Gripping tongs, gripping system, and use of gripping tongs

Abstract

The present invention is, A housing (11) having a central axis, The housing (11) includes at least one piston (12) that is slidably disposed along the central axis, A plurality of gripping arms (13), each of which is mounted in and / or on the housing (11) so as to be rotatable about a hinge axis, A gripping tong (10) for gripping an object, particularly in a sewage system, The present invention relates to a gripping tong (10) having at least one lifting element (14) connected to the piston (12), the lifting element (14) being connected to the gripping arm (13) such that when the piston (12) strokes away from the gripping arm (13), the gripping arm (13) moves from an open position to a closed position.

Description

Technical Field

[0001] The present invention relates to gripping tongs, a gripping system, and the use of such gripping tongs or gripping systems. The gripping tongs described in the first part of claim 1 are known, for example, from DE 20 2010 012 511 U1.

Background Art

[0002] Objects may accumulate in water, manholes, or sewer pipes, restricting the flow within the pipes or even causing blockages. Such objects include, for example, foreign matter that has flowed into the pipe system or those formed by solids deposited within the pipe. To prevent pipe blockages, it is common to use gripping tongs to remove such objects from the pipes.

[0003] For example, DE 20 2010 012 511 U1 describes gripping tongs having gripping arms that can be actuated by compressed air. To close the gripping arms, pressure is applied to the piston with compressed air to move it in the direction of the gripping arms. The piston interacts with the end of the gripping arm to move the gripping arm from the open position to the closed position. The piston is guided within the housing, and the gripping arm is also rotatably mounted within this housing. In the non-operating state, a first spring is used to return the piston to its initial position, and a plurality of second springs are used to open the gripping arm.

[0004] Due to its structure, the gripping tongs of DE 20 2010 012 511 U1 have a relatively long design and are thus difficult to pass through pipes, especially bends, elbows, and branches.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, the present invention is based on the problem of providing a gripping tong for gripping an object that is compact and easy to handle due to an improved design. The present invention is also based on the problem of providing a gripping system, as well as the use of the gripping tong and gripping system. [Means for solving the problem]

[0006] According to the present invention, this problem is solved with respect to the gripping tongs by the subject matter of claim 1. With respect to the gripping system, the above problem is solved by the subject matter of claim 15, and with respect to use, the above problem is solved by the subject matter of claim 16.

[0007] In particular, this problem is solved by a gripping tong for gripping objects, especially in sewage systems, comprising at least one housing having a central axis, at least one piston slidably disposed within the housing along the central axis, and a plurality of gripping arms each rotating about a hinge axis within and / or on the housing.

[0008] According to the present invention, the gripping tongs include at least one lifting element connected to a piston, the lifting element being connected to the gripping arm such that when the piston performs a stroke motion away from the gripping arm, the gripping arm moves from an open position to a closed position.

[0009] In other words, the gripping arm is pulled from the open position to the closed position by the piston, and the lifting element is connected to the piston on one side and to the gripping arm on the other. Therefore, the lifting element acts as a connecting part between the piston and the gripping arm in order to convert the stroke motion of the piston into rotational motion around the hinge axis of the gripping arm. That is, the lifting element is configured to close the gripping arm when the piston strokes away from the gripping arm. This corresponds to the gripping state in which the gripping tongs can grasp one or more objects.

[0010] By connecting the lifting element to the gripping arm according to the present invention, the gripping tongs can be structurally simple and compact, particularly in terms of their length. This means that the gripping tongs can be quickly and easily passed through the pipeline system during use. In particular, the gripping tongs can be passed more easily through pipeline passages with changing direction, such as curves, bends, and branches, making them easier to handle overall.

[0011] The lifting element is connected to the piston. The lifting element and the piston are preferably able to move together and slide. The lifting element is preferably able to move together with the piston along the central axis of the housing. The lifting element is preferably positioned on the central axis of the housing. It is especially preferable that the lifting element is firmly, and particularly impervious to displacement, connected to the piston. The lifting element can be connected to the piston by fitting, joining of materials, and / or pressure fitting. The lifting element can be connected to the piston directly or indirectly. It is preferable that the piston is mechanically connected to the gripping arm via the lifting element.

