pair of energized electrodes when areas of the lines of electrically conductive marking material outlining the artwork pass between the electrodes. However, conduction does not occur when only the dielectric sheet material is interposed between the electrodes.

Accordingly, as the sheet material passes between the electrodes and the marking material becomes interposed between them, conduction occurs between the top electrode 52 and the particular one of the bottom electrode segments 56 which, at that instant, is connected through the rotary contact 80 of the switch to the transformer 88. Conduction between such bottom electrode segment and the top electrode thus produces an electric spark of short duration which burns a tiny hole through the sheet material on a line of electrically conductive marking material.

As the sheet material passes between the electrodes and the rotary contact 80 of the switch rotates into contact with each of the terminals 62 to energize each of the bottom electrode segments 56 in sequence, the resulting succession of sparks produces a plurality of tiny holes at spaced intervals along the lines of marking material 102. The result of this operation is illustrated in FIG. 6 wherein the illustrated letter L is outlined by a plurality of spaced holes 104.

In this regard it is to'be noted that the holes are formed precisely along the lines of the marking material illustrated in FIG. 5. Accordingly, it will be un derstood that the precision with which the perforated sign template is formed is dependent only upon the precision with which the lines of marking material are formed on the sign pattern sheet.

Further, the holes formed in the sheet material are perfectly round and devoid of ragged edges. Thus,

pattern of holes, there is transferred to the surface a plurality of tiny spots which correspond to the precise shape and arrangement of the holes 104. The outline of the artwork thus is transferred precisely to the surface and this outline then may be utilized as a guide for painting the sign or for cutting out the sign, as desired.

It willbe understood that the provision of the voltage divider affords varying the stepped up output voltage from the secondary winding'of the transformer to adjust the level of conduction between the electrodes. In this manner the apparatus accommodates the use of various types of sign pattern sheet material which may vary in dielectric property overa considerable range. In this regard it has been found convenient to employ ordinary sheet paper for the sign pattern and ordinary lead pencil for the electrically conductive marking material. However,. various types of synthetic plastic sheet material and various types of electrically conductive marking. inks may be utilized, as desired. The. provision of variable speed motors for moving the sheet materialthrough the apparatus and for driving the rotary multiple contactswitch accommodates adjustment of the spacing between holes 104 over a substantialrange. It is to be understood, however,.th at one .or both of the drive motors may be of the constant speedtype, if desired. Further, one of the motors 'may be omitted,the remaining motorserving to drive the feed rolls and the rotary switch. Although the sheet material may be arrangedto remain stationary and the electrode structure moved relative thereto, the simplified arrangement illustrated is preferred.

The rotary switch may be replaced with any conventional form of device capable of producing an intermittent electric potential output. In such event the output may be connected to all of the lowerelectrode seg ments for simultaneous energizatiomon an intermittent cycle, to provide substantially the same results as the rotary switch. 1

Referring now to the embodiment illustrated in FIGS. 7-9, the apparatus illustrated therein includes a hollow housing defined by a bottom wall 110, top wall 112, front wall 114, rear wall 116 and side walls 118. Supported by. spaced brackets 120- and extending between the front and rear walls, intermediate the top and bottom walls, are a pair of vertically spaced

guide plates

122 and 124. The infeed and outfeed ends of these guide plates terminate inwardly of the front and rear walls in alignment with vertically spaced infeed plates 12.6 which extend through the front wall and vertically spaced outfeed plates 128 which extend through the rear wall.

lnterposed between the infeed plates 126 and the adjacent ends of the

infeed guide plates

122, 124 are a pair of infeed rolls 130 and 132 mounted on shafts supported by the brackets 120. Intermediate the outfeed plates 128 and the adjacent ends of the

guide plates

122, 124 are a pair of outfeed rolls 134 and 136 mounted on shafts which are also supported by the brackets 120. The lower rolls are driven by common connection to the output shaft of an electric motor 138 through sprockets 140 and chain 142. The motor preferably is of the variable speed type to accommodate adjustment of speed of movement of sign pattern sheet material through the apparatus.

As in the embodiment previously described, this apparatus alsoincludes a pair of spaced electrodes. Thus, the lower electrode 144 (FIG. 9) is formed of a single elongated strip of electrically conductive material mounted on an insulating base 146 secured to the lower guide plate 124 in such manner that the electrode extends transversely substantially the full width of the guide plate. v

The other electrode of the pair comprises at least one single elongated strip 146 of electrically conductive material mounted spirally about an elongated rotor 148 of electrically non-conductive material. Although in the embodiment illustrated only one spiral strip is mounted on the rotor, it will be understood that a plurality of spiral strips may be employed, spaced circumferentially with respect to each other.

The rotor is supported for rotation a spaced distance above-the first named electrode 144. Preferably, it is supported for vertical adjustment. Thus, one end of the rotor is journaled in a bearing 150 secured to the lower end of an arm 152. The .upper, portion ofthe' arm is received freely in. a channel shaped bracket 154 secured at its upper end to an elongated structural channel beam 156. The arm is provided with a vertically elongated slot 158 which freely receives a lock bolt 160 mounted in a threaded opening in the bracket. Thus, the'armmay be adjusted vertically relative to the bracket, by loosening the lock bolt.

