Actuator for seat adjustment devices

Abstract

Actuator (1) for seat adjustment devices, comprising at least one electric motor (2), a downstream reduction gear (3), and a clutch device (4) having a clutch engagement spring (5) which, during motor operation, ensures an engaged position of the clutch device (4) and allows manual disengagement against its spring force. The clutch device (4) has a clutch lever (6) pivotably mounted in a pivot bearing (49) of a bearing block (7), which is connected on one side of the pivot bearing (49) to a mechanical actuating unit (20) and from which, on the other side of the pivot bearing (49), a clutch means (10) for disengaging the clutch device (4) is adjustable. The clutch means (10), at least in the engaged state, executes a rotary movement during motor operation and is not in contact with the clutch lever (6).wherein the clutch lever (6) is held away from the clutch means (10) by a return spring (11) during motor operation or in the rest state, wherein the return spring (11) is received in the bearing block (7) and is supported by it, and wherein the bearing block (7) has a projection (14) which keeps the return spring (11) under pretension (11).

Description

[0001] The invention relates to an actuator (1), in particular for seat adjustment devices, with at least one electric motor (2), a downstream reduction gear (3), a clutch device (4) which has a clutch engagement spring (5) which, in motor operation, ensures an engaged position of the clutch device (4) and allows manual disengagement against its spring force, wherein the clutch device (4) has a clutch lever (6) which is pivotally mounted in a pivot bearing (49) of a bearing block (7), which clutch lever is connected on the one hand to the pivot bearing (49) to a mechanical actuating unit (20) and from which a clutch means (10) can be adjusted on the other hand to disengage the clutch device (4) of the pivot bearing (49).

[0002] Actuators, particularly for seat adjustment devices, increase the comfort of a seat occupant. In the event of a power failure or other defect, adjustment of the seat would no longer be possible, especially when using self-locking gears. For safety reasons, aircraft seats require that the seat be manually adjustable even in the event of a power failure. For this reason, coupling devices are usually provided that allow the power flow from the actuator to a seat control element to be interrupted. The actuators are often installed in inaccessible parts of the seat, meaning that the coupling device cannot be disengaged directly at the actuator. To solve this problem, Bowden cables or other mechanical devices, such as rods, are usually used to bridge a larger distance between the actuator and an operating lever or button.

[0003] In a conventional actuator, the clutch lever is always in contact with a clutch element. Since the clutch element rotates during motor operation, this can lead to friction losses, noise, and wear.

[0004] In conventional solutions, return springs are arranged around a Bowden cable's pull cord to keep the cable under tension at all times and return an actuating lever to its home position after manual actuation. Since the Bowden cable is usually not part of the actuator, the return spring must be installed by the user, which is inconvenient. This can lead to assembly errors, and its functionality can hardly be tested in advance.

[0005] Bowden cables are subject to friction. The frictional force that must be overcome by a return spring depends heavily on the seat geometry, the number of bends, and their radii. To ensure that the actuating lever always returns to its original position, the spring action must be easily adaptable to the specific application.

[0006] EP 1 862 351 A2 discloses an actuator for seat adjustment devices, with at least one electric motor, a downstream reduction gear, a decoupling device which has a clutch engagement spring which ensures an engaged position of the clutch device during motor operation and allows manual decoupling against its spring force, wherein the clutch device has a clutch lever which is pivotally mounted in a pivot bearing of a bearing block, which clutch lever is connected on the one hand to a mechanical actuating unit of the pivot bearing and from which a clutch means can be adjusted on the other hand to disengage the clutch device of the pivot bearing, wherein the clutch means and the clutch lever do not touch each other during motor operation.

[0007] DE 10 2016 207 155 A1 discloses an actuator for seat adjustment devices with at least one electric motor, a downstream reduction gear, a clutch device which has a clutch engagement spring which ensures an engaged position of the clutch device during motor operation and allows manual disengagement against its spring force, wherein the clutch device has a clutch lever which is pivotally mounted in a pivot bearing of a bearing block, which clutch lever is connected on the one hand to the pivot bearing with a mechanical actuating unit and from which a clutch means can be adjusted on the other hand to disengage the clutch device, wherein the clutch means executes a rotary movement at least in the engaged state during motor operation and is in contact with the clutch lever.

