Spring arm arrangement and support arm system for holding a medical and / or lighting device

Abstract

The invention relates to a spring arm arrangement (1) for a support arm system (100) for holding a medical appliance and / or a lighting appliance, the spring arm arrangement comprises a spring tube (3) arranged on a fastening unit (5) for rotation about a first axis of rotation (21), a spring rod (4) arranged at least partially inside the spring tube (3) and displaceable relative to the spring tube (3) in a longitudinal direction (2) of the spring tube (3), and a lever element (6) connected to the spring rod (4) for rotation about a second axis of rotation (22) oriented parallel to the first axis of rotation (21), the lever element (6) being arranged for rotation about a third axis of rotation (23) at its end opposite the spring rod (4) on the fastening unit (5), the spring tube (3) has a third axis of rotation (21) which is spaced apart from the first axis of rotation (21) and is oriented parallel to the first axis of rotation (21), the lever element (6) being arranged radially outside the spring tube (2) with respect to the longitudinal direction (2) of the spring tube (3). The invention also relates to a support arm system (100) comprising such a spring arm device (1) for holding a medical appliance and / or a lighting appliance.

Description

Technical Field

[0001] The present invention relates to a spring arm device of a support arm system for holding a medical instrument and / or a lighting instrument, and to a support arm system for holding a medical instrument and / or a lighting instrument. Background Art

[0002] Support arm systems are used in operating rooms, for example, to hold medical equipment or instruments in a spatially displaceable manner. For example, the support arm can be movably anchored to the ceiling, wall, or floor via a bearing assembly. Mounting on a frame with casters is also possible. Support arm systems designed to hold medical instruments can also be designated as medical support systems. Support arm systems typically have at least one axis of movement, allowing the held medical instruments (which can also be designated as technical medical instruments and may include, for example, lighting fixtures (such as OR lights), monitors, examination equipment, one or more syringes, OR instruments, or dental drills) to be moved as needed. The movable bearings can also be designated as articulations or support arm articulations, which can also include the support arm. This means that medical instruments can be moved into a comfortable and safe position for performing corresponding medical procedures and investigations. Spatial displacement of medical instruments is necessary in many medical procedures to facilitate the work of medical staff or to make it possible.

[0003] However, by rotating the support arm, the lever arm relative to its bearing can vary. In particular, when the support arm is rotated about a substantially horizontal axis, the height of the medical device held in the support arm can vary, and the lever arm of the weight of the medical device relative to the mounting or support of the support arm can vary. Nevertheless, it is still desirable that the medical device be retained in a set position by rotating the support arm, and that adjustments to the position of the medical device, particularly against gravity, be made without expending excessive force on the user's part.

[0004] For this purpose, a spring-balanced support arm is often used, primarily as a spring arm or spring arm arrangement. In this case, two arm elements are provided, which are movable relative to one another and supported by a spring. Rotating the spring arm changes the lever arm corresponding to the spring force of the load, allowing the medical device to be held equally well in different positions. Alternatively or additionally, the spring can also be compressed or stretched by rotation, thereby varying the corresponding support force.

[0005] Such a support arm system and a spring arm device are known, for example, from EP 1 478 872 A1. Typically, the spring arm device comprises a spring tube, which is arranged on a mounting unit so as to rotate about a substantially horizontal axis of rotation; a spring rod, which is at least partially arranged inside the spring tube and is displaceable relative to the spring tube; and a lever element, one end of which is rotatably connected to the spring rod inside the spring tube and the other end of which is rotatably arranged on the mounting unit. Summary of the Invention

[0006] Based on the known prior art, the object of the present invention is to provide an improved spring arm device for a support arm system for holding medical instruments and / or lighting fixtures, as well as a corresponding support arm system for holding medical instruments and / or lighting fixtures. In particular, a spring arm device with a relatively large range of motion should be provided.

[0007] This object is achieved by a spring arm arrangement for a support arm system for holding medical and / or lighting devices having the features of claim 1. Advantageous further embodiments are described in the dependent claims, the description and the drawings.

