Spring arm device and support arm system for holding a medical appliance and / or lighting appliance
Patent Information
- Application Number
- EP2024703227
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-02-15
- Filing Date
- 2024-02-08
- Publication Date
- 2025-12-24
AI Technical Summary
Conventional spring arm devices for support arm systems in medical settings have limited pivoting ranges and require excessive effort to adjust positions against gravity, especially when holding medical devices or lighting equipment.
A spring arm device with a spring tube and lever element arranged radially outside the spring tube, allowing for a significantly increased pivoting range without collision, and a connecting part that enables free movement while transmitting forces and moments through a rotary bearing, along with a hollow rod for media or power supply.
The solution provides a spring arm device with a greatly enhanced pivoting range and reduced effort required for adjusting positions, enabling comfortable and secure holding of medical devices or lighting equipment, while maintaining structural simplicity and allowing for media or power supply through the hollow rod.
Smart Images
Figure EP2024053260_22082024_PF_FP
Abstract
Description
[0001] GRAF VON STOSCH PATENTANWALTSGESELLSCHAFT MBH Our Ref. Date ON01P146EP February 8, 2024 Applicant: 5 Ondal Medical Systems GmbH Spring arm device and support arm system for holding a medical device and / or a lighting device 10 Technical field The present invention relates to a spring arm device for a support arm system for holding a medical device and / or a lighting device, and to a support arm system for holding a medical device and / or a lighting device. State of the art 15 Support arm systems are used, for example, in operating rooms for the spatially relocatable holding of a medical device or a medical device. For example, a support arm can be movably anchored to a ceiling, wall, or floor by means of a bearing arrangement. Fastening to a frame with casters is also possible.A support arm system designed to hold medical devices can also be referred to as a medical support system. Support arm systems typically have at least one axis of movement so that the supported medical device, which can also be referred to as a medical device and may include, for example, a lighting device such as a surgical lamp, a monitor, examination equipment, one or more injectors, surgical instruments, or dental drills, can be moved according to the respective requirements. The support that enables the movement can also be referred to as an articulated device or support arm articulated device, which can also include a support arm. This allows the medical device to be moved into a comfortable and safe position for performing the respective medical procedures and monitoring.The spatial relocation of medical devices is essential in many medical procedures in order to facilitate the work of medical personnel or to enable it at all. However, by pivoting a support arm, a lever arm can be changed with respect to its mounting. In particular, when pivoting the support arm around a substantially horizontal axis, which allows the height of the medical device held on it to be changed, a lever arm of the weight of the medical device is changed with respect to the attachment or mounting of the support arm. Nevertheless, it is desired that the medical device remain in a position set by pivoting the support arm, and that an adjustment of the position of the medical device, particularly against gravity, should be possible without excessive effort from the operator. For this purpose, spring-balanced support arms, in this case as spring arms orSpring arm devices are used. Two arm elements are provided that are movable relative to one another and support each other via a spring. By pivoting the spring arm, the lever arm of the spring force changes correspondingly to the lever arm 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 pivoting, which also allows a corresponding support force to be changed. Such support arm systems and spring arm devices can be found, for example, in EP 1478872 A1.Spring arm devices generally comprise a spring tube arranged on a fastening unit so as to be rotatable about a mostly horizontal axis of rotation, a spring rod arranged at least partially inside the spring tube and displaceable relative to the spring tube, and a lever element which is rotatably connected to the spring rod at one end inside the spring tube and rotatably arranged on the fastening unit at the other end. Description of the invention Based on the known prior art, it is an object of the present invention to provide an improved spring arm device for a support arm system for holding a medical device and / or a lighting device, as well as a corresponding support arm system for holding a medical device and / or a lighting device. In particular, a spring arm device with a comparatively large range of motion is to be provided.The object is achieved by a spring arm device for a support arm system for holding a medical device and / or a lighting device with the features of claim 1. Advantageous further developments emerge from the subclaims, the description and the figures.Accordingly, a spring arm device for a support arm system for supporting a medical device and / or a lighting device is proposed, comprising a spring tube arranged on a fastening unit so as to be rotatable about a first axis of rotation, a spring rod arranged at least partially inside