Field of application
[0001] The present invention regards a fabric roller blind provided with a device for adjusting
the tension according to the preamble of the independent claim 1.
[0002] The fabric roller blind equipped with the present adjusting device is intended to
be advantageously employed for adjustably closing provided openings or gaps of building
walls, in particular relative to windows, doors, French windows, skylights and similar
doors/windows/shutters, since it is possible to precisely adjust the tension of elastic
means adapted to exert, through a take-up roller, an elastic return force on the fabric
roller of the blind.
[0003] The fabric roller blind equipped with the device for adjusting the tension, object
of the present invention, is therefore inserted in the industrial field of production
of doors/windows/shutters, or also in the field of production of fabrics for sun-protection
or air-protection, or also in the field of production of mosquito screens or similar
products.
State of the art
[0004] Blinds are known on the market for intercepting the openings of doors/windows/shutters
(such as windows, doors or French windows) provided with a rolling-shutter box which
is fixed to a building wall or to a ceiling above the opening to be closed and at
its interior houses a roller, on which a flexible fabric is susceptible of being wound
and unwound.
[0005] The fabric usually has rectangular form and is provided with an upper edge fixed
to the roller and with a lower edge fixed to a bottom bar aimed to stretch the fabric
itself.
[0006] In addition, the blind usually also comprises two lateral guides vertically arranged
along the corresponding sides of the opening and to which the bottom bar is slidably
constrained.
[0007] In particular, the bottom bar is obtained with an aluminum section closed at the
lateral ends by two lateral terminals slidably coupled to the respective lateral guides.
[0008] Each lateral guide is obtained with a corresponding aluminum profile of rectangular
section, internally hollow and provided with an internal side (facing the internal
side of the other lateral guide) on which a longitudinal slit is made, in which the
corresponding lateral terminal of the bottom bar is slidably inserted.
[0009] In addition, each lateral guide is longitudinally extended between an upper end,
fixed to the rolling-shutter box, and a lower end closed by a base terminal fixed
to the floor at the lower edge of the opening.
[0010] In operation, the roller of the blind can be driven, typically through a motor, to
rotate in order to move the fabric between a collected position, in which the fabric
is wound around the roller with the bottom bar arranged in abutment against the rolling-shutter
box, and an extended position, in which the fabric is unwound from the roller to close
the opening and the bottom bar is arranged at base terminals placed at the lower ends
of the lateral guides.
[0011] In particular, blinds are known on the market provided with elastic return means,
which are adapted to maintain the fabric taut when this is situated in the extended
position and to allow the re-winding of the fabric itself in order to attain its collected
position. Such elastic return means usually comprise a helical spring wound around
the roller and torsion-loaded such that when the fabric is unwound from the roller
(in order to attain the extended position) the spring is further loaded, storing elastic
energy, and it produces a return action opposing the unwinding, i.e. a resistant torque
which maintains the fabric roller under tension. In this manner, during the reverse
rotation of the roller, in order to reach the collected position of the fabric, the
elastic return means release the energy stored during the unwinding and produce a
drive torque on the roller assisting the winding of the fabric around the roller,
in order to easily attain the aforesaid collected position.
[0012] If the tension of the elastic return means is too weak, the fabric cannot be completely
rewound and never reaches the collected position, or it may be slack when situated
in extended position.
[0013] For the purpose of remedying such drawback, fabric roller blinds have been known
on the market for some time which are provided with a device for adjusting the tension
of the elastic return means, in particular provided with a gear positioned at a lateral
end of the roller. Such gear, once driven to rotate from the outside (for example
by means of an Allen wrench), loads or unloads the elastic return means for a suitable
adjusting of the tension thereof. Nevertheless, the gear is accessible by means of
a hole made on the external side (facing the wall on which the opening to be screened
is made) of one of the lateral guides, in a position substantially coaxial to the
roller.
[0014] The fabric roller blind equipped with the adjusting device of known type, briefly
described herein thus far, has in practice proven that it does not lack drawbacks.
