Telescopic boom for working device, in particular crane or mobile crane

Abstract

The invention relates to a telescopic boom (1) for a working device, in particular a crane or a mobile crane, comprising at least three telescopic joints (3, 4, 5), the first telescopic joint (3) being arranged at least partially around the second telescopic joint (4) and the second telescopic joint (4) being arranged at least partially around the third telescopic joint (5); the at least one driving device (6) is used for enabling the second expansion joint (4) to retract and / or stretch out relative to the first expansion joint (3); and at least one synchronization device (7), by means of which the third expansion joint (5) can be expanded in particular synchronously with respect to the second expansion joint (4), the at least one synchronization device (7) being arranged substantially completely within the second expansion joint (4).

Description

Technical Field

[0001] The invention relates to a telescopic boom for a working device, in particular a crane or a mobile crane, comprising: at least three telescopic sections, wherein a first telescopic section is at least partially arranged around a second telescopic section and the second telescopic section is at least partially arranged around a third telescopic section; at least one drive device for retracting and / or extending the second telescopic section relative to the first telescopic section; and at least one synchronizing device, by means of which the third telescopic section can be extended and retracted, in particular synchronously, relative to the second telescopic section. The invention also relates to a working device, in particular a crane or a mobile crane, having at least one such telescopic boom. The invention also relates to a method for retracting or extending such a telescopic boom. Background Art

[0002] A telescopic boom having a telescopic telescopic section is already known from WO 2014 / 006474 A1.

[0003] Disadvantages of the prior art are that the hydraulic system for the telescopic movement is heavy and the hydraulic control is maintenance-intensive. Furthermore, the innermost telescopic section is usually provided for accommodating the extension and / or the load receiving means, which limits the adaptability of the known hydraulic systems. In hydraulic systems, the load is disadvantageous for the efficient use of the working device, in particular due to the distribution of the center of gravity and / or the dead weight in the telescopic section, wherein the arrangement of the hydraulic system in the innermost telescopic section is not considered for reasons of space and technical feasibility. Summary of the invention

[0004] The objective technical task of the present invention is therefore to provide a telescopic boom which is improved compared to the prior art, in which the above-mentioned disadvantages of the prior art are at least partially eliminated and which is distinguished in particular by efficient space utilization and / or efficient weight distribution of the telescopic section and / or low maintenance with a small number of component parts.

[0005] This object is achieved by the features of claim 1 .

[0006] According to the invention, it is therefore provided that the at least one synchronization device is arranged substantially completely within the second telescopic section.

[0007] This allows the storage space in the third telescopic section (usually the innermost telescopic section) to be used for accommodating the synchronization device. Thus, a particularly compact telescopic boom can be provided.

[0008] At least in one operating position, at least one synchronization device is arranged substantially completely within the second telescopic section. Particularly preferably, such an arrangement exists both in the retracted operating position and in the extended operating position of the second and / or third telescopic section.

[0009] Furthermore, the advantageous property results that, in the presence of a hydraulic control of the telescopic section or of the telescopic push-pull arm, a range increase can be achieved by means of an additional telescopic section, a third telescopic section, without having to rely on an additional external extension at the telescopic section.

[0010] Particularly preferably, the synchronization device itself is not controlled (hydraulically, electrically or similarly), but can produce a mechanical coupling of the third telescopic section with the second telescopic section via the first telescopic section, so that when the second telescopic section is telescopically moved from the first telescopic section, a telescopic movement of the third telescopic section from the second telescopic section is automatically caused. The synchronization chain or tracking control device is arranged at least partially outside the telescopic section, at least outside the second telescopic section.

[0011] Furthermore, the synchronization device can be designed in such a way that the telescopic movement of the third telescopic section can be deactivated. A particularly favorable distribution of the center of gravity can be achieved by at least one synchronization device arranged completely in the telescopic section, wherein at least one synchronization device is protected from dirt and / or weather influences. Compared to hydraulic systems and / or electrical controls, mechanical synchronization devices are significantly lighter, wherein the inherent moment at the telescopic boom is only minimally increased due to the internal arrangement and in particular due to the arrangement in the penultimate telescopic section (second telescopic section).

[0012] Furthermore, the range increase produced by the at least one synchronous device can be flexibly implemented or retrofitted in a plurality of different telescopic booms and / or working devices, such as cranes, crane trucks, etc. By means of the defined range increase, comfort functions, such as overload monitoring and / or range measurement, can be adjusted to the at least one synchronous device.