the spring tube and displaceable relative to the spring tube in the longitudinal direction of the spring tube, and a lever element which is connected to the spring rod so as to be rotatable about a second axis of rotation oriented parallel to the first axis of rotation and is arranged on its side opposite the spring rod so as to be rotatable about a third axis of rotation spaced from the first axis of rotation and oriented parallel to the first axis of rotation. In the proposed spring arm device, the lever element is arranged radially outside the spring tube with respect to the longitudinal direction of the spring tube.As a result, the pivoting range of the spring tube about the first axis of rotation is not restricted, in contrast to spring arm devices according to the prior art, in which the lever element extends into the interior of the spring tube and is connected there to the spring rod, and the range of motion is limited by the collision points between the lever element and the inside of the spring tube. Rather, the arrangement of the lever element radially outside the spring tube allows the spring tube and the lever element to pivot essentially freely relative to each other without this leading to a collision between the lever element and the spring tube. The possible pivot angle of the spring tube about the first axis of rotation is therefore essentially limited only by the connection of the spring tube to the fastening unit, but not by the lever element.Accordingly, the spring arm device according to the invention has a greatly increased pivoting range around the first rotational axis compared to conventional spring arm devices according to the prior art. 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 thus designed and constructed for the spatially displaceable support of a medical device or a medical device, for example, a medical lighting device. In this document, a rotatable bearing is understood in particular to mean that only a rotational movement of the rotatably mounted components relative to one another about the respective rotational axis is possible. In particular, compressive and tensile forces as well as moments that do not act about the rotational axis are transmitted by the pivot bearing. The spring rod and the pivot element are preferably connected to one another via a connecting part.The connecting part is preferably connected to the spring rod radially inside the spring tube, thus generally inside the spring tube, and to the lever element radially outside the spring tube. The connecting part preferably extends in the direction of the second axis of rotation and / or preferably through a recess provided in the spring tube from the inside of the spring tube to radially outside the spring tube. "Radially inside" is understood here to mean the region which, with respect to the longitudinal direction of the spring tube, has an extension transverse to the longitudinal direction that is less than or equal to the inner radius of the spring tube or its inner surface in the case of non-circular spring tubes. The term "radially outside" describes any region which, with respect to the longitudinal direction of the spring tube, has an extension transverse to the longitudinal direction that is greater than the outer radius of the spring tube or its outer surface in the case of non-circular spring tubes.It has proven advantageous if the recess is a longitudinally oriented elongated hole, wherein the connecting part is movable longitudinally along the elongated hole. According to a preferred embodiment, the lever element has a predetermined distance from the spring tube in the direction of the first axis of rotation, in particular from a connection or connection area of the spring tube to the fastening unit. This ensures that the lever element and the spring tube do not collide when the spring tube pivots about the first axis of rotation. If the spring rod is designed as a hollow rod, at least one supply channel, for example a media supply, such as compressed air, oxygen or nitrogen, and / or a power and / or data supply, for a medical device and / or a lighting device attached to the spring arm device can be arranged through the interior of the hollow rod.According to a preferred embodiment, the fastening unit comprises a joint section, in which the spring tube and the lever element are connected to the fastening unit, and further comprises a connecting section, preferably designed as a pin, for connecting the fastening unit to a supporting structure, preferably a ceiling, a wall, or a floor of a room, or a support frame or support arm, wherein the joint section and the connecting section are spaced apart by a predetermined distance in the direction of the first axis of rotation. Due to this spatial separation or spacing of the connecting section and the joint section, the spring arm device, and in particular a housing for enclosing at least the joint section, can have a comparatively simple structure.In other words, with respect to a plane oriented perpendicular to the first axis of rotation, the joint section lies on a first side of the plane and the connection section lies on the other side of the plane. The spring tube and the lever element and their connections are therefore located completely and exclusively on the side of the joint section. This allows the spring tube to be moved past the connection section relative to the connection section without colliding with it. This can be achieved structurally by the specified