[0015] A first drawback lies in the fact that the adjusting of the tension of the elastic
return means can only be executed during installation of the blind, otherwise it is
necessary to disassemble the lateral guides of the blind in order to be able to access
the hole for accessing the tensioning gear of the elastic return means. Therefore,
the elastic return means are hard to adjust.
[0016] A second drawback of the fabric roller blind equipped with the adjusting device of
known type lies in the fact that the adjustment requires the operator to carry out
long and difficult operations for disassembling the lateral guides of the blind and
accessing the adjustment of the elastic return means.
[0017] A third drawback lies in the fact that the adjustment is not precise, since it is
not possible to operate in a controlled manner on the gear, as it is only possible
to rely on the experience of the operator.
[0018] A further drawback lies in the fact that the adjustment of the tension of the elastic
return means requires the final user to possess technical knowledge of the field.
Presentation of the invention
[0019] In this situation, the problem underlying the present invention is to provide a fabric
roller blind provided with a device for adjusting the tension, which allows adjusting
the elastic return means even after the installation of the blind, without requiring
the disassembly thereof.
[0020] Another object of the present invention is to provide a fabric roller blind provided
with a device for adjusting the tension, which is entirely reliable in operation,
and in particular capable of ensuring a precise adjustment of the elastic return means.
[0021] Another object of the present invention is to provide a fabric roller blind provided
with a device for adjusting the tension, which is entirely efficient in operation,
and in particular capable of ensuring the adjustment of the elastic return means without
requiring particular effort/exertion by the final user and which does not require
particular technical knowledge of the field.
[0022] Another object of the present invention is to provide a device for adjusting the
tension of the elastic return means of a windable cover, which is structurally simple
and inexpensive to make and install.
Brief description of the drawings
[0023] The technical characteristics of the invention, according to the aforesaid objects,
are clearly seen in the contents of the below-reported claims and the advantages thereof
will be more evident in the following detailed description made with reference to
the enclosed drawings, which represent a merely exemplifying and non-limiting embodiment
of the invention, in which:
- figure 1 shows a front perspective view of a blind provided with a device for adjusting
the tension of the elastic return means, which is the object of the present invention;
- figure 2 shows a front axonometric view of a detail of the blind illustrated in figure
1, relative to a vertical upright provided with a through hole for accessing the adjusting
device;
- figure 3 shows an exploded perspective view of the device for adjusting the tension
of the elastic return means, object of the present invention;
- figure 4 shows a rear axonometric view of a detail of the adjusting device relative
to a housing seat made in a sealing cover, in which a first toothed wheel of a transmission
member thereof is housed.
Detailed description of a preferred embodiment
[0024] With reference to the set of drawings, reference number 1 overall indicates the fabric
roller blind, object of the present invention.
[0025] The blind 1 is usable in operation for adjustably closing an opening A of a portal
provided in a wall of a building or the load-bearing structure of any building premises,
such as a window, a door or a French window,
[0026] With the term blind, it must be intended any one cover adapted to at least partially
close an opening, for example a brise soleil, a mosquito screen or the like.
[0027] In accordance with the embodiment illustrated in figure 1, the blind 1 comprises
a support frame 2 intended to be fixed to the portal, in which the opening A is obtained,
and preferably comprising a rolling-shutter box 3 intended to be positioned in the
upper part of the opening A itself.
[0028] Advantageously, the rolling-shutter box 3 comprises a hollow tubular body, in particular
obtained with an aluminum extrusion, which is extended with substantially horizontal
axis between two opposite ends closed by two lateral caps, in particular made of plastic
material.
[0029] The blind 1 also comprises a take-up roller 4 rotatably supported by the support
frame 2, advantageously housed inside the rolling-shutter box 3, in particular between
two uprights 7 and provided with a substantially horizontal rotation axis X.
[0030] Around the take-up roller 4, a flexible fabric 5 is susceptible of being wound and
unwound which preferably passes through a lower slit of the rolling-shutter box 3.
