EP0005915A1

EP0005915A1 - Sign-making method and apparatus, character carrier sheets therefor

Info

Publication number: EP0005915A1
Application number: EP79300780A
Authority: EP
Inventors: Gregory R. Waldron
Original assignee: Scott Machine Development Corp
Current assignee: Scott Machine Development Corp
Priority date: 1978-05-15
Filing date: 1979-05-08
Publication date: 1979-12-12

Abstract

Method and apparatus for sign-making using dry transfer of letters from carrier sheets allows any of a number of different character sizes and row spacings to be provided. A carrier sheet (s) bearing characters of a desired size is positioned relative to a carriage (20) in dependence upon whether a row to be formed contains all upper case characters, or some or all lower-case characters. The carriage (20) is movable smoothly in a horizontal direction to allow any desired horizontal spacing of characters, but movable vertically only in discrete increments. A plurality of row spacing indicators (8,9) are positionable adjacent a sign blank (B) to afford a preview of how characters of a given size having a given spacing will appear on a sign blank.

Description

This invention relates to sign-making, and more particularly to improved method and apparatus for constructing signs, such as types which may be used on doors, walls and directories of commercial and public buildings, desk nameplates, and for a variety of other purposes. Many such signs have been made in the past by engraving. Rows of master characters can be readily aligned relative to a strip to be engraved, and then clamped, and a complete sign can then be engraved quite rapidly using a known form of pantograph engraver, without having to re-position the master characters, and with assurance that the finished characters will be accurately aligned along a row. Further, master characters can be readily aligned to countless different orders, so that any desired words or the like can be readily engraved for a sign. Engraving, however, tends to require use of a rotating cutter, which undesirably limits the number of fonts which can be produced, since corners of characters produced by engraving are rounded. Signs which do not have the grooves which engraving provides are also desirable for some applications.
Characters having any desired font or style and no grooves can be transferred from a flexible carrier sheet to a receiving surface or substrate, such as a plastic strip, or sign blank, by use of a pressure-transfer process described in U. S. Patents Nos. 3, 131, 106 and 3, 212, 913, for example. Carrier sheets carrying entire alphabets of transferable characters with non-transferred reference lines extending below them can be inexpensively produced. To produce a row of characters on a substrate, one need merely place one side of such a sheet in direct contact with the substrate with a selected letter positioned atop a desired location on the substrate and apply pressure by means of stylus on the other side of the sheet in order to transfer the selected letter to the substrate. To place a given letter of a row at the proper vertical location, one moves the sheet until the reference line below the letter is aligned with a temporary reference line drawn across the substrate. The use of pressure transfer (often called dry transfer) for production of signs of the type described has been quite limited, however, because, it is believed, of the serious difficulties involved in properly positioning successive characters atop the substrate or sign blank, particularly when plural rows of characters are needed. Rather than positioning a row of master characters once as in the case of engraving, production of a row of characters using pressure transfer tends to require that the carrier sheet be repositioned relative to the substrate for every successive character, and sometimes that different carrier sheets be submitted, so that numerous chances for positioning errors are involved. Mis-positioning even a single character may spoil the appearance of a sign and require that the results of much work be scrapped. It is possible, of course, to print some carrier sheets so that a desired row of characters, and even plural rows of characters, are positioned on a sheet with the spacings desired on a final sign. While that strategm eliminates a need to repeatedly re-position the carrier sheet, it is only useful for standard or pre-arrange signs, and does not lend itself to economical and rapid production of signs to be devised at locations remote from the carrier sheet printing plant. A countless number of different carrier sheets would have to be produced, with great waste, to obtain sheets carrying even a small fraction of the words or messages which are usually needed. Because of such problems, the use of pressure lettering has largely been restricted to limited applications where high labor costs involving tedious positioning operations performed by persons with substantial artistic skill can be tolerated.
While manually aligning reference lines under successively used characters on a carrier sheet with a temporary line drawn on a sign blank is tedious, it can provide characters of a given row accurately vertically spaced relative to each other. However, it does nothing to provide proper vertical spacing between successive rows, nor to space any of the rows relative to the eventual sight of the sign blank. One attempt to overcome these further positioning problems associated with transfer lettering is shown in U. S. Patent No. 3, 945, 141. Trans fer sheets made the same size as sign blanks carry non-transferable - reference lines and a matrix of transferable guide marks as well as characters. Transferring the guide marks to a sign blank allows one to thereafter align the transfer sheet in different positions somewhat more easily and accurately than one can without guide marks, but accurate positioning still tends to be tedious and time-consuming, and the vertical spacing accomplished is disadvantageously dictated by how the guide marks are spaced at the printing plant. One object of the present invention is to provide sign-making method and apparatus which allows an operator in the field to select any of numerous different vertical spacings of rows of characters. Some persons have much less ability than others to visualize how a finished sign having rows of characters of a given size with a given row spacing will look. One object of the present invention is to provide sign-making method and apparatus which readily allows a sign-maker to readily select among a number of size and row spacings which have been previously found to be acceptably attractive, so that sign-making need depend less upon the artistic skill or taste of the operator.
Another aid for transfer lettering comprises a rigid plastic open frame on which the edges of a transfer sheet may be adhesively mounted, with numerical scales inscribed along the edges of the frame to facilitate positioning. Such an arrangement still tends to require substantial operator calculation and provides many chances for error. These prior art methods depend for precise alignment, upon the visual acuity and manual dexterity of the operator. One object of the present invention is to provide improved sign-making method and apparatus for dry lettering transfer with which precise alignment can be obtained much more independently of the visual acuity and. manual dexterity of the operator.
One important object of the present invention is to provide improved method and apparatus for sign-making which allows pressure transfer to be used rapidly and economically to produce. signs having their characters accurately aligned along rows in both translational and rotational senses, with plural rows accurately extending parallel to each other with desired spacings between successive rows of characters, and with the rows accurately spaced relative to edges of the sign.
While a row of successive characters if commonly termed a "line" in ordinary parlance, to avoid confusion the word "row" will be used in this description and the appended claims. The term "line" and various variants such as "baseline" and "centerline" will be used in a geometrical sense. The term "vertical centerline" used with respect to a sign blank, other area or other object will be used to mean a line defining the midpoint between the upper and lower extremities of the area or other object, such a line of course extending horizontally. In the discussions below the term "integral multiple" describing distances defined by a varying integer i and a predetermined distance d will be meant to include integers 0 and 1 as well as other integers. The term character is meant to include not only alphanumeric characters, but also punctuation marks, ampersands, arrows and various other symbols used on signs.