[0012] The housing of the gripping tongs houses the piston. For this purpose, the housing preferably has a piston operating chamber in which the piston is slidably positioned. The housing is formed so that the piston can slide longitudinally along its central axis. In other words, the piston is positioned to move longitudinally within the housing. The piston preferably divides the piston operating chamber into a first operating area and a second operating area.

[0013] Preferably, the housing, and especially the piston operating chamber, is formed so that the piston and especially the lifting element can slide along the central axis by 0 mm to 20 mm, especially 0 mm to 15 mm, and especially 0 mm to 10 mm. Particularly preferably, the housing, and especially the piston operating chamber, is formed so that the piston and especially the lifting element can be displaced along the central axis by 0 mm to 8 mm, preferably at least 6 mm. This stroking motion of the piston is sufficient to move the gripping arm from the open position to the closed position and vice versa.

[0014] When the gripping tongs are operated, that is, when the gripping arms are moved from the open position to the closed position, a working fluid, preferably compressed air, is pressurized and filled into at least one of the working areas of the piston working chamber. Other working fluids, such as liquids or gases, can also be used. However, the gripping tongs of the present invention are preferably pneumatically operated gripping tongs.

[0015] The piston, under the pressure of the working fluid, moves along its central axis away from the gripping arms. The lifting element moves or rotates the multiple gripping arms around their respective hinge axes to the closed position. This brings the gripping tongs into the gripping position.

[0016] Preferably, the gripping arms move toward each other outside the housing when transitioning from an open position to a closed position. In this case, the gripping arms particularly preferably move toward the central axis of the housing. The gripping arms are preferably arranged inside and / or on the housing, particularly at equal intervals, with respect to the central axis.

[0017] In a preferred embodiment, the lifting element is radially positioned between the hinge axes of the multiple gripping arms, particularly in the operating and / or non-operating states of the gripping tongs. Preferably, the lifting element is radially connected to the gripping arms between the hinge axes.

[0018] In the operating state, the piston is subjected to pressure from the working fluid. In the non-operating state, the piston is not subjected to any pressure from the working fluid. This does not preclude the possibility of applying at least one type of pressure medium to the piston, for example, to reset it.

[0019] Gripping tongs are preferably used to grip and / or remove objects from water systems, particularly wastewater systems, sewage facilities, and / or manhole systems. These gripping tongs are particularly suitable for insertion into pipes, especially pipelines, to remove objects such as sediment, mud, fine solids, and / or coarse solids. Alternatively, gripping tongs can be used for other gripping activities, such as gripping activities outside of such systems and pipelines.

[0020] In a preferred embodiment, the gripping arm has at least one particularly short first leg, at least part of which is located within the housing and guided in a fitted state on a lifting element so that the gripping arm rotates around a hinge axis. The first leg, together with the lifting element, forms a lever mechanism. This lever mechanism converts the stroke motion of the piston into rotation of the gripping arm around the hinge axis. This lever mechanism allows for a particularly compact design of the gripping tongs.

[0021] The first leg is preferably the shorter of at least two legs of the gripping arm. The first leg of the gripping arm extends from the hinge axis to the lifting element. The first leg preferably has at least one claw-shaped leg end that engages with the lifting element.

[0022] In another preferred embodiment, the gripping arm is formed in an L-shape, and at least a second leg of the gripping arm extends outward from the housing for at least a portion, and especially a large portion, to grip an object. The second leg of the gripping arm extends outward from the hinge axis. The second leg of the gripping arm is preferably longer than the first leg. The second leg has a free end outside the housing. The free end of the second leg is preferably hook-shaped to allow for better gripping when gripping an object.

[0023] The lifting element is preferably positioned on a first piston rod portion, which is connected to the piston and extends from the piston along its central axis in a first direction, particularly in the direction opposite to the gripping arm. That is, the first piston rod portion extends longitudinally through the housing toward the gripping arm. The first piston rod portion is preferably an elongated extension on which the lifting element is positioned. It is advantageous that the first piston rod portion is a cylindrical extension. This improves the guidance of the piston during stroke motion.

