IMPROVED GEARED MOTOR FOR ROLLING SHUTTERS

Abstract

 A geared motor (100) for rolling shutters, comprises: an electrical motor (1) provided with a drive shaft (1a) that slides axially; a reducer (2) coupled to the drive shaft (1a) and to the winding shaft of a rolling shutter, uncoupling means (7) of the electrical motor (1) from the reducer (2); a non-return device (D) connected to the drive shaft (1a) to make the transmission of motion from the electrical motor (1) to the reducer irreversible, an emergency device (E) to uncouple the drive shaft (1a) from the reducer (2) when the uncoupling means (7) are operated; the emergency device (E) comprises: a toothed cover (4) slidingly integral with the drive shaft (1a) and rotationally integral with the non-return device (D) and with the reducer (2); and a helical compression spring (5) to push the toothed cover (4) in engagement with the reducer (2).

Description

[0001] The present patent application for industrial invention relates to an improved geared motor for rolling shutters.

[0002] Rolling shutters are known, which are suitable for being disposed in correspondence of an opening in order to permit/prohibit the passage through said opening.

[0003] The rolling shutters of the prior art comprise a shutter with a plurality of hinged elements that are wound around a winding shaft. More precisely, one end of the shutter is connected to the winding shaft that rotates in order to wind and/or unwind the elements of the shutter around the winding shaft, in such a way that the elements of the shutter can be in a first position, wherein the opening is closed by the elements, and in a second position, wherein the opening is not closed by the elements.

[0004] Said rolling shutters of the prior art are balanced by a set of springs that are loaded when the elements of the shutter move from the second position to the first position and are unloaded when the elements of the shutter move from the first position to the second position.

[0005] The description of the prior art continues with reference to Figs. 1 and 2. The rolling shutters of the prior art comprise a geared motor (200) comprising:

• an electrical motor (1) provided with a drive shaft (1a);
• a reducer (2) that is coaxially coupled with said motor (1) in such a way that the drive shaft (1a) of the electrical motor (1) transmits the motion to the elements of the reducer (2).

[0006] Said reducer (2) is suitable for being connected to the winding shaft of the rolling shutter in order to transmit the motion from the electrical motor (1) to the winding shaft of the rolling shutter.

[0007] The drive shaft (1a) is mounted in such a way to slide axially with short axial travels.

[0008] The geared motor (200) comprises uncoupling means (7) of the electrical motor (1) from the reducer (2). The uncoupling means (7) are connected to the drive shaft (1a) in order to make the drive shaft (1a) slide away from the reducer (2).

[0009] The geared motor (200) comprises an emergency anti-return device (DE) that is connected to the drive shaft (1a) and to the reducer (2), which is suitable for:

• transmitting the motion from the motor (1) to the reducer (2) and preventing the transmission of the motion from the reducer (2) to the electrical motor (1) when the emergency anti-return device (DE) is coupled with the reducer;
• uncoupling the drive shaft (1a) from the reducer (2) in case of emergency. In particular, the emergency anti-return device (DE) is disposed between the reducer (2) and the electrical motor (1).

[0010] The emergency anti-return device (DE) of the prior art comprises a pair of toothed cylindrical cups (203a, 203b) that are contained one inside the other one with concavity facing towards the motor (1).

[0011] A helical torsional spring (8) is contained in the internal cup (203a) and is provided at the ends with two radial hooks (80, 81) that are faced outwards. One of said hooks is engaged against the edge of one of the teeth of the internal cup (3a), whereas the other one of said hooks is engaged against the edge of a tooth of the external cup (203b).

[0012] The internal cup (203a) has a square hole that is coupled with the drive shaft (1a) in such a way that the drive shaft (1a) can drive the internal cup (203a) in rotation, which in turn drives the external cup (203b) in rotation by means of the interposition of the helical torsional spring (8). In such a case, the helical torsional spring (8) is extended, and the hooks transmit the motion from the internal cup (203a) to the external cup (203b).

