Electric positioning arm

Abstract

The present invention relates to a motorized positioning arm (1000) for positioning instruments, particularly medical instruments. The motorized positioning arm (1000) comprises at least two arm elements (1100a, 1100b) pivotally connected to one another about a pivot axis by a central joint (1001). At least one of the arm elements (1100a, 1100b) comprises an additional joint (1110a, 1110b) at an end (1120a, 1120b) opposite the central joint (1001). The motorized positioning arm (1000) comprises a blocking mechanism (1200) for blocking and unlocking the central joint (1001) and the at least one additional joint (1110a, 1110b). The blocking mechanism 1200 includes a central shaft 1210 arranged coaxially with the pivot axis and at least one transmission device 1220 from the central shaft 1210 to at least one additional joint 1110a, 1110b. The blocking mechanism 1200 includes an electric blocking device 1230 configured to engage the central shaft 1210 to enable blocking and unblocking of the joints 1001, 1110a, 1110b. The electric blocking device 1230 is configured to move along the central shaft 1210.

Description

Technical Field

[0001] The present invention relates to an electric positioning arm for positioning an instrument, particularly a medical instrument.

Background Art

[0002] Various positioning arms with various requirements are known from the prior art for various applications. Particularly in the case of a positioning arm for positioning a medical instrument, for example, the requirements for the stability, reliability, and operability of the positioning arm are very high. Therefore, in the prior art, numerous attempts have been made to develop and improve positioning systems taking these requirements into consideration.

[0003] For example, a positioning arm having a rotating body or a swivel joint and two arm elements pivotable with respect to it is known from Patent Document 1. Here, the angle between the two arm elements can be fixed by a ratchet attached to the rotating body via a coupling, and the coupling is provided with a switch that fixes the angular positions of the arms relative to each other at the switch position.

[0004] The positioning arm known from Patent Document 1 has the advantage that the rotary joint of the positioning arm can be fixed, i.e., blocked, with a simple and relatively small force by a ratchet. Particularly, the ratchet can be easily operated even in a sterile environment, for example, even under a sterile cover sheet. Furthermore, since a certain minimum torque can be set by the ratchet, the blocking of the positioning arm can be surely performed.

[0005] However, the positioning arm known from Patent Document 1 still suffers from the drawback that its operation is always dependent on the user. Therefore, if the user does not operate the ratchet correctly and the arm shifts during surgery, a residual risk remains during use. Furthermore, its ergonomics or ease of use are still not optimal. For example, when positioning the positioning arm, the user must simultaneously hold an instrument at the end of the positioning arm and keep their eyes on the surgical field. Such simultaneous actions are very difficult for the user, especially since a relatively large force must be applied when fixing the arm, and the rotational motion when turning the ratchet may be in the opposite direction to the movement of the other hand. Moreover, since the position of the positioning arm must be changed frequently before, during, and after the procedure, i.e., multiple releases and locks are required, a faster operating option is desirable. Furthermore, when using sterile drapes, the ratchet must move under and within the sterile drape, which is inconvenient and may lead to wear and damage to the drape. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2017 / 144172A1 [Overview of the project] [Problems that the invention aims to solve]

[0007] Based on the prior art described above, the object of the present invention is to provide a positioning arm that overcomes the problems and drawbacks of systems known from the prior art and has corresponding advantages over those systems. In particular, the object is to provide a positioning arm that enables ergonomic, comfortable, and fast operation that is largely independent of the user, even through a sterile drape. [Means for solving the problem]

[0008] The above objective is addressed by the subject matter of independent claim 1. Further possible embodiments of the present invention are specified in particular in the dependent claims. The solution of the present invention is to provide an electric positioning arm for positioning instruments, in particular medical instruments. The electric positioning arm comprises at least two arm elements pivotably connected to one another about a pivot axis by a central joint, at least one of the arm elements having an additional joint at the end opposite to the central joint, the electric positioning arm comprises a blocking mechanism for blocking and unlocking the central joint and at least one additional joint, the blocking mechanism comprising a central axis positioned coaxially with the pivot axis and at least one transmission device from the central axis to at least one additional joint, the blocking mechanism comprises an electric blocking device configured to engage with the central axis to enable blocking and unlocking of the joint, preferably the electric blocking device is configured to move along the central axis.

