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EP 2 813 366 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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23.03.2016 Bulletin 2016/12 |
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Date of filing: 18.07.2013 |
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Previously filed application: 12.06.2013 EP 13171748 |
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International Patent Classification (IPC):
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Fixed thermal head print mechanism with controlled gear play
Druckmechanismus mit festem Wärmekopf mit gesteuertem Getrieberadspiel
Mecanisme d'impression thermique a tête fixe et jeu d'engrenage réduit
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Designated Contracting States: |
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AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL
NO PL PT RO RS SE SI SK SM TR |
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Priority: |
12.06.2013 EP 13171748
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Date of publication of application: |
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17.12.2014 Bulletin 2014/51 |
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Proprietor: APS Trading OOD |
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2140 Botevgrad (BG) |
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Inventor: |
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- Montagutelli, Denis
49100 Angers (FR)
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Representative: Benatov, Emil Gabriel et al |
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Dr. Emil Benatov & Partners
Asen Peykov Str. No. 6 1113 Sofia 1113 Sofia (BG) |
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References cited: :
EP-A1- 2 305 478 FR-A1- 2 923 411
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WO-A1-98/17475 JP-A- 2011 056 691
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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TECHNICAL FIELD OF THE INVENTION
[0001] The present invention concerns a direct thermal printer mechanism.
PRIOR ART
[0002] It is widely known that a thermal print mechanism comprises a frame for holding all
the constitutive printers elements, a thermal printhead, where a dot line can be electrically
activated in order to heat a thermal paper sheet, a platen roller that is kept in
contact with the thermal printhead by pressure means and a motor with a gear train
in order to activate the platen roller in rotation. The last gear of the gear train
is integral with one end of the platen roller. The thermal paper sheet is pressed
between the platen roller and the thermal printhead by the pressure means, and combining
the motion of the paper by the motor and the selection of the portion of the thermal
printhead dot line to be heated a printout is formed on such a thermal paper sheet.
[0003] In almost all the cases and to simplify the mechanical force transmission from the
motor to the platen roller, and also avoid any tolerance issue between all the elements
of the gear train including the last one which is the gear of the platen roller, all
the motion elements forming the gear train are integral with the frame. Doing so,
the play from one gear to the adjacent ones can be very tight, allowing good print
quality, mechanical efficiency and low noise.
[0004] Since the platen roller is made of a metallic shaft over-moulded with a soft rubber
which is pressed against the thermal printhead via the pressure means, the distance
between the platen roller shaft axis and the thermal dot line may vary according to
the force of the pressure means and the paper thickness, to the concentricity of the
platen roller, but also according to temperature and humidity which affect the rubber
hardness.
[0005] In order to keep a stable pressure between the thermal paper sheet and the thermal
dot line to get a consistent printout all along the thermal paper sheet, the thermal
printhead is always mounted on a thermal head holder, assembled trough hinges on the
frame, ideally with two freedom degrees, but also often only along a rotation axis
parallel to the printhead dot line, and is pushed on its back by some pressure means
in order to compensate the geometrical dimensions variations of the platen roller
and the thermal paper sheet when printing.
[0006] Many documents since years are describing such configuration.
[0007] In a further step, the platen roller has been made detachable from the frame in order
to simplify the paper insertion between the platen roller and the thermal printhead.
Many arrangements have been described in order to remove and locate the platen roller
to a closed, so called, printing position.
[0008] Then, the trend has always been to decrease the thermal print mechanism overall dimensions,
in particular, the distance from the back of the print mechanism to the thermal printer
dot line.
[0009] International publication
WO9817475 discloses such arrangement, where the thermal printhead is mounted integral to the
printer frame and the platen roller is removable. In this arrangement, the printhead
is fixed on the frame and the gear train is made of circular gear up to the last one
which is mounted on the platen roller.
[0010] When sizing-down such arrangement, the play between the gear mounted on the platen
roller and the last gear mounted on the frame cannot be kept under control, in particular,
if the pressure of the pressure means increases or if the rubber gets softer, the
play will be dramatically reduced leading to a gear interference between the last
gear of the gear train mounted on the frame and the gear mounted on the platen roller.