[0031] The fabric 5 can be intended for making a shading screen, e.g. in substitution of
a rolling shutter, a brise soleil screen for filtering the sunlight or even for making
a mosquito screen. Generally, the fabric 5 can be dedicated to closing the opening
of a door/window/shutter in order to protect an internal area from the sun and/or
from the wind and/or, more generally, from the weather conditions of the outdoor environment.
The fabric 5, as a function of its different applications, can be made of synthetic
or natural material fabric and it can have the form of a mesh or have a continuous
surface of shading, filtering or transparent type.
[0032] The fabric 5 preferably has rectangular form and is provided, in a manner
per se known to the man skilled in the art, with an upper edge fixed to the take-up roller
4 and with a lower edge preferably fixed to a bottom bar 6 arranged parallel to the
take-up roller 4 and adapted to stretch the fabric 5.
[0033] The blind 1 also comprises two vertical uprights 7 extended parallel to each other
and side-by-side and between which the fabric 5 is susceptible of sliding following
its winding and unwinding around the take-up roller 4.
[0034] More in detail, each vertical upright 7 is longitudinally extended according to a
respective extension direction Y, preferably vertical and substantially orthogonal
to the rotation axis X of the take-up roller 4, between an upper end thereof, preferably
arranged at the rolling-shutter box 3, and an opposite lower end intended to be arranged
at the lower edge of the opening A, for example on a floor or on a windowsill.
[0035] The two vertical uprights 7 are arranged along corresponding sides of the opening
A and are mechanically fixed to the portal (where the opening A itself is made) for
example by means of anchoring pressure screws.
[0036] Advantageously, each vertical upright 7 is preferably obtained by means of extruded
metallic sections, in particular made of aluminum.
[0037] More in detail, each vertical upright 7 is preferably provided with an open side,
arranged facing the open side of the other vertical upright 7, on which a longitudinal
slit is made in which the bottom bar 6 is slidably constrained.
[0038] Preferably, the bottom bar 6 of the blind 1, fixed to the lower edge of the fabric
5, is longitudinally extended along a second extension direction Z parallel to the
rotation axis X of the take-up roller 4, between two lateral terminals thereof slidably
engaged with the respective vertical uprights 7.
[0039] The blind 1 also comprises a return spring 8 mechanically associated with the take-up
roller 4 and adapted to exert an elastic return torque on the latter.
[0040] In particular, the take-up roller 4 is susceptible of being rotated around the rotation
axis X in order to move the fabric 5 between a retracted position, in which the fabric
5 is wound around the take-up roller 4, and an extended position, in which the fabric
5 is unwound from the take-up roller 4 to at least partially close the opening A.
[0041] In particular, when the fabric 5 is in the retracted position, the bottom bar 6 is
preferably placed in abutment against the rolling-shutter box 3 and, when the fabric
5 is in the extended position, the bottom bar 6 is preferably placed at the lower
ends of the vertical uprights 7 with the fabric 5 unwound to substantially totally
close the opening A.
[0042] The fabric 5 is therefore completely guided in its winding and unwinding following
the rotation of the take-up roller 4, with its lateral edges advantageously engaged
in rails (not shown) placed inside the vertical uprights 7, and with the lower edge
fixed to the bottom bar 6, in turn engaged to the vertical uprights 7 themselves through
the lateral terminals.
[0043] In particular, the bottom bar 6, during the movement of the fabric 5, keeps the fabric
5 itself extended and is moved remaining horizontal, with its lateral terminals engaged
with the vertical uprights 7. For such purpose, the uprights are preferably obtained
with aluminum or plastic extrusions with guides made along the extension thereof for
the sliding of the lateral terminals.
[0044] Preferably, the aforesaid return spring 8 has helical form and is wound at least
partially around the axis of the take-up roller 4 and is constrained at one end thereof
to the rotary take-up roller and at the other end thereof to a part of the fixed frame,
such as preferably to an adjustment shaft 141 coaxially arranged inside the roller
and carrying, wound thereon, the helical spring.