The opposite end of the rotor is connected through a coupling 162 to the output shaft of an electric motor 164. An arm 152 securedat one end to the motor extends upward therefrom and is received freely in a channel shaped bracket 154 secured to the beam 156. A lock bolt 160 threaded to the bracket 154 extends through an elongated slot 158 in the arm, to accommodate vertical adjustment, as previously described.

The intermediate portion of the upper guide plate 122 is removed (FIG. 8) to provide an opening registering with the rotor 148.

One end of the spiral electrode 146 is connected to an electrically conductive collector ring 166 encircling one end of the rotor. A spring pressed brush 168, mounted on a bracket 170 extending from the motor 164, slidably engages the ring. A flexible electrical conductor 172 interconnects the brush and one end of the secondary winding of a step-up transformer 174. The opposite end of the secondary winding is connected through the flexible electrical conductor 176 to the lower electrode 144 of the pair. The conductors preferably are connected to the transformer secondary through a rectifier R, and the primary winding of the transformer is connected, preferably through a voltage divider 178, to a source of electric potential, as previ ously described.

In the operation of the apparatus illustrated in FIGS. 7-9, a sheet 100 (FIG. 5) provided with electrically conductive artwork outline 102 is fed between the infeed rolls 130, 132 forwardly between the

guide plates

122, 124 toward the outfeed end. The sheet material thus passes between the vertically spaced pair of electrodes, the upper, spiral electrode 146 of which is conductive outline material 102 is interposed'between them. The result of this operation is illustrated in FIG. 6. a

' Since mostsign artwork has many lines extending perpendicular to the-direction of movement of the sheet material through the apparatus, it is preferred that the

electrodes

144 and 146 be disposed at a slight angle with respect to said direction of movement, in order to insure the production of aplurality of spaced holes along such lines. I

The embodiment illustrated in FIGS. 10 and 11 provides manually operable apparatus of minimum cost, but embodying the same mode of operation of the embod iments previously described. An elongated, electrically conductive rotor 180 is milled or otherwise contoured to provide a plurality of circumferentially spaced, radially projecting ribs 182, each of whichconstitutes an electrode segment of one electrode of a pair. Theprojecting, reduced diameter ends of the rotor are journaled inelectrically non conductive' bearings 184 supported at the bifurcated ends of a handle 186, the opposite end of which is provided with a hand grip 188. An electrically conductive collector ring 190 is supported rotatably'in an annular groove in one of the bearings and is in positive engagement with the associated reduced end portion of the rotor. A flexible electrical conductor 192 extends through the hollow handle andmakes electrical contact with the collector ring 190, as by means of a spring pressed brush.

Adjacent each end of the rotor is mounted an annular spacer ring 194 of electrically non-conductive material, such as rubber or synthetic plastic O-rings. These rings-project radially outward of the electrode segments 182 and thus space the latter from a cooperating second electrode which as illustrated in FIG. 10, comprises an electrically conductive plate 196 of metal supported upon a table 198. This electrode is connected through a flexible electric conductor 200 to one end of the secondary winding of a step-up transformer 202, the opposite end of which secondary winding is connected to the rotor 180 through the conductor I92. The conductors preferably are connected to the transformer secondary through a rectifier R, as shown, and the primary winding of the transformer is connected, preferably through a voltage divider 204, to a source of electric potential, in manner previously explained.

In the operation of the apparatus illustrated in FIGS. 10 and 11, a sheet 100 of sign pattern material having sign artwork outlined thereon, as previously explained, is placed upon the electrically conductive plate electrode 196. With thehandle 186 supported by the hand of the operator, the rotor 180 is disposed over the sheet 100 with the rings 194 contacting the sheet and thus spacing the rotor electrode segments above it. The

operator then manipulates the handle to cause the rotor to roll over the surface of the sheet 100, in any random direction. Thus, as each of the rotor electrode segments 182 is moved into minimum spacing relative to the other electrode 196, electrical conduction occurs in those areas in which portions of the electrically conductive marking material 102 is interposed between the electrodes. The result of such operation is illustrated in FIG. 6.

The minimum spacing between the electrode 196 and the rotor electrode segments 182 may be varied by substituting annular spacer rings 194 of different outside diameters, as will be understood.

The rotor 180 and associated electrode 182 may be provided in a form similar to the embodiment illustrated in FIGS. 7 and 8. Thus, the rotor 180 may be of electrically non-conductive material and the electrode 182 may be formed of one or more electrically conductive strips. The strips may be arranged parallel to each other, as are the ribs 182, or in the spiral manner of electrode 146. The strips may be connected to a source of electric potential by means similar to collector ring 166.

From the foregoing it will be appreciated that the method and apparatus of this invention provides for the making of perforated sign templates automatically from sign pattern sheets with a degree of speed and precision far surpassingthat of conventional manual procedures. The apparatus is of simplified construction 'for economical manufacture, making it available for wide spread use at minimum capitalinvestment.

