SUPPORT ARM FOR AN AUXILIARY ELEMENT EQUIPPED WITH A ROTARY MECHANISM WITH VARIABLE FRICTION

Abstract

The invention relates to a support arm device comprising a variable friction rotary mechanism (17) including: - a housing (20) fixed to a fixed support, - a fixed axis (21), the support arm being mounted to rotate freely relative to the fixed axis (21), - a compression ring (23), - at least one elastic element (24), - the compression ring (23) having a contact face (25) against which a pin carried by the support arm makes contact, - said contact face (25) having friction zones (27.1-27.3) such that moving the pin successively along the different friction zones (27.1-27.3) allows the compression level of the elastic elements (24) to be varied, and therefore the level of friction force applied to the support arm. Figure 2b

Description

Title of the invention: SUPPORT ARM FOR AN AUXILIARY ELEMENT EQUIPPED WITH A ROTARY MECHANISM WITH VARIABLE FRICTION

[0001] The present invention relates to a support arm for an auxiliary element equipped with a rotating mechanism with variable friction. The invention finds a particularly advantageous, but not exclusive, application in supporting a video screen.

[0002] Unlike other passengers in an aircraft cabin, a passenger seated in the front row does not have a video screen on the seat in front of them. To remedy this, it is known to provide a support arm fixed to a structural element of the front row seat and carrying a remote video screen below the tray table. The support arm is movable between a stowed position, in which the arm is lowered so that the video screen is positioned below the tray table, and a deployed position, in which the arm is raised so that the video screen is within the field of vision of the passenger seated in the seat.

[0003] Generally, following the activation of a support arm release button, there is no friction during the support arm's release period so that the passenger can observe a reaction from the support arm. During the opening phase, and when the support arm is in the deployed position, a friction mechanism applies friction to the support arm to maintain it in a deployed position and limit screen vibrations during flight.

[0004] Document EP3019371 describes a deployment device comprising a deployment object, a support arm with a first end coupled to the deployment object and a second end having a pivot, and a hinged assembly rotatably fixed to the pivot of the support arm. The hinged assembly comprises a housing and a friction device disposed inside the housing such that the friction device includes a friction washer configured to be pressed against a lateral surface of the pivot of the support arm such that the friction washer provides a predetermined torque. However, such a system is not adjustable insofar as the applied friction, which depends on the size and positioning of the friction washer, is always the same.

[0005] The invention aims to effectively remedy the aforementioned drawbacks by proposing a support arm device comprising: - a fixed support intended to be attached to a structural element, - a support arm mounted to rotate relative to the fixed support between a stored position and a deployed position, said support arm being intended to support an auxiliary element, and - a rotating mechanism with variable friction mounted between the fixed support and the support arm, - said variable friction rotary mechanism comprising: - a housing fixed to the fixed support, - a fixed axis relative to the housing, the support arm being mounted to rotate freely relative to the fixed axis, - a compression ring, - at least one elastic element disposed between the housing and the compression ring, - the compression ring having a contact face against which a pin carried by the support arm makes contact, - said contact face having friction zones such that a successive movement of the pin along the different friction zones makes it possible to vary a level of compression of the elastic element between the reaction wall of the housing and the compression ring and therefore a level of friction force applied to the support arm.

[0006] The invention thus makes it possible to modulate, as needed, the friction following the rotation of the support arm while maintaining a compact mechanism. By modifying the position and shape of the machining of the friction zones on the compression ring, as well as the number of elastic elements, the invention makes it possible to modulate the presence of the maximum friction zone, the level of friction force, and thus the desired position of the support arm in its deployed position. The invention also has the advantage of being implementable at low cost.

[0007] According to one embodiment of the invention, said contact face comprising a first substantially flat friction zone, a second friction zone comprising a slope and a third substantially flat friction zone, - so that during a movement of the support arm from the stored position to the deployed position, the pin moves angularly along the first friction zone for which the clearance between the compression ring and the housing, called the operating clearance, is at its maximum, resulting in a minimum or zero friction force; - the pin then comes into contact and moves angularly along the slope of the second friction zone, so that the operating clearance gradually decreases to a minimum operating clearance, resulting in a progressive compression of the elastic element generating a progressive friction force up to a maximum friction force. - the pin moves, during a final phase, angularly along the third friction zone, so that the operating clearance is kept to a minimum and the friction force remains at a maximum to maintain the support arm in any angular position during this final phase.