[0045] The return spring 8 is elastically opposed to the unwinding of the fabric 5 from
the retracted position to the extended position and facilitates the re-winding of
the fabric 5 from the extended position to the retracted position. Therefore, when
the fabric 5 is in extended position the elastic torque exerted by the return spring
8 on the take-up roller 4 maintains the fabric 5 taut, preventing the formation of
folds or wrinkles of the material that forms the fabric 5 itself.
[0046] The blind 1, object of the present invention, also comprises means 10 for adjusting
the tension of the return spring 8, which are mechanically connected to the take-up
roller 4 in order to vary the tensioning of the spring 8.
[0047] The adjusting means 10 therefore allow varying the elastic torque which the return
spring 8 exerts on the take-up roller 4, in order to vary the elastic force with which
the spring 8 opposes the unwinding and simultaneously in order to vary the elastic
force with which it facilitates the re-winding of the fabric 5.
[0048] According to the idea underlying the present invention, the adjusting means 10 of
the blind 1 comprise an actuator member 13, rotatably mounted inside at least one
of the uprights 7 of the support frame 2, preferably inside a housing seat thereof.
Such actuator member 13 is accessible by means of a hole 71 made on the same upright
7 from within the opening A, in a position facing the opposite upright, and is susceptible
of being rotated into different angular positions, preferably inside the aforesaid
housing seat, exerting an adjusting torque on the actuator member 13 itself.
[0049] The means 10 for adjusting the tension of the return spring 8 also comprise mechanical
engagement means 20 provided for mechanically engaging the actuator member 13 to the
upright 7 in the aforesaid angular positions and transmission means 18 for transmitting
the rotation torque of the actuator member 13 to the take-up roller 4, consequently
varying the tensioning of the return spring 8.
[0050] Preferably, the upright 7 of the support frame 2, in which the actuator member 13
of the adjusting means 10 is housed, comprises a lateral cap 19 fixed to the same
upright 7 at the upper part of the opening A.
[0051] Advantageously, the lateral cap 19 is provided with an external support shell 11
intended to face the internal face of the portal and with an internal shell 12 mechanically
fixed to the external shell 11. The external and internal shells 11, 12 delimit a
containment space inside of which the transmission means 18 are housed. In addition,
the aforesaid shells 11, 12 delimit the seat 121 in which the actuator member 13 is
housed for the means 10 for adjusting the tension of the return spring 8. Advantageously,
the actuator member 13 of the adjusting means 10 comprises a first toothed wheel 131
rotatably and idly mounted on a pin 17 fixed to the lateral cap 19, and it is housed
inside the seat 121 delimited by the external 11 and internal 12 shells of the cap
19 itself.
[0052] Advantageously, the actuator member 13 also comprises elastically pliable means 15
interposed between the toothed wheel 131 and the external shell 11 of the lateral
cap 19 which are adapted to exert an axial elastic force along the pin 17 on the actuator
member 13.
[0053] Preferably, the first toothed wheel 131 of the actuator member 13 is provided with
a central hole 136 axially and slidably engaged on the pin 17, which is fixed to the
external support shell 11 of the lateral cap 19.
[0054] The elastically pliable means 15 of the actuator member 13 advantageously comprise
a second helical spring coaxially wound around the pin 17 fixed to the external shell
11 of the lateral cap 19.
[0055] The mechanical engagement means 20 for the adjusting means 10 preferably comprise
at least one first shaped face of the first toothed wheel 13 and at least one second
shaped face of the seat 121 in which the actuator member 13 is housed. Such two shaped
faces are forced in a mechanical retention relationship against each other by the
elastic force exerted by the elastically pliable means 15 of the actuator member 13.
[0056] In particular, the first shaped face of the first toothed wheel 131 of the actuator
member 13 is provided with at least one locking tongue 132, and in particular is preferably
provided with two locking tongues 132 each positioned at 180° with respect to each
other. Such tongue 132 projectingly protrudes towards the second shaped face of the
seat 121, which is provided with at least one housing cavity 123 of the locking tongue
132 in order to define the aforesaid retention engagement therewith.