[0008] The object of the invention is to provide a generic actuator with both reliable electrical and reliable manual operation, high efficiency in electrical operation and simple installation.

[0009] This object is achieved according to the invention by the subject matter having the features of claim 1. Since the clutch lever (6) and the clutch means (10) do not touch during electrical operation, friction-related efficiency losses, noise emissions, and abrasion particles cannot occur.

[0010] To ensure that the clutch means (10) does not drag on the clutch lever (6), a return spring (11) is provided which keeps the clutch lever (6) away from the clutch means (10).

[0011] The return spring (11) is housed in the bearing block (7) and supported by it. As a result, the return spring (11) is no longer arranged around a pull cable (25) of a Bowden cable (30), as is the case with conventional solutions. This frees the user from complex assembly work. Frictional forces of the actuating unit (20) can be compensated for by the return spring (11). This is particularly important for long Bowden cables, with a large number of bends, and especially for bends with tight radii.

[0012] The bearing block (7) has a projection (14) which positively receives the return spring (11) and keeps it under pretension.

[0013] Further developments of the invention are presented in the subclaims. The return spring (11) is supported on the clutch lever (6) and, for this purpose, is positively received in a recess (15), in particular a receiving bore, or on a receiving pin (36). This makes the return spring (11) easy to install and ensures its secure and reliable retention.

[0014] The spring travel of the return spring (11) is expediently limited by a stop (12), wherein the stop is fastened to the bearing block (7) or to a housing (13) or is part of the bearing block (7) or the housing (13).

[0015] It is conceivable that the bearing block (7) is mounted on the housing (13) or is part of the housing (13).

[0016] To ensure reliable power transmission, the coupling device (4) features a locking coupling (16). This provides a positive connection in the direction of rotation when engaged.

[0017] The clutch lever (6) has a bevel (21) as an actuating surface, which in the disengaged state of the clutch is at right angles to a spherically shaped shaft end of the clutch means (10) ( Fig. 1c). This allows for a selective rolling movement when the clutch lever (6) is manually operated. During manual operation, a torque acts from the seat to the gearbox, causing the clutch to rotate. In this situation, the bevel (21), with optimal design, touches the center of the spherical shaft end. The friction radius and thus the frictional resistance are thus minimal, and the seat can be reliably adjusted manually.

[0018] The return spring (11) must be able to overcome the friction of an actuating unit (20) and move it back to its starting position.

[0019] To ensure reliable return of the actuating unit (20) in different applications, it is proposed to adapt the spring properties of the return spring (11) to the friction conditions of the respective application. The separate functionality between the return spring (11) and the clutch engagement spring (5) significantly facilitates this adaptation.

[0020] Compression springs and torsion springs are particularly suitable as return springs (11) because they are easy to install.

[0021] A Bowden cable (30) for manually actuating the actuating arm (9) and thus the clutch lever (6) is essentially aligned at right angles or parallel to the direction of movement of the clutch means (10). In principle, however, other arrangements are also conceivable in which the Bowden cable (30) is aligned at any angle to the clutch axis (24).

[0022] In the case of a Bowden cable (30) aligned substantially at right angles to the coupling axis (24), a leg spring is preferably used as the return spring (11), and in the case of a Bowden cable (30) aligned substantially parallel to the coupling axis (24), a compression spring is preferably used as the return spring (11).

[0023] For aircraft seats, regulations require that the seat be manually adjustable even in the event of a power failure. Therefore, in most cases, there must be no self-locking gear stages between the electric motor and the actuator. For this reason, a non-self-locking spindle is used for linear actuators.

[0024] In order to ensure that the seat is held securely in its position in any seating position, a brake is required, in particular a friction brake, which is actuated electromechanically in electrical operation (power-off brake).

