[0001] The present invention relates to a method for applying and forming a thermoplastic
cladding to displays and buttons of covers and/or boxes for electrical or electronic
instruments, particularly control, actuation and adjustment instruments and instruments
for the most disparate functions.
[0002] Current electrical or electronic instruments for controlling and adjusting systems
or machines are notoriously constituted by a box which accommodates the specific instruments
and by a cover which allows to functionally read them and to intervene, by means of
buttons, in order to adjust and calibrate the operating conditions of the system connected
to each individual instrument.
[0003] These instruments are generally arranged on suitable panels which cluster them in
appropriate subframes in order to have an overall view and control of the entire system
or structure of the machine to which the various instruments are assigned.
[0004] Each box of these instruments must be fixed to the panel or subframe so as to ensure
that it is hermetic with respect to external agents and ensure that the cladding is
transparent, in order to view the measurable data, and is flexible so as to be able
to apply the necessary pressure to the various buttons of the instruments that compose
it.
[0005] According to the current art, these characteristics are generally achieved by cladding
the display and the outer surface of the cover with a transparent and sufficiently
flexible film which is associated with the cover by means of a frame provided with
adapted screw or snap-on couplings which allow to anchor it to the box.
[0006] The current art further provides for the interposition of adapted gaskets between
the cover and the edge of the box, as well as between the edge of the box and the
edge of the compartment for housing it in the panel, in order to ensure the prescribed
hermetic sealing of the panel with respect to external agents.
[0007] It is evident that although this method ensures the required conditions of transparency,
flexibility and sealing, it requires a plurality of operations which affect preparation
times and costs as well as the hermetic seal and are entrusted to the technical skill
of the individual installer.
[0008] The aim of the present invention is to provide a cover or a box, for instruments
of the exemplified type, which ensures the best conditions in terms of hermetic sealing
and of adequate flexibility and transparency, regardless of the skill of the installer.
[0009] Within the scope of this aim, an object of the present invention is to minimize the
number of parts to be produced and associated, eliminating the need for cladding containment
frames.
[0010] Another object of the present invention is to minimize the time and cost for assembling
the cladding on the cover or part of the box to be applied to the panel and be made
transparent, flexible and hermetic.
[0011] This aim, these objects and others which will become apparent hereinafter are achieved
with the treatment method according to the present invention, as defined in claim
1.
[0012] A characteristic of the present invention is that the cladding of said covers or
boxes is performed by injection-molding with multi-component materials, one or more
materials being meant for injection in order to form one or more rigid parts for fixing,
supporting and viewing the elements of the individual specific instruments, an additional
material being meant to externally clad the previously molded rigid parts and also
act as a gasket, in order to hermetically seal the box that contains the instruments
applied to the control panel.
[0013] Further characteristics and advantages of the invention will become apparent from
the following detailed description of a preferred but not exclusive embodiment of
the method according to the invention, illustrated only by way of non-limitative example
in the accompanying drawings, wherein:
Figure 1 is a sectional view of a rigid and transparent element to be clad in order
to provide a hermetic and internally visible cover executed according to the invention,
to be applied to boxes for containing electrical or electronic instruments for controlling
the most disparate systems or machines;
Figure 2 is a sectional view of a cover for a box of electrical or electronic instruments,
provided by using the rigid and transparent element of Figure 1, and of the box to
which the cover is to be associated;
Figure 3 is a sectional view of a different embodiment of the cover of Figure 2.
[0014] In all the figures, the same details are designated by the same reference numeral.
[0015] According to the constructive solution proposed in the accompanying figures, as an
application of the method according to the invention, a cover A of a box B is constituted
by a rigid part 10, made of a suitable transparent material, and by a cladding 20,
made of a suitable soft and flexible material, and the two parts 10, 20 are interconnected
and produced in two different steps of a single process for molding with two-component
materials, in order to obtain a cover A which is adapted to be associated with the
box B of the instrument, ensuring the required qualities of transparency, hermetic
sealing and flexibility.
[0016] The cover and the box are made of a rigid material, such as the plastic material
known commercially as polycarbonate or by the trade-name Bayblend of the German company
Bayer.
[0017] Such material is used in its semitransparent formulation, known for example by the
trade-name Makrolon of the German company Bayer, for the cover.
[0018] The cladding is made of soft and/or flexible material, for example known commercially
as thermoplastic rubber or polyurethane or by the trade-name Desmopan of the German
company Bayer.
[0019] According to the current art in the field of molding with two-component or multiple-component
materials, each molding step can be performed independently, with a mold which provides
for the formation of a first element and with successive molds into which the already-formed
elements are inserted, or the various steps can be performed in succession with a
molding machine in which in any case a first molded element is associated and included
in the molding of the successive elements.