[0057] More in detail, the second shaped face of the seat 121 delimited between the external
11 and internal 12 shells of the lateral cap 19 is provided with two or more teeth
124 which delimit the corresponding housing cavity 123 therebetween.
[0058] Advantageously, each tooth 124 of the seat 121 is provided with a slide profile 1241
in a first rotation direction, in particular in the rotation direction in which the
tension of the return spring 8 increases, in order to facilitate the sliding of the
locking tongue 132 of the first toothed wheel 131 thereon during the rotation of the
actuator member 13, and with a step profile 1242 in a second rotation direction, in
particular in the rotation direction in which the tension of the return spring 8 decreases,
in order to lock the locking tongue 132 in the housing cavity 123.
[0059] In accordance with a different embodiment of the blind 1 not illustrated in the enclosed
figures, the first shaped face of the first toothed wheel 131 of the actuator member
13 is provided with at least one first friction surface, for example a plurality of
knurling, i.e. roughness, i.e. a material layer with high static friction coefficient,
such as a composite with polymer matrix, directed towards the second shaped face of
the seat 121 of the first toothed wheel 131, which is in turn provided with at least
one second friction surface in order to define the aforesaid retention engagement
with the first friction surface of the first toothed wheel 13.
[0060] Preferably, the transmission means 18 comprise at least one second toothed wheel
14 coaxially fixed to the take-up roller 4, in particular along the rotation axis
X, and mechanically engaged with the first toothed wheel 131 of the actuator member
13.
[0061] In accordance with the preferred embodiment illustrated in the enclosed figures,
the second toothed wheel 14 is centrally provided, on the face directed away from
the lateral cap 19, with a projecting tubular portion, which is mechanically connected
to the adjustment shaft 141 which internally retains the first end of the helical
return spring 8 by means of a retention mouth (not illustrated in the enclosed figures)
housed inside the adjustment shaft 141. The return spring 8 is therefore positioned
inside the take-up roller 4 and mechanically constrained at its second end to the
opposite upright. Simultaneously, the other end of the shaft 141 is rotatably supported
by the cap of the opposite upright itself.
[0062] The rotation of the second toothed wheel 14 allows changing the angular position
of the adjustment shaft 141 in which the first end of the return spring 8 is retained
and then varying the tensioning force thereof.
[0063] Advantageously, the internal shell 12 is provided with a through hole 125 aligned
with the aforesaid projecting tubular projection, which protrudes towards the interior
of the opening A through such through hole 125 of the internal shell in order to be
coaxially engaged with the shaft 141 mounted inside the take-up roller 4.
[0064] In accordance with the preferred embodiment illustrated in the enclosed figures,
the transmission means 18 preferably also comprise at least one third toothed wheel
16 idly mounted on the lateral cap 19, in particular pivoted on a further pin 160
fixed to the internal shell 12 of the lateral cap 19, and mechanically engaged to
the first and second toothed wheel 131, 14 for transmitting the motion between the
first toothed wheel 131 and the second toothed wheel 14.
[0065] The kinematic chain obtained by means of the aforesaid first, second and third toothed
wheels 131, 14, 16 can be enlarged with other members and in particular with other
toothed wheels, for the purpose of varying the transmission ratio, without departing
from the protective scope of the present patent.
[0066] Preferably, such toothed wheels 131, 14, 16 are made of plastic material, such as
polystyrene, or a thermosetting resin.
[0067] In accordance with the preferred embodiment illustrated in the enclosed figures,
the actuator member 13 also comprises a projecting central portion 134, which protrudes
from the first shaped face of the first toothed wheel 131
[0068] The aforesaid projecting central portion 134 is inserted in a through hole 122 which
is made on the internal shell 12 of the lateral cap 19, at the seat 121, and is aligned
with the access hole 71 obtained on the upright 7, in which the lateral cap 19 itself
is installed.