[0008] Therefore, a spring arm device of a support arm system for holding medical instruments and / or lighting instruments is proposed, which includes: a spring tube, which is arranged on a mounting unit to rotate around a first rotation axis; a spring rod, which is at least partially arranged in the interior of the spring tube and can be displaced relative to the spring tube in the longitudinal direction of the spring tube; and a lever element, which is connected to the spring rod to rotate around a second rotation axis oriented parallel to the first rotation axis, and the lever element is arranged on the mounting unit at its end opposite to the spring rod to rotate around a third rotation axis spaced apart from the first rotation axis and oriented parallel to the first rotation axis.

[0009] In the proposed spring-arm device, the lever element is positioned radially outside the spring tube, relative to the longitudinal direction of the spring tube. In this way, in contrast to prior art spring-arm devices, in which the lever element extends inside the spring tube and is connected to a spring rod therein, and whose range of movement is limited by a collision point between the lever element and the interior of the spring tube, the rotational range of the spring tube about the first rotational axis is unrestricted in terms of its range of movement. Furthermore, positioning the lever element radially outside the spring tube means that the spring tube and the lever element can rotate substantially freely relative to each other without causing a collision between the lever element and the spring tube. Therefore, the possible rotation angle of the spring tube about the first rotational axis is substantially limited only by the connection of the spring tube to the mounting unit, and not by the lever element. Accordingly, the spring-arm device according to the present invention has a significantly increased rotational range about the first rotational axis compared to conventional prior art spring-arm devices.

[0010] The spring arm device can be a component of an operating room support arm system. As a spring arm device of an operating room support arm system, it is therefore configured and constructed for holding a medical device or medical instrument, such as a medical lighting instrument, in a spatially displaceable manner.

[0011] The term "rotatable bearing" in this document is to be understood to mean only that a rotational movement of the components of the rotatable bearing relative to one another about a respective axis of rotation is possible. In particular, compressive and tensile forces as well as torques not acting about the axis of rotation are transmitted by the rotatable bearing.

[0012] The spring rod and the lever element are preferably connected to one another via a connecting element. The connecting element is preferably connected to the spring rod radially inwardly of the spring tube, thus typically within the spring tube, and is connected to the lever element radially outwardly of the spring tube. The connecting element preferably extends in the direction of the second rotational axis and / or preferably extends from the interior of the spring tube to the radial exterior of the spring tube through a recess provided in the spring tube.

[0013] The term "radially inner" is understood here to mean a region having, relative to the longitudinal direction of the spring tube, an extent transverse to the longitudinal direction which is less than or equal to the inner radius of the spring tube or, in the case of a non-circular spring tube, the inner radius of its inner surface.

[0014] The term “radially outer” describes a region having, relative to the longitudinal direction of the spring tube, an extent transverse to the longitudinal direction which is greater than the outer radius of the spring tube or, in the case of a non-circular spring tube, the outer radius of its outer surface.

[0015] It has been found to be advantageous if the recess is an elongated hole oriented in the longitudinal direction, wherein the connecting element is displaceable in the longitudinal direction along the elongated hole.

[0016] According to a preferred embodiment, the lever element is located at a predetermined distance from the spring tube in the direction of the first rotational axis, in particular from a connection portion or region of the spring tube for connection to the mounting unit. This ensures that the lever element and the spring tube do not collide when the spring tube is rotated about the first rotational axis.

[0017] When the spring rod is configured as a hollow rod, at least one supply channel (e.g., a supply of a medium (such as compressed air, oxygen or nitrogen, etc.) and / or a supply of electricity and / or data) for a medical instrument and / or lighting instrument attached to the spring arm device can be provided through the interior of the hollow rod.