[0024] Preferably, the lifting element is non-slidable to the first piston rod portion. The lifting element may be connected to the first piston rod portion by material-to-material joining, fitting, and / or pressure fitting. Particularly preferably, the lifting element is screwed onto the first piston rod portion. Alternatively, the lifting element may be attached to the first piston rod portion by adhesive and / or sealant to provide a strong permanent connection.

[0025] The first piston rod portion is preferably formed integrally with the piston. That is, the piston and the first piston rod portion are one unit. This makes it easier to manufacture the piston, for example, as a machined part. Alternatively, the first piston rod portion may be connected to the piston as a separate part. For example, the first piston rod portion may be screwed onto the piston.

[0026] More preferably, the lifting element has several cutouts on its outer periphery, and the gripping arm engages with these cutouts, particularly by means of the hook-shaped leg ends. The lifting element preferably has at least one guiding part, particularly a pin, for each cutout, and this guiding part extends in a transverse direction with respect to the central axis of the housing and guides the gripping arm engaged with the cutout. Thus, the gripping tongs have a simple structural design.

[0027] The guiding part preferably engages with the hook-shaped leg end of the first leg. The guiding part preferably forms a transmission mechanism that rotates the engaged gripping arm about its hinge axis during the stroke movement of the piston. The guiding part preferably extends in a transverse direction with respect to the central axis of the housing.

[0028] Particularly preferably, the gripping tongs have at least one first spring element, particularly a first conical compression spring, which interacts with the lifting element such that when the piston is in the non-operating state, the lifting element holds the gripping arm in the open position. The first spring element is preferably a first telescopic spring that moves the piston to the initial position in the non-operating state, and thus moves the gripping arm from the closed position to the open position. The first spring element can also be a first spiral spring or a first, particularly multi-layered, corrugated spring. Other types of springs are also possible.

[0029] Preferably, the first spring element is arranged concentrically with the central axis of the housing. Thereby, the spring pressure is evenly distributed to the lifting element. Also, the gripping tongs can be made compact.

[0030] In a preferred embodiment, the first spring element is arranged on the first piston rod part and abuts against the lifting element so as to apply a spring force in the central axis direction with respect to the lifting element. The first spring element preferably extends around the first piston rod part. The first spring element is preferably arranged such that in the biased state, the spring force acts in the opposite direction to the stroke movement of the piston.

[0031] Preferably, at least one guide support element is positioned between the piston and the lifting element, thereby closing the piston operating chamber of the housing. The first operating area, into which working fluid is introduced to close the gripping tongs, is preferably located between the piston and the guide support element. The guide support element preferably has at least one circumferential portion that protrudes into the piston operating chamber. This circumferential portion is in sealed contact with the inner wall of the housing. Alternatively, at least one sealing material, such as an O-ring, can be placed on the circumferential portion to enhance the sealing effect.

[0032] The guide bearing element has the advantage of dividing the housing into two areas. In the first area, the working fluid is arranged according to the operating state, and in the second area, the stroke motion is transmitted to the gripping arm. If maintenance work is required in the second area, for example on the lifting element, the second area can be opened independently of the piston working chamber. This prevents contamination of the piston working chamber.

[0033] The guide bearing element preferably has at least one through hole through which the first piston rod portion is slidably guided. That is, the first piston rod portion preferably extends through the through hole. The guide bearing element is used to guide the first piston rod portion, and thus the piston, during stroke motion, i.e., in the operating state. In the non-operating state, the guide bearing element is used to support the first piston rod portion, i.e., the piston. An advantage of this embodiment is that the guide bearing element makes the design of the gripping tongs more compact through functional integration.

[0034] In one embodiment, the guide bearing element has at least one spring seat, particularly a recess, that supports a first spring element. The spring seat of the guide bearing element forms a stationary contact portion of the first spring element. The first spring element is supported on the spring seat such that the lifting element is biased with a predetermined spring force. The advantage of this is that the first spring element is fixedly positioned on the guide bearing element. This increases the functional reliability of the first spring element and prevents unwanted positional displacement.