[0008] According to one embodiment of the invention, said support arm device further comprises a friction ring movable in rotation relative to the housing and intended to cooperate with a friction washer, said friction ring comprising a pin receiving hole into which is inserted a pin linked in rotation with the support arm, so that a rotation of the support arm causes friction by rotation of the friction ring against the friction washer.

[0009] According to one embodiment of the invention, the compression ring has a circular arc-shaped groove along which the pin of the support arm is able to slide.

[0010] According to one embodiment of the invention, said support arm device comprises a second friction washer, the elastic element(s) being arranged axially between the two friction washers.

[0011] According to one embodiment of the invention, said support arm device comprises a bearing arranged radially between a radially external face of the compression ring and a radially internal face of the friction ring.

[0012] According to one embodiment of the invention, said support arm device comprises a bearing arranged radially between a radially external face of a central tubular portion of the housing and a radially internal face of the compression ring.

[0013] According to one embodiment of the invention, said support arm device comprises two elastic elements consisting of two corrugated washers.

[0014] According to one embodiment of the invention, the housing has at least one notch on its outer periphery in which is inserted at least one circumferential tab of corresponding shape made in the compression ring to prevent rotation of the compression ring relative to the housing.

[0015] According to one embodiment of the invention, said support arm device includes an ejection member equipped with a spring enabling the support arm to move from the stored position to the deployed position.

[0016] The invention also relates to a seat equipped with a support arm device as previously defined.

[0017] The present invention will be better understood and other features and advantages will become apparent upon reading the following detailed description, which includes embodiments given by way of illustration with reference to the accompanying figures, presented by way of non-limiting examples, which may serve to supplement the understanding of the present invention and a description of its implementation and, where applicable, contributing to its definition, on which:

[0018] [Fig-1] The [Fig. 1] is a side view of a lower part of a first-row seat in an aircraft cabin equipped with a support arm device according to the invention in the stored position;

[0019] [Fig. 2a] [Fig. 2b] Figures 2a and 2b are respectively perspective views and in exploded view perspective of a variable friction rotary mechanism integrated into the support arm device according to the invention;

[0020] [Fig. 3a] [Fig. 3b] Figures 3a and 3b are respectively front and side views longitudinal section of a rotary mechanism with variable friction according to the invention during a first phase of movement of a pin carried by the support arm against a first friction zone;

[0021] [Fig.4a] [Fig.4b] [Fig.4c] Figures 4a, 4b and 4c are respectively a view of side of the support arm carrying the auxiliary element as well as front and longitudinal section views of a variable friction rotary mechanism according to the invention during a second phase of movement of a pin carried by the support arm against a second friction zone;

[0022] [Fig. 5a] [Fig. 5b] [Fig. 5c] Figures 5a, 5b and 5c are respectively a view of side of the support arm carrying the auxiliary element as well as front and longitudinal section views of a variable friction rotary mechanism according to the invention during a third phase of movement of a pin carried by the support arm against a third friction zone.

[0023] It should be noted that in the figures, structural and / or functional elements common to the different embodiments may have the same reference numerals. Thus, unless otherwise stated, such elements have identical structural, dimensional, and material properties.

[0024] Figure 1 shows a side view of the lower part of a front-row seat 10 in an aircraft cabin comprising a structural element 11 such as a seat arm. A support arm device 12 carries a video screen 13 disposed within a corresponding housing 14 positioned under the seat cushion 10 when the device 12 is in the stored position.

[0025] More specifically, the support arm device 12 comprises a fixed support 15 for attachment to the structural element 11, and a support arm 16 rotatably mounted relative to the fixed support 15 between a stored position and a deployed position. The elongated support arm 16 is designed to support an auxiliary element, in this case the video screen 13. In the stored position shown in [Fig. 1], the support arm 16 is lowered so that the video screen 13 is positioned under the seat 10 inside the housing 14. In the deployed position, the support arm 16 is raised so that the video screen 13 is located in the field of vision of the passenger sitting in seat 10.