[0013] The first telescopic section itself can be telescopic, but this is generally not a mandatory requirement. In the retracted operating position of the telescopic boom, the first telescopic section at least partially surrounds two further telescopic sections, wherein the third telescopic section is arranged in a plane spanned by the sides of the second telescopic section. A telescopic boom or a telescopic jib can be considered synonymous as a telescopic section.

[0014] In this context, telescopic section can be used synonymously with the term telescopic boom. Preferably, at least one synchronization device brings about a synchronous movement of the innermost telescopic boom, or the third telescopic boom, wherein generally an asynchronous movement can be generated by the at least one synchronization device, for example via a transmission.

[0015] As mentioned at the outset, protection is also claimed for a working device, in particular a crane or a mobile crane, having at least one such telescopic boom, wherein in particular at least one further telescopic section is provided which is arranged at least partially around the at least three telescopic sections.

[0016] This creates a working device which has an additional, in particular non-external and / or hydraulically actuated telescopic section or, in the case of an equal number of telescopic sections, effectively utilizes the last telescopic section for simultaneous telescopic extension and retraction with the penultimate telescopic section.

[0017] As mentioned at the beginning, protection is also claimed for a method for retracting or extending such a telescopic boom, wherein the following method steps, which are particularly to be performed in parallel, are performed: the second telescopic section is moved translationally relative to the first telescopic section by means of a drive, particularly a hydraulic drive, and the third telescopic section is moved translationally relative to the second telescopic section by means of the movement of the second telescopic section via at least one synchronization device, preferably synchronously.

[0018] Advantageous embodiments of the invention are defined in the dependent claims.

[0019] According to an advantageous embodiment of the invention, it is provided that the first telescopic section is designed to be telescopic or non-telescopic relative to at least one further telescopic section via at least one further drive device.

[0020] The number of telescopic sections of a telescopic boom is usually arbitrary. The first telescopic section can thus be the telescopic section closest to the crane base, which is not telescopic itself, or is designed to be telescopic relative to another telescopic section. By the telescopic movement of the second telescopic section relative to the first telescopic section, the innermost third telescopic section is automatically moved along by at least one, preferably mechanical, synchronization device.

[0021] Advantageously, provision is made for the at least one synchronization device to be arranged at least partially within the third telescopic section and completely within a plane spanned by at least four, preferably all, side surfaces of the third telescopic section.

[0022] Preferably, at least one synchronization device is preferably completely arranged in the second (penultimate) telescopic section during the entire telescopic movement, and at least partially moves into the first telescopic section during the retraction movement, and / or at least partially moves out of the third telescopic section during the extension movement.

[0023] It has proven to be advantageous if at least one synchronizing device is designed in the form of a chain, a belt and / or a rope, wherein it is preferably provided that the chain, the belt and / or the rope is elastically deformable.

[0024] Particularly preferably, the synchronization device is in the form of a chain, which is preferably arranged directly via the fastening means at the second telescopic joint and / or at the third telescopic joint.

[0025] According to an alternative embodiment of the present invention, at least one synchronization device is designed as a rack with a gear, wherein it is preferably provided that the gear is arranged at the second telescopic section, preferably at the rear wall of the second telescopic section, and extends at least partially into the third telescopic section in a manner positioned in the second telescopic section, and / or the rack is at least partially, particularly preferably completely, arranged in the third telescopic section.

[0026] It has proven to be advantageous if at least one synchronizing device comprises at least one deflection wheel, wherein the at least one synchronizing device is guided around the at least one deflection wheel and / or is connected to the at least one deflection wheel itself, wherein preferably at least two spatially separated deflection wheels are provided.

[0027] The translational movement of the second telescopic section is transmitted to the third telescopic section via at least one steering wheel via at least one synchronization device, wherein the at least one steering wheel is preferably arranged in the first and / or second and / or third telescopic section, preferably in the second telescopic section in all operating positions.

[0028] An advantageous variant is that the second telescopic section comprises at least one fastening device, preferably a profile or a profile tube, which is indirectly or directly arranged on the second telescopic section, preferably on the rear wall of the second telescopic section and which at least partially extends into the third telescopic section, wherein at least one steering wheel is arranged on at least one fastening device.

[0029] By arranging at least one fastening device on the second telescopic section, a kinematic coupling of at least one synchronization device to the second telescopic section can be achieved, wherein the third telescopic section preferably moves together with the second telescopic section and / or extends synchronously by kinematic coupling to the at least one synchronization device.

[0030] However, it is generally also conceivable to fasten the at least one fastening device on the third telescopic section, wherein the at least one fastening device is moved partially out of the second telescopic section during the telescopic process.