[0035] In a preferred embodiment, the guide support element is connected to the housing by pressure fitting and / or interlocking. The guide support element may have a circumferential ring portion that connects to the housing. In particular, the guide support element, especially its ring portion, can be positioned at least partially between two housing portions of the housing. Thus, the housing can be designed with at least two portions. The advantage of this is that the guide support element can be mounted to or within the housing in a simple and space-saving manner.

[0036] The housing preferably has a bottom with at least one through-hole through which the second piston rod portion, particularly the portion opposite to the gripping arm, is slidably guided. This allows the piston to be stably guided along the central axis.

[0037] The second piston rod portion preferably extends along the central axis in a second direction from the piston, particularly away from the gripping arm. That is, the second piston rod portion extends longitudinally in the housing away from the gripping arm. The second piston rod portion is preferably an elongated extension portion that is at least partially located within the through-hole at the bottom. It is advantageous that the second piston rod portion is a cylindrical extension portion. This improves the guidance of the piston at the bottom of the housing during the stroke motion.

[0038] The second piston rod portion is preferably formed integrally with the piston. That is, the piston and the second piston rod portion are integral. This makes it easier to manufacture the piston, for example, as a machined part. Alternatively, the second piston rod portion may be connected to the piston as a separate part. For example, the second piston rod portion may be screwed onto the piston.

[0039] The housing preferably has at least one perforation connecting a second operating area of ​​the piston operating chamber to the external environment. The second operating area is on the opposite side of the piston from the first operating area. The perforation is preferably formed in the housing wall. This perforation has the advantage, on the one hand, of allowing air in the second operating area to escape when the piston is operating, so that back pressure is not generated against the piston in the second operating area when the gripping arm is closed. On the other hand, when the piston moves to its initial position, air from the external environment can flow into the second operating area of ​​the piston operating chamber through the perforation.

[0040] To prevent the piston operating chamber from being contaminated with dust, a filter is preferably placed over the perforation. The filter is preferably one that covers the perforation. The filter can be a sintered filter. Other types of filters are also acceptable.

[0041] In addition to or instead of the above, the gripping tongs may have at least one second spring element, in particular a second conical compression spring, which interacts with the piston so that the lifting element holds the gripping arm in the open position when the piston is in a non-operating state. The second spring element supports the first spring element to hold the gripping arm in the open position via the lifting element in the non-operating state. The second spring element is preferably a second extension spring, which moves the piston to its initial non-operating position, and thus moves the gripping arm from the closed position to the open position. The second spring element may also be a second spiral spring, or a second, in particular, multi-layered, corrugated spring.

[0042] Preferably, the second spring element is positioned concentrically with the central axis of the housing. This ensures that the spring pressure is evenly distributed to the piston. It also allows for a more compact gripping tong.

[0043] In a preferred embodiment, the second spring element is positioned on the second piston rod portion and in contact with the piston to apply a spring force in the axial direction. Preferably, the second spring element is positioned within the piston working chamber and in contact with the piston to apply a spring force in the axial direction. The second spring element preferably extends around the second piston rod portion. The second spring element is preferably positioned such that, in the biased state, the spring force acts in the opposite direction to the stroke motion of the piston. The spring forces of the first and second spring elements are in the same direction. Because the second spring element is positioned within the piston working chamber, the gripping tongs become even more compact.

[0044] Preferably, the second piston rod portion and / or the piston has at least one passage formed therein, which fluidly connects a connector for supplying working fluid, particularly compressed air, to a first working area of ​​the piston working chamber formed between the guide bearing element and the piston. This passage preferably forms a bypass to a second working area of ​​the piston working chamber. The advantage is that it eliminates the need to create another passage for supplying working fluid. By integrating the functions in this way, the complexity of the gripping tongs can be reduced.

[0045] Preferably, at least one connector for supplying a working fluid, particularly compressed air, is connected to the housing, and this connector has at least one mating contour formed on its outer circumference, particularly a hexagonal contour. This connector is preferably connected to a passage for supplying the working fluid to a first working area of ​​the piston working chamber. The mating contour has the advantage that torsional force can be transmitted to the housing, for example, via a hose, and thus to the entire gripping tong. This eliminates the need for a compression spring. An air push rod can also be used.