The production of a sign having an optimum appearance tends to require consideration of numerous factors. The factors can be generally grouped into two classes, those of inter-character and other horizontal positioning of characters, and those of inter-row and other vertical positioning of characters. Even totally neglecting the horizontal positioning of characters in a sign, the making of a sign involves consideration of the size of a sign blank, selection of the nominal size of characters to be formed and selection of a desired font or style, how many rows of characters are to be placed on the sign blank, whether the rows use only upper-case characters, or only lower-case characters, or a mixture of both upper-case and lower-case characters, how closely together successive rows should be spaced, whether the rows should be vertically centered relative to the vertical centerline of the sign blank or instead some other line across the sign, and how the rows should be vertically centered relative to one line or another across the sign. If an odd number of rows of characters are to be used, it is usually desired that one row pass through the vertical centerline of the "sight", or portion of the sign blank eventually to remain exposed, while conversely, when an even number of rows are provided, it is usually desired that the vertical centerline of the sight extend between two rows of characters. However, the sight within which the rows are to be placed may depend upon whether a sign holder will obscure a strip 'along the upper edge of a sign blank or instead the lower edge, or whether neither edge will be obscured. Further complicating the vertical placement of characters on a sign is in fact that most fonts deemed desirable do not contemplate simple placement of successive characters along a row with all their upper edges, or all their lower edges, or all their vertical centerlines falling on a common line, but rather that accepted "baselines" for the different characters fall on a common line, and different characters have their respective baselines located at various vertical locations relative to their extremities. Because of these numerous factors and others, vertical placement of characters on a sign has often tended to require that sketches of one or more sign layouts be made so that their probable appearances can be evaluated before actually beginning production of a sign. It is believed that difficulties associated with vertical positioning of characters combine multiplicatively or exponentially with difficulties associated with horizontal positioning, and that most operators can provide attractive horizontal spacing with far greater ease if they need not simultaneously be concerned with vertical spacing. While the calculations, measurements and making of sketches involve only elementary arithmetic, they tend to involve numerous chances for error, precluding the use of some classes of unskilled and inartistically-inclined labor, as well as being tedious and time consuming. One object of the present invention is to provide improved method and apparatus for pressure- transfer sign-making which can be used rapidly and accurately by unskilled labor.
In accordance with one aspect of the present invention, we provide a sign making kit which uses a transfer sheet positioning machine to position special character-bearing transfer sheets having their characters spaced on the sheets to match an incremental movement characteristic of the machine. The machine allows one to rapidly and accurately position such sheets relative to any of a plurality of standard size sign blanks or substrates placed in the machine.
In accordance with one important concept of the present invention, the speed and accuracy with which pressure lettering can be done are markedly increased by constraining the vertical locations at which reference'portions of characters can be placed to a relative few discrete locations. The machine to be described allows a transfer sheet, once it has been gripped in the machine, to be moved vertically through a distance well exceeding its height, but allows the sheet to be stopped and held fixed only at a plurality of discrete or specific positions within that range of travel. If the operator moves the sheet to a position somewhere in between two of the discrete positions, the machine then automatically'moves the sheet to one or the other of the two discrete positions. In a row of characters on a sign, it is particularly important that the baselines of all characters of the row fall on a common line, and thus when a row of plural characters is being applied to a sign, the baselines of different successive characters on the transfer sheet must be successively moved to the same vertical position on the sign blank. While it is difficult to manually and visually position a transfer sheet repeatedly to a common line with translational and rotational tolerances within say 0. 003 inch and 1° using prior art techniques, the machine can readily provide such positioning accuracy. Importantly, the accuracy for repeated positioning tends to no depend upon or require any precise adjustments by the operator, but instead require only a "coarse" or rough adjustment which he can make rapidly. Thus another object of the invention is to provide improved apparatus for positioning a character-bearing transfer sheet relative to a receiving surface wherein only a coarse adjustment is required by an operator in order to provide precise positioning of the transfer sheet. To have great utility and to be economically feasible, sign -making apparatus must accommodate more than one nominal character size, and must allow a number of different types of vertical spacings between rows. While the use of a predetermined incremental motion in the machine to be described might initially suggest that its usage is limited to a single character size and a single type of vertical spacing, it will become clear as the description proceeds that numerous different character sizes and numerous different vertical spacings can be provided using a single incremental motion by proper placement of characters on the carrier sheet used with the invention, and provision of method and apparatus which allow use of different character sizes and spacings with a single form of incremental motion is another object of the invention.
Using prior art techniques, an architect may have to specify a large amount of font size and spacing data to a sign-maker to order the signs required for a building. The production of signs could be appreciably expedited if the architect could instead merely select a sign having font sizes and spacings deemed attractive from a catalog, giving only a catalog number and desired sign wording to a sign-maker, and yet be assured that signs having the same appearance would result. Also, it is often desired that signs be made by a sign-maker using the same font sizes and vertical spacing as were previously provided on signs made by a different sign-maker. Another object of the invention is to provide method and apparatus which will enable a sign-maker to rapidly and accurately make pressure-transferred signs having a variety of different "standard" font sizes and spacings, so that orders can be conveniently transmitted and accurately executed, and so that new signs can be readily made to be compatible with earlier-made signs.
Other objects of the invention will in part be obvious and will in part appear hereinafter.
The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, and the apparatus embodying features of construction, combination of elements and arrangement of parts which are adapted to effect such steps, all as exemplified in the following detailed disclosure, and the scope of the invention will be indicated in the claims.
For a fuller understanding of the nature and objects of the invention reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

Fig. 1 is a semi-diagrammatic plan view illustrating one form of apparatus constructed in accordance with the present invention.
Fig. la is an enlarged view of one portion of Fig. 1.
Figs. 2a to 2f are diagrams illustrating various rows of characters and useful in understanding various problems associated with sign-making.
Fig. 3a is a geometrical diagram illustrating certain features of one form of transfer letter sheets constructed according to the invention.
Fig. 3b is a geometrical diagram useful in understanding the invention.
Fig. 4 illustrates several sections of a tape used in a preferred embodiment of the invention.
Figs. 5a and 5b are partial plan and elevation views respectively illustrating details of one form of cursor-rack arrangement which may be used with the invention.
Figs. 6a and 6b are side and end cross-section views illustrating details of one form of tape guiding arrangement which may be used I with the present invention; and Fig. 6c is a cross-section view illustrating an alternative form of vertical row-spacing indicator means.
Fig. 7 is a diagram illustrating an alternative form of carrier sheet.
Fig. 8 is a partial plan view illustrating an alternate arrangement for aligning a carrier sheet in the carriage of the invention.
Figs. 9a and 9b are diagrammatic cross-section views illustrating one form of carriage detent means which may be used with the present invention.