[0013] On the side facing the reducer (2), the external cup (203b) comprises a front-toothed coupling (203c) that transmits the motion from the external cup (203b) to the reducer (2).

[0014] If the user tried to move the shutter manually, said front-toothed coupling (203c) would receive the motion from the shutter, and not from the electrical motor (1), and the rotation imposed on the external cup (203b) would cause a shortening of the helical torsional spring (8) that prevents the motion from being transmitted from the external cup (203b) to the internal cup (203a). In view of the above, the emergency anti-return device (DE) prevents the manual movement of the shutter.

[0015] The emergency anti-return device (DE) of the prior art comprises a helical compression spring (205) disposed between the external cup (203b) and the electrical motor (1) in such a way that the external cup (203b) is constantly compressed by an axial thrust against the reducer (2). In view of the above, the constant engagement between the front-toothed coupling (203c) and the reducer (2) is guaranteed.

[0016] Means, such as for example a seeger ring (203d), are disposed between the external cup (203b) and the drive shaft (1a) to transfer the travels of the drive shaft (1a) in backward direction, that is to say towards the electrical motor (19 to the external cup (203b).

[0017] By actuating the uncoupling means (7) with a force that is sufficient to overcome the antagonist force of the helical compression spring (205), the drive shaft (1a) and the external cup (203b) are translated backwards, and the front-toothed coupling (203c) is uncoupled from the reducer (2).

[0018] By interrupting the actuation of the uncoupling means (7), the helical compression spring (205) is automatically extended, pushing the drive shaft (1a) and the external cup (203b) towards the reducer (2), in such a way to restore the connect between the front-toothed coupling (203c) and the reducer (2).

[0019] The geared motor (200) of the prior art is impaired by a drawback related to the fact that, because of the translation of the external cup (203b) relative to the internal cup (203a), the hooks (80) of the helical torsional spring (8) frictionally create grooves on the teeth of both cups (203a, 203b) that prevent the external cup (203b) from correctly sliding relative to the internal cup (203a). Otherwise said, with the passing of time, jamming can be produced when the uncoupling means (7) are actuated to uncouple the electrical motor (1) from the reducer (2) and vice versa.

[0020] EP0848137 discloses a geared motor according to the preamble of claim 1. The purpose of the present invention is to overcome the drawbacks of the prior art by providing a geared motor comprising a long-lasting emergency device. Another purpose is to disclose a geared motor that is reliable and safe. These purposes are achieved according to the invention with the characteristics described in the appended independent claim 1. Advantageous embodiments appear from the dependent claims.

[0021] The geared motor of the invention is defined by the independent claim 1.

[0022] The advantages of the geared motor according to the invention are evident, wherein by actuating the uncoupling means, the antagonist force of the helical compression spring can be overcome, uncoupling the toothed cover from the reducer.

[0023] For the sake of clarity, the description of the geared motor according to the invention continues with reference to the attached drawings, which have a merely illustrative, not limiting value, wherein:

Fig. 1 is an exploded axonometric view of a geared motor according to the prior art;

Fig. 2 is a sectional view of the geared motor according to the prior art, cut along a vertical plane passing through the axis of the drive shaft;

Fig. 3 is an axonometric exploded view of the geared motor according to the invention;

Fig. 3A is an enlargement of the detail enclosed in the circle A of Fig. 3;

Fig. 4 is a sectional view of the geared motor according to the invention, cut along a vertical plane passing through the axis of the drive shaft, wherein the motor and the reducer are coupled;

Fig. 4A is an enlargement of the detail enclosed in the circle A of Fig. 4;

Fig. 5 is a sectional view of the geared motor according to the invention, cut along a vertical plane passing through the axis of the drive shaft, wherein the motor and the reducer are not coupled;

Fig. 5A is an enlargement of the detail enclosed in the circle A of Fig. 5;

Fig. 6 is an axonometric exploded view of a detail of the geared motor according to the invention.

[0024] In the following description the parts that are identical or correspond to the parts described above are identified with the same numerals, omitting their detailed description.

