Method of moulding and applying marks on a surface

A method by which an elastomer is applied to a model (1) with relief marks to be reproduced. The purpose of the elastomer once set is to form a mold membrane (14) and incorporate within its own material the shape of the marks on the model. The mold membrane is then separated from the model and filled with a setting material, and the mold membrane is applied to a support in order to transfer the marks after preliminary pasting.

FIELD OF THE INVENTION 
The present invention relates to the field of fixing elements to supports 
and relates more particularly to a process for molding and applying 
three-dimensional indications to a surface such as a timepiece dial which 
acts as a support. 
BACKGROUND OF THE INVENTION 
Processes for fixing elements to supports, such as the processes of 
transfer printing by means of an etched block and a pad, have been known 
for a long time and give very good results when the indications to be 
reproduced are flat and thin, but these processes becomes [sic] more 
difficult to use when it is desired to obtain more substantial 
thicknesses. Other techniques such as insertion or adhesive coating have 
hitherto enabled three-dimensional indications to be fixed by placing them 
individually. 
Other processes exist in which the indications to be affixed, for example 
to a dial, are produced by cutting a sheet consisting of a compound 
possibly containing luminescent material, the indications obtained having 
a flat shape. However, this process, on the one hand, does not allow the 
production of indications of elaborate shape and, on the other hand, 
presupposes a manipulation carried out by an operator in order to place 
them on the support. 
SUMMARY OF THE INVENTION 
The present invention aims to overcome all these drawbacks and more 
particularly to allow the creation of indications of any shape and/or 
thickness, while eliminating the manipulation of the indications by an 
operator during the procedure of laying them on the support. The process 
for transferring indications to a surface according to the invention is 
characterized in that an elastomer is applied to a pattern having at least 
one indication in relief to be reproduced, this elastomer, after having 
cured, being intended to form a membrane-mold and to reproduce in negative 
the indication in relief on the pattern, in that the membrane-mold is 
separated from the pattern, in that the membrane-mold is filled with a 
compound capable of curing and in that the membrane-mold containing the 
indication filled with the cured compound, or the compound in the process 
of curing, is applied to a support so as to transfer the indication after 
having precoated the place or the visible surface of the indication with 
adhesive. 
The invention also relates to a tool for implementing this process, 
characterized in that it comprises a retaining piece having at least one 
orifice, the piece having at least one indexing notch or perforation, 
molding pieces gripping the retaining piece and the pattern for producing 
the membrane-mold by molding. 
The subject of the invention is also the support obtained by implementing 
the process.

DETAILED DESCRIPTION OF THE INVENTION 
The pattern in FIG. 1 is a dial pattern for a timepiece having 
three-dimensional indications exhibiting a certain relief. The standard 
dial in FIG. 1 represents a definitive pattern which will serve to produce 
the tooling devices and the molds used for the mass manufacture of 
timepieces to be reproduced. It comprises a disk 1 on which the 
indications 2-5 to be molded are produced either by machining or by 
bonding or welding to the surface. The pattern serves as a die for a first 
operation of molding and positioning the indications on surfaces 
representing the blank for the dials to be manufactured. 
Although the pattern shown is a timepiece, it is obvious that the process 
which will be described below is not limited to this application and that 
it may be applied to the production of dials or any surface bearing 
three-dimensional indications used in mechanical engineering, electronics, 
etc. 
The initial pattern shown in FIG. 1 is in the form of a disk 1, the surface 
of which has various indications 2, 3, 4, 5 which may have varied 
three-dimensional shapes. This pattern will be used for producing one or 
more molds which will make it possible to manufacture and contain the 
indications in accordance with the original. The indications contained in 
the molds may then be fixed to a support in a single operation. The edge 
of the disk 1 furthermore has an indexing notch 6. 
With the pattern in FIGS. 1 and 2, the first operation carried out is the 
manufacture of at least one membrane-mold. In order to support this 
membrane-mold, a ring 7, shown in FIGS. 3 and 4 and provided with an 
indexing notch 8 corresponding to the notch 6 in the disk 1, is 
advantageously used. The ring 7 is machined with a dovetail internal 
profile 9 so as to be able to retain the membrane. 
The disk 1 and the ring 7 are placed freely, without any clearance, as 
shown in FIG. 5, inside a molding device or die 11, the disk 1 and the 
ring 7 being placed in superposition, making the indexing notch 6 in the 
disk 1 coincide with the indexing notch 8 in the ring 7. 