In Fig. 2a three upper-case characters of a given nominal size of a font known as Helvetica Medium are shown aligned in a row. The size of a group of characters intended to be used together is usually stated in terms of the approximate height of most of its upper case characters, and is termed nominal because some of the characters may have substantially different heights. Line b-b constitutes the baseline for the characters. Fonts are designed so that the baselines of all characters in a row are intended to coincide. Line b-b coincides with the lower extremities of flat-bottomed characters, such as the A and T shown, but passes through round-bottom characters slightly above their lower extremities, as in the case of the letter C shown. With some letters extending slightly below their baselines and others of the same nominal size and case not so extending, it will be apparent that one cannot merely align lower extremities of characters to provide a properly appearing sign.
Line a-a is shown located midway between the upper and lower extremities of the letters A and T, and substantially midway between the upper and lower extremities of the letter C. Line a-a constitutes what may be termed the apparent vertical centerline of the row of upper-case characters shown in Fig. 2a. The apparent vertical centerline of the row in Fig. 2a is not established with complete mathematical precision, its location being slightly subjective. One might instead deem it to lie midway between the upper and lower extremities of the letter C. In any event, when a row of upper-case characters is placed on a sign blank, such as that represented by rectangle B, almost all persons will agree that some apparent vertical centerline approximately midway between the upper and lower extremities of most of the characters should lie midway between the upper and lower edges of the sign blank, i.-e. that dimension c_l equal dimension c₂ in Fig. 2a, so that the row of characters will be visually centered on the sign. If a sign-holder will obscure a strip portion h when the sign is placed in use, the row of characters should be moved down so that the apparent vertical centerline a-a lies midway between the upper and lower edges of the remaining sight, which is shown having height e in Fig. 2a. If plural rows of upper-case characters are used on a sign, it is deemed desirable for an attractive appearance, that their apparent vertical centerlines be equally spaced apart, and that the aparent vertical centerlines of the uppermost and lowermost rows be spaced equal respective distances from the upper and lower edges of the eventual sight of the sign blank. Any row of upper-case characters of a given font and nominal size, and any character of that row, can be deemed to have a specific vertical distance between its baseline and its apparent vertical centerline, and in Fig. 2a that distance is shown by dimension 1:
Fig. 2b illustrates a row of lower-case characters from the same font and nominal type size as those in Fig. 2a. The intended or accepted baselines of all of the lower-case characters are shown aligned on line b-b, some lower-case characters, such as the "g" shown extending below their baselines. The apparent vertical centerline of the row of lower-case characters is shown by line a-a in Fig. 2b. Because lower-case characters are in general not as tall as upper-case characters, the distance (dimension k in Fig. 2b) between the baseline and the apparent vertical centerline is somewhat less than dimension j in Fig. 2a. The exact location of the apparent vertical centerline of a row of lower-case characters is also slightly subjective. As with upper-case characters, the eye perceives a row of lower-case characters to be centered on an apparent vertical centerline, and hence the spacing of rows formed of all lower-case characters should also be based on the apparent vertical centerlines of such rows. Thus if the lower-case characters of Fig. 2b were to be placed on the sign blank B of Fig. 2a in lieu of the upper-case characters thereshown, their baseline should be above the baseline shown for the upper-case characters.
Fig. 2c illustrates a "mixed" row of characters of the same nominal size and font as that of Figs. 2a and 2b, the row having an initial upper-case character P followed by a plurality of lower-case characters, all the characters having their baselines aligned on line b-b. The apparent vertical centerline of a row containing both upper case and lower case characters might conceivably be deemed to lie above the baseline by a distance which is some form of average between dimensions j_ and k of Figs. 2a and 2b. However, form visually inspecting a large number of signs, it is my belief that the visual or apparent vertical centerline perceived by most persons for such a mixed row substantially corresponds with that of a row of all lower- case characters. This is probably because most signs contain words, most words contain more than two characters, and upper case characters are usually used only as the initial characters of words having both upper and lower case characters in the English language and many other languages, so that rows containing both upper-case and lower-case characters ordinarily have more characters of lower case than of upper case. Accordingly, in the row of mixed upper and lower case charac- . ters in Fig. 2c the apparent vertical centerline can be deemed to lie distance k above the baseline, just as in Fig. 2b, and the present invention operates with that assumption. Thus one can summarize as follows: The apparent vertical centerline of a row may be deemed to lie at one distance k above the baseline of the characters if the row contains any lower case characters, but lies higher at distance j above the baseline of the characters if the row contains only upper case characters. Stated in another way, one should use the apparent centerlines of lower case characters.
It is important to note that the apparent centerline to baseline distances j and k shown in Figs. 2a to 2c relate to only characters having the nominal size shown in those Figures, and larger or smaller characters will have larger or smaller j and k distances. If a method and apparatus are to be useful with plural sizes of characters, say sizes labelled #1 through #4, the method and apparatus must accommodate use of any one of four sets of j and k distances.
In Fig. 2d the second "e" is shown having a rather gross upward translational mis-registration, i.e. its baseline is above those of the other characters, and the second upper-case "F" is shown with a gross rotational mis-registration. Under the standards of most professional signmakers and architects, a translational mis-registration any more than 1. 5 percent of character height, or a rotational mis-registration exceeding 0. 75 degree, would render a sign unacceptable.
If a sign is to carry an odd number of rows of characters, it is usually desired that the apparent vertical centerline of the middle row lie on the vertical centerline of the eventual sight of the sign, as is illustrated in Fig. 2e, while if a sign carriers an even number of rows, as in Fig. 2f, it is instead desired that a pair of middle rows be spaced equal distances above and below the vertical centerline of the eventual sight of the sign. The types of vertical spacing shown in Figs. 2e and 2f will be referred to as odd spacing and even spacing, respectively. In addition to that difference between their vertical spacings, the signs of Figs. 2e and 2f will be seen to differ in that much more vertical space is provided between successive rows in Fig. 2e than in Fig. 2f. That difference will be termed the breadth or narrowness of vertical spacing.
The method and apparatus of the present invention may be better understood by reference now to Fig. 3a. The letter carrier sheet S thereshown includes a pair of target marks T₁, T₂ defining an imaginary primary reference line A_o extending horizontally across the sheet. The sheet can also be envisioned as having numerous further imaginary reference lines A₁ to An each running parallel to line ^A _o and each spaced a respective distance id therefrom, where i is an integer, and d is a predetermined distance which will be termed the incrementing distance, and which is described as 0. 250 inch in an exemplary embodiment.
In accordance with a preferred embodiment of the invention, all lower-case characters are placed on such transfer sheets so that their .apparent vertical centerlines are situated on one or another of the imaginary reference lines. In Fig. 3b four characters of different sizes intended to represent lower case o's are shown with their apparent centerlines aligned on the same imaginary reference line A_i. Such placement results in lower case characters of sizes #1 to #4 having their baselines located respectively distances k_i to k₄ below the reference lines on which their visual centerlines lie. Next, all upper case characters on all transfer sheets are vertically located so that their baselines either coincide with those of lower case characters of the same size or are displaced therefrom by a distance id. For example, the baseline of an upper case I of size #1 is shown distance k₁ below reference line Ai, while the baseline of an upper case E of size #4 is located distance k₄ below line A_i. Various characters of either upper or lower case, and particularly those of larger sizes, extend across one or more of the imaginary reference lines adjacent to the one to which their location is primarily referenced. For example, while all the characters in Fig. 3b are shown located with reference to imaginary line A_i, various of them extend across nearby lines A_i+1, A_i+2, etc. Thus the baseline of any character lies a distance (id+k_m) from reference line A_o on any transfer sheet, where m is the size number of the