[0031] Typically, the third telescopic section can be extended together with the second telescopic section to the same extent, moved out of the second telescopic section to the same extent as the second telescopic section is extended from the first telescopic section (synchronous movement), and / or moved out of the second telescopic section to a reduced or increased extent compared to the extension of the second telescopic section from the first telescopic section. This is similar for the extension process.

[0032] It is particularly preferably provided that the deflection wheel, preferably close to the front side of the second telescopic joint, can be pretensioned by at least one chain tensioner, preferably arranged on at least one possibly present fastening device.

[0033] Thereby, undesired rope slack and / or inappropriately high chain tensions may be reduced.

[0034] In one embodiment of the invention, it is provided that at least one chain tensioner is designed in the form of a translationally extendable fastening device, a plug connection and / or a thread arranged on the fastening device.

[0035] For example, the fastening device comprises a thread, by means of which the fastening device can be extended and retracted in order to increase the chain tension. However, it is generally also possible to provide a tensioning device separate from the fastening device or arranged at the fastening device, which tensioning device increases the tension of at least one synchronous device, for example by pressure. The term "chain tensioner" is to be interpreted broadly in this context, i.e., it can also apply to other synchronous devices, such as belts or ropes.

[0036] According to a preferred embodiment of the present invention, at least one synchronization device is arranged at a first fixing point on the third telescopic joint, wherein it is preferably provided that the first fixing point is constructed as a bolt connection, a magnetic connection, a threaded connection and / or a material-matched connection between the at least one synchronization device and the third telescopic joint.

[0037] Via the first fixing point, a motion coupling with the third telescopic section can be produced when the second telescopic section moves. The magnetic connection, if any, can be switched to be inactive or active via the rear side of the second telescopic section or remotely.

[0038] It has proven to be advantageous if the first fastening point is arranged in the retracted operating position of the third telescopic section close to the rear side of the third telescopic section and / or in the region of a possibly present deflection wheel.

[0039] This simplifies deactivation of the kinematic coupling and / or accessibility for maintaining the at least one synchronization device. However, it is also possible to arrange the first fixing point near the front side of the third telescopic section.

[0040] Furthermore, it is preferably provided that at least one synchronization device can be arranged, preferably detachably, at or on a second fastening point to the first telescopic section via at least one fastening means.

[0041] Via the second fastening point, a movement coupling to the second telescopic section can be produced, in particular via a fastening device, in order to move together with the third telescopic section.

[0042] In a further embodiment, it can be provided that the second fastening point is arranged in the retracted operating position of the third telescopic section close to the front side of the third telescopic section and / or in the region of a possibly present deflection wheel.

[0043] This simplifies deactivation of the kinematic coupling and / or accessibility for maintaining at least one synchronization device. However, it is also possible to arrange the second fixing point near the rear side of the second telescopic section.

[0044] According to an advantageous design of the present invention, at least one fastening mechanism of the second fixing point

[0045] - is in the form of at least one bolt connection which can be released and / or connected manually, preferably from the front side of the third telescopic section, and / or mechanically, preferably hydraulically, and / or

[0046] In the form of at least one magnetic connection, which can be released and / or activated manually, preferably from the front side of the third telescopic joint, or electromagnetically.

[0047] The bolt connection, which can generally also be used as a first fastening point, is a structurally simple kinematic connection to at least one synchronizing device.

[0048] The magnetic connection, which can generally also be used for the first fastening point, is a connection to the at least one synchronous device that can be easily deactivated and can be used remotely, for example, in the case of inaccessible fastening points.

[0049] Preferably, the two fixing points are spatially spaced apart from one another in the retracted operating position, preferably substantially by the longitudinal extension of at least one fastening device and / or by the spatial distance of the two deflection wheels, so that a high telescopic stroke can be generated, in particular substantially by the longitudinal extension of the third telescopic section, without having free space for an optional telescopic section extension.

[0050] According to an advantageous design of the present invention, the first telescopic section comprises at least one retaining element arranged at the first telescopic section, preferably at the rear wall of the first telescopic section, which retaining element extends into the second telescopic section and at least in the retracted operating position of the third telescopic section, wherein at least one fastening mechanism is arranged at at least one retaining element, wherein it is preferably provided that at least one retaining element is constructed in the form of a profile or a profile tube, particularly preferably a U-shaped profile.

[0051] The holding element can effect a motion coupling of the third telescopic section to the first telescopic section via at least one synchronization device, wherein preferably the third and the first telescopic section are connected to the at least one synchronization device via two fixing points.

