ELECTRIC ARMREST FOR VEHICLES

Abstract

Armrest (20) for a seat (12) with a backrest (18) and a seat surface (16), wherein the armrest (20) comprises: a housing (38) rotatable relative to the backrest (18); and a motor (34) configured to maintain a position of the housing (38) relative to the seat surface (16) when the backrest (18) is moved relative to the seat surface (16); characterized in that the motor (34) is arranged in the housing (38); wherein a screw (36) driven by the motor (34) extends from the motor (34) and is configured to rotate a lever (30) in contact with the backrest (18) in order to adjust a position of the housing (38) relative to the backrest (18); wherein the screw (36) and the lever (30) are arranged inside the housing;and wherein the lever (30) comprises a main body (48) with an opening (52) and a projection (50) extending from the main body (48), the opening (52) receiving a shaft (54) of the backrest (18) so that the lever (30) is rotatable about the shaft (54) relative to both the backrest (18) and the housing (38).

Description

INTRODUCTION The present invention relates generally to an armrest according to the preamble of claim 1 for a vehicle, of the type essentially known from KR 10 2005 0 022 800 A. Further state of the art can also be found in the publications DE 10 2014 212 881 A1 , DE 10 2020 201 014 A1 and DE 10 2021 111 843 A1 . Vehicle seats often have one or more armrests that extend from the back of the seat. The armrests typically extend from the backrest towards the front of the seat so that a passenger sitting on the seat cushion can rest their arms on them. Conventional armrests can be pivotally attached to the seatback, allowing them to move between an extended and a folded position. In the extended position, the armrests extend away from the seatback toward the front of the vehicle seat, allowing a passenger sitting on the seat cushion to adjust them comfortably. When entering or exiting the vehicle, force can be applied to the armrests to rotate them from the extended to the folded position, thus creating space for entry or exit. Specifically, one or more of the armrests can be rotated relative to the seatback so that a longitudinal axis of the armrest(s) is essentially parallel to a longitudinal axis of the seatback.As a result, the armrest no longer extends from the backrest and is essentially moved out of the way when a vehicle occupant sits down or stands up. Although the armrests can be moved from the extended to the folded position when a vehicle occupant sits down or stands up, they can also be moved into the folded position when the backrest is folded down onto the seat cushion and / or when the backrest and seat cushion are rotated from a functional or upright position into a folded position. Moving the armrests into the folded position prevents them from obstructing the rotation of the backrest into the folded position relative to the seat cushion. While conventional armrests adequately support the vehicle occupant's arms during use and can be moved between an extended and a folded position, the angle of the armrests to the seatback is fixed when the armrests are in the extended position. Consequently, when the seatback is rotated relative to the seat to adjust the angle, the armrests are essentially not parallel to the vehicle floor, but are often at an upward or downward angle to the floor, depending on the angle of the seatback. Therefore, the armrests may not be at a desirable angle for the vehicle occupant while seated. SUMMARY According to the invention, an armrest is provided for a seat with a backrest and a seat surface, wherein the armrest is characterized by the features of claim 1. The armrest can have one or more of the following optional features. For example, a first sensor can be configured to detect the number of motor revolutions. In one configuration, the first sensor can be a Hall-effect sensor. A screw can extend from and be driven by the motor, the screw being configured to rotate a lever in contact with the backrest to adjust a position of the housing relative to the backrest. The screw and lever can be located within the housing. Additionally or alternatively, the lever can define a first and a second stop that work together to define a range of movement of the armrest relative to the backrest. The armrest can be installed in a vehicle. In an unclaimed embodiment, a seat is provided comprising a seat surface, a backrest rotatably attached to the seat surface, an armrest rotatably attached to the backrest, and an actuator configured to move the armrest relative to the backrest when the backrest is moved relative to the seat surface in order to maintain a position of the armrest relative to the seat surface. The seat may have one or more of the following optional features. The actuator may, for example, be located in a housing in the armrest and / or include a motor. Additionally or alternatively, the actuator may include a screw extending from and driven by the motor, the screw being configured to rotate a lever in contact with the backrest to adjust a position of the housing relative to the backrest. In a training system, a backrest position sensor can be configured to detect the position of the backrest relative to the seat, and an armrest position sensor can be configured to detect the position of the armrest relative to the backrest. The