[0018] According to a preferred embodiment, the mounting unit comprises a joint portion, in which the spring tube and the lever element are connected to the mounting unit; and a connecting portion, preferably configured as a journal, for connecting the mounting unit to a load-bearing structure, preferably a ceiling, wall, or floor of a room, or a support frame or support arm, wherein the joint portion and the connecting portion are located at a predetermined distance from each other in the direction of the first rotational axis. This spatial separation or spacing of the connecting portion and the joint portion allows the spring arm device, and in particular, the housing for enclosing at least the joint portion, to have a relatively simple construction. In other words, relative to a plane oriented perpendicular to the first rotational axis, the joint portion is located on a first side of the plane, and the connecting portion is located on the other side of the plane. The spring tube and the lever element, as well as their connection, are thus located entirely and exclusively on the joint portion. This means that the spring tube can move relative to the connecting portion past the connecting portion without colliding with it. This is achieved structurally by a predetermined distance between the joint portion and the connecting portion in the direction of the first rotational axis. In other words, the predetermined distance exists between a first plane oriented perpendicular to the first rotational axis and a second plane oriented perpendicular to the first rotational axis. The first plane is defined by the point of the joint portion and includes the spring tube closest to the connecting portion. Accordingly, the second plane is defined by the point of the connecting portion closest to the joint portion.

[0019] Advantageously, the lever element is arranged opposite the connecting portion relative to the spring tube.

[0020] Preferably, a first housing portion is provided, which is preferably connected to the spring tube in a rotationally fixed manner and surrounds the connection portion. Furthermore, preferably, a second housing portion is provided, which is preferably connected to the connection portion in a rotationally fixed manner and preferably surrounds at least a portion of the connection portion. A dividing plane between the first and second housing portions can be oriented perpendicular to the first rotation axis and, viewed in the direction of the first rotation axis, can be located in the region between the connection portion and the connection portion. In other words, with respect to exactly one dividing plane oriented perpendicular to the first rotation axis, the first housing portion is located on a first side of the dividing plane, and the second housing portion is located on the other side of the dividing plane. Thus, the first housing portion is located entirely and exclusively on the connection portion side, and the second housing portion is located entirely and exclusively on the connection portion side. The dividing plane can be designated as, or coincident with, the aforementioned plane oriented perpendicular to the first rotation axis, with the connection portion located on one side and the connection portion located on the other side. In principle, the dividing plane can be any plane perpendicular to the first rotation axis between the aforementioned first and second planes.

[0021] A seal for sealing the first housing part and the second housing part with respect to the environment can also be provided at the location of this separating plane.

[0022] According to another preferred embodiment, the spring bar is mounted for translation in the spring tube, preferably slidably mounted, wherein the spring bar preferably comprises at least one bracket mounted for translation relative to the spring tube, preferably slidably mounted. Preferably, on a first side, the spring bar comprises a first bracket mounted for translation relative to the spring tube, and on a second side, the spring bar comprises a second bracket mounted for translation relative to the spring tube.

[0023] Advantageously, at least within the range of movement of the spring rod in the spring tube, the spring rod has a maximum outer diameter that is smaller than the minimum inner diameter of the spring tube. Advantageously, at least one bracket positions the spring rod at a distance from the spring rod, preferably concentrically. Consequently, a predetermined distance exists between the maximum outer diameter of the spring rod and the inner wall of the spring tube. In other words, the spring rod is preferably spaced a certain distance from the inner wall of the spring tube within the spring tube.

[0024] The spring rod can be prestressed relative to the spring tube by a spring element, thereby prestressing the spring rod relative to the spring tube. In particular, the spring element can be a compression spring disposed within the spring tube and extending radially outside and around the spring rod. In other words, the spring rod can pass through the compression spring. In yet other words, the spring element, for example in the form of a compression spring, can advantageously be configured as a coil spring that is pushed onto the spring rod.

[0025] The spring element can be stopped at one end by a stop on the spring tube and at its other end by a stop on the spring rod.