[0011] One solution to keep the gear play constant is shown on figure 1. A partial circle
profile (1) having for center the center of the last circular gear (2) fixed on the
frame (7) is arranged on each side of the frame, allowing the platen roller (4) to
move back and forth along such profile (1) when urged by the pressure means. Such
possibility will keep the gear play constant and will also keep a stable pressure
on the thermal paper sheet all along the printhead width, at the same time the alignment
between the thermal printhead dot line and the platen roller will be lost, since the
platen roller, when moving along the profile (1), will move also in a direction parallel
to the thermal printhead, leading to poor print quality due to the alignment loss.
[0012] This problem is of very big importance when the platen roller diameter and the gear
module decrease, which is the case for the small thermal print mechanisms widely used
in the payment terminal industry and low cost application.
SUMMARY OF THE INVENTION
[0013] The present invention is aiming to size down a thermal print mechanism and to simplify
it. In particular the invention object is to provide a compact thermal printing device
with simple construction with printhead fixed to the frame and to minimize the number
of parts in order to decrease the overall cost of such a printer maintaining the high
quality of printing.
[0014] Another object of the invention is to keep the possibility to remove the platen roller
for loading and unloading of the thermal paper sheet.
[0015] The present invention proposes a device where the thermal printhead is integral with
the frame, the gear play is constant between the platen roller gear and the last gear
mounted on the frame and the thermal printhead alignment with the platen roller is
also kept constant.
[0016] These objects are achieved by the thermal printing mechanism according to the present
invention that comprises:
- a frame comprising on each side a flat profile portion,
- a thermal printhead comprising a thermal dot line, said thermal printhead being integral
and fixed to the frame in a direction substantially perpendicular to the flat profile
portion of the frame,
- a platen roller having a gear at one end of its axle, said axle being able for tangent
contact with the flat profile portion of the frame and being able to move in translation
along such flat profile portion of the frame, in order to be guided and aligned to
the thermal printhead dot line,
- pressure means to urge the platen roller against the printhead, and
- a motor to move in rotation the platen roller.
The thermal printing mechanism further comprises a helicoid screw for transmitting
of the mechanical power from the motor to the platen roller gear, said helicoid screw
being positioned substantially perpendicular to the printhead and engaged with the
platen roller gear when the platen roller axle is in tangent contact with the flat
profile portion of the frame.
[0017] In a preferred variant of the thermal printer mechanism, on each side of the frame
there is a shoulder shape profile adjacent to the flat profile portion of the frame
and outlining a nest for the platen roller axle in printing position. Said shoulder
shape profile forms a position of unstable equilibrium between two positions of stable
equilibrium of the platen roller axis, the platen roller being able to move from the
first stable printing position, in tangent contact with the flat profile portion of
the frame, to a second stable position, at outer end of the of the shoulder shape
profile that is opposite to the flat profile portion.
[0018] According to another embodiment of the thermal printer mechanism the platen roller
is rotatably mounted on a platen roller holder.
[0019] Preferably the pressure means pressing the platen roller against the thermal printhead
are held by the platen roller holder, and an oblong orifice is arranged on each side
of the platen roller holder in a substantially parallel direction to the flat profile
portion of the frame in order for the axle of the platen roller to overpass the shoulder
profiles of the frame when the platen roller holder moves from an open position to
the printing position.
[0020] Preferably on each side of the frame there is an abutment that is arranged at the
front of the frame in order to delimit a rest for the platen roller holder and balance
the force of the pressure means against the platen roller. Alternatively said abutments
are arranged in a hook shape in order to lock the platen roller holder by interconnection
with a corresponding element of the platen roller holder.
[0021] In a preferred variant, the platen roller holder also holds a shaft that is substantially
parallel to the printhead. Said shaft is able to engage with the hook shape of the
abutments of the printer frame when the platen roller engages into the printer frame.
Said shaft is spring loaded in the platen roller holder in order to urge the shaft
against the abutments of the frame.
[0022] Advantageously the thermal printer mechanism further comprises a lever that is rotatably
mounted on the platen roller holder for moving of the platen roller in a direction
substantially opposed to the printhead, allowing the platen roller axle to overpass
the frame shoulder profiles, thus disengaging the platen roller axle from the frame.
