Fire resisting shutter automatic release remote actuator

Abstract

The utility model provides a fire resisting shutter automatic release remote actuator. The fire resisting shutter automatic release remote actuator comprises a shell, a winding wheel and a locking assembly. The shell is used for being fixed to the wall height position around the fire resisting shutter and facilitating manual operation. The winding wheel is rotationally connected into the shell, a pull wire is wound on the winding wheel, and one end of the pull wire penetrates out of the shell and is connected with the brake release mechanism; the locking assembly is arranged in the shell and provided with a locking end and an operating end, and the locking end has a locking state in which the locking end is connected with the winding wheel to limit rotation of the winding wheel and an unlocking state in which the locking end is separated from the winding wheel; the operation end penetrates out of the shell and is used for driving the locking end to switch the state. According to the fire resisting shutter automatic release remote actuator, remote control over automatic release of a fire resisting shutter can be achieved, operation convenience and safety are improved, response to closing of the fire resisting shutter can be made in time according to fire, and fire spreading is avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of fireproof rolling curtains, and in particular relates to an automatic-releasing remote actuator for fireproof rolling curtains. Background Art

[0002] Fire shutters use transmission devices and control systems to raise and lower the curtain, providing fire protection and isolation. They are typically installed in commercial, industrial, and residential buildings. Because fires are often accompanied by power outages, fire shutters must be able to close solely by their own weight, independent of external power sources.

[0003] In the existing technology, fire shutters are equipped with an exposed brake release mechanism on the roller shutter mechanism. When a fire occurs and the power goes out, the brake release mechanism can be manually operated to release the braking force of the roller shutter mechanism, allowing the fire curtain to close under its own weight. The problem is that large commercial complexes often have a large number of fire shutters, and the roller shutter mechanism itself is installed at a high position, making manual operation very inconvenient. Therefore, it is difficult to close all the fire shutters in a short time in the event of a fire. If the fire shutters are not closed in time, it can easily cause the fire to spread. In addition, relying entirely on manual operation in the event of a power outage also poses a significant threat to the personal safety of the operator. Utility Model Content

[0004] An embodiment of the utility model provides a remote actuator for automatically releasing a fireproof rolling shutter, aiming to improve the convenience of manual release operation of the fireproof rolling shutter.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: to provide a remote actuator for automatic release of a fireproof roller shutter, comprising a shell, a winding wheel, and a locking assembly; the shell is used to be fixed at a wall height position around the fireproof roller shutter for easy manual operation; the winding wheel is rotatably connected to the shell, and a pull wire is wound around the winding wheel, one end of the pull wire passes through the shell and is connected to the brake release mechanism of the fireproof roller shutter; the locking assembly is arranged in the shell, and has a locking end and an operating end, wherein the locking end has a locking state connected to the winding wheel to limit the rotation of the winding wheel, and also has an unlocking state separated from the winding wheel; the operating end passes through the shell and is used to drive the locking end to switch states.

[0006] In combination with the first aspect, in a possible implementation, a ratchet is coaxially connected to one side of the winding wheel, and a pawl is provided at the locking end. In the locked state, the pawl is engaged with the wheel groove of the ratchet.

[0007] In some embodiments, the locking assembly includes:

[0008] A first swing rod, one end of which is rotatably connected to the inner wall of the housing and provided with a ratchet, and the other end of which forms a clamping portion;

[0009] A second swing rod, the middle portion of which is rotatably connected to the inner wall of the housing, one end of the second swing rod being close to the clamping portion and provided with a receiving groove, and the other end of the second swing rod being provided with an operating rod extending out of the housing to form an operating end;

[0010] an elastic traction member, one end of which is connected to the first rocker arm near the clamping portion, and the other end of which is connected to the inner wall of the housing or the operating rod;

[0011] Among them, when the clamping part is clamped into the receiving groove, the elastic traction member is in a stretched state, and the pawl is clamped into the wheel groove of the ratchet to form a locked state; when the second rocker arm is driven by the operating rod to swing until the clamping part is disengaged from the receiving groove, the first rocker arm swings under the action of the elastic traction member until the pawl is disengaged from the ratchet to form an unlocked state.