[0009] In particular, electric positioning arms are used to reliably, that is, safely and accurately, position or hold medical instruments during patient procedures. Reliable positioning of such instruments, such as surgical hooks, endoscopes, or needles, is essential during surgical or biopsy procedures. Electric positioning arms allow for electric fixation of joints. The movement or positioning of the positioning arm itself can be performed entirely manually.

[0010] When using an electric positioning arm to position medical instruments, for example, one of the arm elements may be configured to connect to a clamping device on the operating table via an additional joint. The other arm element may be configured to connect to an instrument holder via an additional joint accordingly. The instrument holder is preferably configured as a clamping connection. In this way, medical instruments can be clamped to the instrument holder from the outside without damaging the sterile drape surrounding the electric positioning arm.

[0011] The central shaft, which is configured coaxially with the pivot axes of the two arm elements, may have threads. For example, the central shaft may be a clamp bolt. For example, the transmission device may include at least one clamp sleeve positioned on the central shaft. The clamp sleeve may be configured as a threaded sleeve that screws onto the threads of the central shaft, or it may be axially slidable on the central shaft.

[0012] The transmission device may further comprise a push rod extending axially within the arm element, which is operably connected to a clamp sleeve so that the transmission device can fix, i.e., block, an additional joint at the end of the arm element. For this purpose, the clamp sleeve may comprise an inclined rolling surface on which a transmission body, such as a ball, is mounted. Alternatively, the clamp sleeve may comprise a joint socket into which a cam, for example, positioned on the transmission body, is inserted. Generally speaking, the transmission device can be used to transmit the axial movement of the central axis to the axial movement of the push rod. This causes the axial movement of the push rod to block the corresponding joint at the end of the arm element.

[0013] Blocking with a block device is primarily electrically powered, but manual blocking or release of joints may also be possible. Therefore, the block device can also be operated without electricity. The electrical energy required to operate the block device is preferably supplied by an accumulator. This eliminates the need for wiring in the operating room, which could be a source of risk.

[0014] The above objectives are fully achieved by the electric positioning arm according to the present invention. As an electric drive unit or actuator, the electric blocking device is very convenient and particularly easy to operate through a sterile drape. When using an electric drive unit, elements such as ratchets do not need to move under the sterile drape. In addition to simplifying operation, it also reduces wear on the sterile drape. Furthermore, the operation is configured to be at least substantially user-independent. In contrast to manual blocking devices, the blocking mechanism here cannot be adjusted very loosely, so the electric positioning arm is always sufficiently stable and does not shift during operation. Moreover, the electric blocking device enables very fast operation. The joints of the electric positioning arm can be completely blocked in a few seconds.

[0015] Another advantage of electric, or electrically operated, block devices is their compactness. Significant technological advancements have been made in electric drive systems in recent years. Alternative pressure systems (using compressed air, oil, etc.) are too expensive to manufacture, complex to use and maintain, and pose avoidable risks to the sterile surgical field and user due to the fluids used. Particularly in terms of sterility, the ability of electric drive systems, i.e., motors including associated electronics, to be used in a sterilizable form, especially in an autoclavable form, is advantageous. This is particularly important in applications where sterile drapes cannot be used.

[0016] Another advantage of the electric positioning arm is that the block mechanism is mounted on the central axis. This allows for progressive locking of the joints. Because the block mechanism can be engaged from the outside via the central axis in the mechanical block mechanism of the electric positioning arm, transmission devices such as push rods can be moved simultaneously or progressively within the arm elements with high tensile and compressive forces. This progressive movement allows for progressive locking and unlocking of the entire electric positioning arm or individual joints of the arm. In particular, progressive unlocking of individual joints is desirable to prevent the electric positioning arm from being in an unstable fully open state where it moves unstably back and forth.

[0017] When the electric block device is configured to move relative to a central axis, particularly along the central axis, the electric block device is configured as a movable clamping unit. In particular, the electric block device is also configured to move relative to other parts of the positioning arm, for example, relative to the arm element on which the electric block device is positioned.