[0052] Advantageously, provision is made for the at least one fastening device and / or the at least one retaining element to be designed such that the at least one synchronization device can be supported on the at least one fastening device and / or the at least one retaining element when the at least one synchronization device is relaxed.

[0053] For example, the at least one retaining element can be a chain pulley for guiding the at least one synchronizing device.

[0054] It has proven to be advantageous if at least one drive device and / or at least one further drive device, if present, is designed as a hydraulic cylinder unit, an electric drive unit and / or a cable-pulling drive unit, wherein preferably provision is made for at least one drive unit to be arranged on the outside of the second telescopic joint.

[0055] It is particularly preferably provided that at least one synchronization device comprises a transmission, by means of which the extension and retraction speed of the third telescopic section can be slowed down and / or accelerated relative to the extension and retraction speed of the second telescopic section.

[0056] Thereby, any extension and retraction speed of the third telescopic section can be set.

[0057] According to a preferred embodiment of the invention, it is provided that in the retracted operating position of the third telescopic section, free space remains between the front side of the third telescopic section and the at least one synchronization device for connecting at least one telescopic section extension.

[0058] For example, a load receiving device or a crane boom extension to be optionally fastened to the telescopic boom can be arranged via this free space.

[0059] In another embodiment of the present invention, at least one fastening mechanism is provided for coupling the movement of the second telescopic section with the third telescopic section, wherein, through the at least one fastening mechanism, when the second telescopic section moves relative to the first telescopic section, the third telescopic section moves together with the second telescopic section.

[0060] This makes it possible to achieve a kinematic coupling of the three telescopic sections of the telescopic boom.

[0061] In a preferred embodiment of the invention, it is provided that at least one preferably driven sprocket is arranged on at least one synchronizing device.

[0062] By means of the sprocket, at least one transmission can be particularly advantageously implemented as an asynchronous movement for the third telescopic section or the telescopic boom. In addition, in the case of a drive unit, for example electric or hydraulic, directly connected to at least one sprocket, a drive unit, particularly hydraulic, arranged outside at the telescopic section can be omitted.

[0063] For example, a positive connection with at least one synchronous device can be achieved via at least one sprocket and / or an alternative or additional drive device for at least one synchronous device can be provided, which is preferably designed as an integrated drive. Particularly preferably, a sensor device, such as a rotation angle sensor, can be connected to at least one sprocket for determining and / or further processing of measurement data.

[0064] By means of a drive for the synchronization device, which is preferably arranged directly at the synchronization device and / or at the shaft of the sprocket and / or is electric and / or arranged in the second telescopic boom, the innermost / third telescopic boom can be telescoped relative to the second telescopic boom without an indirect kinematic coupling between the outermost / first telescopic boom and the second telescopic boom. Thus, a relative movement of the innermost telescopic section can be achieved without an external drive (e.g. a hydraulic drive). Decoupling from the first telescopic section can be achieved, for example, by releasing a fixing point associated with the first telescopic section.

[0065] The synchronization device can act as a transmission of the rotational movement of the shaft, preferably via a drive arranged directly on the shaft, particularly preferably at least one sprocket, to cause a translational movement of the third telescopic section. In this case, no additional drive of the first telescopic section is required to extend the innermost telescopic section from the second telescopic section.

[0066] It is particularly preferred if the working device has at least one fastening point which is separate from the first telescopic section and at which at least one retaining element is arranged.

[0067] It is preferably arranged that at least one synchronization device is preferably decoupled from the second telescopic section via at least one fastening mechanism, and the second telescopic section is preferably coupled to the third telescopic section movement via at least one fastening mechanism if possible, so that in the case of translational movement of the second telescopic section, the third telescopic section moves together with the second telescopic section relative to the first telescopic section.

[0068] By decoupling at least one synchronization device, the relative telescopic movement between the second telescopic section and the third telescopic section can be deactivated, so that the second telescopic section and the third telescopic section can be telescoped together to the same extent relative to the first telescopic section. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Features of the device claim can be applied to the method claim and vice versa. Further details and advantages of the invention are explained in detail below with reference to the embodiments shown in the drawings with the aid of the accompanying drawings. It is shown that:

[0070] Figure 1 A cross-sectional view of a telescopic boom according to a particularly preferred embodiment is shown in side view,

[0071] Figure 2a , Figure 2b A telescopic boom with three telescopic sections is shown in a side view and in a perspective view in the retracted operating position.