[0012] Exemplarily, the locking assembly further includes an electric telescopic member connected to the housing, wherein an output end of the electric telescopic member is connected to the second swing rod and is used to drive the second swing rod to swing.

[0013] For example, electric telescopic parts include:

[0014] A fixed sleeve is connected to the inner wall of the shell, and an electromagnet is provided on the fixed sleeve;

[0015] An iron core, one end of which is slidably inserted into the fixed sleeve and the other end of which is connected to the second swing rod;

[0016] An elastic pushing member is sleeved on the iron core and located between the second rocker arm and the fixed sleeve;

[0017] The elastic pushing member is used to push the iron core outward when the electromagnet is de-energized, and the electromagnet is used to attract the iron core to slide into the fixed sleeve when energized.

[0018] In a possible implementation, the locking assembly further includes a rotary reset member rotatably connected to the housing, and the rotary reset member is connected to the first rocker arm to drive the first rocker arm to reset by overcoming the pulling force of the elastic traction member.

[0019] In some embodiments, the rotary reset member includes a rotating shaft rotatably connected to the housing and a push rod provided on the peripheral wall of the rotating shaft; wherein the center of the rotating shaft has a first operating hole suitable for inserting a tool, and the push rod abuts against the first rocker arm.

[0020] Exemplarily, a limit pin is connected to the inner wall of the shell, and the limit pin is used to block the push rod when in the unlocked state.

[0021] For example, the pawl is hinged to the first rocker arm and an elastic torsion piece is provided between the two. The elastic torsion piece is used to elastically press the pawl against the ratchet wheel.

[0022] In some embodiments, a second operating hole suitable for inserting a tool is provided in the center of the reel.

[0023] The beneficial effect of the automatic release remote actuator for fireproof roller shutter provided by the utility model is that: compared with the existing technology, the automatic release remote actuator for fireproof roller shutter provided by the utility model installs the shell at a height convenient for manual operation, and tightens the pull wire by the winding wheel to pull the brake release mechanism of the roller shutter machine to maintain the braking state of the fireproof roller shutter. When a fire occurs and the fireproof roller shutter needs to be closed, the operating end of the locking assembly can be manually operated to unlock its locking end, so that the winding wheel can rotate freely and relax the pull wire, and then the brake release mechanism releases the brake of the roller shutter machine, so that the fireproof roller shutter can automatically close under the action of its own gravity, thereby realizing remote control of the automatic release of the fireproof roller shutter, improving the convenience and safety of operation, and being conducive to timely response to the fire and closing the fireproof roller shutter to avoid the spread of fire. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the internal structure of the automatic release remote actuator for fireproof rolling shutters provided by an embodiment of the present utility model in a locked state;

[0025] Figure 2 A schematic diagram of the internal structure of the automatic release remote actuator for fireproof rolling shutters provided by an embodiment of the present invention in the unlocked state;

[0026] Figure 3 for Figure 1 Schematic diagram of the locally enlarged structure at point A in the middle.

[0027] In the figure: 10, housing; 20, winding wheel; 21, ratchet; 22, second operating hole; 30, pull wire; 40, locking assembly; 400, pawl; 41, first rocker arm; 411, clamping portion; 42, second rocker arm; 421, receiving groove; 422, operating rod; 43, elastic traction member; 44, electric telescopic member; 441, fixing sleeve; 442, electromagnet; 443, iron core; 444, elastic pushing member; 45, rotary reset member; 451, rotating shaft; 452, push rod; 4511, first operating hole; 46, limit pin. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] It should be noted that when an element is referred to as being "disposed on" or "connected to" another element, it can be directly on the other element or indirectly on the other element. It should be understood that the terms "upper", "lower", "front", "back", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. The terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" and "several" mean two or more, unless otherwise clearly and specifically defined.