character, and it lies distance k_m below some particular one of the reference lines. Because the visual centerline of an upper case character of a given size lies further up (dimension j in Fig. 2a) from its baseline than that of a lower case character, the visual centerlines of all upper case characters lie slightly above various of the reference lines. For example, the visual centerline of the upper case I of size #1 lies distance (j₁-k₁) above line A_i, and the visual centerline of the upper case E of size #4 lies distance (j₄-k₄) above line A_i in Fig. 3b. The illustration in Fig. 3b of characters of different nominal sizes located relative to line A_i is not intended to imply that a given transfer sheet must carry characters of different nominal sizes. In general I prefer that a given transfer sheet carry only characters of one nominal size, though it is possible and within the scope of the invention to have characters of plural nominal sizes on the same transfer sheet. The targets T₁, T₂ preferably define a line somewhere near the vertical center of the sheet S as shown. The targets could instead define a line near the lower edge or the upper edge of the sheet, but defining a line near the center is preferred for the reason that vertical positioning errors due to stretching of the sheet then tend to be minimized. While all the imaginary line A₁ to An are shown in Fig. 3a spaced at integral multiples of distance d from the reference line A_o defined by targets T_l and T₂, it is quite possible to use an arrangement where all of them are vertically shifted some arbitrary distance a relative to line A_o, as will become clear below.
The invention can perhaps be best understood by consideration next of the semi-diagrammatic plan view of Fig. 1. The invention may include a generally flat base 10 which in some respects resembles a drafting board, and which may be supported atop a table or desk, or provided with legs (not shown) in the manner of some drafting boards. The left-right direction and the up-down direction in Fig. 1 will be termed X and Y directions, respectively. A cursor 12 extends across base 10 in the Y direction and is freely slidable across the base in the X direction except when locked in a given X position by cursor lock means CL. Gear racks lla and 11b are affixed to and extend parallel to each other in the X direction across respective upper and lower edges of base 10. A shaft 14 extending inside the cursor and journalled therein carries pinions 13a, 13b on its ends, with the pinions engaging the racks lla, 11b and insuring that both ends of the cursor travel the same distance, thereby maintaining an edge or surface 12a of the cursor aligned in the Y direction.
A further gear rack 17 is mounted inside the cursor to extend in the Y direction the entire length of the cursor. A transfer sheet carriage or chase 20 includes a spring-operated gripping means 21 for gripping the lefthand edge of a flexible transfer letter sheet S. The carriage preferably grips sheet S at a distance above the surface of base 10 approximating the thickness of the thickest sign blank to be used, such that the sheet may lie flat atop a sign blank B when the cursor is moved rightwardly from the position shown in Fig. 1. Carriage 20 is mounted on cursor 12 to be freely movable along the cursor in the Y direction whenever the operator pushes lever 26 to disengage a spring-biased detent means 25 which otherwise engages rack 17 and prevents movement of carriage 20 in the Y direction. The pitch of the teeth of rack 17 is chosen to establish a selected Y increment distance, such a 0. 250 inch, this being the value referred to as d in the preceding discussion of Figs. 3a and 3b. Whenever the operator releases lever 26, the detent means engages rack 17, constaining the carriage to move to the nearest one of a plurality of discrete Y positions spaced 0. 250 inch apart, and preventing the carriage from occupying some other Y position in between a pair of the discrete positions. Thus if the total range of travel of the carriage along the cursor is of the order of 16 inches, the carriage can occupy only something of the order of 64 evenly spaced Y positions. It is important that the detent means 25 engage the rack to fix the carriage Y position with no appreciable backlash or play, and important that rack 17 have uniform tooth pitch along its entire length. Various known forms of detent means may be used.
A pair of shafts 28, 29 journalled on base 10 to extend in the X direction may be rotated by cranks 31, 32 to rotate spools 34, 35 carried on the shafts, thereby reeling portions of a flexible tape 36 from one spool toward the other, and thereby positioning a selected section of the length of the tape below window or opening 10e where it may be viewed. Tape 36, as will be further explained below, carries a plurality of marks such as the rectangular boxes 9a-9d shown in Fig. la, with the heights of such boxes and spacings between boxes different along different sections of tape 36. In an alternative embodiment separate rigid strips are substituted for the continuous length of flexible tape. A plurality of index marks 8a to 8e inscribed atop base 10 at the edge of window 10e lead to sign blank height bars shown inscribed on base 10 in the manner of bar graph elements. The bottom edges of the bars depicted are all shown aligned on a reference line Y_o. A pair of thin plates 40, 41 carried atop base 10 slidingly abut along a line 42 which is canted from the X direction. The plates are each shown carrying five labelled index marks, and upper plate 41 also carries a target index line TL. The position of plate 40 on base 10 is fixed, and plate 41 is slidable against plate 40. When a sign is to be made with its row or rows having all lower-case characters or a mixture of lower-case and upper-case characters, the two plates are relatively positioned as shown so that their two left-most index marks (which are labelled "Lower Case or Mixed") are registered, and target line TL will have a predetermined Y position. That position is labelled Y₁ for sake of explanation. The other index marks on the plates each relate to a respective one of four different nominal character sizes #1 to #4, which might be, for example, 3/8, 1/2, 3/4 and 1 inch nominal sizes. The pair of lines relating to the desired nominal character size are aligned with each other if the row or rows on the sign being made contains only upper-case characters. For example, if the 3/8 inch or #1 size marks are aligned, target line TL will be moved distance (j₁-k₁) below line Y₁, while if the 1- inch or #4 size marks are aligned, the target line TL will lie distance (j₄-k₄) below line Y₁. As plate 41 is slid rightwardly to align different pairs of similarly-labelled index marks, target line TL will be moved downwardly to different Y positions below line Y₁. Thus plate 41 will be seen to form scale means for moving target line TL to .different Y positions relative to line Y₁ in accordance with a selected character height or mix of character heights. As will be seen below, moving target line TL downwardly a given distance below line Y_l later results in the transfer sheet which is used being mounted downward .relative to carriage 20 by that distance. Various alternative means for positioning a transfer sheet relative to the carriage will be described below.
Respective edges of a further pair of thin plates 44, 45 carried on board 10 similarly engage each other along a line shown centered at an angle from the X direction. Each of these plates has a trio of index marks labelled "Bottom", "Neither", and "Top", pertaining to which edge, if either, of a sign to be lettered will be partially covered when the sign is put into use. If plate 45 is positioned in the centered position shown so that the two "Neither" marks register, the upper edge 45a of plate 45 will have one predetermined Y position on base 10, while sliding plate 45 rightwardly or leftwardly to register the "Bottom" marks or "Top" marks, respectively, will move edge 45a downwardly or upwardly, respectively, in any case keeping edge 45a aligned precisely in the X direction. Edge 45a _com- prises a reference edge against which sign blank B may be abutted and then temporarily affixed atop base 10, as by means of adhesive tape 46, for example while a sign is being made. Thus plate 45 will be seen to comprise scale means for determining the Y position of an edge of a sign blank atop base 10 in accordance with the location of an edge of the sign which will later be occluded in use. In a typical application moving slide 45 from its centered position will shift the mounting position of the sign blank about 1/4 inch. The use of single pairs of "Bottom" and "Top" marks assumes use of holders which will cover a known width of strip at the upper or lower edge of a sign. A plurality of additional scale marks (not shown) may be carried on plates 44 and 45 to allow edge 45a (and hence the sign blank B) to be positioned at various other positions to accommodate sign holders which cover different edge areas of signs. When slide is in its centered "Neither" position, its edge 45a and the lower edge of sign blank B lie at reference line Y_OS the same Y position as the bottom of window 10e and the bottoms of the height bars shown. The heights of different standard-size sign blanks preferred for use with the invention are each integral multiples of the incrementing distance d, and in an exemplary embodiment those multiples are 3, 6, 18, 24 and 36. Each index mark of the group 8a to 8e (Fig. la) is inscribed above line Y_o at a distance equal to one-half of the sign blank height with which it is associated. For example, index line 8a associated with signs 9 inches high lies 4. 5 inches above line Y_ol It now will be seen that when a given size sign blank is abutted against edge 45a, its actual vertical centerline is aligned with the index mark associated with that size of sign blank assuming slide 45 is in the, "Neither" position, and the vertical centerline of its eventual sight is associated with the index mark if slide 45 is in its "Top" or its "Bottom" position. Thus one of the index lines 8a to 8e always indicates the vertical centerline to be used for a sign blank affixed to base 10 if the sign blank has one of the five standard heights shown. The sign blank B is placed against edge 45a with its left edge on one of four left margin guidelines 7a-7d, each of which is labelled with a respective on of the four standard character sizes intended to be used.