[0072] Figure 3a , Figure 3b The side view and the perspective view show Figure 2a The telescopic boom of an embodiment in a partially extended state,

[0073] Figure 4a , Figure 4b The side view and the perspective view show Figure 2a The telescopic boom of the embodiment of the invention is in the extended operating position,

[0074] Figure 5 A telescopic boom with a sprocket according to another preferred embodiment is shown in a side view in cross section. DETAILED DESCRIPTION

[0075] Figure 1 A telescopic boom 1 for a working device in the form of a crane or a mobile crane is shown, which includes three telescopic sections 3, 4, and 5, wherein the first telescopic section 3 is arranged around the second telescopic section 4, and the second telescopic section 4 is arranged around the third telescopic section 5. The telescopic boom also includes at least one drive device 6 for retracting and / or extending the second telescopic section 4 relative to the first telescopic section 3 and at least one synchronization device 7, by which the third telescopic section 5 can be synchronously extended and retracted relative to the second telescopic section 4.

[0076] Typically, the synchronization device 7 may include a transmission device 31, with which the extension speed of the third telescopic section 5 can be slowed down or accelerated relative to the extension speed of the second telescopic section 4, so that the extension and retraction movements are performed asynchronously despite the same extension and retraction directions. However, this is not mandatory.

[0077] The first telescopic section 3 can be telescopic relative to the further telescopic section 8 via a further drive device 9 , wherein the first telescopic section 3 can also be a non-telescopic telescopic section (if the working device has, for example, only three telescopic sections).

[0078] In the telescopic boom 1 , the synchronization device 7 is arranged completely within the second telescopic section 4 .

[0079] In the telescopic boom 1, the synchronization device 7 is arranged completely in the first telescopic section 3 and partially in the third telescopic section 5 in the retracted operating position 25 shown. It is generally also conceivable that in the retracted operating position 25, it is arranged completely in the third telescopic section 5. In the partially extended operating position, the synchronization device 7 is arranged partially in the third telescopic section 5 and is partially moved out of the first telescopic section 3 during the telescopic movement. In the fully extended operating position, the synchronization device 7 can also be arranged completely outside the first telescopic section 3 or the third telescopic section 5.

[0080] A further telescopic section 8 is provided in the telescopic boom 1 , which is arranged around the three telescopic sections 3 , 4 , 5 and can be actuated by a further drive device 9 .

[0081] The drive device 6 and the further drive device 9 are designed as hydraulic cylinder units 29 , and one or all of the drive devices 6 , 9 can also be designed as electric drive units or cable-pulled drive units. The drive unit 6 is arranged on the outer side 30 of the second telescopic section 4 .

[0082] The synchronization device 7 comprises a chain 10. It is also possible to include a plurality of synchronization devices 7 in the telescopic boom 1. As an alternative or in addition, the synchronization device 7 can be configured as a belt or a rope. The chain 10 itself can be elastically deformed by means of chain links.

[0083] With the help of Figures 2a to 4b The extension process of the telescopic boom 1 is explained, wherein the method for retracting or extending the telescopic boom can be explained as follows: the second telescopic section 4 is moved translationally relative to the first telescopic section 3 via a hydraulic or electrical drive device 6, and in parallel, the third telescopic section 5 is moved translationally and synchronously relative to the second telescopic section 4 via a synchronization device 7 through the movement of the second telescopic section 4.

[0084] If necessary, the synchronization device 7 can be decoupled from the second telescopic section 4 by the fastening mechanism 24, and the second telescopic section 4 and the third telescopic section 5 are coupled in motion by the fastening mechanism 24, so that when the second telescopic section 4 moves in translation, the third telescopic section 5 moves together with the second telescopic section 4 relative to the first telescopic section 3.

[0085] Figure 2a It is shown that the synchronization device 7 comprises two deflection wheels 11, wherein the chain 10 is guided around the two deflection wheels 11 and is connected to the deflection wheels themselves. The two deflection wheels 11 are arranged spatially separated from one another on the telescopic boom 1.

[0086] exist Figure 2bIt can be seen that in the retracted operating position 25 of the third telescopic section 5, a free space 32 for connecting a telescopic section extension 33 remains between the front side 15 of the third telescopic section 5 and the synchronization device 7. The telescopic section extension 33 shown is in the form of a load receiving device, wherein alternatively or additionally, other telescopic section extensions 33 (e.g. articulated arm systems) can be connected to the telescopic boom 1.

[0087] A fastening mechanism 24 is provided for kinematically coupling the second telescopic section 4 to the third telescopic section 5 , wherein the third telescopic section 5 moves together with the second telescopic section 4 via the fastening mechanism 24 when the second telescopic section 4 moves relative to the first telescopic section 3 .