[0030] Please also refer to Figures 1 to 3 The automatic fire shutter release remote actuator provided by the present invention is now described. The automatic fire shutter release remote actuator comprises a housing 10, a reel 20, and a locking assembly 40. The housing 10 is used to be fixed to a wall height position around the fire shutter for easy manual operation. The reel 20 is rotatably connected to the housing 10. A pull wire 30 is wound around the reel 20. One end of the pull wire 30 passes through the housing 10 and is connected to the brake release rod. The locking assembly 40 is disposed in the housing 10 and has a locking end and an operating end. The locking end has a locking state in which it is connected to the reel 20 to restrict the rotation of the reel 20, and also has an unlocking state in which it is separated from the reel 20. The operating end passes through the housing 10 and is used to drive the locking end to switch states.

[0031] It should be noted that the fireproof roller shutter's rolling door machine can be manually released from braking by operating its exposed brake release mechanism. In this case, the brake release lever of the brake release mechanism can be directly pulled by the pull wire 30 to maintain the braking state of the rolling door machine. When the pull wire 30 is released, the brake release lever swings based on the spring built into the mechanism, thereby releasing the braking state of the rolling door machine. At this time, the fireproof curtain of the fireproof roller shutter, under the action of its own gravity, drives the rolling door machine to rotate and unwind, ultimately achieving automatic closing of the fireproof roller shutter. In addition, the brake release mechanism can also be externally connected to the pull wire 30. The fuse can specifically be an elastic telescopic member connected by a fusible alloy or a mercury glass tube. When the temperature reaches a safety threshold, such as 70 degrees Celsius, it automatically breaks, causing the elastic telescopic member to extend under the elastic force, thereby generating a traction force on the pull wire 30 connected to the elastic telescopic member on the brake release lever, thereby releasing the braking force of the rolling door machine.

[0032] In this embodiment, the winding wheel 20 is locked by tightening the wire 30 through the winding wheel 20 and then locking the locking end of the locking assembly. Of course, in the locked state, the winding wheel 20 can be completely locked and unable to rotate, or the rotation direction of the winding wheel 20 to loosen the wire 30 can be simply restricted. At this time, the winding wheel 20 can still rotate in the other direction to continue tightening the wire 30.

[0033] The fire shutter automatic release remote actuator provided in this embodiment, compared with the prior art, has a housing 10 installed at a height that is convenient for manual operation. The wire 30 is tightened by the winding wheel 20 to pull the brake release mechanism of the rolling door machine to maintain the brake state of the fire shutter. When a fire occurs and the fire shutter needs to be closed, the operating end of the locking assembly 40 can be manually operated to unlock its locking end, so that the winding wheel 20 can rotate freely and the wire 30 can be loosened, thereby allowing the brake release mechanism to release the brake of the rolling door machine, so that the fire shutter can automatically close under the action of its own gravity. In this way, remote control of the automatic release of the fire shutter can be achieved, which improves the convenience and safety of operation and is conducive to timely response to the fire shutter closing to prevent the spread of fire.

[0034] In some embodiments, see Figure 1 and Figure 2 A ratchet 21 is coaxially connected to one side of the reel 20, and a pawl 400 is provided at the locking end. In the locked state, the pawl 400 engages with the wheel groove of the ratchet 21. The use of the ratchet 21 and the pawl 400 to lock the reel 20 not only simplifies the structure but also ensures the stability of the locked state. At the same time, the reel 20 can continue to be tightened in the locked state, thereby facilitating the reset of the locking assembly 40 from the unlocked state to the locked state, improving the convenience of operation.

[0035] As a specific embodiment of the locking assembly 40, please refer to Figures 1 to 3The locking assembly 40 includes a first rocker arm 41, a second rocker arm 42 and an elastic traction member 43; one end of the first rocker arm 41 is rotatably connected to the inner wall of the housing 10 and is provided with a pawl 400, and the other end forms a clamping portion 411; the middle portion of the second rocker arm 42 is rotatably connected to the inner wall of the housing 10, one end of the second rocker arm 42 is close to the clamping portion 411 and is provided with a receiving groove 421, and the other end is provided with an operating rod 422 extending out of the housing 10 to form an operating end; one end of the elastic traction member 43 is close to the first rocker arm 41 The position of the clamping portion 411 is connected, and the other end is connected to the inner wall of the shell 10 or the operating rod 422; wherein, when the clamping portion 411 is clamped into the receiving groove 421, the elastic traction member 43 is in a stretched state, and the pawl 400 is clamped into the wheel groove of the ratchet 21 to form a locked state; when the second rocker arm 42 is driven by the operating rod 422 to swing until the clamping portion 411 is disengaged from the receiving groove 421, the first rocker arm 41 is swung under the action of the elastic traction member 43 until the pawl 400 is disengaged from the ratchet 21 to form an unlocked state.