distance between the joint section and the connection section in the direction of the first axis of rotation. In other words, the specified distance exists between a first plane oriented perpendicular to the first axis of rotation and a second plane oriented perpendicular to the first axis of rotation. The first plane is defined by the point of the joint section closest to the connection section, including the connected spring tube.The second plane is correspondingly defined by the point of the connection section closest to the joint section. The lever element is advantageously arranged opposite the connection section with respect to the spring tube. A first housing part is preferably provided, which is preferably connected in a rotationally fixed manner to the spring tube and encloses the joint section. Furthermore, a second housing part is preferably provided, which is preferably connected in a rotationally fixed manner to the connection section and preferably encloses at least part of the connection section. A parting plane between the first housing part and the second housing part can be oriented perpendicular to the first axis of rotation and—viewed in the direction of the first axis of rotation—can be arranged in a region between the joint section and the connection section.In other words, with respect to the plane oriented perpendicular to the first axis of rotation, exactly one parting plane contains the first housing part on a first side of the exactly one parting plane, and the second housing part on the other side of the parting plane. The first housing part therefore lies completely and exclusively on the side of the joint section, and the second housing part therefore lies completely and exclusively on the side of the connection section. The parting plane can be designated as, or coincide with, the aforementioned plane oriented perpendicular to the first axis of rotation, on the first side of which the joint section is arranged and on the other side of which the connection section is arranged. The parting plane can, in principle, be any plane perpendicular to the first axis of rotation between the aforementioned first plane and the second plane.At the level of this parting plane, a seal for sealing the first housing part and the second housing part against the environment can be arranged. According to a further preferred embodiment, the spring rod is translationally mounted, preferably slide-mounted, in the spring tube, wherein the spring rod preferably comprises at least one slide mounted, preferably slide-mounted, translationally relative to the spring tube. Preferably, the spring rod comprises, on a first side, a first slide mounted translationally relative to the spring tube and, on a second side, a second slide mounted translationally relative to the spring tube. The spring rod advantageously has a maximum outer diameter that is smaller than a minimum inner diameter of the spring tube, at least in the range of movement of the spring rod in the spring tube.The spring rod is advantageously positioned at a distance, preferably concentrically, from the spring rod by the at least one slide. A distance of a predetermined size therefore 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 positioned in the spring tube at a distance from the inner wall of the spring tube. The spring rod can be preloaded relative to the spring tube by a spring element for preloading the spring rod relative to the spring tube. The spring element can, in particular, be a compression spring arranged inside the spring tube and extending radially outside the spring rod around it. In other words, the spring rod can extend through the compression spring. In other words, the spring element, for example in the form of a compression spring, advantageously designed as a spiral spring, can be pushed onto the spring rod.The spring element can abut against a stop on the spring tube at one end and against a stop on the spring rod at its other end. According to a preferred embodiment, a slide, for example the first or second slide described above, can represent a stop for the spring element on the spring rod on a side opposite the fastening unit with respect to the spring element. The spring element can thus be supported via the slide on the spring rod in the longitudinal direction of the spring rod or spring tube. The spring element can also be supported at its other end against a stop on the spring tube, for example in the form of an indentation in the spring tube. If a distance in the longitudinal direction between the two stops is less than a zero length of the spring element, which it has in a relaxed state, the spring element can be preloaded.The magnitude of the preload provided by the spring element can be adjusted via an optional adjustment unit that can be arranged on the fastening unit. The adjustment unit can, for example, be designed to change the distance of the third axis of rotation relative to the first axis of rotation. The above-stated object is further achieved by a support arm system for holding at least one medical device and / or a lighting device with the features of claim 9. Advantageous further developments emerge from the present description and the figures. Accordingly, a support arm system for holding at least one medical device and / or a lighting device is proposed, which comprises at least one spring arm device according to one of the preceding embodiments.The advantages and effects described with regard to the spring arm device