When rotated the lever brings closer the platen roller and the spring movable shaft
to each other and thus enable the platen roller to overpass the frame shoulder profiles,
and the spring movable shaft to overpass the abutments, thus disengaging the platen
roller axle from the frame.
[0023] According to alternative embodiment of the thermal printer mechanism the pressure
means are hold by the printer frame and put into pressure the platen roller against
the thermal printhead when the platen roller engages with the printer frame.
[0024] Preferably each pressure means comprises a wire spring, integral to the frame. Advantageously
the outer part of each pressure means is curved for guiding and locking the platen
roller against the flat profile portion of the frame.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The characteristics of the invention will be disclosed in details in the following
description of preferred embodiments, given as a non-restrictive example, with reference
to the attached drawings wherein:
- Figure 1
- is a schematic sectional view of a possible thermal printing mechanism given as a
comparative example;
- Figure 2
- is a schematic sectional view of a first embodiment of the thermal printing mechanism
according to the present invention;
- Figure 3
- is a schematic sectional view of a variant of the first embodiment of the thermal
printing mechanism according to the present invention shown on figure 2;
- Figures 4
- and 5 are schematic sectional views of further embodiment of the thermal printing
mechanism according to the present invention with a platen roller holder in open and
closed position;
- Figure 6
- and 7 is a schematic sectional view of a further variant of the embodiment shown on
figures 4 and 5 with a lever for unlocking of the platen roller holder form the frame.
- Figure 8
- is a schematic sectional view of another embodiment of the thermal printing mechanism
according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0026] Figure 2 shows first embodiment of the thermal printing mechanism according to the
present invention. The thermal printing mechanism comprises:
- a frame 7 comprising on each side a flat profile portion 8,
- a thermal printhead 3 comprising a thermal dot line 10, said thermal printhead being
integral and fixed to the frame 7 in a direction substantially perpendicular to the
flat profile portion 8 of the frame 7,
- a platen roller 4 having a gear 6 at one end of its axle 12, said axle 12 being able
for tangent contact with the flat profile portion 8 of the frame 7 and being able
to move in translation along said flat profile portion of the frame, in order to be
guided and aligned to the thermal printhead 3 dot line 10,
- pressure means 11 to urge the platen roller 4 against the printhead,
- a motor 21 to move in rotation the platen roller 4.
The device also comprises a helicoid screw 9 for transmitting of the mechanical power
from the motor 21 to the platen roller gear 6. Said helicoid screw 9 is positioned
substantially perpendicular to the printhead 3 and engaged with the platen roller
gear 6 when the platen roller axle is in tangent contact with the flat profile portion
8 of the frame 7.
[0027] The flat profile portions 8, on each side of the frame 7, allow a movement of the
platen roller only in a direction perpendicular to the thermal printhead dot line
10. Moving so, the platen roller 4 will always remain perfectly aligned to the thermal
printhead dot line 10, whatever is its rubber deformation. The gear 6 integral to
the platen roller 4 and mounted on its axle 12 has a helical profile in order to engage
into a helicoid screw 9, which is arranged in a direction parallel to the flat profile
portion 8. When the platen roller moves back and forth along the flat profile 8, the
distance between the center of the platen roller axle 12 and the helicoid screw axis
remain constant, keeping the gear play constant whatever is the position of the platen
roller on the flat profile.
[0028] With this arrangement, both the play between the last two gears of the gear train
and the dot line 10 alignment to the platen roller does not change whatever is the
position of the platen roller 4 on the flat profile portions 8 and whatever is the
platen roller 4 deformation when the pressure means are pressing the platen roller
4 against the thermal printhead 3.
[0029] The pressure means for the platen roller could be of any suitable kind known from
the prior art. For example they could be helical compression springs. The pressure
means 11 for the platen roller 4 could be mounted on the frame 7 or on the element
that holds the platen roller 4.
[0030] Figure 3 shows a variant wherein on each side of the frame 7 there is a shoulder
shape profile 17 that is arranged adjacent to the flat profile portion 8 of the frame
so as to outline the outer board of a nest for the platen roller axis in printing
position. Said shoulder shape profiles 17 are forming a position of unstable equilibrium
between two positions of stable equilibrium of the platen roller axis, the platen
roller 4 being able to move from the first stable printing position, in tangent contact
with the flat profile portions 8 of the frame, to a second stable position at outer
surfaces of the shoulder shape profiles 17 that are opposite to the flat profile portions
8.