[0018] To move the electric block device, the central shaft may have a male screw that can contact, for example, a component of the electric block device having a female screw. When the component with the female screw rotates, the component screws into the central shaft and moves up and down. The component may be, for example, the output gear of the electric block device. In particular, the component is connected to the rest of the block device so that the rest of the block device moves axially along the central shaft together with the component. For this purpose, the component may be placed on, for example, a base of the block device. In particular, the component may be placed on the base by bearings, for example, dry bearings. As a result, the component can rotate relative to the base, but the base moves axially. The base may be, for example, an angle piece.

[0019] In a preferred embodiment of the present invention, each arm element is provided with one additional joint at the end opposite the central axis, and the block mechanism is provided with one transmission device to each of the additional joints. In this regard, both transmission devices may be configured as described above. For example, one clamp sleeve may be configured to be axially displaceable on the central shaft, and the other clamp sleeve may be configured to screw into the central shaft. Furthermore, a series solution is also conceivable. In that case, one clamp sleeve moves along the other. For example, the central shaft can be blocked by the friction surfaces of two clamp sleeves that press against each other. However, the detailed configuration is secondary here.

[0020] An advantageous embodiment provides that the additional joint is configured as a ball-and-socket joint. The ball joint is a joint having a ball that is rotatable and pivotable. Here, the transmission device includes, for example, a sleeve accommodated in an arm element, and the sleeve can press the ball joint by respective push rods, thereby firmly clamping the joint.

[0021] According to a further advantageous development of the invention, the electric block device comprises an electric motor having an output shaft, and the output shaft is oriented perpendicular to the central axis. With such a configuration, the advantage lies, among other things, in a very high degree of compactness. The electric block device is space-saving and can be arranged on one of the arm elements or integrated with both arm elements. Usually, in most applications, only a very limited space can be used, and it is very important for the surgeon to have the best possible access to the surgical field. Electric positioning arms that extend extremely laterally often cannot be operated well in the surgical field.

[0022] However, as an alternative to the vertical arrangement, it is of course also conceivable to directly drive the central axis axially. Such a design has the advantage that it is technically easy to implement the installation of the electric block device constructively.

[0023] A particularly advantageous embodiment of the invention provides that the electric block device comprises a bevel gear device having an input gear connected to the output shaft of the electric motor and an output gear meshing with the central axis.

[0024] The advantage here is also that the bevel gear device is particularly compact. Furthermore, the bevel gear device can provide a high transmission efficiency independent of the ratio. According to a further advantageous development of this embodiment, the output gear is supported by at least a substantially annular drive bearing.

[0025] Even if all related components are enclosed within the housing as a whole, in the medical field, liquids are always regarded as risk factors, so the use of dry bearings is advantageous here. Preferably, the dry bearing is composed of a sliding-promoting plastic. This enables a dry bearing with low specified resistance. However, alternatively, the use of ball and needle bearings is also conceivable, and these are preferably used without lubricant.

[0026] According to an advantageous embodiment of the present invention, the output gear has an internal thread, and the central shaft has an external thread that meshes with the internal thread. This facilitates the transmission of power from the electric block device to the central shaft.

[0027] In a particularly suitable embodiment, the electric block device is arranged on one of the two arm elements, and the output shaft of the electric motor extends at least substantially parallel to the axial direction of the arm element on which the electric block device is arranged.

[0028] This is a particularly space-saving and compact design, and can provide the advantages already described in this regard. For example, the entire electric block device can be configured to be smaller than 70mm×150mm×50mm.

[0029] According to a further advantageous development of this embodiment, the electric block device is detachably attached to the arm element on which the electric block device is configured. Due to the detachable design, the electric block device can be retrofitted. Therefore, the electric block device can be attached to an existing non-electric positioning arm. In this way, a manual block device such as the system described at the beginning can be improved.

[0030] Alternatively, the electric block device can be integrated with the arm element on which the electric block device is arranged. In this case, integration means that the arm element and the electric block device have a common housing at least in a specific region.

[0031] An advantageous embodiment of the electric positioning arm further provides that the electric block device is configured as a movable clamp unit configured to move in the axial direction of the central axis with respect to the arm element on which the electric block device is positioned.