[0036] When it is necessary to release the fireproof rolling shutter, it is only necessary to move the operating rod 422 to drive the second rocker arm 42 to swing. After the receiving groove 421 is disengaged from the clamping part 411, the first rocker arm 41 can swing under the elastic tension of the elastic traction member 43 such as a tension spring, so that the pawl 400 connected to the first rocker arm 41 is disengaged from the wheel groove of the ratchet 21, thereby releasing the rotational movement restriction of the ratchet 21, allowing the winding wheel 20 to rotate freely and relax the pull wire 30, thereby allowing the brake release mechanism to release the braking force of the rolling door machine; the structure is simple and stable, and the action response sensitivity is high, which can ensure the timeliness of the automatic release of the fireproof rolling shutter.

[0037] It should be noted that, see Figure 1 and Figure 2 The locking assembly 40 further includes an electric telescopic member 44 connected to the housing 10. The output end of the electric telescopic member 44 is connected to the second swing arm 42 and is used to drive the second swing arm 42 to swing. The purpose of providing the electric telescopic member 44 is to ensure that the winding reel 20 can be automatically unlocked by electronic control when the power is on, thereby ensuring the completeness of the electric control closing function of the fire shutter.

[0038] Specifically, such as Figure 2 As shown, the above-mentioned electric telescopic member 44 includes a fixed sleeve 441, an iron core 443 and an elastic pushing member 444; the fixed sleeve 441 is connected to the inner wall of the shell 10, and an electromagnet 442 is provided on the fixed sleeve 441; one end of the iron core 443 is slidably passed through the fixed sleeve 441, and the other end is connected to the second rocker 42; the elastic pushing member 444 is sleeved on the iron core 443 and is located between the second rocker 42 and the fixed sleeve 441; wherein, the elastic pushing member 444 is used to push the iron core 443 outward when the electromagnet 442 is de-energized, and the electromagnet 442 is used to attract the iron core 443 to slide into the fixed sleeve 441 when energized.

[0039] The elastic pushing member 444 can specifically be a spring. When the electromagnet 442 is energized to generate a magnetic field, it can generate an attractive force on the iron core 443 that exceeds the elastic thrust of the elastic pushing member 444, thereby driving the iron core 443 to slide into the fixed sleeve 441. During this process, the iron core 443 pulls the second rocker arm 42 to swing, thereby causing the clamping portion 411 to disengage from the receiving groove 421; when it is necessary to reset the unlocked state to the locked state, the electromagnet 442 can be powered off. At this time, the iron core 443 pushes the second rocker arm 42 to swing in the opposite direction under the elastic thrust of the elastic pushing member 444, so that the clamping portion 411 can abut against the second rocker arm 42. At this time, it is only necessary to swing the first rocker arm 41 in the opposite direction to make the clamping portion 411 automatically snap into the receiving groove 421, which not only facilitates the reset operation, but also utilizes the elastic thrust of the elastic pushing member 444 to improve the clamping reliability of the clamping portion 411 and the receiving groove 421.

[0040] As a further variant structure of the locking assembly 40, please refer to Figure 1 and Figure 2 The locking assembly 40 further includes a rotational reset member 45 rotatably connected to the housing 10. The rotational reset member 45 is connected to the first swing arm 41 to drive the first swing arm 41 to reset itself against the tension of the elastic pulling member 43. The rotational reset member 45 may be a cam or a rotatably connected rod-shaped member. The rotational reset member 45 abuts against the first swing arm 41 to rotate and drive the first swing arm 41 to swing, thereby improving the convenience of resetting the locked state.