[0046] It is advantageous for the gripping arm to have at least one quick-release fitting for replacing the gripping arm portion, and for this fitting to be located outside the housing. This has the advantage of allowing quick and easy access to the quick-release fitting for replacing the gripping arm portion.

[0047] According to a second feature, the present invention relates to a gripping system comprising at least one gripping tong and at least one guide actuator, particularly a hose and / or air push rod, wherein the guide actuator is connected or connectable to a connector of the gripping tong, particularly a connector for compressed air, in a manner capable of withstanding torque, for the purpose of transmitting torque. The advantages described for the gripping tong are now referenced. Furthermore, the gripping system may, in addition to or instead of, have any of the above-described features or combinations thereof for the gripping tong.

[0048] In use relating to the present invention, the gripping tongs and / or gripping system according to the present invention are used to clean pipelines, particularly wastewater systems and / or sewage facilities.

[0049] The present invention will be described in more detail with reference to the accompanying drawings. The embodiments described below are examples illustrating how the gripping tongs and gripping system of the present invention are configured. [Brief explanation of the drawing]

[0050] [Figure 1] This is a perspective view showing gripping tongs of a preferred exemplary embodiment of the present invention. [Figure 2] Figure 1 is a side view of the gripping tongs. [Figure 3] Figure 1 is a longitudinal cross-sectional view of the gripping tongs. [Figure 4] This is a perspective view of a gripping system comprising gripping tongs according to another exemplary embodiment of the present invention. [Figure 5] Figure 4 is a longitudinal cross-sectional view of the gripping tongs. [Modes for carrying out the invention]

[0051] In the following description, identical or similarly functioning parts will be given the same reference numeral.

[0052] Figures 1 to 3 show gripping tongs for gripping objects according to a preferred exemplary embodiment of the present invention. The gripping tongs 10 are preferably used for cleaning pipes in wastewater systems, sewage systems, and / or manhole systems. They can also be used in applications in other fields, particularly outside of pipes. The gripping tongs 10 in Figures 1 to 3 are pneumatically operated gripping tongs.

[0053] The gripping tongs 10 have a housing 11, a piston 12, and a plurality of gripping arms 13. The gripping arms 13 will be described in more detail later. The piston 12 is housed within the housing 11. The housing 11 has a central axis M, and the piston 12 is slidably positioned along this central axis M. The housing 11 consists of two parts. The housing 11 includes a first housing portion 28a as the bottom. The housing 11 further has a second housing portion 28b as a lid. The first housing portion is firmly connected to the second housing portion. In particular, the lid screws onto the bottom of the housing 11. The housing 11 is basically formed with a rounded outer circumference.

[0054] The housing 11 preferably has a maximum diameter D max The length L is preferably 40mm to 60mm, and particularly preferably 50mm. The housing 11 also preferably has a length L from end to end of 40mm to 60mm, and particularly preferably about 51mm.

[0055] As clearly shown in Figure 3, the piston 12 is housed within the first housing portion 28a, particularly within the bottom. For this purpose, the first housing portion 28a has a piston operating chamber 25 in which the piston 12 is slidably positioned. The piston 12 divides the piston operating chamber 25 into a first operating area 38 and a second operating area 34.

[0056] The piston 12 is formed in a disc shape; that is, the piston 12 is plate-like, and particularly flat. The piston 12 is preferably formed in a cylindrical shape. The piston 12 has sealing means, particularly an O-ring, on its outer circumference to seal against the housing 11.

[0057] As can be seen in Figure 3, the piston 12 is provided with a first piston rod portion 18 and a second piston rod portion 32. In particular, the first and second piston rod portions 18 and 32 are integrally formed with the piston 12. This means that the piston 12 and these two piston rod portions 18 and 32 are formed from a single piece.

[0058] The two piston rod portions 18 and 32 extend along the central axis M of the housing 11. The first piston rod portion 18 extends in the direction of the gripping arm 13, and the second piston rod portion 32 extends in the opposite direction to the first piston rod portion 18. The two piston rod portions 18 and 32 are located on opposite sides of the piston 12 and extend in opposite directions.