[0032] Therefore, the electric hoisting device is configured as a floating bearing device. In the case of a fixed device installed on the arm element, the gears move closer together or further apart depending on the opening degree of the electric positioning arm. This presents a significant drawback, particularly with respect to wear on the movable rigid parts. Wear is a serious problem, especially in medical applications. All systems must provide safety throughout their entire service life. Furthermore, wear can lead to inaccurate force measurements in the electric hoisting device, such as motor current, force sensors, or distance sensors. However, these inaccurate force measurements are insufficient to ensure that the electric positioning arm can be safely opened and locked independently of the user via the electric hoisting device.

[0033] As a movable clamping unit, the electric block device is preferably guided only by a central axis. However, further lateral guidance is possible by a housing. This housing can also prevent the electric block device from rotating during blocking and unblocking.

[0034] According to a further embodiment of the present invention, the electric positioning arm comprises a housing capable of at least substantially enclosing an electric block device, the housing being configured in the shape of a handle.

[0035] For example, a housing that encloses the arm element and parts of the electric block device is advantageous for protecting the user and patient and ensuring adequate cleanability and sterilization. The housing is configured in a handle shape, allowing it to be used as a handle to hold the corresponding arm element and move it manually. In this case, the housing is ergonomically designed so that the entire system can be operated while wearing gloves and, if necessary, through a sterile drape. For better grip, the housing can be coated with an anti-slip material in at least some areas.

[0036] The housing can be configured as a separate housing for the electrical block device. The housing may also be configured integrally with the corresponding arm element in at least some areas. In particular, when the housing is configured integrally with the arm element, the housing may be made of a light metal such as aluminum.

[0037] The housing may be provided with a cover to allow easy access to the electrical block device. This cover may be made of, for example, plastic. The housing as a whole preferably meets IP44 protection standards in accordance with DIN EN 60529 (VDE 0470-1):2014-09.

[0038] An advantageous embodiment of the electric positioning arm provides that the electric block device includes a stopper that abuts against the housing to prevent the electric block device from rotating relative to the housing when the joint is being blocked and unlocked.

[0039] Therefore, the housing enables further functionality. In possible alternative embodiments, the housing of the electrical block device can provide more precise guidance. For example, a linear guide may be configured in the direction of the central axis.

[0040] According to an advantageous further embodiment of the present invention, redundant operating elements for controlling an electric motor are arranged on the housing. The operating elements are, for example, push buttons or buttons that are activated by pressing them, and which preferably automatically return to their initial position when released. The operating elements are configured so that their position can be reliably determined by touch. Preferably, the operating elements are placed in pockets. This makes the buttons easier to find and helps prevent accidental pressing. In general, the entire system has the advantage that it can be operated while wearing gloves and, if necessary, through a sterile drape.

[0041] The operating elements are configured redundantly to prevent unintended activation of the blocking device. For example, there are four operating elements: two configured to block the joint and two configured to release the joint. The operating elements are positioned so that the user can hold the corresponding arm element, which is also the majority of the weight of the motorized positioning arm, in a handle-shaped housing, and simultaneously press the operating elements.

[0042] In addition to the operating elements, other devices can also be configured redundantly. For example, pressure sensors, position sensors, displacement sensors, and / or motor current sensors can be configured redundantly. These can accurately control the force applied to the output gear or accurately determine the state of the block device. For example, cable laying can also be configured redundantly.

[0043] Combining different types of sensors to gain additional safety is advantageous. Furthermore, using more than two sensor systems can provide additional redundancy. In a particularly preferred embodiment, a charging coil is located within the housing for wireless charging of an accumulator suitable for driving an electric motor.

[0044] The design for wireless charging eliminates the risks posed by cables in the operating room. Furthermore, since there is no need to access the cables, the housing can be configured to be particularly tightly sealed. The accumulator can be charged by a charging component, which can be located on the housing. For example, the charging component and the housing can have complementary geometric shapes so as to provide a mechanical key-locking principle. In this way, reliable charging of the accumulator can be ensured.

[0045] According to an advantageous embodiment of the present invention, at least one indicator element is disposed on the housing so as to be able to display the charge state of the accumulator and the block state of the block mechanism, or the charge state of the accumulator or the block state of the block mechanism.

[0046] Therefore, the indicator element can indicate the block status (e.g., fully blocked, fully released, partially blocked, semi-soft) of the motorized positioning arm or block device by sound, vibration, and / or visual indication. Preferably, the visual indication is provided by, for example, an LED. Alternatively, or in addition, the charge status of the accumulator, i.e., the remaining charge, and / or the charging mode (e.g., in operation) can also be indicated. The presence of low charge is advantageously indicated by a remaining charge that allows for at least 10 block operations.