[0025] Embodiments of the invention are explained in more detail below with reference to the drawings. They show: Fig. 1a shows a first embodiment of a coupling device of an actuator in a first position, Fig. 1b the first embodiment in a second position, Fig. 1c the first embodiment in a third position, Fig. 1d the first embodiment in a fourth position, Fig. 2a shows a second embodiment of a coupling device of an actuator in a first position, Fig. 2b the second embodiment in a second position, Fig. 2c the second embodiment in a third position, Fig. 2d the second embodiment in a fourth position, Fig. 3a an exploded view of a third embodiment of a coupling device of an actuator, Fig. 3b a sectional view of the third embodiment, Fig. 3c a plan view of the third embodiment, Fig. 4 a coupling device of an actuator according to the prior art and Fig. 5 an actuator with a coupling device according to the prior art.

[0026] Note: Reference symbols with an index and corresponding reference symbols without an index denote details of the same name in the drawings and the drawing description. This refers to the use in a different embodiment, the prior art, and / or the detail is a variant. For the sake of simplicity, the claims, the introduction to the description, the list of reference symbols, and the summary contain only reference symbols without an index.

[0027] Fig. 1a, Fig. 1b, Fig. 1c and Fig. 1d shows a first embodiment of a coupling device 4 of an actuator 1 in four different positions, comprising a housing 13, a coupling means 10 rotatably mounted about a coupling axis 24 by a ball bearing 19 in the housing 13, a clutch disc 17, and a Bowden cable 30. The clutch disc 17 is geared to a final gear stage (not shown here). The coupling means 10 is geared to an electric motor (not shown here) via several gear stages and a friction brake.

[0028] The clutch means 10 carries a pressed-on ring 29 with radially pressed-in clutch pins 18, which positively engage in corresponding recesses 22 of the clutch disc 17. A clutch engagement spring 5 ensures a stable positive connection between the clutch pins 18 and the recesses 22 during motor operation.

[0029] The Bowden cable 30 has a bearing block 7 mounted on the housing 13, a clutch lever 6, a return spring 11, a pull cable 25, a sheath 26, and a bushing 27. The Bowden cable 30 is guided from the actuator to an actuating lever on the seat (not shown here).

[0030] The clutch lever 6 consists of a clutch arm 8 and an actuating arm 9 and is pivotally mounted in the bearing block 7, with the return spring 11 for the Bowden cable 30 being positively received between an angled projection 14 of the bearing block 7 and a recess 15 of the clutch lever 6. To facilitate assembly, the recess 15 is provided with an insertion chamfer.

[0031] The pull cable 25 of the Bowden cable 30 ends with a barrel nipple 28, which is spring-loaded and suspended through a slot 42 in a receptacle 31 of the actuating arm 9. The coupling lever 6 is pivotally mounted about a pivot bearing 49 of the bearing block 7 and has a bevel 21 on the coupling arm 8, which serves as an actuating surface and interacts with a spherical end of the coupling means 10 during manual operation.

[0032] Fig. Figure 1a shows the first embodiment of the clutch device 4 in a first position, in which a Bowden cable 30 is not actuated. The coupling pins 18 of the clutch means 10 are positively engaged in the recesses 22 of the clutch disc 17 and can transmit torque. The clutch engagement spring 5 maintains this state.

[0033] Fig. 1b shows the first embodiment of the coupling device 4 in a second position in which the coupling lever 6 touches the coupling means 10 at its end, but the coupling pins 18 of the coupling means 10 are still positively engaged in the recesses 22 of the coupling disc 17.

[0034] Fig. Figure 1c shows the first embodiment of the clutch device 4 in a third position, in which the clutch lever 6 has maximally displaced the clutch means 10 against the force of the clutch engagement spring 5, so that the clutch pins 18 of the clutch means 10 are disengaged from the recesses 22 of the clutch disc 17. The power flow from the electric motor with electromechanical brake (power-off brake) to the actuator is thus interrupted, allowing manual adjustment of the seat.

[0035] Fig. Figure 1d shows the first embodiment of the clutch device 4 in a fourth position, in which the clutch lever 6 is held back in its initial position by the return spring 11, but the clutch pins 18 rest on the clutch disc 17 in an angular position between the recesses (not visible here), whereby the clutch engagement spring 5 remains tensioned. During a subsequent electrical or manual adjustment, the clutch pins 18 would again engage in the recesses 22 under the action of the clutch engagement spring 5 and transmit a torque.