[0059] As shown in Figure 3, the piston rod portions 18 and 32 each form cylindrical extensions. The first piston rod portion 18 extends into the first operating area 38 of the piston operating chamber 25. The second piston rod portion 32 extends into the second operating area 34 of the piston rod chamber 25. The two piston rod portions 18 and 32 are located on the central axis M of the housing 11.

[0060] Furthermore, the gripping tongs 10 have a lifting element 14 that is non-slidable to the piston 13 via a first piston rod portion 38. This means that the lifting element 14 is able to cooperate with the piston 12. Specifically, the lifting element 14 is located at the longitudinal end of the first piston rod portion 38 opposite to the piston 13. The lifting element 14 is on the central axis M of the housing 11. The lifting element 14 is screwed into the first piston rod portion 38. Specifically, the first piston rod portion 18 has a male thread, and the lifting element 14 has a female thread, which screws into the male thread of the first piston rod portion 38. Alternatively, the screw connection between the lifting element 14 and the first piston rod portion 38 may be fixed with adhesive.

[0061] The lifting element 14 is designed in a disc shape. That is, the lifting element 14 is made of a plate-like, particularly flat, material. The lifting element 14 has multiple notches 21 on its outer circumference 19, into which the gripping arms 13 engage. In particular, the lifting element 14 has one of these notches 21 for each gripping arm 13, into which the gripping arm 13 partially protrudes. The notches 21 are made of grooves that penetrate the lifting element 14 parallel to the central axis M of the housing 11. That is, each notch 21 is open radially outward, forming a passage in the longitudinal direction of the housing 11. As can be seen from Figures 1 and 2, since the gripping tongs 10 have three gripping arms 13, the lifting element 14 has a total of three notches 21.

[0062] The lifting element 14 has a pin-shaped guide portion 22 for each notch 21. This pin is positioned transversely to the central axis M of the housing 11 within the notch 21. In particular, the pin extends transversely to the central axis M through the notch 21. The pin forms a transmission mechanism that rotates the engaged gripping arm 13 around its hinge axis G during the stroke motion of the piston 12. Thus, the pin plays a role in guiding the engaged gripping arm 13 during the stroke motion of the piston 12. The guiding motion, or rotation, of the gripping arm 13 is parallel to the stroke motion of the piston 12.

[0063] The gripping arm 13 is basically designed in an L-shape. In particular, the gripping arm 13 has a first leg 15 and a second leg 17. The first leg 15 is located inside the housing 11, especially inside the lid of the housing 11. The second leg 17 is mostly located outside the housing 11, especially outside the lid. The first leg 15 is shorter than the second leg 17. In other words, the second leg 17 is longer than the first leg 15.

[0064] The first leg portion 15 extends from the hinge axis G to the lifting element 14 and engages with one of the notches 21 of the lifting element 14 at its claw-shaped leg end 16. In other words, the shorter leg portion 15 of each gripping arm 13 has a fork-shaped leg end 16 that engages with the notch 21 of the lifting element 14. At this time, the guide portion 22 of the lifting element 14, in particular the pin, extends through the gap formed between the two claws at the end of the leg portion 16. Thus, the lifting element 14 is connected to the gripping arm 13 in a fitted state for guidance.

[0065] While the piston 12 strokes along the central axis M, the guide portion 22 engages with the gap, guiding the engaged gripping arm 13 to rotate around the hinge axis G. Depending on the direction of the piston 12's stroke, the gripping arm 13 moves from the open position to the closed position, or vice versa.

[0066] As can be seen from Figure 3, the lifting elements 14 are arranged radially between the hinge axes G of the gripping arms 13. The gripping tongs 10 have a total of three gripping arms 13, which are distributed around the central axis M of the housing 11. That is, the gripping arms 13 are distributed circumferentially around the housing 11 and are positioned radially outward with respect to the central axis M. Alternatively, the gripping tongs 10 may have two or more gripping arms 13. The hinge axes G of the gripping arms 13 are located in the outer peripheral region of the housing 11. The hinge axes G are aligned transversely with respect to the central axis M of the housing 11.