[0025] With reference to Fig. 3, a geared motor according to the invention is disclosed, which is generally indicated with reference numeral (100).

[0026] The geared motor (100) is part of a rolling shutter that also comprises a shutter with a plurality of hinged elements that are wound around a winding shaft. The shutter comprises a set of springs that balance the movement of the shutter. The geared motor (100) comprises:

• an electrical motor (1) that is identical to the electrical motor of the prior art, provided with a drive shaft (1a) that slides axially;
• a reducer (2) that is identical to the reducer of the geared motor of the prior art; the reducer (2) is coaxially coupled with the electrical motor (1) and connected to the drive shaft (1a) of the electrical motor (1) and to the winding shaft of the shutter, in such a way to transmit a rotational movement from the drive shaft (1a) of the electrical motor (1) to the winding shaft of the rolling shutter;
• uncoupling means (7) of the electrical motor (1) from the reducer (2) that are identical to the uncoupling means of the geared motor of the prior art; the uncoupling means (7) are connected to the drive shaft (1a) to make the drive shaft (1a) slide away from the reducer (2);
• an anti-return device (D) connected to the drive shaft (1a) to prevent the motion from being transmitted from the reducer (2) to the electrical motor (1);
• an emergency device (E) that cooperates with the anti-return device (D), the drive shaft (1a) and the reducer (2) in order to uncouple the drive shaft (1a) from the reducer (2) when the uncoupling means (7) are operated.

[0027] Until the uncoupling means (7) are not actuated, the electrical motor (1) is normally coupled with the reducer (2).

[0028] With reference to Fig. 3A, the anti-return device (D) comprises a pair of toothed cylindrical cups (3a, 3b) contained one inside the other one with concavity facing towards the electrical motor (1).

[0029] A helical torsional spring (8) is contained in the internal cup (3a) and is provided at the ends with two radial hooks (80, 81) that are faced outwards. A first hook (80) is engaged against the edge of one of the teeth of the internal cup (3a), whereas a second hook (81) is engaged against the edge of a tooth of the external cup (3b).

[0030] The internal cup (3a) has a square hole (34) that is prismatically coupled with a corresponding section (10) of the drive shaft (1a) in such a way that the drive shaft (1a) can drive the internal cup (3a) in rotation. It must be noted that the hole of the internal cup (3a) and the drive shaft (1a) can have a different shape that permits the internal cup (3a) to rotate integrally with the drive shaft (1a). In turn, the internal cup (3a) drives the external cup (3b) in rotation by means of the helical torsional spring (8). In such a case, in fact, the helical torsional spring (8) is extended, and the hooks (80, 81) transmit the motion from the internal cup (3a) to the external cup (3b).

[0031] It the user tried to move the shutter manually, the rotation of the external cup (3b) would cause a shortening of the helical torsional spring (8) that would prevent the rotational motion from being transmitted from the external cup (3b) to the internal cup (3a). In view of the above, the anti-return device (D) prevents the motion from being transmitted backwards from the reducer (2) to the drive shaft (1a) of the electrical motor (1).

[0032] The external cup (3b) has a hole (35) for the insertion of the drive shaft (1a). The drive shaft (1a) is slidingly mounted inside the holes (34, 35) of the internal cup (3a) and of the external cup (3b).

[0033] The emergency device (E) comprises a toothed cover (4) that is coupled with the external cup (3b) of the anti-return device (D) in such a way to be driven in rotation by the external cup (3b).

[0034] The toothed cover (4) is coupled with the drive shaft (1a), in such a way to follow its axial translation travels in backward direction. More precisely, a seeger ring (3d) is mounted on the drive shaft (a) (Figs. 4A and 5A), which interferes with said toothed cover (4), in such a way to move it backwards, integrally with the drive shaft (1a), when the uncoupling means (7) are actuated.