[0088] The synchronization device 7 is arranged at a first fixing point 20 on the third telescopic joint 5, wherein the first fixing point 20 is configured as a bolt connection 21. As an alternative or supplement, the first fixing point can also be configured as a threaded connection, a material-fitted connection, or a magnetic connection between the synchronization device 7 and the third telescopic joint 5.

[0089] In the retracted operating position 25 of the third telescopic section 5 , the first fastening point 20 is arranged close to the rear side 22 of the third telescopic section 5 and in the region of one of the two deflection wheels 11 .

[0090] The synchronization device 7 is arranged at the second fixing point 23 in a detachable manner with the first telescopic section 3 via a fastening means 24 , wherein a non-detachable connection is generally also possible.

[0091] In the retracted operating position 25 of the third telescopic section 5 , the second fastening point 23 is arranged close to the front side 15 of the third telescopic section 5 and in the region of one of the two deflection wheels 11 .

[0092] The synchronization device 7 is connected to the first telescopic section 3 via the retaining element 27 , to the second telescopic section 4 via the fastening device 13 and to the third telescopic section 5 via the first fixing point 20 .

[0093] The fastening means 24 of the second fixing point 23 is designed as a magnetic connection 26, which can be released and activated manually from the front side 15 of the third telescopic section 5 or the rear wall 12 of the second telescopic section 4 or electromagnetically. The fastening means 24 can usually also be designed by a bolt connection 21 or a screw connection, which can be released and connected manually from the front side 15 of the third telescopic section 5 and mechanically, for example hydraulically. In general, a material connection of the second fixing point 23 is also conceivable, wherein the deactivation of the simultaneous movement of the third telescopic section 5 and the second telescopic section 4 can always be provided, or this deactivation can be achieved by other means, for example, by a deactivation solution provided at the first fixing point 20.

[0094] Figure 3aThe second telescopic section 4 is shown by a drive device 6 (not shown for reasons of clarity, see Figure 2b ) relative to the partially extended operating position of the first telescopic section, whereby the third telescopic section 5 has been automatically extended to the same extent (synchronously) relative to the second telescopic section 4 by the synchronization device 7 (because no transmission ratio is set in this embodiment).

[0095] Figure 3b and Figure 3a The difference lies in the changed viewing angle. It can be seen that the second telescopic section 4 comprises a fastening device 13 arranged at the second telescopic section 4 (at the rear wall 12 of the second telescopic section 4) in the form of a profile tube 14. In this operating position, the profile tube 14 partially extends into the third telescopic section 5 and the first telescopic section 3, wherein the two deflection wheels 11 are arranged at the fastening device 13, for example welded laterally.

[0096] The deflection wheel 11 closer to the front side 15 of the second telescopic section 4 can be pretensioned by a chain tensioner 16 arranged on the fastening device 13. Generally, the chain tensioner 16 can also be arranged spatially separate from the fastening device 13 on the telescopic boom 1.

[0097] The chain tensioner 16 is present in the form of a translationally extendable fastening device 13 as a thread arranged on the fastening device 13. As an alternative or in addition, the chain 10 can also be tensioned by means of a plug connection.

[0098] In both the retracted position and the extended position of the telescopic boom 1 , the synchronization device 7 is arranged completely in a plane spanned by all side faces 10 of the third telescopic section 5 .

[0099] Figure 4a The telescopic boom 1 is shown in the fully extended operating position. The working device on which the telescopic boom 1 is arranged can usually also have a fastening point separate from the first telescopic section 3, at which the retaining element 27 is arranged. The telescopic boom 1 can usually also have a fastening point for the fastening device 13 separate from the second telescopic section 4.

[0100] In this embodiment, the first telescopic section 3 comprises a retaining element 27 arranged at the rear wall 12 of the first telescopic section 3, which extends into the second telescopic section 4 and, in the retracted operating position 25 of the third telescopic section 5, into the third telescopic section 5. A fastening means 24 is arranged on the retaining element 27, wherein the retaining element 27 is designed in the form of a U-shaped profile 28.

[0101] exist Figure 4b In the telescopic boom 1, the viewing direction is relative to Figure 4aThe fastening device 13 and the holding element 27 are designed so that when the synchronizing device 7 is loose, the synchronizing device 7 can be supported by gravity on the fastening device 13 and on the holding element 27. However, this is not necessary if the synchronizing device 7 is sufficiently prestressed by the chain tensioner 16.