[0067] The gripping tongs 10 further have a guide support element 24 positioned between the piston 12 and the lifting element 14. The guide support element 24 closes the first operating area 38 of the piston operating chamber 25 of the housing 11. That is, the first operating area 38 into which the working fluid is introduced to close the gripping tongs 10 is located between the piston 12 and the guide support element 24. The guide support element 24 has a circumferential portion 24a that protrudes into the first operating area 38 of the piston operating chamber 25. This circumferential portion 24a is in sealed contact with the housing 11, particularly the housing inner wall 43 of the first housing portion 28a. Furthermore, the circumferential portion 24a accommodates sealing means, particularly an O-ring, to enhance the sealing effect.

[0068] The guide bearing element 24 has a through hole 26 through which the first piston rod portion 18 is slidably guided. That is, the first piston rod portion 18 extends through the through hole 26. The guide bearing element 24 has sealing means, in particular an O-ring, which is positioned within the through hole 26 and makes sealed contact with the first piston rod portion 18. The guide bearing element 24 is used to guide the first piston rod portion 18, and thus the piston 12, during stroke motion, i.e., in the operating state. In the non-operating state, the guide bearing element 24 is used to support the first piston rod portion 18, i.e., the piston 12.

[0069] As shown in Figure 3, the guide support element 24 has a spring seat 27 that supports the first spring element 23. The spring seat 27 of the guide support element forms the stationary contact portion of the first spring element 23. The first spring element 23 is supported by the spring seat 27 so that the lifting element 14 is biased with a predetermined spring force. The first spring element 23 will be described in more detail later.

[0070] The guide support element 24 is connected to the housing 11 by pressure fitting and / or interlocking. The guide support element 24 has a circumferential annular portion 24b that connects to the housing 11. More specifically, the annular portion 24b is positioned between two housing portions 28a, 28b of the housing 11.

[0071] As described above, the gripping tongs 10 have a first spring element 23 which interacts with the lifting element 14. The first spring element 23 introduces a spring force to the lifting element 14 so as to hold the gripping arm 13 in the open position when the piston 12 is not being actuated. The first spring element 23 is positioned on the first piston rod portion 18 between the guide bearing element 24 and the lifting element 14. The first spring element 23 is resting on and supported by the spring seat 27 of the guide bearing element 24. As is clear from Figure 3, the first spring element 23 is a first conical compression spring. The first conical compression spring is positioned so that the apex of the cone abuts against the contact surface of the lifting element 14.

[0072] The gripping tongs 10 also have a second spring element 35, which is located within the second operating area 34 of the piston operating chamber 25. Specifically, the second spring element 35 is located between the piston 12 and the bottom 29 of the first housing portion 28a. The second spring element 35 interacts with the piston 12. The second spring element 35 introduces a spring force to the piston 12 so as to complement the spring force of the first spring element 23. Since the lifting element 14 is firmly connected to the piston 12 via the first piston rod portion 18, the spring force of the second spring element 35 is also transmitted to the lifting element 14.

[0073] Therefore, similar to the first spring element 23, the second spring element 35 also plays a role in holding the gripping arm 13 in the open position when the piston 12 is not being actuated. The second spring element 35 is positioned on the second piston rod portion 32. The second spring element 35 is mounted and supported on the spring seat 44 of the piston 12. As is clear from Figure 3, the second spring element 35 is a second conical compression spring. The second conical compression spring is positioned so that the apex of the cone abuts against the contact surface at the bottom of the housing 11.

[0074] The two spring elements 23 and 35 are positioned so that when the piston 12 is in operation, the spring force acts in the opposite direction to the stroke motion of the piston 12. Therefore, in the non-operating state, the spring elements 23 and 35 return the piston 12 to its initial position and move the gripping arm 12 from the closed position to the open position. Consequently, the spring forces of the first and second spring elements 23 and 35 are in the same direction.

[0075] The bottom 29 of the housing 11 has a through-hole 31 concentric with the central axis M. The second piston rod portion 32 is partially positioned within the through-hole 31. The second piston rod portion 32 protrudes into the through-hole 31 of the bottom 29 with its end facing away from the piston 12. The bottom 29 is part of the first housing portion 28a. In particular, the second piston rod portion 32 is slidably engaged within the through-hole 31. That is, the second piston rod portion 32 is guided within the through-hole 31 so as to be movable in the longitudinal direction.