[0047] All of the above advantages can be used particularly well in electric positioning arms for positioning medical devices. [Brief explanation of the drawing]

[0048] Further features, advantages, and embodiments of the present invention are disclosed in the following description with reference to the drawings. [Figure 1] A diagram of the electrically operated positioning arm according to the present invention, with the housing closed. [Figure 2]This figure shows the motorized positioning arm shown in Figure 1, with the cover element absent and the charging device lifted. [Figure 3] A more detailed diagram of an electric positioning arm according to the present invention, having a housing that is not partially shown and a visible electric block device according to the present invention. [Figure 4] A more detailed diagram of an electric positioning arm according to the present invention, having a housing that is not partially shown and an electric block device according to the present invention removed from the central axis. [Figure 5] A diagram showing a simplified cross-sectional view of the electrically operated positioning arm according to the present invention. [Modes for carrying out the invention]

[0049] Similar elements are generally shown in the figures with the same or similar reference numerals. Figure 1 shows a diagram of the electric positioning arm 1000 according to the present invention. The electric positioning arm 1000 comprises two arm elements 1100a and 1100b. The two arm elements 1100a and 1100b are pivotally connected to each other by a central joint 1001.

[0050] The arm element 1100a has two ends. One end is connected to the central joint 1001, and the other end 1120a is connected to an additional joint 1110a. The additional joint 1110a is configured as a ball-and-socket joint. The additional joint 1110a is connected to a clamping device 1500. Here, the clamping device 1500 is shown, for example, as a screwable connector. The clamping device 1500 can be connected, for example, to an operating table.

[0051] The arm element 1100b also has two ends. Here, one end is connected to the central joint 1001, and the other end 1120b is connected to an additional joint 1110b. The additional joint 1110b is also configured as a ball joint. The additional joint 1110b is connected to an instrument holder 1400. For example, a medical instrument can be placed on the instrument holder 1400. Although the instrument holder 1400 is shown as a screw connection, the instrument holder 1400 is preferably configured as a clamp connection. In this way, a suitable clamp piece on the medical instrument can be clamped to the instrument holder from the outside without damaging the sterile drape enclosing the motorized positioning arm 1000.

[0052] All joints 1001, 1110a, and 1110b can be fixed and released by a common block mechanism 1200. The block mechanism 1200 is located within the housing 1300 and is therefore not visible in Figure 1.

[0053] The housing 1300 includes a cover element 1360. The cover element 1360 may be made of, for example, plastic. The remaining portion of the housing 1300 may be integrally constructed with the arm element 1100a, as shown in Figure 1. Therefore, the remaining portion of the housing 1300 may be made of the same material as the arm element 1100a, for example, aluminum.

[0054] The housing 1300 is equipped with operating elements 1310a and 1320a for operating the block mechanism 1200. In the combination of Figures 1 and 5, it can be seen that operating elements 1310a and 1320a are each equipped with redundant operating elements 1310b and 1320b on the opposite side. This allows for particularly safe operation. Here, operating elements 1310a and 1310b and operating elements 1320a and 1320b form a group, that is, they must be operated together. Here, operating elements 1310a, 1310b, 1320a, and 1320b are configured as buttons located in the pocket 1370 of the housing 1300, or more precisely, in its cover element 1360. For the pocket 1370, the operating elements 1310a, 1310b, 1320a, and 1320b are, on the one hand, tactilely perceptible, and on the other hand, protected from unintended operation.

[0055] The entire housing 1300 is ergonomically configured as a handle. Therefore, the user can grasp the handle-shaped housing 1300, and for example, the thumb and index finger, or the thumb and middle finger, can simultaneously operate the operating elements 1320a, 1320b or 1310a, 1310b. For example, the operation of operating elements 1310a, 1310b may block joints 1001, 1110a, 1110b, and the operation of operating elements 1320a, 1320b may release joints 1001, 1110a, 1110b, and vice versa. The rest of the hand can then grasp or hold the housing 1300 and position the arm element 1100a, with the palm resting on the housing 1300. The housing 1300 may also include a structure 1380 that assists in grasping the housing 1300. Alternatively, or in addition, the housing 1300 may be coated with an anti-slip coating.