Assume that target line TL lies at line Y₁, the situation when all lower-case or mixed lower case and upper case characters are to be used. If a transfer sheet is slidingly positioned in carriage 25, with the carriage detent engaged, until targets T_land T₂ on the transfer sheet are aligned on target line TL and then gripped by the carriage gripping means, one is assured that thereafter, whenever the detent means is engaged, that all of the imaginary lines A_o to An on the transfer sheet lie integral multiples of increment distance d from target line TL; and further, because the apparent vertical centerlines of all lower case characters are situated on various of those imaginary lines as previously explained, one is assured that those apparent centerlines lie integral multiples of increment distance d from target line TL. Still further, because the Y distances from line Y₁ to each of index marks 8a to 8e are all integral multiples of d, one is assured that if the carriage is vertically moved to place a lower case character on the transfer sheet substantially centered (say within 0. 5d) over a selected one of those index marks and then detented, the apparent vertical centerline of that lower case character will then be exactly centered on the selected index mark. If the selected on of the index marks, say mark 8a, for example, coincides with the vertical centerline of the sight of sign blank B, it now will be apparent that one can readily position a row of lower case characters (or mixtures of lower case and upper case characters, which are assumed to have the same apparent centerlines), so that the apparent centerline of the row accurately coincides with the centerline of the sight of the sign.
Further, since the vertical centerlines of boxes 9a to 9d on tape 36 are spaced apart at distances which are integral multiples of increment distance d, it will become apparent that it the vertical centerline of box 9b is aligned with index mark 8a as shown, by moving the carriage and then detenting it, lower case characters (or mixtures of lower case and upper case characters) can be readily spaced along rows so that the apparent vertical centerlines of those further rows accurately coincide with the vertical centerlines of any of boxes 9a-9d on .tape 36. Thus accurate odd vertical spacing is readily achieved. Still further, if "Even" mark 5 on tape 36 lies a distance from the centerlines of boxes 9b and 9c which is an integral multiple of distance d, and if that "Even" mark is aligned with a selected one of index marks 8a to 8e, it will be apparent that rows of lower case characters (or mixtures of upper and lower case) may be accurately spaced so that the apparent vertical centerlines of those rows lie equal distances above and below the selected index mark (of the group 8a to 8e), thereby providing "even" vertical spacing of rows on the sign blank.
If a transfer sheet is positioned in carriage 24 as was just described, by aligning its targets with target line TL when line TL lies at the Y₁ reference position, the apparent centerlines of lower case characters on the sheet are accurately positioned to lie at distances which are integral multiples of distance d from the reference marks 8a to 8e, but the apparent centerlines of upper case characters then will lie distances (j_m-k_m) above lines which are integral multiples of distance d. Thus when rows are to be formed of all upper case characters, so that strings of lower case characters do not dominate them to lower the overall apparent centerlines of the rows, proper vertical spacing of the apparent centerline of such rows is assured by merely lowering target line TL a distance (j_m-k_m) below reference position Y₁, by sliding plate 41 to align the pair of index marks on plates 41, 42 pertaining to the nominal size of characters being used, and then when the transfer sheet targets are aligned with target line TL, the apparent centerlines of all upper case characters on the transfer sheet lie at distances from index marks 8a to 8e which are integral multiples of distance d, thereby vertically centering rows formed entirely of upper case characters.
In the foregoing description all of the imaginary reference lines on the transfer sheet with respect to which characters are located were said to lie distances id from line A_o defined by targets T₁, T₂. With such an arrangement, characters may be located with respect to line A_o in the same manner as with respect to the other imaginary lines. It is not necessary, however, that the target line A_o lie distances id from the other imaginary lines. Assume, for example, that line A_o lies a wholly arbitrary distance a equal to 0. 030 inch below distances id from the other imaginary lines. Exactly the same results as those previously described will be obtained if, in addition, reference line Y₁ is merely moved downwardly the arbitrary distance 0. 030 inch, so that line Y₁ lies 0. 030 inch below distances which are id from reference line Y_o and index marks 8a to 8e. With such an arrangement, all lower case character centerlines on a sheet will lie 0. 030 inch above distances id from line A_o.
To illustrate typical operation of the invention, it will be assumed that three rows of one-inch or #4 size capital letters are to be placed on a 9-inch high sign blank which will be used in a bottom edge holder, that "wide" row spacing is to be provided, and that a 1-inch margin is to be provided at the left edge of the sign. The following simple procedure may be used.
Plate 45 is slid to register the pair of "Bottom" index marks, and the sign blank is butted against edge 45a and line 7d and taped to base 10. The vertical centerline of the "sight", or portion of the sign blank to be eventually displayed will then lie aligned with index mark 8a. Plate 41 is then slid to register the pair of 1-inch index marks. Cranks 31 and 32 are turned until a section of tape 36 is labelled "1- inch wide" appears in window 10e.
Because an odd number (i. e. 3) of rows are assumed to be required and the sign blank to be used is 9 inches high, the centerline 6 (labelled "odd") of the selected section of tape 36 is aligned with the index line 8a leading from the 9-inch height bar to window lOe. Line 8a will be aligned with the center of the sight to be used on the 9-inch sign blank, and hence moving centerline 6 into alignment with index line 8a serves to vertically position the boxes 9a-9c at the same Y positions as the three rows of 1-inch characters should have on the sign blank. With the boxes 9a-9d on tape 36 then visible adjacent the left end of the sign blank, the operator is immediately afforded an indication of character size and vertical spacing which helps him visualize how the finished sign will look, allowing him to select another character size and/or spacing if that first selected seems to be vertically too crowded, for example. The cursor is then moved to the far left, the carriage moved downwardly, and the detent means engaged. The transfer letter sheet S is then inserted in the carriage, slightly shifted until the two targets T₁, T₂ on the letter sheet are vertically aligned on target line TL on plate 41, and then clamped in the carriage. Adjusting sheet S in the. carriage to align its targets with target line TL on slide 41 insures that the apparent centerlines of all 1-inch nominal-size upper case characters carried on the sheet then lie either on various of the index lines 8a-8d or are vertically spaced therefrom by distances which are integral multiples of the Y incremental distance, 0. 25 inch.
The cursor and carriage are next moved until the left edge of the first character to be transferred sits on the 1-inch margin guideline 7d, and a small pencil or pen "tick" mark is made on an edge of sheet S to coincide with the selected margin guideline. The cursor and carriage are then moved to position the first character above the box 9a visible on tape 36 through window 10e, (it being assumed that the uppermost of the three rows is to be formed first, which is not really a requirement. When that is done and the carriage release lever is released, the carriage may move some appreciable distance (e. g. 0.0₁0 inch) one way or the other in the Y direction as the detent means 25 seats against rack 17. The cursor is then moved to the right until the tick mark registers with the selected margin guideline, the cursor is locked in place, and the first letter to be transferred is then in proper position to be burnished in place on the sign blank. Whenever the operator moves the cursor rightwardly so that the right edge of sheet S passes the left edge of the sign blank, he lifts the right edge of the transfer sheet so that it does not catch on the left edge of the blank.
After the first character in the first row has been transferred, the cursor and carriage then may be moved to position the second letter and successive letters of the first row at their correct Y positions over the sign blank without making any further vertical alignment operations other than the extremely simple one of insuring that a selected letter ready to be transferred is not vertically misplaced by one or more discrete Y increments, i. e. 0. 25 inch or a multiple thereof in the exemplary embodiment. The operator can, of course, readily detect any such gross misalignment. The horizontal or inter-character spacing between letters along a line must be properly adjusted by the operator, of course, by proper X movement of the cursor.