[0031] On the figure 4, 5 and 8 the gear train is not represented to ease the reading of
the variant of embodiments.
[0032] In a preferred embodiment of the invention sown on figs 4 and 5 the platen roller
is hold by a platen roller holder. This is in particular the case when the printer
mechanism is also featuring an easy loading cutter.
[0033] On figure 4 the platen roller holder is represented detached from the printer frame
to ease the understanding. The platen roller 4 is rotatably mounted on the platen
roller holder 15 and the pressure means 11 are hold by the platen roller holder 15.
One oblong orifice 18 is arranged on each side of the platen roller holder in a substantially
parallel direction to the flat profile portion 8 of the frame 7 in order to facilitate
the axle 12 of the platen roller to overpass the shoulder profile 17 of the frame
7 when the platen roller holder 15 goes from the open position to the closed position.
[0034] In a preferred variant the platen roller holder 15 is pivotally mounted to the frame
7 (not shown on the figures). It is also possible for the platen roller holder to
be suitably attached to a movable part, for example a lid, of the device where the
printer mechanism is assembled.
[0035] As shown on the same figure 4, on each side of the frame 7 there are an abutment
20 that is arranged on the front of the frame in order to delimit the rest for the
platen roller holder 15 and to balance the force of the pressure means 11 against
the platen roller 4.
[0036] Further, a shaft 19 that is substantially parallel to the printhead is mounted on
the platen roller holder 15 at the end of the pressure means that is opposite to the
platen roller 4. This shaft 19 is able to engage with hook shapes of the abutments
20 of the printer frame when the platen roller 4 engages with the printer frame 7
in printing position as shown on fig. 5. Said shaft 19 is spring loaded in the platen
roller holder 15 in order to be urged against the abutments 20 of the frame.
[0037] The figures 6 and 7 show a lever 16 mounted rotatably on the platen roller holder
15, so as to unlock the platen roller holder 15 from the frame 7. When this lever
is rotated it brings closer the platen roller 4 and the movable shaft 19 to each other
in order for the platen roller 4 to overpass the frame shoulder profiles 17, and for
the movable spring-loaded shaft 19 to overpass the abutments 20, thus disengaging
the platen roller axle 12 from the frame 7. In a preferred variant shown on the figures
the lever 16 is a bracket-like element that on each lateral side has an arm to engage
with the platen roller axle. Additionally the lever 16 has on each lateral side an
irregular loop-shape part to engage with the shaft 19. When the lever 16 is rotated
said arms push the platen roller axle 12 back in the oblong orifices 18 against the
force of pressure means 11 while simultaneously said loop-shape parts of the lever
16 move the shaft 19 toward the platen roller 4.
[0038] Figure 8 shows another embodiment of the present invention with alternative arrangement
for the pressure means 11. The pair pressure means 11 that push the platen roller
4 against the thermal printhead 3 are integral to the frame 7. The pressure means
11 are made from a wire spring. Moreover an outer part of this wire spring 11 is curved
in order to create a locking profile 13 to generate a component of force to keep the
platen roller in contact with the flat profile portion 8 of the frame 7. In a preferred
variant shown on the figure 8 said locking profiles 13 have an inclined straight portion
for guiding of the platen roller axle 12 when the platen roller 4 is moving to the
printing position.
[0039] In a preferred variant not shown on the figures the platen roller is simply attached,
by appropriate way known from the state of the art, to a movable part, for example
a lid, of the device where the printer mechanism is assembled.
[0040] Various modifications and/or additions of parts will be apparent to those skilled
in the art that will remain within the field and scope of the present invention defined
in appended claims. All the parts may further be replaced with other technically equivalent
elements.