are also achieved by the support arm system, which is why their repeated description is omitted here to avoid redundancies. Brief Description of the Figures Preferred further embodiments of the invention are explained in more detail in the following description of the figures.The drawings show: Figure 1 schematically a perspective side view of a support arm system with a spring arm device; Figure 2 schematically a further perspective side view of the spring arm device from Figure 1; Figure 3 schematically a perspective side view of a partial area of the support arm system from Figure 1; Figure 4 schematically a further perspective side view of the partial area from Figure 3; Figure 5 schematically a representation of a pivoting area of a spring tube of the spring arm device about a first axis of rotation; and Figure 6 schematically a perspective side view of the spring arm device from Figure 1 with a point cloud of a holding area of the spring tube for holding a device. Detailed description of preferred exemplary embodiments Preferred exemplary embodiments are described below with reference to the figures.Identical, similar, or equivalent elements in the different figures are provided with identical reference numerals, and a repeated description of these elements is partially omitted to avoid redundancies. Figure 1 schematically shows a perspective side view of a support arm system 100 with a spring arm device 1. The support arm system 100 is designed to hold a medical device (not shown) or, alternatively, a lighting device. The spring arm device 1 comprises a spring tube 3 extending in a longitudinal direction 2. Arranged inside the spring tube 3 is a spring rod 4 that is displaceable in the longitudinal direction 2 relative to the spring tube 3, as explained in more detail with regard to Figure 2. The spring tube 3 is arranged on a first side on a fastening unit 5 so as to be rotatable about a first axis of rotation 21, which in the present case is oriented substantially horizontally in an installed state of the spring arm device at the site of use.The spring arm device 1 further comprises a lever element 6, which is rotatably connected to the spring rod 4 about a second rotational axis 22 oriented parallel to the first rotational axis 21, and is arranged on the fastening unit 5 on its side opposite the spring rod 4 about a third rotational axis 23 spaced from the first rotational axis 21 and oriented parallel to the first rotational axis 21. As can be seen from Figure 1, the lever element 6 is arranged radially outside the spring tube 3 with respect to the longitudinal direction 2. The spring rod 4 and the lever element 6 are connected to one another via a connecting part 7, which is connected radially inside, i.e., in the interior, of the spring tube 3 to the spring rod 4 and radially outside the spring tube 3 to the lever element 6. In the present case, the connecting part 7 extends through a recess 8 provided in the spring tube 3 in the form of an elongated hole extending in the longitudinal direction 2.At its end opposite the fastening unit 5, the spring tube 3 has a holding section 9 in the form of a connection for attaching a device to be held. Holding a device is understood here to mean that the device to be held is attached to the holding section 9 by transferring the weight of the device at the holding section to the spring tube 3. "Holding" here also includes the arrangement of an additional support arm, for example, an additional spring arm, or a holding device between the device and the spring tube. Figure 2 schematically shows a perspective side view of the spring arm device from Figure 1 from a different viewing direction, with a portion of the spring tube 3 shown cut away to reveal the interior of the spring tube 3. The spring rod 4 extends in the longitudinal direction 2 inside the spring tube 3.At its end facing the fastening unit 5, it comprises a first slide 10, which is slide-mounted in the spring tube 3 in a translational manner in the longitudinal direction 2. The connecting element 7 connected to the spring rod 4 extends in the region of the first slide 10. On its opposite side, the spring rod 4 comprises a second slide 11, which is slide-mounted in a translational manner relative to the spring tube 3. On the side of the spring rod 4 opposite the fastening unit 5, the second slide 11 represents a stop for a spring element 12, here designed as a compression spring, for pretensioning the spring rod 4 relative to the spring tube 3. The spring element 12 is supported on the other side by an indentation 13 in the spring tube 3. The distance in the longitudinal direction 2 between the second slide 11 and the indentation 13 is less than a zero length of the spring element 12, which it has in a relaxed state.The spring element 12 is thus preloaded. The magnitude of the preload can be adjusted via an adjustment unit 14 on the fastening unit 5. The adjustment unit 14 makes it possible to change the distance of the third axis of rotation 23 relative to the first axis of rotation 21. The preload is essentially dependent on the lever length, i.e., the distance between the first axis of rotation 21 and the third axis of rotation 23. Reference numeral 15 denotes a power cable that extends from the fastening unit 5 through the spring rod 4, designed as a hollow rod, to the holding section 9. As can be seen from a view of Figures 1 and 2 together, the spring tube 3 comprises a fork-shaped connection area 16 for connection to the fastening