[0056] The housing 1300 includes at least one indicator element 1340 configured to display, for example, the status of the block mechanism 1200. In Figure 1, the indicator element 1340 is configured as a visual indicator, more specifically as an LED.

[0057] Figure 2 shows the motorized positioning arm 1000 shown in Figure 1, without the cover element 1360. Most of the components shown in Figure 2 have already been described with reference to Figure 1. Most known embodiments will not be described again below. However, all embodiments or components already described with respect to Figure 1 are applicable to Figure 2 and subsequent figures.

[0058] Since the cover element 1360 is not shown in Figure 2, we can see the first component of the electric block device 1230 belonging to the block mechanism 1200, which is housed in the housing 1300.

[0059] In particular, we can see the accumulator 1238, which plays a role in driving the electric block device 1230. The accumulator 1238 is inductively chargeable by the charging coil 1330. The charging coil 1330 is located at least approximately directly below the cover element 1360.

[0060] To charge the accumulator 1238, the motorized positioning arm 1000 is equipped with a charging device 1350. The charging device 1350 is shown in Figure 1 in the position for charging the accumulator 1238, and is positioned on the housing 1300, more specifically on its cover element 1360. In the case of the charging device 1350 shown in Figure 2, it is lifted and rotated 90 degrees, and the charging coil 1351 corresponding to the charging coil 1330 is shown.

[0061] The indicator element 1340 may be configured to display, for example, the charging state of the accumulator 1238 and the blocking state of the blocking mechanism 1200, or the charging state of the accumulator 1238 or the blocking state of the blocking mechanism 1200.

[0062] Figure 2 further shows the cover 1239 of the electric block device 1230 of the block mechanism 1200. Figure 3 shows a more detailed view of the electric positioning arm 1000 according to the present invention, where the housing 1300 is not shown in half to show the block mechanism 1200 in more detail.

[0063] In addition to the electric block device 1230, the block mechanism 1200 includes a transmission device 1220 configured to transmit a block or release operation to additional joints 1110a and 1110b. For simplicity, in Figure 3, the transmission device 1220 is shown only for arm element 1100a.

[0064] The transmission device 1220 includes a clamp sleeve 1221 that can transmit motion to the push rod 1222 via a cam 1223. More specifically, in Figure 3, as the clamp sleeve 1221 moves downward, the push rod 1222 moves to the left. The movement of the push rod 1222 to the left blocks an additional joint 1110a.

[0065] The electric block device 1230 includes an electric motor 1231. As can be seen in Figure 3, the electric motor 1231 is oriented and positioned at least substantially parallel to the axial direction of the arm element 1100a. Therefore, the electric motor 1231 can be positioned on the arm element 1100a in a particularly space-saving manner. However, such an arrangement of the electric motor 1231 requires the conversion of the output motion of the electric motor 1231. For this purpose, the electric block device 1230 includes a bevel gear device 1233.

[0066] For example, the bevel gear 1233 is not visible in Figure 2 because it is covered by the cover 1239. The cover 1239 serves to protect the bevel gear 1233. However, in Figure 3, the cover 1239 is not shown in order to make the mechanism easier to see.

[0067] The bevel gear unit 1233 comprises an input gear 1233a formed as a bevel gear and an output gear 1233b formed as a bevel gear. The output gear 1233b is larger than the input gear 1233a, so that a reduction in transmission occurs, i.e., a speed reducer is provided. The shafts on which the input gear 1233a and the output gear 1233b are arranged are perpendicular to each other.

[0068] This is better illustrated in Figure 4, which shows a more detailed view of the electric positioning arm 1000 according to the present invention, having a housing 1300 that is not shown and an electric block device 1230 that is spaced apart from the rest of the electric positioning arm 1000. In Figure 4, the electric block device 1230 is shown detached from the central shaft 1210. The central shaft 1210 is operably coupled to the output gear 1233b. For this purpose, the central shaft 1210 has a male thread 1211 and the output gear 1233b has a female thread 1236. As can be seen in Figure 4, the electric motor 1231 has an output shaft 1232, which is a shaft positioned perpendicular to the central shaft 1210 to which the input gear 1233a is mounted.