[0041] Alternatively, see Figure 1 In this embodiment, the rotary reset member 45 includes a rotating shaft 451 rotatably connected to the housing 10 and a push rod 452 disposed on the peripheral wall of the rotating shaft 451. The rotating shaft 451 has a first operating hole 4511 at its center for inserting a tool, and the push rod 452 abuts against the first rocker arm 41. The housing 10 defines a clearance hole aligned with the first operating hole 4511 to facilitate tool insertion. The first operating hole 4511 can be a polygonal hole, such as a hexagonal hole. Inserting a tool, such as an Allen wrench, into the first operating hole 4511 from outside the housing 10 rotates the rotating shaft 451, causing the push rod 452 to push the first rocker arm 41 to overcome the tension of the elastic traction member 43 and achieve a swing reset. This allows the reset operation to be completed without opening the housing 10, providing increased convenience.

[0042] In order to prevent the rotating shaft 451 from rotating too far after unlocking, Figure 2 As shown, a limit pin 46 is connected to the inner wall of the housing 10 , and the limit pin 46 is used to block the ejector rod 452 when in the unlocked state.

[0043] It should be understood that the pawl 400 is hingedly connected to the first rocker arm 41, and an elastic torsion member is disposed therebetween. The elastic torsion member is used to elastically press the pawl 400 against the ratchet 21. The elastic torsion member (not shown) can be a torsion spring. The elastic torsion member maintains an elastic torsion force within the angular range of the pawl 400, thereby achieving elastic engagement between the pawl 400 and the ratchet 21. This restricts only the unidirectional rotational freedom of the ratchet 21 in the locked state. This allows the cable 30 to continue to be tightened in the locked state, facilitating the reset operation from the unlocked state to the locked state.

[0044] In order to facilitate the tightening operation of the pull wire 30, as shown in FIG. Figure 1 As shown, the center of the reel 20 is provided with a second operating hole 22 suitable for inserting a tool. The second operating hole 22 can be a polygonal hole such as a hexagonal hole. The housing 10 is provided with a clearance hole aligned with the first operating hole 4511. When tightening the cable 30, a tool such as an hexagonal wrench can be inserted into the second operating hole 22 and rotated, which is simple and convenient.

[0045] Based on the above, please combine Figures 1 to 3 It is understood that the working process of the automatic release remote actuator of the fireproof roller shutter provided in this embodiment is as follows:

[0046] When the rolling door machine is in the brake holding state, the winding wheel 20 tightens the pull wire 30, the pawl 400 is engaged in one of the wheel grooves of the ratchet 21, the engaging portion 411 is engaged in the receiving groove 421, the elastic traction member 43 is in a stretched state and the elastic pushing member 444 outputs a pushing force to the second rocker arm 42.

[0047] When the fireproof roller shutter needs to be released, the brakes of the rolling door machine are released by electric release and manual release. The electric release process is that the electromagnet 442 is energized to attract the iron core 443, and the iron core 443 pulls the second rocker arm 42 to swing, and the clamping part 411 is disengaged from the receiving groove 421. The first rocker arm 41 swings under the elastic pulling force of the elastic pulling member 43 to make the pawl 400 disengage from the wheel groove of the ratchet 21 to complete the unlocking; the manual release process is that the operator manually pulls the operating lever 422 to drive the second rocker arm 42 to swing, so that the clamping part 411 is disengaged from the receiving groove 421, and the first rocker arm 41 swings under the elastic pulling force of the elastic pulling member 43 to make the pawl 400 disengage from the wheel groove of the ratchet 21 to complete the unlocking.