[0036] Fig. 2a, Fig. 2b, Fig. 2c and Fig. 2d shows a second embodiment of a coupling device 4 of an actuator 1a in four different positions, comprising a housing 13a, a coupling means 10a rotatably mounted about a coupling axis 24a by a ball bearing 19a in the housing 13a, a clutch disc 17a, and a Bowden cable 30a. The clutch disc 17a is geared to a final gear stage (not shown here). The coupling means 10a is geared to an electric motor (not shown here) via several gear stages.

[0037] The clutch means 10a carries a pressed-on ring 29a with radially pressed-in clutch pins 18a, which positively engage in corresponding recesses 22a of the clutch disc 17a. A clutch engagement spring 5a ensures a stable positive connection between the clutch pins 18a and the recesses 22a during motor operation.

[0038] The Bowden cable 30a has a bearing block 7a mounted on the housing 13a, a clutch lever 6a, a return spring 11a, a pull cable 25a, a sheath 26a, and a bushing 27a. The clutch lever 6a consists of a clutch arm 8a, an actuating arm 9a, and two side parts 58a angled from a center piece 57a. The pivot bearing 49a is arranged in the side parts 58a. The clutch arm 8a is angled from the center piece 57a and has a Z-shape. The actuating arm 9a is angled from the center piece 57a and has an L-shape. The Bowden cable 30a is guided from the actuator to an actuating lever on the seat (not shown here). The bushing 27a of the Bowden cable 30a is supported on a separate angle plate 32a, which is fastened to the housing 13a by screws.The return spring 11a is designed here as a leg spring arranged around a pivot pin 53a of a pivot bearing 49a, with a retaining leg 33a of the leg spring being held on an angled retaining section 50 of the bearing block 7a, and an actuating leg 34a acting on the clutch lever 6a via the center piece 57a. The clutch lever 6a is pivotally mounted in the bearing block 7a, consists of a stamped and bent part, is angled several times, and is supported on a stop 12a mounted in the bearing block 7a.

[0039] The pull cable 25a of the Bowden cable 30a ends with a barrel nipple 28a, which is spring-loaded and suspended from an actuating arm 9a.

[0040] Fig. Figure 2a shows the second embodiment of the clutch device 4a in a first position, in which a Bowden cable 30a is not actuated. The clutch pins 18a of the clutch means 10a are positively engaged in the recesses 22a of the clutch disc 17a and can transmit torque. The clutch engagement spring 5a maintains this state.

[0041] Fig. Figure 2b shows the second embodiment of the coupling device 4a in a second position in which the coupling lever 6a touches the coupling means 10a at its end, but the coupling pins 18a of the coupling means 10a are still positively engaged in the recesses 22a of the coupling disc 17a.

[0042] Fig. Figure 2c shows the second embodiment of the clutch device 4a in a third position, in which the clutch lever 6a has maximally displaced the clutch means 10a against the force of the clutch engagement spring 5a, so that the clutch pins 18a of the clutch means 10a are disengaged from the recesses 22a of the clutch disc 17a. The power flow from the electric motor with electromechanical brake (power-off brake) to the actuator is thus interrupted, allowing manual adjustment of the seat.

[0043] Fig. Figure 2d shows the second embodiment of the clutch device 4a in a fourth position, in which the clutch lever 6a is held back in its initial position by the return spring 11a. However, the clutch pins 18a rest in an angular position between the recesses 22a on the clutch disc 17a, whereby the clutch engagement spring 5a remains tensioned. During a subsequent electrical or manual adjustment, the clutch pins 18a would again engage in the recesses 22a under the action of the clutch engagement spring 5a and transmit a torque.