[0020] By way of example and for the sake of simplicity in description, the steps of the
present method are described hereinafter, assuming that the method is performed with
a succession of mutually independent or non-independent injections performed with
a single machine for molding a plurality of materials.
[0021] With particular reference to Figures 1 and 2, which hypothetically represent the
case of providing a cover which has only one transparent surface in order to view
the display of the instruments, in a first step a mold for forming the rigid part
10 and a second mold for forming the cladding 20, associated with the preceding rigid
part 10, are prepared.
[0022] Since the box B for containing the instruments is provided with a rim B1, the mold
for the rigid part 10 must have a perimetric recess 11 which surrounds for example
a flat transparent part 12 of the cover A.
[0023] The perimetric recess 11 is provided by forming an outer wall 13 which has, on its
lower perimetric rim, a perimetric groove 14 and a suitable number of locators 15
which protrude at right angles with respect to said groove toward the inside of the
cover and are suitable to allow the snap-on engagement of the rigid part 10 on the
rim B1 of the box B.
[0024] The rigid part 10 advantageously has, on the flat transparent part 12, a groove 16
adapted to delimit the region where the cladding 20 is applied around the display
viewing surface that the box B is meant to contain.
[0025] The second mold to be prepared in order to form the cladding 20 of the cover A, according
to the present method, provides for a surface for resting against the internal surface
of the rigid part 10, such as to leave free the outer wall 13, the groove 14 and its
locators 15.
[0026] The mold further has a suitable lateral filling volume in order to form an external
cladding wall 21, with a lower rim 22 provided with a perimetric tooth 23, produced
by filling the groove 14 of the rigid part 10.
[0027] The same mold then provides for the filling of a suitable volume in order to obtain
a region 24 for partially cladding the outer surface of the flat transparent part
12, obtaining at least one free space 25 delimited by the groove 16 provided in the
rigid part 10.
[0028] After preparing the two molds as described above, and after preparing the materials
to be injected into the two different molds, the plastic material is injected in a
subsequent step in order to form the rigid part 10 and/or a semitransparent part.
[0029] In an additional step, the rigid part 10 is accommodated in the mold in order to
form the cladding 20, so as to ensure the formation of the outer cladding walls 21
and of the lower rim 22 with a first perimetric tooth 23 and of the partial cladding
region 24 with the free space 25.
[0030] Said free space 25 is delimited by the groove 16 and the partial cladding region
24 has a second tooth 26.
[0031] The fact is noted that the presence of the second perimetric tooth 26 and of the
first perimetric tooth 23, in addition to ensuring maximum hermetic sealing of the
cover A, also ensures maximum cohesion between the rigid part 10 and the cladding
20 even if they have different thermal expansions.
[0032] The cover A thus formed can be easily applied to the box B after the chosen control
instruments have been inserted therein, with an optional display to be arranged at
the free space 25 for perfect reading thereof.
[0033] With reference to Figure 3, as mentioned, the hypothetical case is considered of
producing a cover A' in which it is necessary to form, in addition to the free space
25, a flexible cladding 27 which covers a button located inside the cover A' and meant
to be actuated repeatedly.
[0034] As easily understandable, during the preparation of the molds a hole 17 is provided
in the flat transparent portion 12 of the rigid part 10, so as to allow the button
to pass and allow the passage of the mold in order to form the internal part of the
flexible cladding 27.
[0035] Likewise, the second mold for forming the cladding 20 has a suitable shaping of the
region of the flexible cladding 27; the remainder of its shape remains unchanged.
[0036] The other steps for injection-molding and forming the cover A', according to what
has already been illustrated, also remain fully unchanged.
[0037] From the above description it is evident that with the present method it is possible
to obtain a cover A having adequate visibility, flexibility and hermetic sealing,
despite being formed by a minimal number of parts to be produced and assembled, according
to the specified aim and objects.
[0038] In particular, attention is drawn to the fact that the lower rim 22 and the first
tooth 23, along the entire outer wall 13 of the cover A, constitute a safe and stable
gasket against infiltrations between an appropriately provided supporting panel and
the box B with the cover A, which contains and supports the chosen control, actuation
and adjustment instruments, eliminating any problem relating to poorly executed assembly,
in accordance with one of the stated objects.
[0039] As mentioned, the various execution steps of the proposed method can actually be
modified and adapted to specific requirements: by way of example, mention is made
of the possibility to provide the present cladding method by using normal multi-component
injection-molding machines, with consequent adaptation of the described method.
[0040] It is also possible to provide covers A which are composed for example of a transparent
rigid part associated with an opaque rigid part and are clad with a soft or flexible
cladding 20, forming a plurality of molds and consequently extending the forming steps,
always and in any case according to the illustrated method.