backrest position sensor and / or the armrest position sensor can include a Hall effect sensor. The seat can be installed in a vehicle. In yet another unclaimed embodiment, a system for controlling the position of an armrest relative to a seat with a backrest and a seat surface is provided. This system comprises a first motor configured to set a position of the armrest relative to the backrest, and a second motor configured to set an angular position of the backrest relative to the seat surface. The backrest can be moved by the second motor between a number of angular positions relative to the seat surface. The system also includes an armrest control module configured to synchronize the operation of the first motor with the operation of the second motor in order to maintain a position of the armrest relative to the seat surface during and after the movement of the backrest relative to the seat surface between the number of angular positions. The system may have one or more of the following optional features. For example, the first motor may be located in a housing within the armrest. A first sensor may be configured to detect the position of the armrest relative to the backrest, and a second sensor may be configured to detect the position of the backrest relative to the seat. The first sensor may monitor the first motor, and the second sensor may monitor the second motor. The first sensor and / or the second sensor may be a Hall-effect sensor. The system can be installed in a vehicle. BRIEF DESCRIPTION OF THE DRAWINGS The drawings described here serve only to illustrate selected embodiments. Fig. 1 is a perspective view of a vehicle according to the principles of the present invention; Fig. 2 is a perspective rear view of a vehicle seat for use with the vehicle from Fig. 1; Fig. 3A is a side view of the vehicle seat from Fig. 2 with an armrest according to the principles of the present invention in an extended position; Fig. 3B is an enlarged view of the armrest from Fig. 3A, wherein part of the housing has been removed to show internal components of the armrest in the extended position; Fig. 4A is a side view of the vehicle seat from Fig. 2 in a reclined position; Fig. 4B is an enlarged view of the armrest from Fig. 3A, wherein part of the housing has been removed to show internal components of the armrest when the vehicle seat from Fig. 4A is in the reclined position; Fig.Fig. 5A is a side view of the vehicle seat from Fig. 2, with the armrest from Fig. 3A in a folded position; Fig. 5B is an enlarged view of the armrest from Fig. 3A, with part of the housing removed to show internal components of the armrest in the folded position; and Fig. 6 is a schematic representation of a system for synchronizing the movement of the armrest from Fig. 3A with the movement of a backrest of the vehicle seat from Fig. 2. Corresponding reference symbols identify corresponding parts in the drawings. DETAILED DESCRIPTION With reference to the figures, a vehicle 10 is provided with a plurality of seats 12 arranged in a cabin 14 of the vehicle 10. As shown in Fig. 2, the seats 12 comprise a seat surface 16, a backrest 18 rotatably attached to the seat surface 16, and an armrest 20 pivotably attached to the backrest 18. As described below, the movement of the armrest 20 is synchronized with the movement of the backrest 18, so that the armrest 20 is held substantially parallel to a vehicle floor 22 of the vehicle 10 (Fig. 3A) and / or to the seat surface 16, irrespective of the angular position of the backrest 18 relative to the seat surface 16. As shown in Fig. 2, the armrest 20 is attached to a side wall 24 of the backrest 18. The armrest 20 is pivotally attached to the side wall 24 so that it can be selectively rotated relative to the backrest 18 between an extended position (Fig. 2, Fig. 3A, Fig. 4A) and a folded position (Fig. 5A). Furthermore, the position of the armrest 20 relative to the backrest 18 can be adjusted by adjusting the angle of the backrest 18 relative to the seat surface 14, in order to keep the armrest 20 substantially parallel to the vehicle floor 22 of the vehicle 10 and / or to the seat surface 16. In particular, when the backrest 18 is moved from an upright position (Fig. 3A) to a reclined position (Fig. 4A) by rotating the backrest 18 clockwise (CW) as shown in Fig. 4A, the armrest 20 is automatically rotated counterclockwise (CCW) as shown in Fig. 4A.4A rotated to keep a longitudinal axis of the armrest 20 essentially parallel to the vehicle floor 22 and / or to the seat surface 16. The armrest 20 comprises a housing 26, a linear actuator assembly 28, and a lever 30. The linear actuator assembly 28 and the lever 30 are supported by and within the housing 26 and thus move with the housing 26 when the housing 26 is moved or rotated relative to the backrest 18. The housing 26 can be made of a rigid or semi-rigid material such as steel and / or plastic and includes an outer foam layer covered with fabric and / or leather, defining an outer surface 32 of the armrest 20. The actuator assembly 28 comprises a motor 34, a threaded screw or rod 36 extending from a housing 38 of the motor 34, and an armrest position sensor 40 configured to detect the position of the screw 36 relative to the housing 38. In one embodiment, the motor 34 is an electric motor configured to rotate the screw 36 either clockwise (CW) or