[0069] As can be seen in Figures 3 and 4, the electric hoist device 1230 includes an angle piece 1234 that supports the bevel gear device 1233. The angle piece 1234 is further configured to prevent the electric hoist device 1230 from rotating during operation. As shown in Figure 4, for this purpose, the angle piece 1234 includes a fastener 1234a. The fastener 1234a prevents the electric hoist device 1230 from rotating by contacting the housing 1300.

[0070] During operation, if the electric block device 1230 is positioned on the central axis 1210 as shown in Figure 3 or Figure 5, the electric block device 1230 moves downward or upward along the central axis 1210. Thus, the electric block device 1230 is suspended, i.e., movable, within the housing 1300. For example, the movement of the electric block device 1230 may be guided laterally only by the central axis 1210 and by the housing 1300 and fasteners 1234a that prevent rotation. However, instead, linear guides may be positioned in the housing 1300.

[0071] When the electric blocking device 1230 moves downward in the axial direction of the central axis 1210, i.e., in the direction of arm elements 1100a and 1100b, joints 1001, 1110a, and 1110b are blocked. The blocking of joints 1001, 1110a, and 1110b does not have to occur simultaneously. Rather, it is preferable that joints 1001, 1110a, and 1110b are blocked progressively. If joints 1001, 1110a, and 1110b can be blocked or released progressively or sequentially, the degrees of freedom of movement of the electric positioning arm 1000 are also restricted and released only progressively. Thus, on the one hand, the position of the electric positioning arm 1000 can be adjusted more easily, and on the other hand, a certain stability during release can be achieved. For example, the additional joint 1110a may be blocked first, then the central joint 1001, and then the additional joint 1110b.

[0072] The order in which joints 1001, 1110a, and 1110b are blocked may be achieved by adjusting the components of the transmission device 1220. Adjustments can be made to arm element 1100a by changing the lengths of the clamp sleeve 1221 and the push rod 1222. The same applies to arm element 1100b, where the lengths of the associated clamp sleeve and push rod can also be changed. For example, if the clamp sleeve 1221 is shortened, the clamping of the central joint 1001 will occur later than the clamping of the additional joint 1110a.

[0073] During the block, the electric block device 1230, which moves downward by the functional connection of the female thread 1236 and the male thread 1211 as shown in Figure 5, also pushes the clamp sleeve 1221 downward. As a result, the cam 1223 located in the joint socket 1224 on the clamp sleeve 1221 moves downward with the clamp sleeve 1221, pushing the push rod 1222 to the left, i.e., towards the additional joint 1110a. This blocks the additional joint 1110a. The transmission device of the other arm element 1100b is not shown. However, this transmission device can also be made up of a clamp sleeve and a push rod. The transmission device or part of the transmission device of the other arm element 1100b is similarly configured. However, for example, the clamp sleeve of the other arm element 1100b may have a female thread so as to move upward (block movement) or downward (release movement) when the electric block device 1230 is blocked.

[0074] When released, the electric block device 1230 moves upward along the central axis 1210. To restrict the upward movement of the electric block device 1230, the electric block device 1230 is equipped with a stopper 1237. In particular, as can be easily seen in Figure 4, the stopper 1237 is configured in an annular shape and is positioned at the upper end of the central axis 1210.

[0075] To enable the movement of the electric block device 1230, the output gear 1233b is supported by a dry bearing 1235. In particular, as can be seen in Figure 4, the dry bearing 1235 is configured to be at least substantially annular. For example, the dry bearing is configured as a sliding-promoting plastic ring.

[0076] As can be seen in Figure 5, the housing 1300 is equipped with a centering 1301. This centering 1301 plays a role in ensuring the secure positioning of the charging device 1350 (see Figure 1).