[0041] Reference signs for technical features are included in the claims 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. Thermal printer mechanism comprising:
- a frame (7) comprising on each side a flat profile portion (8),
- a thermal printhead (3) comprising a thermal dot line (10), said thermal printhead
being integral and fixed to the frame (7) in a direction substantially perpendicular
to the flat profile portion (8) of the frame (7),
- a platen roller (4) having a gear (6) at one end of its axle (12), said axle (12)
being able for tangent contact with the flat profile portion (8) of the frame (7)
and being able to move in translation along such flat profile portion of the frame,
in order to be guided and aligned to the printhead thermal dot line (10),
- pressure means (11) to urge the platen roller (4) against the printhead,
- a motor (21) to move in rotation the platen roller (4),
characterized in that
it further comprises a helicoid screw (9) for transmitting of the mechanical power
from the motor (21) to the platen roller gear (6), said helicoid screw (9) being positioned
substantially perpendicular to the printhead (3) and engaged with the platen roller
gear (6) when the platen roller axle (12) is in tangent contact with the flat profile
portion (8) of the frame (7).
2. Thermal printer mechanism according to claim 1 wherein on each side of the frame (7)
there is a shoulder shape profile (17) adjacent to the flat profile portion (8) of
the frame (7) and outlining a nest for the platen roller axle (12) in printing position,
said shoulder shape profile (17) forming a position of unstable equilibrium between
two positions of stable equilibrium of the platen roller axis, the platen roller (4)
being able to move from the first stable printing position, in tangent contact with
the flat profile portion (8) of the frame, to a second stable position, at outer surface
of the shoulder shape profile that is opposite to the flat profile portion (8).
3. Thermal printer mechanism according to any of the previous claims wherein the platen
roller (4) is rotatably mounted on a platen roller holder (15).
4. Thermal printer mechanism according to claim 3, wherein the pressure means (11) pressing
the platen roller (4) against the thermal printhead (3) are held by the platen roller
holder (15), and an oblong orifice (18) is arranged on each side of the platen roller
holder in a substantially parallel direction to the flat profile portion (8) of the
frame (7) in order for the axle (12) of the platen roller (4) to overpass the shoulder
profiles (17) of the frame (7) when the platen roller holder (15) moves from an open
position to the printing position.
5. Thermal printer mechanism according to claim 4, wherein on each side of the frame
there is an abutment (20), that is arranged at the front of the frame (7) in order
to delimit a rest for the platen roller holder (15) and balance the force of the pressure
means (11) against the platen roller (4).
6. Thermal printer mechanism according to any of the previous claims wherein the abutments
(20) are arranged in a hook shape in order to lock the platen roller holder (15) by
interconnection with a corresponding element of the platen roller holder (15).
7. Thermal printer mechanism according to claim 6, wherein the platen roller holder (15)
also holds a shaft (19) that is substantially parallel to the printhead (3), said
shaft (19) being able to engage with the hook shape of the abutments (20) of the printer
frame (7) when the platen roller (4) engages into the printer frame (7), wherein said
shaft (19) is spring loaded in the platen roller holder (15) in order to urge the
shaft (19) against the abutments (20) of the frame.
8. Thermal printer mechanism according to any of the claims 3 to 7, wherein there is
a lever (16) that is rotatably mounted on the platen roller holder (15) for moving
of the platen roller (4) in a direction substantially opposed to the printhead (3)
direction, allowing the platen roller axle (12) to overpass the frame shoulder profiles
(17), thus disengaging the platen roller axle (12) from the frame (7).
9. Thermal printer mechanism according to claims 8, wherein the lever (16) is rotatably
mounted on the platen roller holder (15), so as when rotated to bring closer the platen
roller (4) and the spring movable shaft (19) to each other in order for the platen
roller (4) to overpass the frame shoulder profiles (17) and for the spring movable
shaft (19) to overpass the abutments (20), thus disengaging the platen roller holder
(15) from the frame (7).
10. Thermal printer mechanism according to claim 1, wherein the pressure means (11) are
held by the printer frame (7) and put into pressure the platen roller (4) against
the thermal printhead (3) when the platen roller (4) engages with the printer frame
(7).
11. Thermal printer mechanism according to claim 10, wherein each pressure means (11)
comprises a wire spring, integral to the frame (7).
12. Thermal printer mechanism according to claim 11, wherein the outer part of each pressure
means (11) is curved (13) for guiding and locking the platen roller (4) against the
flat profile portion of the frame (7).