[0044] Fig. Figure 3a shows an exploded view of a third embodiment of a coupling device 4b of an actuator 1b, comprising a bearing block 7b, a coupling lever 6b, a return spring 11b in the form of a compression spring, a pivot pin 53b, and a stop 12b. To accommodate the pivot pin 53b and the stop 12b, pivot pin receptacles 55b and stop pin receptacles 56b are provided in the bearing block 7b. Pivot pin passages 23b are formed in the pivot lever 6b to accommodate the pivot pin 53b. Fig. 3a, the pivot pin and the stop 12b are shown with caulked ends; however, during assembly, at least the caulking 59b on one side is only created after these components have been mounted in the bearing block 7a. The bearing block 7b has an L-shaped angled projection 14b, which is provided with two notches 35b. These serve as support points for the return spring 11b. A receiving pin 36b is fastened (riveted here) in the clutch lever 6a, which serves as a guide for the return spring 11b. To facilitate assembly, the receiving pin 36b is provided with a distinct chamfer. For this purpose, the receiving pin 36b has a rivet pin 54b, which is positively connected to the clutch lever 6b. The annular area 51b extending around the receiving pin 36b (see Fig. 3b) of the coupling lever 6b forms a support for the return spring 11b. The coupling lever 6b consists of an actuating arm 9b and a coupling arm 8b. The coupling arm 8b has a bevel 21b, which serves as an actuating surface for a coupling means (not shown here). The actuating arm 9b is designed at its end as a receptacle 31b for a barrel nipple at the end of a traction cable (not shown here). The receptacle 31b is provided with a slot 42b open towards its end, which serves to facilitate assembly of the traction cable. The bearing block 7b has two side cheeks 37b, which are connected to one another by a yoke 38b. In the yoke 38b there is a passage 39b for a Bowden cable. A support 40b is angled onto each of the side cheeks 37b. The supports 40b are provided as contact surfaces on a housing 13.

[0045] Fig. Figure 3b shows a sectional view of the third embodiment, with the bearing block 7b, the projection 14b, the return spring 11b, the receiving pin 36b, and the clutch lever 6b with the receptacle 31b on the actuating arm 9b and the clutch arm 8b, and with the bevel 21b. The clutch lever 6a is stiffened by stiffening cheeks 41b.

[0046] Fig. Figure 3c shows a top view of the third embodiment, with the bearing block 7b, the projection 14b, the clutch lever 6b, the pivot bearing 49b (formed by the pivot pin 53b, the pivot pin receptacle 55b on the bearing block 7b, and the pivot pin passage 23b on the clutch lever 6b), and the stop 12b. The clutch lever 6b has the clutch arm 8b, the actuating arm 9b, and the slot 42b. Screw holes 52b are provided in the supports 40b.

[0047] Fig. 4 shows a coupling device 4d of an actuator 1d according to the prior art, with a coupling means 10d rotatable about a coupling axis 24d, a coupling disc 17d, a bearing block 7d (only indicated here), a Bowden cable 30d, and a coupling lever 6d. The coupling means 10d has a toothing 47d and a pressed-on ring 29d with radially pressed-in coupling pins 18d that engage in recesses 22d of the coupling disc 17d. The toothing 47d is dimensioned such that, upon axial movement of the coupling means 10d, a gearwheel (not shown) engaged therewith remains engaged in every coupling position. Furthermore, a clutch engagement spring 5d is arranged between an axial ball bearing 43d and a retaining ring 44d on the clutch means 10d, wherein the retaining ring 44d is held by a lock washer 45d.A sleeve 46d is arranged around the clutch engagement spring 5d, which is also supported on the axial ball bearing 43d and serves as a stop for the retaining ring 44d when the clutch device 4d is actuated. The clutch lever 6d pivots about a pivot bearing 49d and consists of an actuating arm 9d and a clutch arm 8d. The pivot bearing 49d is part of the bearing block 7d. A pull cable 25d of the Bowden cable 30d is guided through the return spring 11d. The return spring 11d is arranged between the bearing block 7d (dashed line) and the actuating arm 9d. The end of the pull cable 25d is provided with a barrel nipple 28d, which rests against the actuating arm 9d. A significant disadvantage of this known coupling device 4d is that, due to the installation position of the return spring 11d, it cannot be integrated into a compact actuator. Therefore, it must be installed by the user.