counterclockwise (CCW) to either screw the screw 36 in or out. In one embodiment, for example, rotating the screw 36 counterclockwise causes it to protrude further from the housing 38, while rotating it clockwise causes it to be recessed into the housing 38. The extent to which the screw 36 protrudes from the housing 38 is directly controlled by how strongly and in which direction (i.e. clockwise or counterclockwise) the motor 34 turns the screw 36.Referring to Fig. 3B and Fig. 4B, the screw 36 in Fig. 3B, for example, protrudes further from the housing 38 than in Fig. 4B, because the motor 34 turns the screw 36 counterclockwise. The screw 36 has a first end 42, which is received in the housing 38 of the motor 34, a second end 44, which is rotatably attached to the lever 30, and a series of threads 46 arranged between the first end 42 and the second end 44. The threads 46 are driven by a threaded spindle (not shown) which engages with the threads 46 of the screw 36. Specifically, the threaded spindle is driven or rotated by the motor 34 and causes the screw 36 to rotate relative to the housing 38 due to the engagement between the threads (not shown) of the threaded spindle and the threads 46 of the screw 36. As already described, the screw 36 is either turned out of or into the housing 38, depending on the direction of rotation of the screw 36. The direction of rotation is determined by the direction in which the motor 34 rotates the threaded spindle. The armrest position sensor 40 can count the number of rotations of the threaded spindle, the screw 36, and / or the revolutions of a rotor (not shown) of the motor 34 to determine the position of the screw 36 relative to the housing 38. In one embodiment, the armrest position sensor 40 includes, for example, a Hall effect sensor that detects the number of rotations of the threaded spindle, the screw 36, and / or the rotor to determine the position of the screw 36 relative to the housing 38. Although the armrest position sensor 40 is described as comprising a Hall effect sensor, it could be any sensor capable of determining the number of rotations of one or more of the aforementioned components, such as an optical sensor.The sensor 40 is referred to as the armrest position sensor 40, since the position of the screw 36 relative to the housing 38 determines the position of the armrest 20 relative to the backrest 18, as will be described in more detail below. The second end of the screw 36 is rotatably connected to the lever 30 so that the screw 36 can rotate the lever either clockwise (CW) as shown in Fig. 3B or counterclockwise (CCW) as shown in Fig. 3B when the screw 36 is screwed in or out of the housing 38. The lever 30 can be an angled lever and comprises a main body 48 and a projection 50 extending from the main body 48. The main body 48 includes an opening 52, which is rotatably attached to a shaft 54 ​​of the backrest 18 so that the lever 30 can rotate about the shaft 54 ​​relative to the backrest 18. The main body 48 further includes a recess 56 that defines an arcuate track 58. The arcuate track 58 extends between a first end face 60 and a second end face 62, which define a first stop 64 and a second stop 66, respectively.Although the main body 48 is comprehensively described as a recess 56 defining the arc-shaped track 58, the recess 56 could be replaced by a slot (not shown) formed by a thickness of the main body 48, with the ends of the slot defining the first stop 64 and the second stop 66 respectively. In one embodiment, the recess 56 is formed by bending a portion of the main body 48 into the shape of the arcuate track 58. The first stop 64 and the second stop 66 are formed at opposite ends of the arcuate track 58 and are created where parts of the main body 48 are bent into the shape shown in Figs. 3B, 4B, and 5B. The recess 56 accommodates a pin 68, which is movably connected to the backrest 18. Consequently, when the armrest 20 is rotated relative to the backrest 18, the pin 68 passes through the recess 56 between the first stop 64 and the second stop 66, which interact to define a range of motion for the armrest 20 relative to the backrest 18, as described in more detail below. During operation, the backrest 18 can initially be in a substantially upright position, as shown in Fig. 3A. In this position, the armrest 20 is positioned such that the longitudinal axis of the armrest 20 runs substantially parallel to the vehicle floor 22 of the vehicle 10. In this position, the armrest 20 is prevented from rotating further counterclockwise (CCW) relative to the backrest 18, as shown in Fig. 3B, due to the engagement between the pin 68 of the backrest 18 and the first stop 64 of the lever 30. When the backrest 18 is rotated or reclined relative to the seat surface 16, it moves into the position shown in Fig. 4A. As shown, the armrest 20 is held in a position essentially parallel to the vehicle floor 22 of the vehicle 10 and / or to the seat surface 16 by the interaction of the linear actuator assembly 28 and the lever 30. When the backrest 18 is rotated relative to the seat surface 16, a backrest position sensor 70 (Fig. 6) can detect, in particular, the degree and direction of rotation of the backrest 18 relative to the seat surface 16. The backrest 18 can be driven by a backrest motor (not shown), which, when activated, causes a movement of the backrest 18 