[0102] Figure 5 An embodiment of a telescopic boom 1 is shown, in which two sprockets 34 are provided instead of the deflection wheels 11, wherein the two sprockets 34 are arranged on the synchronization device 7. At least one sprocket 34 is driven electrically or hydraulically (this is generally not absolutely necessary) by a drive unit (not shown in the figure for reasons of clarity) arranged in the second telescopic section 4, so that the hydraulic cylinder unit 29 arranged outside the telescopic boom 1 can be omitted or can be used in addition.

[0103] The synchronization device 7 combined with the sprocket 34 includes a transmission device 31 with a pinion device, by which the extension speed of the third telescopic section 5 can be slowed down or accelerated relative to the extension speed of the second telescopic section 4, so that although the extension direction is the same, the extension movement is performed asynchronously.

[0104] In this telescopic boom 1 , the first fixing point 20 is designed as a detachable magnetic connection 26 and the second fixing point 23 is designed as a bolt connection 21 , wherein generally both fixing points 20 , 23 can also be designed as magnetic connections 26 .

[0105] Other structural features associated with the deflection wheel 11, such as the chain tensioner 16, can also be used in the embodiment with the sprocket 34. A combination of the deflection wheel 11 and the sprocket 34 is also possible.

[0106] Even in the absence of the first telescopic section 3 or when the first telescopic section 3 is decoupled, the third telescopic section 5 can be driven by the synchronization device 7 to perform relative movement.

Claims

1. A telescopic boom (1) for a working device, in particular a crane or a mobile crane, comprising - at least three telescopic sections (3, 4, 5), wherein: The first telescopic section (3) is at least partially arranged around the second telescopic section (4), and the second telescopic section (4) is at least partially arranged around the third telescopic section (5), - at least one drive device (6) for retracting and / or extending the second telescopic section (4) relative to the first telescopic section (3), and at least one synchronization device (7), by means of which the third telescopic section (5) can be telescoped relative to the second telescopic section (4), in particular synchronously, Characterized in that the at least one synchronization device (7) is arranged substantially completely inside the second telescopic section (4).

2. The telescopic boom (1) according to claim 1, wherein: The first telescopic section (3) is configured to be telescopic or non-telescopic relative to at least one further telescopic section (8) via at least one further drive device (9).

3. The telescopic boom (1) according to claim 1 or 2, wherein: The at least one synchronization device (7) is arranged at least partially within the third telescopic section (5) and completely within a plane spanned by at least four, preferably all side surfaces (17) of the third telescopic section (5).

4. A telescopic boom (1) according to any one of the preceding claims, wherein: The at least one synchronization device (7) is designed in the form of a chain (10), a belt and / or a rope, wherein it is preferably provided that the chain (10), the belt and / or the rope are elastically deformable.

5. Telescopic boom (1) according to any one of the preceding claims, wherein: The at least one synchronization device (7) comprises at least one steering wheel (11), wherein the at least one synchronization device (7) is guided around the at least one steering wheel (11) and / or is connected to the at least one steering wheel itself, wherein preferably at least two steering wheels (11) are provided which are spatially separated from each other.

6. The telescopic boom (1) according to claim 5, wherein: The second telescopic section (4) comprises at least one fastening device (13), preferably a profile or a profile tube (14), which is arranged indirectly or directly at the second telescopic section (4), preferably at the rear wall (12) of the second telescopic section (4), and which at least partially extends into the third telescopic section (5), wherein the at least one steering wheel (11) is arranged at the at least one fastening device (13).

7. The telescopic boom (1) according to claim 5 or 6, wherein: The deflection wheel (11) preferably close to the front side (15) of the second telescopic joint (4) can be pretensioned by at least one chain tensioner (16) which is preferably arranged at at least one possibly present fastening device (13).

8. The telescopic boom (1) according to claim 7, wherein: The at least one chain tensioner (16) is designed in the form of a translationally extendable fastening device (13), a plug connection and / or a thread arranged on the fastening device (13).

9. Telescopic boom (1) according to any one of the preceding claims, wherein: The at least one synchronization device (7) is arranged at a first fixing point (20) on the third telescopic joint (5), wherein it is preferably provided that the first fixing point (20) is constructed as a bolt connection (21), a magnetic connection (26), a threaded connection and / or a material-fit connection between the at least one synchronization device (7) and the third telescopic joint (5).

10. The telescopic boom (1) according to claim 9, wherein: The first fixing point (20) is arranged in the retracted operating position (25) of the third telescopic section (5) close to the rear side (22) of the third telescopic section (5) and / or in the region of a possibly present steering wheel (11).