Claims

1. An electric positioning arm (1000) for positioning an instrument, It comprises at least two arm elements (1100a, 1100b) that are pivotably connected to each other around a pivot axis by a central joint (1001), At least one of the arm elements (1100a, 1100b) is provided with an additional joint (1110a, 1110b) at the end (1120a, 1120b) opposite to the central joint (1001), The electric positioning arm (1000) includes a blocking mechanism (1200) for blocking and unlocking the central joint (1001) and the at least one additional joint (1110a, 1110b), In an electric positioning arm (1000), the block mechanism (1200) comprises a central shaft (1210) arranged coaxially with the pivot axis and having a male screw (1211), and at least one transmission device (1220) from the central shaft (1210) to the at least one additional joint (1110a, 1110b), The blocking mechanism (1200) includes an electric blocking device (1230) configured to engage with the central shaft (1210) to block and unblock the central joint (1001) and the at least one additional joint (1110a, 1110b), The electric block device (1230) has an output gear (1233b) having a female screw (1236) that engages with a male screw (1211) of the central shaft (1210), and is configured such that the electric block device (1230) moves along and relative to the central shaft (1210) as the output gear (1233b) rotates. The transmission device (1220) includes a push rod (1222) that extends axially within at least one of the arm elements (1100a, 1100b), An electric positioning arm (1000) that, by means of the transmission device (1220), transmits the blocking and unlocking operations of the electric blocking device (1230) as axial movement of the push rod (1222) to at least one of the arm elements (1100a, 1100b), thereby blocking and unlocking the at least one additional joint (1110a, 1110b).

2. The motorized positioning arm (1000) according to claim 1, wherein two of the at least two arm elements (1100a, 1100b) each have the additional joints (1110a, 1110b) at the end (1120a, 1120b) opposite to the central joint (1001).

3. The motorized positioning arm (1000) according to claim 1 or 2, wherein the additional joints (1110a, 1110b) are configured as ball joints.

4. The electric positioning arm (1000) according to any one of claims 1 to 3, wherein the electric block device (1230) comprises an electric motor (1231) having an output shaft (1232), and the output shaft (1232) is arranged perpendicular to the central shaft (1210).

5. The electric positioning arm (1000) according to claim 4, wherein the electric block device (1230) comprises a bevel gear device (1233) having an input gear (1233a) connected to the output shaft (1232) of the electric motor (1231) and an output gear (1233b) that engages with the central shaft (1210).

6. The motorized positioning arm (1000) according to claim 5, wherein the output gear (1233b) is supported by an annular dry bearing (1235).

7. The electric positioning arm (1000) according to any one of claims 4 to 6, wherein the electric block device (1230) is positioned on one of the two arm elements (1100a, 1100b) (1100a), and the output shaft (1232) of the electric motor (1231) extends parallel to the axial direction of the arm element (1100a) on which the electric block device (1230) is positioned.

8. The electric positioning arm (1000) according to claim 7, wherein the electric block device (1230) is detachably disposed on the arm element (1100a) on which the electric block device (1230) is located.

9. The transmission device (1220) further comprises a clamp sleeve (1221), The electric block device (1230) is configured as a movable clamp unit and is movable in the axial direction of the central axis (1210) relative to the arm element (1100a) on which the electric block device (1230) is positioned. The electric positioning arm (1000) according to claim 7 or 8, wherein the electric block device (1230) is configured to push down the clamp sleeve (1221) when moving downward to block the central joint (1001), and to move the push rod (1222) axially to block the at least one additional joint (1110a, 1110b).

10. The electric block device (1230) is provided with a housing (1300) that can enclose it. The motorized positioning arm (1000) according to any one of claims 4 to 9, wherein the housing (1300) is configured to have a shape that can be grasped by a user.

11. The electric positioning arm (1000) according to claim 10, wherein the electric block device (1230) comprises a stopper (1234a) that abuts against the housing (1300) to prevent the electric block device (1230) from rotating when the central joint and the at least one additional joint (1001, 1110a, 1110b) are blocked and unlocked.

12. An electric positioning arm (1000) according to claim 10 or 11, wherein operating elements (1310a, 1310b, 1320a, 1320b) are arranged in the housing (1300) for controlling the electric motor (1231).

13. An electric positioning arm (1000) according to any one of claims 10 to 12, wherein a charging coil (1330) for wireless charging of an accumulator (1238) suitable for driving the electric motor (1231) is disposed within the housing (1300).

14. The motorized positioning arm (1000) according to claim 13, wherein at least one indicator element (1340) is disposed in the housing (1300), and the indicator element (1340) can display the charging state of the accumulator (1238) and the blocking state of the blocking mechanism (1200), or the charging state of the accumulator (1238) or the blocking state of the blocking mechanism (1200).

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