[0035] More precisely, on the side facing towards the electrical motor (1), the toothed cover (4) is provided with first front teeth (44) that slidingly engage in corresponding counter-teeth (37) provided on the edge of the external cup (3b) facing towards the reducer (2). Obviously, such an engagement guarantees the transmission of the motion from the electrical motor (1) to the reducer, and vice versa, it being understood that the anti-return device (D) will prevent the motion from being transmitted from the reducer (2) to the electrical motor (1). Moreover, the toothed cover (4) is suitable for being rotationally engaged with the reducer (2). On the side facing the reducer (2) the toothed cover (4) is provided with a second set of front teeth (45) that engage with the first gear (22) (Fig. 3) of the reducer (2), in such a way that the reducer (2) rotates integrally with the toothed cover (4) when the uncoupling means (7) are not operated.

[0036] More precisely, the second teeth (45) of the toothed cover (4) are inserted in the hole (21) of a flange (20) that closes the compartment that contains the anti-return device (D) and the emergency device (E).

[0037] The emergency device (E) comprises a helical compression spring (5) disposed between the anti-return device (D) and the toothed cover (4) in such a way as to push and engage the toothed cover (4) with said reducer (2). More precisely, the helical compression spring (5) is interposed between the external cup (3b) and the toothed cover (4), in such a way that the toothed cover (4) and the external cup (3b) act as counter-surface for the helical compression spring (5).

[0038] Therefore, the toothed cover (4) is constantly subject to an axial thrust towards the reducer (2). In view of the above, until the uncoupling means are operated (7), the coupling between the second front teeth (45) and the first gear (22) of the reducer (2) is maintained. Simultaneously with the coupling between the second teeth (45) of the toothed cover (4) and the first gear (22) of the reducer (2), also the first teeth (44) of the toothed cover (4) are coupled with the counter-teeth (37) of the external cup (3b).

[0039] With reference to Figs. 5 and 5A, an actuation of the uncoupling means (7) that is sufficient to overcome the antagonist force of the helical compression spring (5) causes a backward translation of the drive shaft (1a) and of the toothed cover (4), uncoupling the toothed cover (4) from the reducer (2). In particular, the second teeth (45) of the toothed cover (4) come out of the housings of the first gear (22) of the reducer, in such a way not to engage any longer with said first gear (22). In view of the above, the reducer (2), and consequently the winding shaft of the shutter, can rotate freely in the anti-return device (D), so that in case of an emergency, the user can directly intervene on the shutter after disabling the coupling between the reducer (2) and the electrical motor (1).

[0040] With reference to Figs. 4 and 4A, by interrupting the actuation of the uncoupling means (7), the helical compression spring (5) is automatically extended, pushing forward the toothed cover (4) that, in turn, pushes the drive shaft (1a) forward towards the reducer (2). When the toothed cover (4) reaches the end of its forward travel, its second front teeth (45) restore the coupling with the first gear (22) of the reducer (2). It must be noted that, during the alternate travels of the toothed cover (4), its first teeth (44) remain always engaged with the counter-teeth (37) of the external cup (3b).

[0041] Fig. 6 shows a variant of the geared motor (100) that comprises a rubber gasket (9) disposed between the toothed cylindrical cups (3a, 3b) in such a way to act as friction.

[0042] Such a rubber gasket (9) prevents the external cup (3b) from moving relative to the internal cup (3a). More precisely, if the compensation springs of the shutter are not correctly adjusted, when the shutter is rolled down, the weight of the shutter drives the external cup (3b) in rotation with a higher speed than the one imposed by the drive shaft (1a) on the internal cup (3a).

[0043] Because of such a difference in the rotational speed, the anti-return device (D) does not operate correctly and the movement of the external cup (3b) relative to the internal cup (3a) causes a clicking noise. By means of the provision of the rubber gasket (9), friction can be created between the external cup (3b) and the internal cup (3a), avoiding the relative movement between the two cups (3a, 3b), in such a way that the teeth of the external cup (3b) never lose contact with the teeth of the internal cup (3a) until the drive shaft (1a) rotates in the rotational direction that corresponds to the motorized descending travel of the shutter.