[0026] A variable friction rotary mechanism 17 with axis X is mounted between the fixed support 15 and the support arm 16. As illustrated in Figures 2a and 2b, the variable friction rotary mechanism 17 comprises a housing 20 fixed to the fixed support 15. The housing 20 has a reaction wall 20.1 on the outer periphery of which extends a peripheral wall 20.2 delimiting an internal volume within which the various components of the variable friction rotary mechanism 17 are arranged. A central tubular portion 20.3 projects from the reaction wall 20.1. The tubular portion 20.3 has an axis X corresponding to the axis of the friction mechanism 17 and the axis of rotation of the support arm 16. In the following description, the axial or radial extensions of the various elements are understood to be with respect to the axis X.

[0027] The variable friction rotary mechanism 17 also includes a shaft 21 fixed relative to the housing 20. The fixed shaft 21 is cylindrical in shape. The support arm 16 is mounted to rotate freely relative to the fixed shaft 21. For this purpose, the fixed shaft 21 can be screwed onto the housing 20. As can be seen in particular in [Fig. 3b], the fixed shaft 21 has a threaded tubular portion 21.1 inserted into the central tubular portion 20.3 of the housing 20. One end of the portion 20.3 of the housing 20 bears against a shoulder of the fixed shaft 21 which retains the internal components of the variable friction rotary mechanism 17. A screw 22 passing through a central opening in the housing 20 is screwed into the threaded tubular portion 21.1.

[0028] A compression ring 23 comprises an annular axial extension portion 23.1 and an annular radial extension portion 23.2 extending from one end of the annular axial extension portion 23.1.

[0029] At least one elastic element 24 is disposed between the housing 20 and the compression ring 23. In the example shown, two elastic elements 24 consisting of two wave washers are used. Alternatively, the elastic elements 24 may consist of helical springs, spring washers, or any other elastic element suitable for the application. It is possible to use one or more than two elastic elements 24 depending on the desired level of friction force.

[0030] The compression ring 23 has a contact face 25 against which a pin 26 carried by the support arm 16 makes contact. The contact face 25 extends in a plane perpendicular to the X-axis. The contact face 25 has a first friction zone 27.1 that is substantially flat, a second friction zone 27.2 that has a slope, and a third friction zone 27.3 that is substantially flat. The slope extends between the first friction zone 27.1 and the second friction zone 27.2. The slope of the second friction zone 27.2 thus creates an axial offset by ratio to the X axis between the first friction zone 27.1 and the second friction zone 27.2. The slope of the second friction zone 27.2 is preferably a linear slope but can alternatively be a curved slope.

[0031] As explained in more detail below, moving the pin 26 successively through the different friction zones 27.1-27.3 allows for varying the level of compression of the elastic elements 24 between the reaction wall 20.1 of the housing 20 and the compression ring 23, and therefore the level of friction force applied to the support arm 16. The friction zones 27.1-27.3 are located at different axial levels with respect to an axis of the compression ring 23. Each of the friction zones 27.1-27.3 corresponds to a specific level of friction force applied to the support arm 13. There is not necessarily significant friction between the pin 26 and a friction zone 27.1-27.3 per se.

[0032] The housing 20 has at least one notch 40 on its outer periphery into which is inserted at least one circumferential tab 41 of corresponding shape formed in the compression ring 23 to prevent rotation of the compression ring 23 relative to the housing 20. The "notch 40-tab 41" assembly also ensures translational guidance of the compression ring 23 relative to the housing 20 during movement of the pin 26. In this case, the housing 20 has two diametrically opposed notches 41 intended to each receive a tab 41 of corresponding shape.

[0033] Furthermore, a friction ring 30 is mounted to rotate freely relative to the housing 20. The friction ring 30 is intended to cooperate with a friction washer 31. The friction washer 31 is arranged axially between the friction ring 31 and the elastic elements 24.