[0026] According to a preferred embodiment, a bracket (e.g., the first or second bracket described above) can form a stop for the spring element on the spring rod on the side of the spring element opposite the mounting unit. Thus, the spring element can be supported on the spring rod via the bracket in the longitudinal direction of the spring rod or spring tube. Furthermore, the other end of the spring element can be supported on the stop on the spring tube, for example, in the form of a notch in the spring tube. When the distance between the two stops in the longitudinal direction is less than the neutral length of the spring element, representing a stress-free state, the spring element can be prestressed.

[0027] The level of pretension provided by the spring element may be adjusted via an optional alignment unit which may be provided on the mounting unit.The alignment unit may eg be configured to change the distance of the third rotation axis relative to the first rotation axis.

[0028] The above object is also achieved by a support arm system for holding at least one medical instrument and / or lighting instrument having the features of claim 9. Advantageous further embodiments will become apparent from the present description and the accompanying drawings.

[0029] Therefore, a support arm system for holding at least one medical instrument and / or lighting instrument is proposed, comprising at least one spring arm device according to one of the present embodiments.

[0030] The advantages and effects described with respect to the spring arm arrangement are also obtained by the support arm system, so to avoid redundancy, a repeated description is omitted here. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Preferred further embodiments of the present invention will be described in more detail in the following description of the accompanying drawings, in which:

[0032] Figure 1 schematically shows a perspective side view of a support arm system with a spring arm arrangement;

[0033] Figure 2 Schematically shows Figure 1 Another perspective side view of the spring arm device;

[0034] Figure 3 Schematically shows Figure 1 a perspective side view of a sub-portion of a support arm system;

[0035] Figure 4 Schematically shows Figure 3 Another perspective side view of a sub-portion of;

[0036] Figure 5 A diagram schematically showing the range of rotation of a spring tube of a spring arm arrangement about a first axis of rotation; and

[0037] Figure 6 Schematically shows Figure 1 A perspective side view of a spring arm device with a point cloud of the holding area for the spring tube holding the appliance. DETAILED DESCRIPTION

[0038] Below will be described preferred exemplary embodiments with the aid of accompanying drawings.In this respect, the same or similar one or more elements with the same action will be provided with the same reference numerals in the various drawings, and in order to avoid redundancy, the repeated description of these elements will be partially omitted.

[0039] Figure 1 Schematically shown is a perspective side view of a support arm system 100 with a spring arm arrangement 1. The support arm system 100 is configured to hold a medical instrument (not shown) or alternatively a lighting instrument.

[0040] The spring arm device 1 comprises a spring tube 3 extending in a longitudinal direction 2. A spring rod 4 which can be displaced relative to the spring tube 3 in the longitudinal direction 2 is arranged inside the spring tube 3, as shown in FIG. Figure 2 On a first side, the spring tube 3 is rotatably arranged on the mounting unit 5 about a first, essentially horizontally oriented, rotational axis 21 , as shown in the assembled state of the spring arm arrangement in the deployed position.

[0041] Furthermore, the spring-arm arrangement 1 comprises a lever element 6 which is connected to the spring lever 4 for rotation about a second rotation axis 22 which is oriented parallel to the first rotation axis 21 and on a side thereof opposite the spring lever 4, and which is arranged on the mounting unit 5 for rotation about a third rotation axis 23 which is oriented parallel to the first rotation axis 21 and at a distance therefrom.

[0042] As in Figure 1 As can be seen in FIG, the lever element 6 is arranged radially outside the spring tube 3 with respect to the longitudinal direction 2 .

[0043] The spring rod 4 and the lever element 6 are connected to one another via a connecting piece 7, which is connected to the radial interior of the spring rod 4, i.e., inside the spring tube 3, and to the lever element 6 radially outside the spring tube 3. Here, the connecting piece 7 extends through a recess 8 in the form of an elongated hole extending in the longitudinal direction 2, which is provided in the spring tube 3.

[0044] At its end opposite the mounting unit 5, the spring tube 3 has a holding portion 9 in the form of a connection piece for connecting the device to be held. The term "holding" of the device should be understood here to mean that the device to be held is connected to the holding portion 9, wherein the weight of the device on the holding portion is transferred to the spring tube 3. The term "holding" here also includes the fact that another supporting arm (for example, another spring arm) or a holding device can be provided between the device and the spring tube.