unit 5. Figure 3 schematically shows a side view of a portion of the spring arm device 1 from Figure 1.From this view, it can be seen that the lever element 6 has a predetermined distance 24 from the spring tube 3 in the direction of the first rotation axis 21, more precisely from the connection of the spring tube 3 to the fastening unit 5. Accordingly, it is possible for the lever element 6 and the spring tube 3 to move past each other without colliding. The fastening unit 5 is divided into a joint section 18, in which the spring tube 3 and the lever element 6 are connected to the fastening unit 5, and a connecting section 19, connected to the joint section 18 and designed as a pin, for connecting the fastening unit 5 to a supporting structure, for example a ceiling, a wall or a floor of a room, or a support frame or support arm. The joint section 18 and the connecting section 19 have a predetermined distance 25 from each other in the direction of the first rotation axis 21.This makes it possible to provide a parting plane 26 oriented perpendicular to the first axis of rotation 21 for a two-part housing (see Figure 4) - viewed in the direction of the first axis of rotation 21 - between the joint section 18 and the connection section 19. In other words, with respect to exactly one plane oriented perpendicular to the first axis of rotation, which here represents the parting plane 26, the joint section 18 lies on a first side of the parting plane 26 and the connection section 19 lies on the other side of the parting plane 26. The spring tube 3 and the lever element 6 and their connections are therefore also located completely and exclusively on the side of the joint section 18. Figure 4 shows a schematic perspective side view of the partial area from Figure 3, wherein a two-part housing 30 is also shown here. The housing 30 encloses the joint section 18 as well as the passage of the power cable 15 in the area of the connection section 19 against the environment.The housing 30 comprises a first housing part 31 which is connected in a rotationally fixed manner to the spring tube 3 and encloses the joint section, and a second housing part 32 which is connected in a rotationally fixed manner to the connection section 19 and encloses a lower part of the connection section 19. The first housing part 31 is pivotable relative to the second housing part 32 about the first axis of rotation 21, wherein the first housing part follows the movements of the spring tube 3. As already described in relation to Figure 3, the parting plane 26 between the first housing part 31 and the second housing part 32 lies in a region between the joint section 18 and the connection section 19, as viewed in the direction of the first axis of rotation 21. A seal for sealing the first housing part 31 and the second housing part 32 against the environment is arranged at the level of the parting plane 26. The seal is designed as a shaft-hub connection with a clearance fit between the housing parts 31, 32.The second housing part 32 comprises a pin section (not visible in Figure 4) extending in a circular cylindrical manner around the first axis of rotation 21, which is received in a hub section extending in a circular cylindrical manner around the first axis of rotation 21. The radial outer surface of the pin section and the radial inner surface of the hub section have a predetermined clearance fit. In other words, with respect to the parting plane 26 oriented perpendicular to the first axis of rotation 21, the first housing part 31 lies on a first side of the parting plane 26, and the second housing part 32 lies on the other side of the parting plane 26. Alternatively or additionally, the seal can also comprise a labyrinth seal and / or a sealing element, for example, a sealing ring. Figure 5 shows a schematic representation of a pivoting range of the spring tube 3 of the spring arm device 1 from Figure 1 around the first axis of rotation 21.The first rotation axis 21 is oriented essentially horizontally in this case. As can be seen from Figure 5, the spring tube 3, from a horizontal position as shown in Figure 5, has a pivoting range of 40° against the acceleration of gravity, i.e., upwards. The spring tube 3 can pivot at the bottom above the vertical, so that the pivoting range from the horizontal against the acceleration of gravity on the other side is also 40°. Overall, the spring arm device 1 results in a pivot angle 28 of the spring tube 3 about the first rotation axis 21 of optionally 260°. The aforementioned pivoting ranges of 40° and 260° are merely examples, and the spring arm device is not limited to these pivoting ranges. They can have different values depending on the application and requirements. The pivoting range relative to the vertical can also be designed differently on one side than on the other.Figure 6 shows a schematic perspective side view of the spring arm device 1 from Figure 5 with a point cloud 29 of the holding area 9 of the spring tube 3. The spring arm device 1 is designed to pivot about a vertical axis of rotation 27. Accordingly, the point cloud 29, i.e. the sum of all points reachable by the holding area 9 due to the range of motion of the spring arm device 1, results in a spherical segment composed of the pivoting area from Figure 5, rotating about the vertical axis of rotation 27. Where applicable, all individual features shown in the exemplary embodiments can be combined and / or exchanged without departing from the scope of the invention.