After the first line of characters has been formed on the sign blank, the cursor and carriage are then moved to position the first character to be used in the second line above the next lower box visible on tape 36, and forming the second line follows the same procedure as that just described. The similar procedure for forming of the third line will be apparent without further explanation.
In the exemplary embodiment which provides for use of sign blanks as high as 9 inches and for use of four different character heights (nominally 0. 35, 0. 50, 0. 71 and 1. 0 inches) window 10e has a Y dimension approximating 9 inches, and tape 36 has 8 sections, arranged in series along the tape, with each section being approximately 9 inches long and having "odd" and "even" index lines of the nature of those shown at 5 and 6 in Fig. 1. Two such sections of tape are preferably provided for each character height, one section relating to "wide" interline spacing and the other relating to "narrow" interline spacing, although sections for various other interline spacings also may be provided, as will be explained.
Fig. 4 illustrates four exemplary sections of tape 36 shown horizontally aligned with a dimension 10e representing an edge of window 10e. Section 36a which is also shown in Fig. la, is labelled "1-inch, Wide", and is shown containipg four boxes 9a-9d each assumed to be 1-inch high, and with "wide" inter-row spacing. Importantly, the vertical centerlines of all of boxes 9a-9d lie vertically spaced apart at distances which are integral multiples of the incrementing distance d. As many 1-inch high boxes with such spacing as can be fitted in the Y dimension (assumed to be 9 inches) of the largest sign blank to be used, without equalling that Y dimension, are preferably provided. It may be noted that a further box 9e shown in dashed lines could be provided on section 36a, but that use of 5 lines of I-inch characters with such 1-inch spacing would result in no upper and lower margins being provided on a 9-inch high sign. Since such a sign is deemed unacceptable, box 9e is not carried on tape section 36a.
Tape section 36b carriers boxes for 1-inch high characters having "narrow" inter-row spacing, so that one-half inch spaces are provided between adjacent pairs of boxes in section 36c. Tape section 36d is shown as carrying boxes each 0. 75 inches high with what may be termed "extra-wide" inter-row spacing, and is shown with 1-inch spacing between adjacent pairs of boxes. Tape section 36e is shown carrying boxes each 0.-75 inch high with what may be termed "extra- narrow" inter-row spacing, which is shown as one-half inch spaces between adjacent pairs of boxes. It will be apparent that further generally-similar sections can be provided along the length of tape 36 having yet further types of inter-row spacing. Significantly, the distance from the bottom, centerline or top of any box in a given section of tape to the bottom, centerline or top of any other box in that section, is an integral multiple of the Y increment distance (assumed to be 0. 250 inch) of the carriage 20 on the cursor 12.
The central box, if an odd number of boxes is provided in a section as is the case shown for sections 36d and 36e, or one of the central pair of boxes if an even number are provided, as for sections 36a-36c, has an index mark 6 labelled "odd" passing through its vertical center and each tape section has an "even" index mark 5 spaced vertically from the odd index mark at a distance which is an integral multiple of the incrementing distance d. If any of the tape sections shown in Fig. 2b is reeled so that part or all of the section is visible in window 10e, and either its odd index line 6 or its even in- . dex line 5 is aligned with any one of the index lines 8a to 8e, the vertical centerlines of all of the boxes of the tape section will lie at Y distances from reference line Y_o which are integral multiples .of the Y increment distance.
Figs. 5a and 5b illustrate an exemplary arrangement for providing rack llb along the lower edge of table 10. Shaft 14 which extends through c ursor 12 above the upper surface of table 10 carries a plastic pinion 13b on its end, the teeth of which engage a taut length of rubber drive belt 11b which acts as a rack. Plate 12b affixed to the lower end of cursor 12 carries a pair of rollers 12c, 12d which maintain belt 11b engaged with pinion or drive wheel 13b. A clamp 47 crimped around one end of rack-belt llb carries a threaded bolt 48 which is shown engaged by a wing-nut 49 allowing the tension in belt 11b to be adjusted. The other end of belt 11b may be fixedly attached to the lower left edge of table 10. Upper rack lla may comprise a similarly operating section of drive belt. Rigid metal or plastic racks can instead be arranged to extend along the upper and lower edges of table 10, but the rubber drive belt arrangement shown is preferred because of its modest expense.
As illustrated in Figs. 6a and 6b film or tape 36 extends between reels 34 and 35, passing over the edges of guide plates 51a, 51b which train the tape up to a position just below window 10e, which preferably carries a transparent plastic or glass insert 10f to protect the tape from accidental damage. Guide plates 51a, 51b are affixed to the bottom of upper plate 10a of base 10.
In embodiments where separate rigid plastic strips 3.6' are used in lieu of tape 36 and the pair of reels, the opening in the upper plate 10a of base 10 preferably has shelf portions 53a and 53b for supporting the edges of each plastic strip 36' carrying spacing indica. The Y position of a strip 36' can be accurately shifted to provide odd of even spacing.
It is important to note that the use of a movable target line TL such as that shown carried on plate 41 in Fig. 1 is not strictly necessary. A modification is illustrated by target lines TL₁ to TL₅ shown in Fig. la in dashed lines. If a plurality of such lines are inscribed on the upper surface of base 10 at appropriate vertical locations, the operator may align the targets T_l and T₂ on a transfer sheet with a selected one of those lines rather than with the line TL₁. The line TL₁ in Fig. la should be a vertical distance id from line Y_o, and the other target line should be spaced distance j₁-k₁, j₂-k₂, etc., below lines which are distances id from line Y_o. Lines TL₁ to TL₅ preferably extend horizontally the entire width of each transfer sheet to facilitate accurate alignment of a transfer with any selected one of them.
In an alternate system of the invention partially illustrated by Figs. 7, no movable target line akin to line TL on slide 41 need be provided. Instead, a fixed line on base 10, such as the line shown at Y_o in Fig. 1 is used, and one or another of two reference lines on a given carrier sheet is aligned with line Y_o, to fix the vertical position of the sheet relative to carriage 20, depending upon whether or not the sign is to use all upper case characters. In Fig. 7 targets T₁ and T₂ define a first reference line across carrier sheet S' and targets T₃ and T₄ define a second reference line. Each sheet carries only characters of one nominal size, though it may carry both upper case and lower case characters of that size, of course. The characters on each sheet, as in the previous example, as all positioned so that their baselines all lie distance id vertically apart. The reference line on each sheet used when all upper case characters are to be formed is shown lying distance (id +j_m - k_m) below that used for lower case or mixed rows. Thus on a sheet carrying all size #1 characters, for example, one reference line lies distance (id + j_i- k_i) below the other, on a sheet carrying all size #2 characters one reference line lies distance (id + j₂- k₂) below the other, etc. The reference line used for making a sign with all upper case characters can lie above the other reference line on the sheet, by merely assuming i to be a negative integer, of course.
It is not strictly necessary that a reference line defined on each transfer sheet be aligned with a target line on base 10 per se. In Fig. 8 the portion 21' of carriage 20 which grips a transfer sheet carries a plurality of vertically spaced index marks, a selected one of which a reference line r on transfer sheet S" is aligned with. The upper left corner of the transfer sheet also carries a vertical line V which appears through a slot 54 in gripping means 21' so that it may be aligned with index marks 55 on the gripping means, insuring that the sheet is positioned in the gripping means so that all character baselines extend precisely in the X direction.
Figs. 9a and 9b semi-schematically illustrate the principles of one form of carriage detent mechanism, with various portion omitted for sake of clarity. The carriage 20 has a member extending below one side of cursor 12 to pivotally support a pair of detent arms 25a, 25b on a pin 56. Tension spring 57 tends to pull the arms together, forcing their ends into a pair of the tooth recesses of rack 17 extending along the cursor, and thereby prevent Y movement of the carriage. Handle 26 carries a pair of pins 26a, 26b which engage arms 25a, 25b to slightly spread the arms apart and clear their ends from the rack when handle 26 is pushed inwardly, allowing the carriage to be moved in the Y direction.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained. Since certain changes may be made in carrying out the above method and in the constructions set forth without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims

1. Apparatus for making a sign by dry transfer of letters to a sign blank from any one of a plurality of carrier sheets, characterised in that said apparatus comprises in combination: a base having a generally planar surface for supporting a planar sign blank; cursor means carried on said base to extend across said base in a first direction and be adjustably movable across said base in a second direction perpendicular to said first direction; carriage means carried on said cursor means and adjustably movable relative thereto in said first direction; and detent means constraining said carriage means to lie in a plurality of discrete positions spaced apart by a predetermined incremental distance in said first direction, said carriage means including means for gripping said one of said carrier sheets.

2. Apparatus as claimed in claim ₁, wherein said gripping means is operative to grip said one of said carrier sheets in or between any of a plurality of different positions of said sheet relative to said carriage means, said one of said carrier sheets carries indicia defining a reference line across said sheet, and said base carries target indicator means with a reference line across said sheet, and said base carries target indicator means with which said indicia on said one of said carrier sheets may be registered to fix said sheet in a selected one of said positions of said sheet relative to said carriage means.

3. Apparatus as claimed in claim 1, including a plurality of strips each carrying indicia representing a respective form of vertical spacing between rows of characters, and means for displaying a selected one of said strips adjacent said sign blank.

4. Apparatus as claimed in claim 1 , wherein said plurality of carrier sheets carry characters of a plurality of different nominal sizes, each of said characters having a baseline, the baselines of the characters of a given nominal size on any given one of said sheets being spaced apart in said first direction at integral multiples of said predetermined incremental distance.