[0045] Figure 2 Schematically shown from different viewing directions Figure 1 1 , wherein a portion of the spring tube 3 is cut away to provide a view of the interior of the spring tube 3 .

[0046] The spring rod 4 extends in the longitudinal direction 2 within the spring tube 3. At its end facing the mounting unit 5, the spring rod 4 comprises a first bracket 10 slidably mounted in the spring tube 3 for translation in the longitudinal direction 2. The connecting element 7 connected to the spring rod 4 extends in the region of the first bracket 10.

[0047] At the opposite side of the spring rod 4 , the spring rod 4 comprises a second bracket 11 slidably mounted to translate relative to the spring tube 3 .

[0048] On the side of the spring rod 4 opposite the mounting unit 5, a second bracket 11 forms a stop for a spring element 12, which is designed here as a compression spring and serves to prestress the spring rod 4 relative to the spring tube 3. On the other side, the spring element 12 is supported in a recess 13 in the spring tube 3. The distance between the second bracket 11 and the recess 13 in the longitudinal direction 2 is less than the neutral length of the spring element 12 in its unstressed state. The spring element 12 is thus prestressed.

[0049] The level of pretension can be adjusted via the alignment unit 14 on the mounting unit 5. The alignment unit 14 enables the distance of the third rotation axis 23 relative to the first rotation axis 21 to be varied. The pretension depends essentially on the lever length, i.e. the distance between the first rotation axis 21 and the third rotation axis 23.

[0050] Reference numeral 15 denotes a power cable extending from the mounting unit 5 to the holding portion 9 through the spring rod 4 configured as a hollow rod.

[0051] Watch by combination Figure 1 and Figure 2 It will be appreciated that the spring tube 3 comprises a fork-shaped connection region 16 for connection to the mounting unit 5 .

[0052] Figure 3 Schematically shows Figure 1Side view of a sub-section of the spring-arm device 1.

[0053] This view shows that in the direction of the first rotational axis 21, the lever element 6 is at a predetermined distance 24 from the spring tube 3, more precisely from the connection of the spring tube 3 to the mounting unit 5. Accordingly, the lever element 6 and the spring tube 3 can move past each other without colliding.

[0054] The mounting unit 5 is divided here into a joint part 18 in which the spring tube 3 and the lever element 6 are connected to the mounting unit 5 and a connecting part 19 which is connected to the joint part 18 and is configured as a journal for connecting the mounting unit 5 to a load-bearing structure, for example a ceiling, a wall or a floor of a room, or a support frame or a support arm.

[0055] Viewed in the direction of the first axis of rotation 21, the joint part 18 and the connecting part 19 are at a predetermined distance 25 relative to one another. This makes it possible to use a two-part housing (see Figure 4 ) can be provided between the joint part 18 and the connecting part 19 , the partition plane 26 being oriented perpendicularly to the first rotation axis 21 when viewed in the direction of the first rotation axis 21 .

[0056] In other words, relative to precisely one plane, here formed by the dividing plane 26 and oriented perpendicularly to the first axis of rotation, the connecting part 18 is located on a first side of the dividing plane 26, and the connecting part 19 is located on the other side of the dividing plane 26. The spring tube 3 and the lever element 6 and their connection are therefore also located completely and exclusively on the side of the connecting part 18.

[0057] Figure 4 Schematically shows Figure 3 , wherein the two-part housing 30 is also shown here.

[0058] The housing 30 seals the sealing connection part 18 and the passage for the power cable 15 from the environment in the region of the connection part 19 .

[0059] The housing 30 comprises a first housing part 31, which surrounds the joint section and is connected to the spring tube 3 in a rotationally fixed manner, and a second housing part 32, which is connected to the connecting section 19 in a rotationally fixed manner and surrounds the lower part of the connecting section 19. The first housing part 31 is rotatable relative to the second housing part 32 about the first rotation axis 21, wherein the first housing part follows the movement of the spring tube 3.