[0069] Advantageously, the projecting central portion 134 of the actuator member 13 is provided
with a terminal face 135 with a shaped seat obtained thereon, which is accessible
from within the opening A, being aligned with the aforesaid through holes 71, 122.
[0070] Such shaped seat is susceptible of receiving, via shape coupling, an actuator tool
for the rotation of the actuator member 13, such as an Allen wrench, or a screwdriver,
movable by a user in order to impart a rotation torque to the actuator member 13 and
thus varying the tension of the return spring 8 in a quick and easy manner.
[0071] In operation, for the purpose of increasing the tension of the return spring 8, the
user applies the aforesaid rotation torque to the actuator member 13 inside the seat
121 in a first rotation direction. The actuator member 13 imparts such rotation torque
to the take-up roller 4 and to the return spring 8 by means of the transmission means
18 housed inside the containment space delimited between the external 11 and internal
12 shells of the external cap 19.
[0072] Each locking tongue 132 slides on the slide profile 1241 of the corresponding tooth
124, until the tongue 132 reaches the cavity 123 obtained between each tooth 124 and
the successive contiguous tooth 124 (successive according to the rotation direction),
in order to then encounter the slide profile 1241 of the subsequent tooth 124. Upon
reaching the desired tension of the return spring 8, the user removes the rotation
torque from the actuator member 13 and the elastic return force of the spring 8 pushes
the tongue 132 in abutment against the step profile 1242 of the preceding tooth 124,
preceding with respect to the aforesaid first rotation direction, locking the actuator
member 13 in such position and simultaneously maintaining the return spring 8 at the
desired tension.
[0073] In addition, for the purpose of decreasing the tension of the return spring 8, the
user pushes the actuator member 13 (preferably by acting on the terminal wall 135
of the projecting central portion 134) in order to overcome the elastic force exerted
by the elastically pliable means 15, and thus to release the first shaped face of
the first toothed wheel 131 of the actuator member 13 from the second shaped face
of the seat 121, and in particular, in accordance with the preferred embodiment illustrated
in the enclosed figures, in order to move beyond the step profile 1242 of the tooth
124 against which each tongue 132 lies in abutment. The elastic return force of the
spring 8 forces the actuator member 13 to rotate, until each tongue abuts against
the step profile 1242 of the preceding tooth 124, therefore upon rotation of the actuator
member 13, the tension of the return spring 8 mechanically associated with the take-up
roller 4 decreases.
[0074] In this manner it is possible to lock the actuator member 13 in different angular
positions, and in particular it is possible to vary the tension of the return spring
8 without having to disassemble the support frame 2 of the blind 1, hence this is
a quick, easy operation, not requiring the final user to possess technical knowledge
of the field. The fabric roller blind 1 provided with a device for adjusting the tension
thus conceived therefore attains the pre-established objects.
1. Fabric roller blind (1), which comprises:
- a support frame (2) provided with at least two vertical uprights (7) and intended
to be fixed in an opening (A) of a portal, of a window or of a door; said two vertical
uprights (7) extended parallel to each other and side-by-side fixed to said portal
along respective sides of said opening (A);
- a take-up roller (4) rotatably supported by said support frame (2), between said
two vertical uprights (7), along a substantially horizontal rotation axis (X), and
intended to be positioned in the upper part of said opening (A);
- a fabric (5) extended between an upper edge thereof fixed to said take-up roller
(4) and a lower edge thereof, and susceptible of sliding between said vertical uprights
(7);
- at least one return spring (8) mechanically associated with said take-up roller
(4) and adapted to exert an elastic torque on said take-up roller (4);
said take-up roller (4) being susceptible of being rotated around the rotation axis
(X) in order to move said fabric (5) between a retracted position, in which said fabric
(5) is wound around said take-up roller (4) and an extended position, in which said
fabric (5) is at least partially unwound from said take-up roller (4);
said return spring (8) being elastically opposed to the unwinding of said fabric (5)
from said retracted position to said extended position and facilitating the re-winding
of said fabric (5) from said extended position to said retracted position;
- adjusting means (10) for adjusting the tension of said return spring (8), mechanically
connected to said take-up roller (4) in order to vary the tensioning of said return
spring (8);
said blind (1) being
characterized in that said adjusting means (10) comprise:
- an actuator member (13), rotatably mounted inside at least one of said uprights
(7) of said support frame (2), accessible by means of a hole (71) obtained on the
same upright (7) in a position facing the opposite upright (7), from within said opening
(A) and susceptible of being rotated into different angular positions; mechanical
engagement means (20) being provided for mechanically engaging said actuator member
(13) with said upright (7) in said angular positions;
- transmission means (18) for transmitting the rotation torque of said actuator member
(13) to said take-up roller (4), consequently varying the tensioning of said return
spring (8).