[0041] Likewise, it is possible to apply the present method also when producing boxes in
which visibility and instrument actuation are arranged at their bottom, or in any
other region thereof, and therefore optionally without a cover, since they are applied
from the inside of said supporting panel.
[0042] The invention is of course susceptible of numerous other modifications and variations,
all of which are within the scope of the same inventive concept.
[0043] The materials and the dimensions that constitute the individual components of the
invention may of course also be the most pertinent according to specific requirements.
[0044] The disclosures in Italian Patent Application No. BL98A000020 from which this application
claims priority are incorporated herein by reference.
[0045] Where technical features mentioned in any claim are followed by reference signs,
those reference signs have been included for the sole purpose of increasing the intelligibility
of the claims and accordingly such reference signs do not have any limiting effect
on the interpretation of each element identified by way of example by such reference
signs.
1. An electronic control instrument, constituted by a cover (A;A

) and an instrument containment box (B) made of rigid and/or semitransparent material,
characterized in that at least one cladding (20) made of soft and/or flexible material
is associated with said cover and/or box.
2. A method for cladding and insulating displays, particularly for electronic control
instruments, characterized in that it comprises the steps of: producing a cover (A)
to be associated with an instrument containment box (B); preparing molds for injection-molding
two-component or multi-component materials, said molds being shaped so as to provide
a rigid part (10), with at least one flat transparent part (12) for instrument viewing,
and so as to provide a soft and flexible cladding (20), which clads exposed regions
of said rigid part (10) and is interposed with a lower rim (22) and a first perimetric
tooth (23) between said cover (A) and said box (B).
3. The cladding method according to claim 2, characterized in that during mold preparation
one or more holes (17) are provided for the passage of the part of the mold that is
meant to form the internal part of a further flexible cladding (27) which covers one
or more buttons to be operated and for the passage and positioning of said buttons,
to be pressed by pushing said further flexible cladding (27).
4. The method according to claim 3, characterized in that in order to provide each cover
(A), after the step for preparing the molds there is a first step for injection-molding
in the mold meant to form said rigid part (10), monolithically or in multiple parts
which are associated to each other by means of successive injections in molds which
comprise the part that has already been molded, in order to obtain said rigid part
(10) provided with an optional flat transparent part (12) for viewing the display
or other parts of the instrument of said box (B) and with said one or more holes (17).
5. The method according to claim 2, characterized in that in a subsequent step said rigid
part (10) is accommodated in a final mold so that it can be clad with said cladding
made of soft and/or flexible material.
6. The method according to claim 2, characterized in that said cladding made of soft
and/or flexible material forms at least one partial cladding region.
7. The instrument according to claim 1, characterized in that said cladding (20) has
outer cladding walls (21), a lower rim (22), and a first perimetric tooth (23).
8. The instrument according to claim 1, characterized in that at least one flat transparent
part (12) is provided on a rigid part (10), a partial cladding region (24) being formed
on the outer surface of said transparent part (12), obtaining at least one free space
(25) delimited by a groove (16) provided in said rigid part (10).
9. The instrument according to claim 8, characterized in that said rigid part has a perimetric
recess (11) which surrounds said flat transparent part (12) of said cover (A), said
perimetric recess (11) being obtained by providing an outer wall (13) which has, on
its lower perimetric rim, a perimetric groove (14), in addition to a plurality of
locators (15) which protrude at right angles to said groove toward the inside of said
cover and are adapted to achieve the snap-on engagement of said rigid part (10) on
a rim (B1) of said box (B).
10. The instrument according to claim 9, characterized in that said rigid part (10) has,
on said flat transparent part (12), said groove (16), which is suitable to delimit
the region where said cladding (20) is applied around the viewing surface of a display
that said box (B) is meant to contain.
11. The instrument according to claim 8, characterized in that said partial cladding region
(24) which forms at least one free space (25) for the best viewing of the instruments,
forms a second tooth (26) which acts as a further seal and provides maximum coupling
of said cladding with said rigid part (10).
12. The instrument according to claim 8, characterized in that said lower rim (22), said
first perimetric tooth (23) and said outer wall (13) of said rigid part (10) form
a gasket surface for sealing said cover (A) and said box (B).
13. The instrument according to claim 8, characterized in that it comprises, on said cover
(A'), at said free space (25), at least one flexible cladding (27) which covers a
button which is arranged inside the cover (A') and is meant to be actuated repeatedly.
14. The instrument according to claim 13, characterized in that on said flat transparent
part (12) of said rigid part (10) there is provided a hole (17) which is suitable
for the passage of the button and for the passage of a mold for forming the internal
part of said flexible cladding (27).