1. Thermodruckermechanismus umfassend:
- Einen Rahmen (7) mit einem Flachprofilabschnitt (8) auf jeder Seite,
- Einen Thermodruckkopf (3) mit einer Thermopunktlinie (10), wobei der Thermodruckkopf
einstückig und an dem Rahmen (7) in einer Richtung im Wesentlichen senkrecht zu dem
Flachprofilabschnitt (8) des Rahmens (7) befestigt ist,
- Eine Druckwalze (4) mit einem Zahnrad (6) an dem einen Ende ihrer Achse (12), wobei
die Achse (12) in der Lage zum Tangentenkontakt mit dem Flachprofilabschnitt (8) des
Rahmens (7) ist und in der Lage ist sich in Vorschub entlang eines Flachprofilabschnitts
des Rahmens zu bewegen, um geführt und an der thermischen Punktlinie (10) des Druckkopfs
ausgerichtet zu werden,
- Druckeinrichtung (11), um die Druckwalze (4) gegen den Druckkopf zu pressen,
- Einen Motor (21), um die Druckwalze (4) in Drehung zu bewegen,
dadurch gekennzeichnet, dass
er ferner eine Mehrfachgewindeschraube (9) zur Übertragung der mechanischen Energie
von dem Motor (21) zu dem Druckwalzenzahnrad (6) aufweist, wobei die Mehrfachgewindeschraube
(9) im Wesentlichen senkrecht zu dem Druckkopf (3) angeordnet und mit dem Druckwalzenzahnrad
(6) eingerastet ist, wenn die Achse (12) der Druckwalze in Tangentenkontakt mit dem
Flachprofilabschnitt (8) des Rahmens (7) ist.
2. Thermodruckennechanismus nach Anspruch 1, wobei auf jeder Seite des Rahmens (7) sich
ein Schulterformprofil (17) neben dem Flachprofilabschnitt (8) des Rahmens (7) befindet
und eine Aufnahme für die Rollenachse (12) der Walze in Druckposition bildet, wobei
der Schulterformprofil (17) eine labile Gleichgewichtslage zwischen zwei stabilen
Gleichgewichtslagen der Rollenachse (12) der Walze bildet, die Druckwalze (4) kann
sich von der ersten stabilen Druckposition in Tangentenkontakt mit dem Flachprofilabschnitt
(8) des Rahmens zu einer zweiten stabilen Position an der äußeren Oberfläche des Schulterformprofils
weiterbewegen, die gegenüber dem Flachprofilabschnitt (8) liegt.
3. Thermodruckennechanismus nach einem der vorhergehenden Ansprüche, wobei die Druckwalze
(4) drehbar auf einem Halter der Druckwalze (15) angebracht ist.
4. Thermodruckennechanismus nach Anspruch 3, wobei die Druckeinrichtung (11), das die
Druckwalze (4) gegenüber dem Thermodruckkopf (3) presst, durch den Halter der Druckwalze
(15) gehalten wird und eine längliche Öffnung (18) auf jeder Seite des Halters der
Druckwalze in einer im Wesentlichen parallelen Richtung zu dem Flachprofilabschnitt
(8) des Rahmens (7) gestaltet ist, damit die Achse (12) der Druckwalze (4) die Schulterformprofile
(17) des Rahmens (7) überführen kann, wenn sich der Halter der Druckwalze (15) aus
einer offenen Position in die Druckposition bewegt.
5. Thermodruckermechanismus nach Anspruch 4, wobei auf jeder Seite des Rahmens sich ein
Anschlag (20) befindet, der an der Vorderseite des Rahmens (7) angeordnet ist, um
eine Auflage für den Halter der Druckwalze (15) abzugrenzen und die Kraft der Druckeinrichtung
(11) gegen die Druckwalze (4) auszugleichen.
6. Thermodruckennechanismus nach einem der vorhergehenden Ansprüche, wobei die Anschläge
(20) in einer Hakenform ausgebildet sind, um die Halter der Druckwalze (15) durch
das Zusammenwirken mit einem entsprechenden Element des Halters der Druckwalze (15)
zu verriegeln.