[0048] The operation for resetting the rolling door machine to the braking state is to insert the wrench tool into the first operating hole 4511, rotate the swing shaft 451, and use the push rod 452 to push the first rocker arm 41 to swing. At this time, the second rocker arm 42 is kept in contact with the clamping part 411 by the force of the elastic pushing member 444 until the first rocker arm 41 swings to the clamping part 411 and is clamped in the receiving groove 421. Then insert the wrench tool into the second operating hole 22 and start rotating the winding wheel 20 to tighten the pull wire 30 until the brake release mechanism swings to the braking state under the traction force of the pull wire 30.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. Fire shutter automatic release remote actuator, characterized by: include: The housing is used to be fixed on the wall around the fireproof roller shutter at a height convenient for manual operation; A winding wheel is rotatably connected to the housing, a pull wire is wound around the winding wheel, and one end of the pull wire passes through the housing and is connected to the brake release mechanism of the fireproof roller shutter; A locking assembly is disposed in the housing and has a locking end and an operating end, wherein the locking end has a locking state in which it is connected to the winding wheel to limit the rotation of the winding wheel, and also has an unlocking state in which it is separated from the winding wheel; the operating end passes through the housing and is used to drive the locking end to switch states.

2. The fire shutter automatic release remote actuator according to claim 1, characterized in that: A ratchet is coaxially connected to one side of the winding wheel, and a pawl is provided at the locking end. In the locking state, the pawl is engaged with the wheel groove of the ratchet.

3. The automatic release remote actuator for fireproof rolling shutter according to claim 2, characterized in that: The locking assembly comprises: a first swing rod, one end of which is rotatably connected to the inner wall of the housing and provided with the pawl, and the other end of which forms a clamping portion; a second swing link, the middle portion of which is rotatably connected to the inner wall of the housing, one end of the second swing link being close to the clamping portion and provided with a receiving groove, and the other end of the second swing link being provided with an operating rod extending out of the housing to form the operating end; an elastic traction member, one end of which is connected to a position of the first rocker arm close to the clamping portion, and the other end of which is connected to the inner wall of the housing or the operating rod; Wherein, when the clamping portion is clamped into the receiving groove, the elastic traction member is in a stretched state, and the pawl is clamped into the wheel groove of the ratchet to form the locked state; when the second rocker arm is driven by the operating rod to swing until the clamping portion is disengaged from the receiving groove, the first rocker arm is swung under the action of the elastic traction member until the pawl is disengaged from the ratchet to form the unlocked state.

4. The automatic release remote actuator for fireproof rolling shutter according to claim 3, characterized in that: The locking assembly further includes an electric telescopic member connected to the housing, wherein an output end of the electric telescopic member is connected to the second swing rod and is used to drive the second swing rod to swing.

5. The automatic release remote actuator for fireproof rolling shutter according to claim 4, characterized in that: The electric telescopic member comprises: A fixed sleeve connected to the inner wall of the shell, wherein the fixed sleeve is provided with an electromagnet; an iron core, one end of which is slidably inserted into the fixing sleeve and the other end of which is connected to the second rocker; an elastic pushing member, sleeved on the iron core and located between the second rocker arm and the fixed sleeve; The elastic pushing member is used to push the iron core outward when the electromagnet is de-energized, and the electromagnet is used to attract the iron core to slide into the fixed sleeve when energized.

6. The automatic release remote actuator for fireproof rolling shutter according to claim 3, characterized in that: The locking assembly further includes a rotary reset member rotatably connected to the housing, and the rotary reset member is connected to the first rocker arm to drive the first rocker arm to overcome the pulling force of the elastic traction member and reset.

7. The automatic release remote actuator for fireproof rolling shutter according to claim 6, characterized in that: The rotary reset member includes a rotating shaft rotatably connected to the housing and a push rod provided on the peripheral wall of the rotating shaft; wherein the center of the rotating shaft has a first operating hole suitable for inserting a tool, and the push rod abuts against the first rocker arm.

8. The automatic release remote actuator for fireproof rolling shutter according to claim 7, characterized in that: A limit pin is connected to the inner wall of the shell, and the limit pin is used to block the push rod in the unlocked state.

9. The automatic release remote actuator for fireproof rolling shutter according to claim 3, characterized in that: The pawl is hinged to the first rocker arm, and an elastic torsion piece is provided between the two. The elastic torsion piece is used to elastically press the pawl against the ratchet wheel.

10. The automatic release remote actuator for fireproof rolling shutter according to any one of claims 1 to 9, characterized in that: A second operating hole suitable for inserting a tool is provided at the center of the winding wheel.

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