relative to the seat surface 16.Like the armrest position sensor 40, which is connected to the linear actuator assembly 28, the backrest position sensor 70 can also include a Hall effect sensor that determines the degree of rotation of the backrest 18 relative to the seat surface 16 by monitoring the backrest motor. While the backrest position sensor 70 can include a Hall effect sensor, it can also include any other sensor configured to detect the direction of rotation of the backrest 18 and the degree of rotation of the backrest 18 relative to the seat surface 16, such as an optical sensor. The armrest position sensor 40 and the backrest position sensor 70 can be connected to an armrest control module 72 and supply the armrest control module 72 with position data of the armrest 20 relative to the backrest 18 and of the backrest 18 relative to the seat surface 16, respectively. The armrest control module 72 can be executed by an on-board power supply control unit (BCU) 74 of the vehicle 10, wherein the armrest control module 72 is stored in the memory hardware 76 of the BCU 74 and executed by the data processing hardware 78 of the BCU 74. When the backrest 18 is moved from the upright position shown in Fig. 3A to the reclined position shown in Fig. 4A, the backrest position sensor 70 determines the direction and degree or extent of rotation of the backrest 18 relative to the seat surface 16. This information is transmitted to the armrest control module 72 of the BSG 74 so that the armrest control module 72 can decide whether to screw the screw 36 into or out of the housing 38 to hold the armrest 20 in a position where the longitudinal axis of the armrest 20 is substantially parallel to the vehicle floor 22 and / or the seat surface 16 of the vehicle 10. The armrest control module 72 can use information it receives from the armrest control module 72 and from the armrest position sensor 40, which determines the current position of the armrest 20 (i.e.,to specify the current position of the screw 36 relative to the housing 38) and to determine whether the screw 36 should be screwed into or unscrewed from the housing 38. Once the armrest control module 72 receives information from the backrest position sensor 70 about the position of the backrest 18 relative to the seat surface 16, the armrest control module 72 can determine how to adjust the position of the screw 36 relative to the housing 38 to ensure that the armrest 20 is held substantially parallel to the vehicle floor 22 and / or to the seat surface 16. As shown in Fig. 3A, the pin 68 is in contact with the first stop 64 when the backrest 18 is in the upright position, preventing the armrest 20 from rotating counterclockwise (CCW) as shown in Fig. 3B. When the backrest 18 is moved from the position shown in Fig. 3A to the position shown in Fig. 4A, the armrest control module 72 actuates the motor 34 to rotate the screw 36 clockwise (CW), thus screwing it into the housing 38. During this process, the second end 44 of the screw 36 exerts a force on the projection 50 of the lever 30 due to the rotatable connection of the second end 44 with the projection 50. The force exerted on the lever 30 causes the lever 30 to rotate clockwise around the shaft 54 ​​in the view shown in Fig. 3B and Fig. 4B.The clockwise rotation of the lever 30 causes the first stop 64 to also move clockwise, which in turn changes the position of the first stop 64 relative to the position of the first stop 64 shown in Fig. 3A. The extent of the clockwise rotation of the lever 30 is determined by the extent to which the screw 36 is screwed into the housing 38 and is based on the extent and direction of rotation of the backrest 18 relative to the seat surface 16. As shown in Fig. 6, the armrest position sensor 40 and the backrest position sensor 70 are connected to the armrest control module 72. Consequently, the armrest control module 72 can simultaneously receive data from both sensors 40 and 70 to control and coordinate the movement of the armrest 20 with the movement of the backrest 18 in real time. For example, if the backrest position sensor 70 indicates that the backrest 18 is being moved relative to the seat surface 16 (i.e., reclined, as shown in Fig. 4A), the armrest control module 72 can actuate the motor 34 to cause a simultaneous movement of the screw 36 and the lever 30. In doing so, the armrest control module 72 can set a position of the first stop 64 to hold the armrest 20 in a position that is substantially parallel to the vehicle floor 22 and / or the seat surface 16. If the lever 30, and thus the first stop 64, is rotated clockwise relative to the views shown in Figs. 3B and 4B, the armrest 20 is rotated counterclockwise relative to the backrest 18. In particular, the armrest 20 is pre-tensioned by its own weight so that it rotates counterclockwise relative to the views shown in Figs. 3B and 4B. Therefore, if the first stop 64 is rotated clockwise, the armrest 20 can rotate counterclockwise due to the changed position of the first stop 64. If the pin 68 of the backrest 18 is moved clockwise due to the clockwise movement of the backrest 18 relative to the seat surface 16, the position of the lever 30 and the first stop 64 must also be moved so that the armrest 20 can be kept in a parallel relationship to the vehicle floor 22 during the entire movement of the backrest 18 relative to the