[0034] As can be seen in [Fig.2b], the friction ring 30 has a pin receiving hole 32 into which a pin 33 is inserted, which is rotationally linked with the support arm 16, so that a rotation of the support arm 16 causes friction by rotation of the friction ring 30 against the friction washer 31. The friction ring 30 is arranged axially between the compression ring 23 and the reaction wall 20.1 of the housing 20.

[0035] The compression ring 23 has a circular arc-shaped groove 35 along which the pin 33 of the support arm 16 is able to slide, as shown in [Fig. 3a]. The groove 35 is a through groove into which the pin 33 is inserted.

[0036] A second friction washer 31 is disposed at the bottom of the housing 20. The elastic elements 24 are disposed axially between the two friction washers 31.

[0037] A bearing 36, visible in particular in Figures 2b and 3b, is arranged radially between a radially external face of the compression ring 23 and a face radially internal to the friction ring 30. The bearing 36 is arranged around the axial annular portion 23.1 of the compression ring 23. The bearing 36 has a radial flange against which the friction ring 30 bears.

[0038] In addition, a bearing 39 is arranged radially between a radially external face of the central tubular portion 20.3 of the housing 20 and a radially internal face of the compression ring 23. The bearing 39 has an annular axial extension portion arranged around the central tubular portion 20.3 and a radial flange against which the compression ring 23 bears. The compression ring 23 has a recess on its inner periphery for receiving the flange of the bearing 39.

[0039] The use of the bearings 36, 39 makes it possible to limit friction between the different parts of the device and to save on lubricant.

[0040] Preferably, an ejection member 43 equipped with a spring enables the support arm 16 to move from its stored position to its deployed position, as shown in [Fig. 4a]. The ejection member 43 is located between the fixed support 15 and the support arm 16. The ejection member 43 is activated by an activation button located near or on the support arm 16.

[0041] The operation of the support arm device 12 as it moves from the stored position to the deployed position is described below with reference to Figures 3a to 5c. The passenger presses the activation button so that the ejection member 43 begins to slightly move the support arm 16 towards the deployed position. The passenger then pulls on the support arm 16 to raise it upwards into the deployed position.

[0042] As illustrated in Figures 3a and 3b, during a movement of the support arm 16 from the stored position to the deployed position, the pin 26 moves angularly along the first friction zone 27.1 for which the clearance between the compression ring 23 and the housing 20, referred to as the operating clearance J, is at its maximum, resulting in a minimum or zero friction force. The elastic elements 24 are then decompressed or very slightly compressed between the compression ring 23 and the reaction wall 20.1 of the housing 20.

[0043] As illustrated in Figures 4a, 4b, and 4c, the pin 26 then comes into contact and moves angularly along the slope of the second friction zone 27.2, so that the operating clearance J gradually decreases to a minimum operating clearance J, resulting in a progressive compression of the elastic elements 24, generating a progressive friction force up to a maximum friction force. The support arm 16 is then moved away from its stored position.

[0044] As illustrated in Figures 5a, 5b and 5c, the pin 26 moves, during a final phase, angularly along the third friction zone 27.3, by so that the operating clearance J is kept to a minimum and the friction force remains at a maximum to maintain the support arm 16 in any angular position during this last phase, especially in the deployed position.

[0045] Alternatively, it is possible to provide more than three friction zones 27.1, 27.2, 27.3 on the contact face 25 of the compression ring 23, or fewer than three friction zones. The ramped, flat, or curved shapes of the friction zones can vary depending on the desired level of friction force.

[0046] Alternatively, the friction ring 30 and the corresponding pin 33 are removed.

[0047] Alternatively, a single elastic element 24 and / or a single friction washer is used 30.

[0048] Alternatively, the support arm device 12 is used with an auxiliary element 13 other than a video screen, such as a meal tray, a portable electronic device holder, a folding armrest, or a disabled access barrier. The extended position of the support arm 12 is a user-selected position for the auxiliary element, while the stored position of the support arm 12 is a position in which the unused auxiliary element is stored.

[0049] Of course, the different features, variants and / or embodiments of the present invention can be combined with each other in various ways insofar as they are not incompatible or mutually exclusive.

