Apparatus for use in connection with dry transfer lettering and analogous sheets

A drawing board device is described of particular value in composing signs using dry transfer lettering sheets. The board has a base and a horizontal rule mounted thereon and capable of moving vertically and horizontally. The rule has one or more magnetic clamps for sheets of transfer material, and one or more sets of register pins for registering with e.g. a preprinted line on or preprinted holes in the sheet. The vertical movement of the rules is preferably stepped, the interline spacing between the lines of letters on the sheet being an integral multiple of the step length.

This invention relates to apparatus for use in connection with dry transfer 
lettering and analogous sheets. 
In recent years the use of dry transfer lettering sheets has become 
widespread in a variety of applications. In particular, dry transfer 
lettering sheets are used in large quantities to produce legends on 
artwork, architectual drawings and engineering drawings and in the 
production of signs. In all of these applications it is desirable to align 
the letters relative to one another with very considerable accuracy in 
order that the resulting word or words looks correct to the eye. Because 
of the Vernier acuity of the human eye, even quite small departures from 
linearity show up very obviously, even to an untrained observer. 
According to the present invention there is provided apparatus for use in 
conjunction with one or more sheets of dry transfer symbols which 
comprises a baseboard, a horizontal rule mounted thereon and capable of 
moving both horizontally and vertically, register pins on the rule for 
registration with predetermined positions on the sheet of dry transfer 
material and a magnetic clamp adapted to clasp one edge of the sheet of 
dry transfer material and hold it engaged on the pins. 
Preferably the magnetic clamp takes the form of a hinged strip of flexible 
magnetic material which may be lifted away from the rule to expose two or 
more registration pins and allow the positioning of a sheet of dry 
transfer lettering thereon. Thereafter, the magnetic strip may be hinged 
down to hold the sheet of dry transfer material clamped firmly against the 
rule, which must naturally be made at least partly of a magnetic material. 
The registration pins may be sharp and used to perforate the transfer sheet 
as it is positioned, e.g. at preprinted positions thereon, or they may be 
blunt and the transfer sheet provided with e.g. two preformed 
appropriately placed holes for fitting over the pins. 
In a particularly preferred embodiment, the rule is of generally triangular 
cross-section having two faces equally oppositely sloped with respect to 
the plane of the baseboard and each face bearing a magnetic clamp and 
register pins. Thus, seen from the position of a user, the horizontally 
extending rule bears an upper clamp for clamping a sheet of dry transfer 
material extending upwardly over the baseboard and a lower clamp for 
bearing a like sheet of material extending downwardly. 
The rule may be provided with associated guides and slides to enable it to 
be moved horizontally and vertically to the desired degree. Such 
mechanisms are known in architects' and engineers' drawing boards and do 
not need to be described further here. In particular, the rule may be a 
short rule horizontally slidable on a horizontally fixed vertically 
moveable rule extending across the entire width of the board, or the 
horizontal rule may be vertically slidable in a vertically extending 
carriage which is horizontally slidable on a rail at the upper horizontal 
edge of the board. In a particularly preferred embodiment, the apparatus 
is of this type and of the type defined above, and is provided with means 
which subdivide the vertical movement of the rule into a plurality of 
equally spaced steps. This is particularly advantageous where the 
interline spacing between the lines of images, usually letters and other 
typographical symbols, on the dry transfer sheet is a multiple of the 
length of each such step. For example, the rule may be arranged to be 
movable vertically in steps of size 3 mm. and adjacent lines of 
typographical symbols on the dry transfer sheet may have a spacing of e.g. 
18, 21 or 24 mm. 
The preferred embodiment in which two clamping members are provided is 
particularly advantageous in that it enables a sheet of upper case letters 
to be clamped in the upper clamp and a sheet of lower case letters to be 
clamped in the lower clamp. This is particularly of value in many sign 
making applications and the present invention is of particular value as an 
aid to the the assembly of an accurately aligned sign from a dry transfer 
lettering material. 
In order to ensure proper location of the lines of images on the dry 
transfer sheet with the register pins in the rule, the dry transfer sheet 
may bear an appropriate mark for piercing by sharp pins or may have 
preformed apertures for registration with the pins. A mark is preferred 
since it can conveniently be printed at the same time as the dry transfer 
sheet is manufactured and accurate alignment and positioning relative to 
the indicia printed on the transfer sheet is automatically achieved. Thus 
for example the base and top of each dry transfer sheet may bear an 
alignment mark in the form of a line having near the left-hand end thereof 
a small circle. In use, the left-hand pin is pierced through the circle 
and the sheet then aligned so that the right-hand pin pierces the line. 
Thereafter the magnetic clamp strip is applied to hold the sheet firmly in 
that position.

Referring to the drawings the apparatus consists of a baseboard 1 having at 
one edge a rail 2 in which a vertical bar 3 slides. The mechanical 
connection between rail 2 and bar 3 is such that bar 3 is at right angles 
to rail 2. Bar 3 in turn carries a rule 4, accurately at right angles to 
bar 3. Rule 4 may slide up and down bar 3 in step-wise fashion by means of 
a sliding guide piece mounted in bar 3 and an associated screw thread of 
large pitch into the thread of which engages a spring loaded ball mounted 
on the slidable member. The screw may be rotated by means of a handle 5 so 
allowing the vertical position of rule 4 to be infinitely varied. 
Rule 4 is made of steel, is of generally triangular cross-section and bears 
on its two inclined upper faces magnetic strips 7 attached by a flexible 
hinge 6 and backed by metal strips. The central portion of hinge 6 is 
adhered to rule 4 and backed by a metal bar 10. Each face of rule 4 bears 
two protruding pins 8, either sharp as in FIG. 3 or blunt as in FIG. 4. 
In use, a sheet of dry transfer lettering 11 may be positioned on each side 
of rule 4 by lifting the magnetic strips 7, positioning the sheet on the 
pins 8 and lowering the magnetic strips firmly to clamp the sheet against 
the bar. The sheets may take up any one of a vertical positions by moving 
the rule up and down and the horizontal position may be adjusted by 
sliding bar 3 on rail 2. 
The apparatus illustrated is of particular value in composing signs on a 
suitable substrate material which is merely stuck to the baseboard 1 e.g. 
using masking tape in known fashion and the rule is then moved to position 
the desired character over the desired position on the substrate material. 
Successive letters are rubbed down in this way until the desired legend is 
composed, whereafter the substrate bearing the legend may be removed from 
the board and used to make a sign. Horizontal alignment of the letters may 
be ensured by using the stepped vertical positioning of the rule 4 
achieved by means of the screw and springloaded ball device in bar 3. 
Preprinted lines on sheets 11 which are aligned with the pins 8 ensure 
correct spacing (at an integral multiple of the screw pitch) between the 
sheet 11 above rule 4 and that below it. Correct lateral spacing may be 
achieved by using spacing marks printed on sheets 11 in known fashion.