11. Telescopic boom (1) according to any one of the preceding claims, wherein: The at least one synchronization device (7) is preferably detachably attachable via at least one fastening means (24) at or on a second fastening point (23) to the first telescopic section (3).

12. The telescopic boom (1) according to claim 11, wherein: The second fixing point (23) is arranged in the retracted operating position (25) of the third telescopic section (5) close to the front side (15) of the third telescopic section (5) and / or in the area of ​​a possibly present steering wheel (11).

13. The telescopic boom (1) according to claim 11 or 12, wherein: at least one fastening means (24) of the second fixing point (23) - is in the form of at least one bolt connection (21) which can be released and / or connected manually, preferably from the front side (15) of the third telescopic section (5), and / or can be released and / or connected mechanically, preferably hydraulically, and / or - is in the form of at least one magnetic connection (26) which can be released and / or activated manually, preferably from the front side (15) of the third telescopic section (5), or can be released and / or activated electromagnetically.

14. The telescopic boom (1) according to any one of claims 11 to 13, wherein: The first telescopic section (3) comprises at least one retaining element (27) which is arranged at the first telescopic section (3), preferably at the rear wall (12) of the first telescopic section (3), the retaining element extending into the second telescopic section (4) and at least in the retracted operating position (25) of the third telescopic section (5), wherein the at least one fastening means (24) is arranged at the at least one retaining element (27), wherein it is preferably provided that the at least one retaining element (27) is constructed in the form of a profile or a profile tube, particularly preferably a U-shaped profile (28).

15. The telescopic boom (1) according to any one of claims 6 to 13 and / or claim 14, wherein: The at least one fastening device (13) and / or the at least one retaining element (27) are designed such that the at least one synchronization device (7) can be supported on the at least one fastening device (13) and / or the at least one retaining element (27) when the at least one synchronization device (7) is loose.

16. Telescopic boom (1) according to any one of the preceding claims, wherein: The at least one drive device (6) and / or at least one possibly present further drive device (9) are configured as a hydraulic cylinder unit (29), an electric drive unit and / or a rope-pulling drive unit, wherein it is preferably provided that the at least one drive unit (6) is arranged on the outer side (30) of the second telescopic joint (4).

17. Telescopic boom (1) according to any one of the preceding claims, wherein: The at least one synchronization device (7) comprises a transmission device (31), by means of which the telescopic speed of the third telescopic section (5) can be slowed down and / or accelerated relative to the telescopic speed of the second telescopic section (4).

18. Telescopic boom (1) according to any one of the preceding claims, wherein: In the retracted operating position (25) of the third telescopic section (5), a free space (32) remains between the front side (15) of the third telescopic section (5) and the at least one synchronization device (7) for connecting at least one telescopic section extension (33).

19. The telescopic boom (1) according to any one of the preceding claims, wherein: At least one fastening mechanism (24) is provided for coupling the movement of the second telescopic section (4) and the third telescopic section (5), wherein, through the at least one fastening mechanism (24), when the second telescopic section (4) moves relative to the first telescopic section (3), the third telescopic section (5) moves together with the second telescopic section (4).

20. The telescopic boom (1) according to any one of the preceding claims, wherein: At least one, preferably driven, sprocket (34) is arranged on the at least one synchronizing device (7).

21. A working device, in particular a crane or a mobile crane, having at least one telescopic boom (1) according to any one of the preceding claims, wherein: In particular, at least one further telescopic section (8) is provided, which is arranged at least partially around the at least three telescopic sections (3, 4, 5).

22. The working device according to claim 21, wherein: The working device has at least one fastening point which is separate from the first telescopic section (3) and at which at least one retaining element (27) is arranged.

23. A method for retracting or extending a telescopic boom (1) according to any one of claims 1 to 20, characterized in that The following method steps are carried out in particular in parallel: - the second telescopic section (4) is moved in translation relative to the first telescopic section (3) by means of a drive device (6), in particular a hydraulic one, and The third telescopic section (5) is moved relative to the second telescopic section (4) by means of the movement of the second telescopic section (4) via at least one synchronization device (7), preferably synchronously and translationally.

24. The method according to claim 23, wherein: Preferably, the at least one synchronization device (7) is decoupled from the second telescopic section (4) by at least one fastening mechanism (24), and the second telescopic section (4) is preferably coupled to the movement of the third telescopic section (5) if possible by at least one fastening mechanism (24), so that when the second telescopic section (4) moves in translation, the third telescopic section (5) moves together with the second telescopic section (4) relative to the first telescopic section (3).

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