7. Thermodruckennechanismus nach Anspruch 6, wobei der Halter der Druckwalze (15) auch
eine Welle (19) hält, die im Wesentlichen parallel zu dem Druckkopf (3) ist, wobei
diese Welle (19) in der Lage ist, mit der Hakenform des Anschlags (20) des Druckerrahmens
(7) in Eingriff zu kommen, wenn die Druckwalze (4) in den Druckerrahmen (7) eingreift,
wobei die Welle (19) mittels einer Feder in den Halter der Druckwalze (15) angebracht
ist, um die Welle (19) gegen die Anschläge (20) des Rahmens zu pressen.
8. Thermodruckermechanismus nach einem der Ansprüche 3 bis 7, wobei er einen Hebel (16)
aufweist, der drehbar an dem Halter der Druckwalze (15) zum Bewegen der Druckwalze
(4) in einer Richtung im wesentlichen entgegengesetzt der Richtung des Druckkopfes
(3) angebracht ist, so dass die Achse (12) der Druckwalze (4) die Schulterformprofile
(17) überführen kann, damit die Achse (12) der Druckwalze von dem Rahmen (7) ausrückt.
9. Thermodruckermechanismus nach Anspruch 8, wobei der Hebel (16) drehbar an dem Halter
der Druckwalze (15) montiert ist, so dass, wenn gedreht, die Druckwalze (4) und die
durch Feder bewegbare Welle (19) näher zueinander zu bringen, damit die Druckwalze
(4) die Schulterformprofile (17) überführen kann und die durch Feder bewegbaren Welle
(19) die Anschläge (20) überführen kann, so dass sich der Halter der Druckwalze (15)
vom Rahmen (7) löst.
10. Thermodruckmechanismus nach Anspruch 1, wobei die Druckeinrichtung (11) durch den
Druckerrahmen (7) gehalten wird und die Druckwalze (4) gegenüber dem Thermodruckkopf
(3) einpresst, wenn die Druckwalze (4) mit dem Druckerrahmen (7) in Eingriff kommt.
11. Thermodruckermechanismus nach Anspruch 10, wobei jede Druckeinrichtung (11) eine Drahtfeder,
einstückig mit dem Rahmen (7) aufweist.
12. Thermodruckmechanismus nach Anspruch 11, wobei der äußere Teil jeder Druckeinrichtung
(11) gekrümmt (13) ist zum Führen und Verriegeln der Druckwalze (4) gegen den Flachprofilabschnitt
des Rahmens (7).
1. Mécanisme d'impression thermique comprenant:
- un châssis (7) étant pourvu sur chacun de ses côtés d'une partie de profil plat
(8),
- une tête d'impression thermique (3) comprenant un ligne de point chauffants, ladite
tête d'impression thermique étant montée et fixée immobile sur le châssis (7) selon
une direction sensiblement perpendiculaire à la partie du profil plat (8) du châssis
(7),
- un cylindre d'impression (4) pourvu d'un engrenage (6) à l'une des extrémités de
son axe (12), ledit axe (12) pouvant être en contact tangent avec la partie de profil
plat (8) du châssis (7) et pouvant effectuer un mouvement de translation sur le long
de cette partie du profil plat du châssis, afin d'être guidé et aligné sur la ligne
de point chauffants (10),
- des moyens de pression (11) pour presser le cylindre d'impression (4) contre la
tête d'impression,
- un moteur (21) pour mettre en rotation le cylindre d'impression (4),
caractérisé en ce qu'il contient
un vis hélicoïdale (9) pour transmettre la puissance mécanique du moteur (21) à l'engrenage
du cylindre d'impression (6), ladite vis hélicoïdale (9) étant positionnée selon une
direction substantiellement perpendiculaire à la tête d'impression (3) et engrenée
avec l'engrenage (6) quand l'axe (12) est en contact tangent avec la partie du profil
plat (8) du châssis (7).
2. Mécanisme d'impression thermique selon la Revendication 1, caractérisé en ce que de chaque côté du châssis (7) est placé un profil en forme d'épaulement (17) adjacent
à la partie de profil plat (8) du châssis (7) et générant une position stable de l'axe
du cylindre d'impression (12) en position d'impression, ledit profil en forme d'épaulement
(17) formant une position d'équilibre instable entre deux positions d'equilibre stables
de l'axe, le cylindre d'impression (4) pouvant se déplacer de la première position
stable ayant un contact tangent avec la partie du profil plat (8) du châssis, à une
seconde position stable, à la surface extérieure du profil en forme d'épaulement et
qui est opposée à la partie de profil plat (8).