[0060] As already about Figure 3As described, when viewed in the direction of the first rotation axis 21, the separation plane 26 is located between the first housing part 31 and the second housing part 32, in the region between the joining portion 18 and the connecting portion 19. A seal for sealing the first housing part 31 and the second housing part 32 from the environment is provided at the location of the separation plane 26. Here, the seal is designed as a shaft-hub connection with a clearance fit between the housing parts 31, 32. The second housing part 32 is included in Figure 4 A straight cylindrical journal portion, not visible in the drawing, extends around the first rotation axis 21 and is accommodated in a straight cylindrical hub portion extending around the first rotation axis 21. The radially outer surface of the journal portion and the radially inner surface of the hub portion have a predetermined clearance fit.

[0061] In other words, with respect to exactly one dividing plane 26 oriented perpendicularly to the first rotational axis 21 , the first housing part 31 is located on a first side of the exactly one dividing plane 26 and the second housing part 32 is located on the other side of the exactly one dividing plane 26 .

[0062] As an alternative or in addition, the seal may also comprise a labyrinth seal and / or a sealing element, such as a sealing ring.

[0063] Figure 5 Schematically shows Figure 1 The spring arm device 1 of the spring tube 3 around the first rotation axis 21 of the rotation range. The first rotation axis 21 is essentially horizontal in orientation. Figure 5 As can be seen from Figure 5 In the horizontal position shown, the spring tube 3 covers a rotation range of 40° against gravity (ie upwards). The spring tube 3 can be rotated downward through the vertical direction so that the rotation range against gravity from the horizontal direction is also 40° on the other side.

[0064] Overall, in the spring arm arrangement 1 , the rotation angle 28 of the spring tube 3 around the first rotation axis 21 is optionally 260°.

[0065] The 40° and 260° rotation ranges mentioned here are examples only, and the spring arm device is not limited to these rotation ranges. Depending on the application and requirements, they can have other values. In addition, the rotation range relative to the vertical direction can be different on one side compared to the other.

[0066] Figure 6 Schematically shows Figure 5A perspective side view of the spring arm device 1 with a point cloud 29 for the holding area 9 of the spring tube 3. The spring arm device 1 can be rotated about the vertical rotation axis 27. This results in a point cloud 29, i.e. the sum of all points that the holding area 9 can reach based on the range of movement of the spring arm device 1, i.e. the sum of all points from Figure 5 The rotation range around the vertical rotation axis 27 consists of segments of a sphere.

[0067] Where applicable, all individual features shown in the exemplary embodiments may be combined and / or exchanged without departing from the scope of the present invention.