[0050] Furthermore, the invention is not limited to the embodiments described above and provided solely by way of example. It encompasses various modifications, alternative forms, and other variants that a person skilled in the art may consider within the scope of the present invention, and in particular all combinations of the different modes of operation described above, which may be taken separately or in combination.

Claims

Demands

1. Support arm device (12) comprising: - a fixed support (15) intended to be fixed to a structural element (H), - a support arm (16) rotatably mounted relative to the fixed support (15) between a stored position and a deployed position, said support arm (16) being intended to support an auxiliary element (13), and - a variable friction rotary mechanism (17) mounted between the fixed support (15) and the support arm (16), characterized in that said variable friction rotary mechanism (17) comprises: - a housing (20) fixed to the fixed support (15), - an axis (21) fixed relative to the housing (20), the support arm (16) being rotatably mounted relative to the fixed axis (21), - a compression ring (23), - at least one elastic element (24) disposed between the housing (20) and the compression ring (23),- the compression ring (23) having a contact face (25) against which a pin (26) carried by the support arm (16) makes contact, - said contact face (25) having friction zones (27.1-27.3) such that a displacement of the pin (26) successively along the different friction zones (27.1-27.3) makes it possible to vary a level of compression of the elastic element (24) between the reaction wall (20.1) of the housing (20) and the compression ring (23) and therefore a level of friction force applied to the support arm (16).

2. Support arm device according to claim 1, characterized in that said contact face (25) comprising a first friction zone (27.1) substantially flat, a second friction zone (27.2) comprising a slope and a third friction zone (27.3) substantially flat, - such that during a movement of the support arm (16) from the stored position to the deployed position, the pin (26) moves angularly along the first friction zone (27.1) for which a clearance between the compression ring (23) and the housing (20), said operating clearance (J), is at its maximum, resulting in a minimum or zero friction force, - the pin (26) then comes into contact and moves angularly along the slope of the second friction zone (27.2), so that the operating clearance (J) gradually decreases to a minimum operating clearance (J), resulting in a progressive compression of the elastic element (24) generating a progressive friction force up to a maximum friction force, - the pin (26) moves, during a final phase, angularly along the third friction zone (27.3), so that the operating clearance (J) is kept to a minimum and the friction force remains at its maximum to maintain the support arm (16) in any angular position during this final phase.

3. Support arm device according to claim 1 or 2, characterized in that it further comprises a friction ring (30) rotatable relative to the housing (20) and intended to cooperate with a friction washer (31), said friction ring (30) having a pin receiving hole (32) into which is inserted a pin (33) rotationally linked with the support arm (16), so that a rotation of the support arm (16) causes rotational friction of the friction ring (30) against the friction washer (31).

4. Support arm device according to claim 3, characterized in that the compression ring (23) has a groove (35) in the shape of an arc of a circle along which the pin (33) of the support arm (16) is able to slide.

5. Support arm device according to claim 3 or 4, characterized in that it comprises a second friction washer (31), the elastic element(s) (24) being arranged axially between the two friction washers (31).

6. Support arm device according to any one of claims 3 to 5, characterized in that it comprises a bearing (36) arranged radially between a radially external face of the compression ring (23) and a radially internal face of the friction ring (30).

7. A support arm device according to any one of claims 1 to 6, characterized in that it comprises a bearing (39) arranged radially between a radially external face of a central tubular portion (20.3) of the housing (20) and a radially internal face of the compression ring (23).

8. Support arm device according to any one of claims 1 to 7, characterized in that it comprises two elastic elements (24) consisting of two corrugated washers.

9. Support arm device according to any one of claims 1 to 8, characterized in that the housing (20) has at least one notch (40) on its outer periphery in which is inserted at least one circumferential tab (41) of corresponding shape made in the compression ring (23) to prevent rotation of the compression ring (23) relative to the housing (20).

10. Support arm device according to any one of claims 1 to 9, characterized in that it comprises an ejection member (43) equipped with a spring enabling the support arm (16) to move from the stored position to the deployed position.

11. Seat (10) equipped with a support arm device (12) defined according to any one of the preceding claims.

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