2. Blind according to claim 1,
characterized in that the upright (7) of said support frame (2) comprises a lateral cap (19) fixed to said
upright (7) at said upper part, and provided with:
- an external support shell (11) intended to face the internal face of the portal;
- an internal shell (12) mechanically fixed to said external shell (11), delimiting
with said external support shell (11) a containment space housing said transmission
means (18) and a seat (121) in which said actuator member (13) is housed.
3. Blind according to claim 2,
characterized in that said actuator member (13) comprises:
- a first toothed wheel (131) rotatably and idly mounted on a pin (17) fixed to said
lateral cap (19), housed within the seat (121);
- elastically pliable means (15) interposed between said toothed wheel (131) and said
lateral cap (11) and adapted to exert an axial elastic force along the pin (17) on
said actuator member (13);
said mechanical engagement means (20) comprising at least one first shaped face of
said first toothed wheel (13) and at least one second shaped face of the seat (121)
in which said actuator member (13) is housed, forced in a mechanical retention relationship
against each other by said elastically pliable means (15).
4. Blind according to claim 3, characterized in that the first shaped face of said first toothed wheel (131) of said actuator member (13)
is provided with at least one locking tongue (132) which projectingly protrudes towards
the second shaped face of the seat (121) of said first toothed wheel (131); the latter
being provided with at least one housing cavity (123) for said locking tongue (132)
in order to define said retention engagement therewith.
5. Blind according to claim 4, characterized in that the second shaped face of the seat (121) of said first toothed wheel (131) of said
actuator member (13) is provided with two or more teeth (124) delimiting corresponding
said housing cavities (123) therebetween.
6. Blind according to claim 5, characterized in that each said tooth (124) is provided with a slide profile (1241) in a first rotation
direction, in order to facilitate the sliding of the locking tongue (132) thereon
during the rotation of the actuator member (13), and with a step profile (1242) in
a second rotation direction in order to lock the locking tongue (132) in said housing
cavity (123).
7. Blind according to claim 3, characterized in that the first shaped face of said first toothed wheel (131) of said actuator member (13)
is provided with at least one friction surface directed towards the second shaped
surface of the seat of said first toothed wheel; the latter being provided with at
least one second friction face in order to define said retention engagement therewith.
8. Blind according to claim 1, characterized in that said transmission means (18) comprise at least one second toothed wheel (14) coaxially
fixed to said take-up roller (4).
9. Blind according to claim 6, characterized in that said transmission means (18) comprise at least one third toothed wheel (16) idly
mounted on said lateral cap (19) and mechanically engaged with said first and second
toothed wheel (131, 14) in order to transmit the motion of the first (131) to the
second (14).
10. Blind according to claim 3 characterized in that said first toothed wheel (131) of said actuator member (13) internally delimits a
central hole (136) slidably engaged with the pin (17) of said external support shell
(11) of said lateral cap (19).
11. Blind according to claim 1 characterized in that said actuator member (13) of said adjusting means (10) is susceptible of being rotated
into different angular positions through a tool insertable in said hole (71) and removably
engageable with a shaped seat of said actuator member (13).