5. Apparatus as claimed in claim 1, wherein said base carries means for locating an edge of said sign blank in a reference position in said first direction, and a plurality of guide marks on said base for indicating the centerline in said first direction of any of a plurality of sign blanks having respective predetermined dimensions in said first direction when they are placed in said reference position.

6. Apparatus as claimed in claim 2, wherein said target indicator means comprises a member movable relative to said base and carrying a target indicium, and scale means for determining the position of said target indicium relative to said base in said first direction.

7. Apparatus as claimed in claim 2, wherein said one of said carrier sheets carries indicia defining two reference lines across said sheet, said reference lines being spaced apart in said first direction at a distance which is an integral multiple of said predetermined incremental distance plus the difference between the baseline to apparent centerline distance of upper case characters on said one of said sheets and the baseline to apparent centerline distance of lowercase characters on said one of said sheets.

8. A plurality of carrier sheets for use in making signs using characters of a plurality of different nominal sizes, each of said sheets carrying a plurality of transferable characters each having a baseline, the baselines of the characters of each respective nominal size on any given sheet being vertically spaced apart at integral multiples of a predetermined distance d, whereby signs having characters of any selected one of said nominal sizes may be made with said characters accurately aligned in a row by successively translating a selected one of said sheets having characters of said selected one of said nominal sizes vertically and incrementally through distances which are all integral multiples of said predetermined distance d as said row is being formed.

9. A plurality of carrier sheets as claimed in claim 8, wherein each of said sheets carries means defining a reference line across the sheet, each lower-case character of any given nominal size on any of said sheets has its apparent vertical centerline located a vertical distance from the reference line on its associated sheet which is an integral multiple of said predetermined distance d, plus a second predetermined distance a, thereby locating the baseline of each lower-case character a vertical distance from said reference line which is an integral multiple of said predetermined distance d, plus said distance a, plus the distance k between the apparent vertical centerline and the baseline of each lower-case character, where k varies for characters of different nominal sizes, and the baseline of each upper-case character is located a vertical distance from the reference line on its associated sheet which is also an integral multiple of said predetermined distance d, plus said distance a, plus said distance k for characters of its nominal size.

₁0. A method of making a sign having a plurality of characters aligned in a row on a receiving surface which comprises the steps of: positioning a sheet carrying transferable letters in a carraige at one of two vertical positions relative to said carriage dependent upon whether said row is to contain any upper-case characters; and thereafter moving said carriage and said sheet horizontally and vertically to locate successive desired letters on said sheet along said row atop said receiving surface, the moving of said carriage vertically comprising stopping said carriage at and only at successive vertical positions all of which are spaced vertically apart at integral multiples of a predetermined distance.

₁1. A method as claimed in claim ₁0, which includes the steps of placing a row spacing indicator adjacent one end of said receiving surface, said row spacing indicator having a plurality of vertically spaced indicia, and wherein said step of moving said carriage and said sheet comprises locating successive desired letters adjacent selected ones of said indicia on said row spacing indicator.

₁2. Apparatus for making a sign having characters of any selected one of a plurality of different nominal sizes and having all lower-case, all upper-case, or a mixture of lower-case and upper-case characters of said selected one of said nominal sizes, comprising, in combination: a plurality of carrier sheets each carrying transferable characters, each of said characters having a baseline, the baselines of the characters of each nominal size being vertically spaced apart on said sheets at integral multiples of a predetermined distance; a base for supporting a sign receiving surface having a vertical centerline with said vertical centerline of said surface at a reference vertical position on said base; a carriage mounted on said base and including means for gripping a selected one of said carrier sheets; means for positioning said carriage to any one of a plurality of discrete positions spaced vertically apart at integral multiples of said predetermined distance; and means for adjusting the vertical position of said selected one of said carrier sheets relative to said carriage to either a first position in which the apparent centerlines of lower-case characters on said sheet lie integral multiples of said predetermined distance from said reference vertical position or a second position in which the apparent centerlines of upper-case characters on said sheet lie integral multiples of said predetermined distance from said reference vertical position.