[0002] List of reference symbols 1 Spring arm device 2 Longitudinal direction 3 Spring tube 4 Spring rod 5 Fastening unit 6 Lever element 7 Connecting part 8 Recess 9 Holding section 10 First slide 11 Second slide 12 Spring element 13 Indentation 14 Adjustment unit 15 Power cable 16 Connection area 18 Joint section 19 Connection section 21 First axis of rotation 22 Second axis of rotation 23 Third axis of rotation 24 Distance 25 Distance 26 Parting plane 27 Axis of rotation 28 Pivot angle 29 Point cloud 30 Housing 31 First housing part 32 Second housing part 100 Support arm system 5
Claims
Claim^ 1. Spring arm device (1) for a support arm system (100) for holding a medical device and / or a lighting device, comprising a spring tube (3) arranged on a fastening unit (5) so as to be rotatable about a first axis of rotation (21), a spring rod (4) arranged at least partially inside the spring tube (3) and displaceable in the longitudinal direction (2) of the spring tube (3) relative to the spring tube (3), and a lever element (6) which is connected to the spring rod (4) so as to be rotatable about a second axis of rotation (22) oriented parallel to the first axis of rotation (21) and is arranged on its side opposite the spring rod (4) so as to be rotatable about a third axis of rotation (23) spaced from the first axis of rotation (21) and oriented parallel to the first axis of rotation (21), characterized in that the lever element (6) is arranged radially outside the spring tube (3) with respect to the longitudinal direction (2) of the spring tube (3). is arranged. 2.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 part (7), wherein the connecting part (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. Spring arm device (1) according to claim 2, characterized in that the connecting part (7) extends through a recess (8) provided in the spring tube (3).
4. 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 part (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 the lever element (6) has a predetermined distance (24) from the spring tube (3) in the direction of the first rotation axis (21), in particular from a connection area (16) of the spring tube (3) to the fastening unit (5).
6. Spring arm device (1) according to one of the preceding claims, characterized in that the spring rod (4) is designed as a hollow rod.
7. Spring arm device (1) according to one of the preceding claims, characterized in that the fastening unit (5) comprises a joint section (18) in which the spring tube (3) and the lever element (6) are connected to the fastening unit (5), and a connection section (19) for connecting the fastening unit (5) to a supporting structure, preferably a ceiling, a wall, or a floor of a room, or a support frame or support arm, wherein the joint section (18) and the connection section (19) are spaced a predetermined distance (25) from one another in the direction of the first axis of rotation (21).
8. Spring arm device (1) according to the preceding claim, characterized in that the connection section (19) is designed as a pin. 9.Spring arm device (1) according to claim 7 or 8, characterized in that a first housing part (31) connected to the spring tube (3) encloses the joint section (18), and a second housing part (32) connected to the connection section (19) encloses at least part of the connection section (19), wherein a parting plane (26) between the first housing part (31) and the second housing part (32) is arranged, as viewed in the direction of the first axis of rotation (21), in a region between the joint section (18) and the connection section (19) perpendicular to the first axis of rotation (21).
10. Spring arm device (1) according to the preceding claim, characterized in that a seal for sealing the first housing part (31) and the second housing part (32) against the environment is arranged at the height of the parting plane (26). 11.Spring arm device (1) according to claim 9 or 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 connection section (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 translationally mounted, preferably slide-mounted, in the spring tube (3).
13. Spring arm device (1) according to the preceding claim, characterized in that the spring rod (4) comprises at least one slide (10, 11) translationally mounted, preferably slide-mounted, relative to the spring tube (3).
14. Spring arm device (1) according to claim 12 or 13, characterized in that the spring rod (4) has a first side opposite the spring tube (3). comprises a translationally mounted first carriage (10) and, on a second side, a second carriage (11) translationally mounted relative to the spring tube (3).
15. Support arm system (100) for holding at least one medical device and / or a lighting device, comprising at least one spring arm device (1) according to one of the preceding claims.