3. Mécanisme d'impression thermique selon l'une quelconque des revendications précédentes,
caractérisé en ce que le cylindre d'impression (4) est monté à rotation sur le support de cylindre d'impression
(15).
4. Mécanisme d'impression thermique selon la Revendication 3, caractérisé en ce que les moyens de pression (11) pressent le cylindre d'impression (4) contre la tête
d'impression thermique (3) et sont montés sur le support du cylindre d'impression
(15), et qu'un orifice oblong (18) est arrangé sur chaque côté du support du cylindre
d'impression selon une direction parallèle de la partie du profil plat (8) du châssis
(7) pour que l'axe (12) du cylindre d'impression (4) parcoure les profils en forme
d'épaulement (17) du châssis (7) quand le support du cylindre d'impression (15) se
déplace d'une position ouverte à la position d'impression.
5. Mécanisme d'impression thermique selon la Revendication 4, caractérisé en ce que sur chaque côté du châssis se trouve une butée (20), qui est arrangée sur le devant
du châssis (7) afin de délimiter un arrêt pour le support du cylindre d'impression
(15) et d'équilibrer la force des moyens de pression (11) contre le cylindre d'impression
(4).
6. Mécanisme d'impression thermique selon l'une quelconque des revendications précédentes,
caractérisé en ce que les butées (20) sont arrangées en forme de crochet afin de bloquer le support du
cylindre d'impression (15) par une interaction avec un élément correspondant du support
du cylindre d'impression (15).
7. Mécanisme d'impression thermique selon la Revendication 7, caractérisé en ce que le support du cylindre d'impression (15) contient aussi un arbre (19) qui est substantiellement
parallèle de la tête d'impression (3), ledit arbre (19) étant capable de coopérer
avec les butées qui sont arrangées en forme de crochet (20) du châssis (7) quand le
cylindre d'impression (4) pénètre dans le châssis (7), et où l'arbre (19) est mis
en pression par des ressorts à l'intérieur du support du cylindre d'impression (15)
afin de presser l'arbre (19) contre les butées (20) du châssis.
8. Mécanisme d'impression thermique selon l'une quelconque des revendications 3 à 7,
caractérisé en ce qu' un levier (16) est monté à rotation sur le support du cylindre d'impression (15)
pour déplacer le cylindre d'impression (4) dans une direction substantiellement opposée
de la direction de la tête d'impression (3), permettre à l'axe (12) de dépasser les
profils en forme d'épaulement (17), et donc de dégager l'axe (12) du châssis (7).
9. Mécanisme d'impression thermique selon la Revendication 8, caractérisé en ce que le levier (16) est monté à rotation sur le support du cylindre d'impression (15),
de façon à rapprocher le cylindre d'impression (4) et l'arbre mis en pression par
des ressorts à l'intérieur du support du cylindre d'impression (19) l'un de l'autre
pour que le cylindre d'impression (4) dépasse les profils en forme d'épaulement (17)
et que l'arbre mis en pression par des ressorts à l'intérieur du support du cylindre
d'impression (19) dépasse les butées (20), et à débrayer le support du cylindre d'impression
(15) du châssis (7).
10. Mécanisme d'impression thermique selon la Revendication 1, caractérisé en ce que les moyens de pression (11) sont montés sur le châssis (7) et pressent le cylindre
d'impression (4) contre la tête d'impression thermique (3) quand le cylindre d'impression
(4) s'engage dans le châssis (7).
11. Mécanisme d'impression thermique selon la Revendication 10, caractérisé en ce que chacun des moyens de pression (11) est composé d'un ressort en fil, monté fixe sur
le châssis (7).
12. Mécanisme d'impression thermique selon la Revendication 11, caractérisé en ce que la partie extérieure de chaque moyen de pression (11) est courbée (13) pour guider
et bloquer le cylindre d'impression (4) contre la partie du profil plat du châssis
(7).
REFERENCES CITED IN THE DESCRIPTION
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It does not form part of the European patent document. Even though great care has
been taken in compiling the references, errors or omissions cannot be excluded and
the EPO disclaims all liability in this regard.
Patent documents cited in the description