seat surface 16.Although the armrest 20 is pre-tensioned in the direction of rotation counterclockwise by its weight as described, it should be noted that a pre-tensioning element, such as a spring not shown, could be additionally used to further pre-tension the rotation of the armrest 20 counterclockwise. As soon as the backrest position sensor 70 detects that the backrest 18 is no longer moving relative to the seat surface 16, the armrest control module 72 stops the rotation of the screw 36 by stopping the motor 34. The armrest control module 72 ensures that the lever 30 rotates exactly clockwise so that the armrest 20 remains essentially parallel to the vehicle floor 22 and / or the seat surface 16 throughout the entire movement of the backrest 18 relative to the seat surface 16. The above example applies when the backrest 18 is rotated clockwise (i.e., reclined) relative to the seat surface 16. If the backrest 18 is rotated counterclockwise relative to the seat surface 16, the armrest control module 72 simply reverses the direction of rotation of the screw 36 to cause the lever 30 to rotate counterclockwise to hold the armrest 20 parallel to the vehicle floor 22 and / or the seat surface 16. With particular reference to Figures 5A and 5B, the operation of the armrest 20 and its movement from an extended position (Figures 3A and 4A) to a folded position (Figure 5A) are described in detail. If a vehicle occupant wishes to fold the armrest 20 to make it easier to sit down or stand up from the vehicle seat 10, or to fold the backrest 18 onto the seat surface 16, the occupant can exert a force on the armrest 20 in a clockwise direction relative to the view shown in Figures 5A and 5B. This causes the armrest 20 to rotate clockwise relative to the backrest 18 and against the counterclockwise rotational preload exerted on the armrest 20 by its own weight. The clockwise rotation of the armrest 20 is enabled by the interaction of the pin 68 and the recess 56. Specifically, the clockwise rotation of the armrest 20 causes the lever 30 to also rotate clockwise. This releases the first stop 64, which moves away from the pin 68 of the backrest 18, which remains stationary. The clockwise movement of the armrest 20 is possible until its full range of motion relative to the backrest 18 is reached. Specifically, the clockwise movement of the armrest 20 is possible until the second stop 66 abuts the pin 68, thereby preventing further clockwise movement of the armrest 20. The armrest 20 can be returned to the unfolded position by rotating the armrest 20 counterclockwise relative to the backrest 18 until the first stop 64 again abuts the pin 68 of the backrest 18. As described, the armrest control module 72 coordinates the movement of the armrest 20 with the movement of the backrest 18 relative to the seat surface 16 to ensure that the armrest 20 remains parallel to the vehicle floor 22 and / or the seat surface 16 throughout the entire movement of the backrest 18.

Claims

Armrest (20) for a seat (12) with a backrest (18) and a seat surface (16), wherein the armrest (20) comprises: a housing (38) rotatable relative to the backrest (18); and a motor (34) configured to maintain a position of the housing (38) relative to the seat surface (16) when the backrest (18) is moved relative to the seat surface (16); characterized in that the motor (34) is arranged in the housing (38); wherein a screw (36) driven by the motor (34) extends from the motor (34) and is configured to rotate a lever (30) in contact with the backrest (18) in order to adjust a position of the housing (38) relative to the backrest (18); wherein the screw (36) and the lever (30) are arranged inside the housing;and wherein the lever (30) comprises a main body (48) with an opening (52) and a projection (50) extending from the main body (48), the opening (52) receiving a shaft (54) of the backrest (18) so that the lever (30) is rotatable about the shaft (54) relative to both the backrest (18) and the housing (38). Armrest (20) according to claim 1, further comprising a first sensor (40) configured to detect a number of revolutions of the motor (34). Armrest (20) according to claim 2, wherein the first sensor (40) is a Hall effect sensor. Armrest (20) according to claim 1, wherein the lever (30) defines a first and a second stop (64, 66) which work together to define a range of movement of the armrest (20) relative to the backrest (18). Armrest (20) according to claim 4, wherein the lever (30) has a recess (56) which defines the first stop (64) and the second stop (66). Armrest (20) according to claim 5, wherein the recess (56) slidably receives a pin (68) which is movably connected to the backrest (18), wherein the movement of the lever (30) between a first position in which the pin (68) is in contact with the first stop (64) and a second position in which the pin (68) is in contact with the second stop (66) defines the range of movement of the armrest (20) relative to the backrest (18). Armrest (20) according to claim 1, wherein the screw (36) has a first end (42) extending from the motor (34) and a second end (44) arranged at an end of the screw (36) opposite the first end (42), wherein the second end (44) is pivotably connected to the lever (30). Vehicle with the armrest (20) and the seat (12) according to claim 1 .

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