[0044] The advantages of the geared motor (100) according to the invention are evident, wherein the provision of the emergency device (E) downstream the anti-return device (D) prevents any relative translation movements between the external cup (3b) and the internal cup (3a) and, consequently the wear friction that can impair the correct operation of the emergency anti-return device of the prior art.

[0045] Numerous variations and modifications can be made to the present embodiment of the invention, which are within the reach of an expert of the field, falling in any case within the scope of the invention as disclosed by the appended claims.

Claims

1. Geared motor (100) for rolling shutters, comprising:

- an electrical motor (1) provided with a drive shaft (1a) that slides axially;

- a reducer (2) coaxially coupled to the electrical motor (1); said reducer (2) being connected to the drive shaft (1a) of the electrical motor (1) and being suitable for being connected to a winding shaft of a rolling shutter (1) in order to transmit a motion from said electrical motor (1) to said winding shaft of the rolling shutter;

- uncoupling means (7) of the electrical motor (1) from the reducer (2); said uncoupling means (7) being connected to the drive shaft (1a) to make the drive shaft (1a) slide away from the reducer (2);

- an anti-return device (D) connected to the drive shaft (1a) to prevent the motion from being transmitted from the reducer (2) to the electrical motor (1); said anti-return device (D) being integral in rotation with the drive shaft (1a);

- an emergency device (E) that cooperates with the anti-return device (D), the drive shaft (1a) and the reducer (2) to uncouple the drive shaft (1a) from the reducer (2) when the uncoupling means (7) are operated;

wherein said anti-return device (D) comprises a toothed cylindrical internal cup (3a) and a toothed cylindrical external cup (3b) that are contained one inside the other one; said anti-return device (D) comprising a helical torsional spring (8) contained in the internal cup (3a) and provided at the ends with two radial hooks (80, 81) that are faced outwards; a first hook (80) being engaged against the edge of one of the teeth of the internal cup (3a); a second hook (81) being engaged against the edge of a tooth of the external cup (3b);
characterized in that said emergency device (E) comprises:

- a toothed cover (4) slidingly integral with the drive shaft (1a); said toothed cover (4) being connected to the anti-return device (D) in such a way to rotate integrally with the anti-return device (D); said toothed cover (4) being suitable for being rotationally engaged with said reducer (2);

- a helical compression spring (5) disposed between the anti-return device (D) and the toothed cover (4) in such a way as to push and engage the toothed cover (4) with said reducer (2);

wherein, when operated, said uncoupling means (7) are able to overcome the antagonist force of said helical compression spring (5), uncoupling the toothed cover (4) from the reducer (2);
wherein on the side facing towards the electrical motor (1), said toothed cover (4) is provided with first front teeth (44) that engage in corresponding counter-teeth (37) provided on the edge of the external cup (3b) facing towards the reducer (2);
wherein on the side facing towards the reducer (2), said toothed cover (4) is provided with second front teeth (45) that engage with a first gear (22) of the reducer (2), in such a way that the reducer (2) rotates integrally with the toothed cover (4) when the uncoupling means (7) are not operated.

2. The geared motor (100) of claim 1, wherein the second teeth (45) of the toothed cover (4) are inserted in a hole (21) of a flange (20) that closes the compartment with the emergency device (E) and the anti-return device (D).

3. The geared motor (100) of claim 1 or 2, wherein the toothed cover (4) is coupled with the drive shaft (1a), in such a way as to follow the backward axial translation travels; said drive shaft (1a) comprising a seeger ring that interferes with said toothed cover (4), in such a way as to drive it in backward travels integrally with the drive shaft (1a), when the uncoupling means (7) are operated.

4. The geared motor (100) of any one of the preceding claims, comprising a rubber gasket (9) disposed between the toothed cylindrical cups (3a, 3b) in such a way to act as friction.

5. Rolling shutter comprising:

- a shutter comprising a plurality of mutually hinged elements;

- a winding shaft around which the shutter is wound;

- a set of springs that balance the movement of the shutter;

- a geared motor (100) of any one of the preceding claims, wherein said reducer (2) is connected to said winding shaft.

Drawing