[0068] Reference Signs List

[0069] 1 Spring arm device

[0070] 2 Vertical direction

[0071] 3 spring tube

[0072] 4 spring rods

[0073] 5 installation units

[0074] 6 lever elements

[0075] 7 Connectors

[0076] 8 recesses

[0077] 9. Keep part

[0078] 10 First bracket

[0079] 11 Second bracket

[0080] 12 spring elements

[0081] 13 notches

[0082] 14 alignment units

[0083] 15 Power Cable

[0084] 16 connection areas

[0085] 18 connector part

[0086] 19 connection part

[0087] 21 first rotation axis

[0088] 22 second rotation axis

[0089] 23 third rotation axis

[0090] 24 distance

[0091] 25 distance

[0092] 26 separation planes

[0093] 27 Rotation axis

[0094] 28 rotation angles

[0095] 29 point clouds

[0096] 30 shell

[0097] 31 first housing part

[0098] 32 second housing part

[0099] 100 support arm system

Claims

1. A spring arm device (1) for a support arm system (100), the support arm system (100) being used to hold a medical device and / or a lighting device, the spring arm device (1) comprising: A spring tube (3) is arranged on a mounting unit (5) so as to rotate about a first rotation axis (21); a spring rod (4) is at least partially arranged in the interior of the spring tube (3) and is displaceable relative to the spring tube (3) in a longitudinal direction (2) of the spring tube (3); and a lever element (6) is connected to the spring rod (4) so ​​as to rotate about a second rotation axis (22) oriented parallel to the first rotation axis (21), and the lever element (6) is arranged on the mounting unit (5) at an end of the lever element (6) opposite to the spring rod (4) so ​​as to rotate about a third rotation axis (23), the third rotation axis (23) being spaced apart from the first rotation axis (21) and oriented parallel to the first rotation axis (21), Its characteristics are: The lever element (6) is arranged radially outside the spring tube (3) relative to the longitudinal direction (2) of the spring tube (3).

2. The spring arm device (1) according to claim 1, characterized in that The spring rod (4) and the lever element (6) are connected to one another via a connecting piece (7), wherein the connecting piece (7) is connected to the spring rod (4) radially inside the spring tube (3) and to the lever element (6) radially outside the spring tube (3).

3. The spring arm device (1) according to claim 2, characterized in that The connecting piece (7) extends through a recess (8) provided in the spring tube (3).

4. The spring arm device (1) according to claim 3, characterized in that The recess (8) is an elongated hole oriented in the longitudinal direction (2), wherein the connecting element (7) is movable along the elongated hole in the longitudinal direction (2).

5. Spring-arm device (1) according to one of the preceding claims, characterized in that In the direction of the first rotation axis (21), the lever element (6) is at a predetermined distance (24) from the spring tube (3), in particular from a connection region (16) connecting the spring tube (3) to the mounting unit (5).

6. Spring-arm device (1) according to one of the preceding claims, characterized in that The spring rod (4) is configured as a hollow rod.

7. A spring-arm device (1) according to any one of the preceding claims, characterized in that The mounting unit (5) comprises a joint portion (18) in which the spring tube (3) and the lever element (6) are connected to the mounting unit (5); and a connecting portion (19) for connecting the mounting unit (5) to a load-bearing structure, preferably to a ceiling, a wall or a floor of a room, or a support frame or a support arm, wherein, in the direction of the first rotation axis (21), the joint portion (18) and the connecting portion (19) are at a predetermined distance (25) relative to each other.

8. Spring-arm device (1) according to one of the preceding claims, characterized in that The connecting part (19) is configured as a journal.

9. The spring arm device (1) according to claim 7 or claim 8, characterized in that A first housing part (31) connected to the spring tube (3) surrounds the joint part (18), and a second housing part (32) connected to the connecting part (19) surrounds at least a portion of the connecting part (19), wherein, viewed in the direction of the first rotational axis (21), a dividing plane (26) between the first housing part (31) and the second housing part (32) is oriented perpendicular to the first rotational axis (21) in the region between the joint part (18) and the connecting part (19).

10. The spring-arm device (1) according to any one of the preceding claims, characterized in that A seal for sealing the first housing part (31) and the second housing part (32) relative to the environment is arranged at the location of the separation plane (26).

11. The spring arm device (1) according to claim 9 or claim 10, characterized in that The first housing part (31) is connected to the spring tube (3) in a rotationally fixed manner, and / or the second housing part (32) is connected to the connecting part (19) in a rotationally fixed manner.

12. Spring-arm device (1) according to one of the preceding claims, characterized in that The spring rod (4) is mounted to translate in the spring tube (3), preferably to be slidingly mounted.

13. Spring-arm device (1) according to the preceding claim, characterized in that The spring rod (4) comprises at least one bracket (10, 11) which is mounted, preferably slidingly mounted, for translation relative to the spring tube (3).

14. The spring arm device (1) according to claim 12 or claim 13, characterized in that On a first side, the spring rod (4) comprises a first bracket (10) mounted for translation relative to the spring tube (3), and on a second side, the spring rod comprises a second bracket (11) mounted for translation relative to the spring tube (3).

15. A support arm system (100) for holding at least one medical device and / or lighting device, comprising at least one spring arm device (1) according to one of the preceding claims.

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