[0048] Fig.5 shows an actuator 1d according to the prior art, with a coupling device (concealed) in the housing 3d, a bearing block 7d, a coupling lever 6d and a spindle 48d. List of reference symbols 1 actuator 2 electric motor 3 reduction gears 4 Coupling device 5 Clutch engagement spring 6 clutch levers 7 bearing block 8 Coupling arm 9 Actuating arm 10 coupling agents 11 Return spring 12 stops 13 housings 14 lead 15 Return 16 Snap-in coupling 17 Clutch disc 18 coupling pins 19 ball bearings 20 operating unit 21 slope 22 Recess 23 Pivot pin passage 24 Coupling axle 25 pull rope 26 Cover 27 socket 28 barrel nipples 29 rings 30 Bowden cable 31 recording 32 angle plate 33 holding legs 34 operating legs 35 Notch 36 locating pins 37 side panel 38 yoke 39 Implementation 40 Support 41 stiffening cheek 42 slot 43 axial ball bearings 44 retaining ring 45 Lock washer 46 sleeve 47 Gearing 48 spindle 49 pivot bearings 50 stopping section 51 ring area 52 Screw-on opening 53 pivot pin 54 rivet pins 55 pivot pin holder 56 Stop pin holder 57 Middle section 58 side panel 59 Caulking

Claims

[1] Actuator (1) for seat adjustment devices, with at least one electric motor (2), a downstream reduction gear (3), a clutch device (4) which has a clutch engagement spring (5) which ensures an engaged position of the clutch device (4) during motor operation and allows manual disengagement against its spring force, wherein the clutch device (4) has a clutch lever (6) pivotally mounted in a pivot bearing (49) of a bearing block (7), which is connected on the one hand to the pivot bearing (49) with a mechanical actuating unit (20) and from which a clutch means (10) for disengaging the clutch device (4) is adjustable on the other hand to the pivot bearing (49), wherein the clutch means (10) executes a rotary movement at least in the engaged state during motor operation and is not in contact with the clutch lever (6),wherein the clutch lever (6) is held away from the clutch means (10) by a return spring (11) during motor operation or in the rest state, wherein the return spring (11) is received in the bearing block (7) and is supported by it, and wherein the bearing block (7) has a projection (14) which keeps the return spring (11) under pretension (11). [2] Actuator (1) according to claim 1, characterized by that the return spring (11) is supported on the clutch lever (6) and for this purpose is positively received in a recess (15), in particular a receiving bore, or on a receiving pin (36). [3] Actuator (1) according to claim 1 or 2, characterized by that the spring travel of the return spring (11) is limited by a stop (12), wherein the stop is fastened to the bearing block (7) or to a housing (13) or is part of the bearing block (7) or the housing (13). [4] Actuator (1) according to at least one of the preceding claims, characterized by that the bearing block (7) is mounted on the housing (13) or is part of the housing (13). [5] Actuator (1) according to at least one of the preceding claims, characterized by that the coupling device (4) has a locking coupling (16). [6] Actuator (1) according to at least one of the preceding claims, characterized by that the clutch lever (6) has an actuating surface (21) which, in the disengaged state of the clutch, is at right angles to a spherically shaped shaft end of the clutch means (10). [7] Actuator (1) according to at least one of the preceding claims, characterized by that the return spring (11) is able to overcome the friction of an actuating unit (20) and move it back to the starting position. [8] Actuator (1) according to at least one of the preceding claims, characterized bythat the return spring (11) with different spring rates can enable a variable return force (spring constant) of the actuating unit (20). [9] Actuator (1) according to at least one of the preceding claims, characterized by that the return spring (11) is a compression spring or a leg spring. [10] Actuator (1) according to at least one of the preceding claims, characterized by that a Bowden cable (30) is aligned substantially at right angles or parallel to the direction of movement / coupling axis (24) of the coupling means (10). [11] Actuator (1) according to at least one of the preceding claims, characterized by that a leg spring is used when the Bowden cable (30) is aligned substantially at right angles to the coupling axis (24). [12] Actuator (1) according to at least one of the preceding claims, characterized bythat a compression spring is used when the Bowden cable (30) is aligned substantially parallel to the coupling axis (24). [13] Actuator (1) according to at least one of the preceding claims, characterized by that a non-self-locking output stage is present, in particular a non-self-locking spindle. [14] Actuator (1) according to at least one of the preceding claims, characterized by that an electromechanical brake is arranged between the electric motor (2) and the reduction gear (3).

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