Placed on this assembly is a cover 12 having the general shape of a funnel 
opening onto a central orifice 13 intended for passage of a silicone 
compound 15 poured onto the assembly. Since the base of the cover is 
substantially planar, the excess silicone 15 in the funnel of the cover 12 
can be recovered. The substance 15 employed in this case is a two-part 
silicone elastomer whose most important characteristics are its 
elasticity, its mechanical strength and chemical resistance, its low 
shrinkage and excellent temperature withstand behavior. Other substances 
with similar properties may be used. 
In this way, a membrane-mold 14 having an elastic character is obtained, 
this membrane-mold 14 being supported by ring 7, as shown in FIG. 6. The 
membrane-mold 14 has hollow regions 16 formed, during molding, by the 
three-dimensional indications 2 to 5. This operation may be repeated 
several times so as to cast the desired number of membrane-molds 14 
intended for the production run. 
The next step in the process corresponds to filling the membrane-mold shown 
in FIG. 6. There are several possibilities. In one preferred alternative, 
illustrated in FIG. 7, one may opt for a system of filling using a 
metering apparatus having a nozzle 17 for dispensing a filling compound 
18, this system being either manual or controlled by a numerical-control 
machine, not shown. In another variant, the filling may be accomplished by 
pouring a suitable amount of filling compound 19 (FIG. 8) and subsequently 
razing the surface using a doctor blade 20 intended to remove the excess 
material. Another alternative would be to carry out the operation by means 
of a vibrating action, not shown. 
FIG. 9 shows a membrane-mold 14 held in the ring, the hollow regions 16 
being filled with the filling compounds 18 or 19. 
The filling compound 18 or 19 is, in a preferred case, composed of a 
transparent lacquer with which has been premixed with a luminescent or 
pigmented powder which polymerizes in a few seconds under ultraviolet 
radiation. Acrylic resins or other resins drying in air or in an oven may 
also be used. The luminescent powders may be based on tritium-treated zinc 
sulfite and sulfate, allowing the indications on the dial to be seen at 
night. 
Other alternative filling substances should be considered in order to vary 
the colors or to obtain other desired effects. 
The molded compounds 18 or 19, depending on their nature, are cured by 
various processes: ultraviolet radiation, oven treatment, ambient air, 
etc. As mentioned above, one or more membrane-molds are necessary for the 
production run, depending on the ratio between the time for the molded 
compounds to cure and the time for applying these compounds on the dial. 
The next phase, illustrated in FIG. 10, consists in applying the cured 
molded compounds to the surface 21 intended to receive them. To do this, 
said surface or the indications must be precoated with adhesive, either 
manually using a metering device or using a metering dispenser mounted on 
a numerical-control machine or by a transfer printing system, which 
process is well known in the manufacture of watch dials. In the latter 
case, a metal block 22 is used which has the indications 23 to be bonded 
etched on its surface to a slightly smaller size. This etching operation 
could be performed by covering the original block 22 with a photosensitive 
film (photographic printing technique) and thereafter treating the 
unmasked parts with acid. Once the block 22 has been fixed to its movable 
frame 24, it is coated with adhesive and, after scraping with a spatula, 
the impression is taken using a gelatin or silicone pad 25. The adhesive 
is deposited on the surface 21 to be coated (dial or indication) using 
said pad 25. The movable frame 24, and likewise the pad 25, is controlled 
by a device, not shown, having, for example, translation sideways and 
limit stops allowing relative positioning of the surface 21 with respect 
to the block 22 (FIG. 10). 
As illustrated in FIG. 11, the membrane-mold 14 is accurately placed, by 
means of an indexing device 26, on the surface 21 having spots of adhesive 
27, leaving a suitable heightwise clearance 28. 
The membrane-mold 14 is pressed against the adhesive-coated surface of the 
support 21 using an application tool 29, shown diagrammatically in FIG. 12 
and 13, and the molded indications 18, 19 are released via the edges of 
the membrane by creating, by means of the ducts 30a, a vacuum in the 
suction chambers 30 provided in the tool 29. Advantageously, the tool 29 
may also be produced from the molding die in FIG. 1 according to the 
following operations: 
a) use of a membrane-mold 14 such as the one produced and described with 
regard to FIG. 6, the membrane-mold 14 being placed in the die shown in 
FIG. 5, after having been turned it upside down; 
b) filling the hollow regions 16 of the membrane-mold 14 using a nonelastic 
material capable of curing, for example polyurethane or polyester resin, 
or else an epoxy; 
c) the cured compounds are recovered on a doublesided rigid self-adhesive 
tape and then transferred by bonding, still using the die shown in FIG. 5, 
to a support disk which will itself be used as the application tool 29 
after having been pierced so as to render the suction chambers 30 
operational. 