It will be apparent to those skilled in the art that various chargesmay be made in the size, shape, number, type and arrangement of parts described hereinbefore without departing from the spirit of this invention.

Having now described my invention and the manner in which it may be used, I claim:

1. The method of making a perforated sign template, comprising a. outlining sign artwork on dielectric sheet material with electrically conductive marking material, arranging a pair of spaced-apart electrodes in an electric circuit for conduction between one electrode and different areas of the other electrode at different times and only when said conductive material is interposed between said areas,

c. interposing said outlined sheet material between said electrodes, and

d. moving the sheet material and electrodes relatively one to the other in a direction to cause small spaced-apart portions of the electrically conductive marking material to be interposed sequentially between the electrodes, whereby to cause conduction between the areas of the electrodes intercepted by the portions of the electrically conductive marking material and produce a plurality of spaced holes in the sheet material along the lines of marking material outlining the sign artwork.

2. The method of claim 1 wherein at least one of the electrodes comprises a plurality of laterally spaced electrode segments.

3. The method of claim 2 wherein the electrode seg ments are energized intermittently, one at a time.

4. The method of claim 1 wherein one of the electrodes is moved relative to the other electrode and both electrodes are energized continuously.

5. The method of claim 4 wherein the sheet material is moved relative to the electrodes.

6. The method of claim 4 wherein the sheet material is maintained stationary and one of the electrodes is moved relative to the other electrode.

7. Apparatus for making a perforated sign tempate from dielectric sheet material having sign artwork outlined thereon with electrically conductive marking material, the apparatus comprising a. a pair of electrodes spaced apart to receive sheet material between them,

b. electrical means including a source of electric potential electrically connected to the electrodes for causing conduction between one of the electrodes and different areas of the other electrode at different times and only when electrically conductive marking material on dielectric sheet material is interposed between said areas, and

c. moving for moving the sheet material and electrodes relatively one to the other, whereby to effect said conduction and produce a plurality of spaced holes in the sheet material along the lines of marking material outlining the sign artwork.

8. The apparatus of claim 7 including voltage divider means in the circuit of the electric potential for adjusting the potential to the electrodes.

9. The apparatus of claim 7 wherein one of the pair electrodes comprises a plurality of laterally spaced electrode segments, and the source of electric potential comprises a source of intermittent electric potential and includes means for connecting each of the segments one at a time to said source of intermittent electric potential.

10. The apparatus of claim 9 wherein the other electrode of the pair is a single elongated electrode common to all of the segments.

11. The apparatus of claim 7 wherein the moving means comprises feed roll means for moving the sheet material relative to the electrodes, and drivemeans for rotating the feed roll means.

12. The apparatus of claim 7 wherein one of the pair of electrodes is supported for rotation relative to the other electrode.

13. The apparatus of claim 12 wherein the rotary electrode is of spiral shape.

14. The apparatus of claim 12 wherein the rotary electrode is power driven and the other electrode is a single, fixed elongated electrode.

15 The apparatus of claim 12 wherein the rotary electrode is mounted on a handle for manual operation and the other electrode comprises a flat plate upon which to support dielectric sheet material.

16. The apparatus of claim 15 wherein the rotary electrode mounts a pair of longitudinally spaced rings of electrically non-conductive material for spacing said electrode from the plate electrode.

Claims

1. The method of making a perforated sign template, comprising a. outlining sign artwork on dielectric sheet material with electrically conductive marking material, arranging a pair of spaced-apart electrodes in an electric circuit for conduction between one electrode and different areas of the other electrode at different times and only when said conductive material is interposed between said areas, c. interposing said outlined sheet material between said electrodes, and d. moving the sheet material and electrodes relatively one to the other in a direction to cause small spaced-apart portions of the electrically conductive marking material to be interposed sequentially between the electrodes, whereby to cause conduction between the areas of the electrodes intercepted by the portions of the electrically conductive marking material and produce a plurality of spaced holes in the sheet material along the lines of marking material outlining the sign artwork.

3. The method of claim 2 wherein the electrode segments are energized intermittently, one at a time.

7. Apparatus for making a perforated sign tempate from dielectric sheet material having sign artwork outlined thereon with electrically conductive marking material, the apparatus comprising a. a pair of electrodes spaced apart to receive sheet material between them, b. electrical means including a source of electric potential electrically connected to the electrodes for causing conduction between one of the electrodes and different areas of the other electrode at different times and only when electrically conductive marking material on dielectric sheet material is interposed between said areas, and c. moving for moving the sheet material and electrodes relatively one to the other, whereby to effect said conduction and produce a plurality of spaced holes in the sheet material along the lines of marking material outlining the sign artwork.

11. The apparatus of claim 7 wherein the moving means comprises feed roll means for moving the sheet material relative to the electrodes, and drive means for rotating the feed roll means.

13. The apparatus of claim 12 wherein the rotary electrode is of spiral shape.

14. The apparatus of claim 12 wherein the rotary electrode is power driven and the other electrode is a single, fixed elongated electrode. 15 The apparatus of claim 12 wherein the rotary electrode is mounted on a handle for manual operation and the other electrode comprises a flat plate upon which to support dielectric sheet material.