This manner of operating has the advantage of producing all the tools 
precisely, starting from the pattern in FIG. 1 and using the die in FIG. 
5. Thus, all the molding, positioning and transfer operations are carried 
out with the same die, starting from the initial pattern in FIG. 1. 
The membrane-mold 14 is extracted by means of the suction chambers 30 and 
the molded indications 18, 19 are applied at the desired point. 
Thereafter, the membrane-mold 14 is released from the application tool 29 
and may be filled again. 
FIG. 14 shows an enlarged scale of a molded indication 32 which is 
particularly high and also has a lateral recess 31 allowed by the process 
described up to now. 
The process which has just been described has the following advantages: 
the indications are no longer touched during the production of a piece, 
this being particularly advantageous when using radioactive indications; 
the precision is uniform during molding and transfer, the indications being 
positioned once and for all during an initial adjustment and all the 
operations being carried out using the membrane-mold and the die in FIG. 
5; 
compared to the processes of the prior art, there is a considerable saving 
in time, given that the work may be carried out in mass production using 
several membrane-molds, all produced with the same initial pattern. 
In order to transfer indications continuously, the process described with 
regard to FIGS. 1 to 14 requires the production of 4 to 8 membrane-molds 
according to FIGS. 3 to 6. Thus, the various stations allowing 
membrane-mold filling, drying, adhesive coating and placing of indications 
on a support, may be provided. 
In the variant of the process described with regard to FIGS. 15 to 17, the 
membrane-molds 40 are produced continuously on a flexible support which is 
in the form of a tape 41 having holes 42 over which said membrane-molds 40 
will be injected. The support 41 has, between the holes 42, perforations 
43 which will serve to position the tape 41 during the various operations 
of producing the membrane-molds 40, filling said membrane-molds and 
placing the indications 44 (FIG. 16) on a support, not shown. In order to 
fasten the tape 41 to the membrane-molds 40 and avoid any relative 
displacement between the two components (tape 41 and membrane-molds 40), 
anchoring perforations 45 placed around the holes 42 are provided on the 
tape 41. Thus, during production of the membrane-molds 40 by injection 
molding, as shown in FIG. 17, the material injected between two jaws 46 
and 47 of the molding device gripping the tape 41 will enter the 
perforations 45 and fasten each membrane-mold to the tape 41. The molding 
device in FIG. 17 is similar to that described with regard to FIG. 5, with 
its cover or top 12 (FIG. 5) containing the initial pattern or disk 48 
corresponding to the pattern 1 in FIG. 1. The lower jaw 47 includes a 
central orifice 13 intended for passage of the silicone compound which is 
injected and which, after having cured, is intended to form the 
membrane-molds 40. The jaws 46, 47 of the molding device in FIG. 17 are 
positioned using a guide punch 49 which enters the perforations 43 for 
positioning the tape 41. 
As described above with regard to FIGS. 4 to 6, the material used for 
producing the membrane-molds is a two-part silicone injected cold into the 
jaws 46, 47 of the preheated mold. Placed at the bottom of one of the jaws 
46, 47 will be a disk, not shown, similar to that in FIG. 1 having the 
indications to be impregnated in the membrane-mold. As a variant, the 
indications to be impregnated in the membrane-mold may be formed on the 
bottom of one of the jaws 46, 47. The support used is a flexible support 
in the form of a polyester or polycarbonate tape. The tape 41 with its 
membrane-molds obtained by overmolding is, after the membrane-molds have 
cured, used for passing on to the phase of filling the indications, as 
shown in FIGS. 6 to 9, and then to the phase of adhesive coating and of 
transferring the indications to a support. The variant which has just been 
described has the advantage whereby the various phases of overmolding the 
membrane-molds, filling the indications, adhesive coating and transferring 
said indications may be carried out separately or continuously. The tapes 
containing the indications may also be stored and the tapes may be used in 
a lost-mold process or be reused after the indications which they 
contained have been transferred. 
The process which has just been described has the following advantages: 
1. Control of the drying time during mold-membrane production and control 
of the drying time during indication filling. 
2. Manipulations by an operator, for example if the indications are 
radioactive, are avoided. Possibility of storing the tapes containing or 
not containing the indications. 
3. No wear--the tapes are simply thrown away after they have been used one 
or more times. Guarantee of quality and precision. 
4. The process may be completely automated and used continuously or in 
separate phases (drying, filling, etc.). 
Finally, the process which has just been described offers the possibility, 
if desired, of placing inserts in the indications or of producing 
multilayer indications.