[0076] The gripping tongs 10 also have a connector 37 for a guide actuation device. In this embodiment, the connector 37 is designed as a connecting nipple that screws into the bottom 29 of the housing 11. The connecting nipple has a passage 45 through which a second piston rod portion 32 is slidably guided. The end portion of the second piston rod portion 32 is partially engaged in this passage 45. The passage 45 is on the central axis M of the housing 11 and is concentric with the second piston rod portion 32.

[0077] The connector 37 has a mating contour formed on its outer circumference. The mating contour is a hexagonal contour. This contour 37 is connected to the bottom 29 of the housing 11 so that a torsional force can be introduced into the housing 11 via the hexagonal contour. This allows the gripping tongs 10 to rotate about the central axis M.

[0078] Generally, the connector 37 is used to supply the working fluid, in this case compressed air, and to rotate the gripping tongs 10. When the piston 12 is actuated, compressed air is introduced through the connector 37. The second piston rod section 32 has an integrated passage 36, which fluidly connects the passage 45 of the connector 37 to the first working area 38 of the piston working chamber 25. When actuated, compressed air is introduced from the connector 37 through the passage 36 to the first working area 38 of the piston working chamber 25.

[0079] As a result, a compressive force acts on the piston 12 in the first operating area 38b, causing the piston 12, and thus the lifting element 14, to move away from the gripping arm 13 along the central axis M of the housing 11. This corresponds to the stroke motion of the piston 12 away from the gripping arm 13. The first and second spring elements 23 and 35 are compressed by the lifting element 14 and the piston 12, respectively, during this stroke motion.

[0080] During this stroke motion, the housing 11, particularly the first housing portion 28a, has a perforation 33 that connects the second operating area 34 of the piston operating chamber 25 to the external environment AU, allowing air in the second operating area 34 to escape. The perforation 33 is clearly visible in Figure 2. Preferably, a filter is placed over the perforation 33 to prevent dust from being drawn in as the piston 12 returns to its initial position. This filter may be a sintered filter.

[0081] Since the lifting element 14 and the gripping arm 13 are fitted together, the gripping arm 13 rotates around the hinge axis G to move from the open position to the closed position. At that time, the second legs 17 of the gripping arm 13 move closer to each other outside the housing 11.

[0082] As long as compressed air is supplied to the first operating area 38 through the connector 37 and pressure is applied to the piston 12, the gripping arm 13 remains in the closed position. When the supply of compressed air is stopped, that is, when pressure is no longer applied to the piston 12 in the first operating area 38, the compression spring elements 23 and 35 move the piston 12 and the lifting element 14 back to their initial positions. This is only possible in the non-operating state. The first and second spring elements 23 and 25 are expansion and contraction springs, respectively. To restrict the piston 12 and the lifting element 14 from stroking in the direction of the gripping arm 13 when the piston 12 is not being operated, the housing 11, particularly the second housing portion 28b, has a stop surface 46 on its inner surface that the lifting element 14 contacts in its initial position (see Figure 3).

[0083] Figures 4 and 5 show a gripping tong 10 according to another embodiment of the present invention. This embodiment differs from the gripping tong 10 in Figures 1 to 3 only in the shape of the connector 37 and the second leg portion 17 of the gripping arm 13. All other features of the gripping tong 10 shown in Figures 1 to 3 are also present in the gripping tong 10 shown in Figures 4 and 5. Furthermore, the gripping tong 10 in Figures 4 and 5 operates as described above.

[0084] The connector 37 of the gripping tongs 10 shown in Figures 4 and 5 has a cylindrical portion 47 for receiving the hose 102. Unlike the gripping tongs 10 shown in Figures 1 to 3, the connector 37 does not have a mating profile which is a hexagonal profile. The gripping tongs 10 of Figures 4 and 5 also have another connector 48, which is located on the opposite side of the hose 102 from the connector 37. This other connector 48 is fluidly connected to the hose 102. This other connector 48 has a mating profile formed on its outer circumference, specifically a hexagonal profile 39.

[0085] The hose 102 is part of the guide actuator 101, which guides the gripping tongs 10 in use within the pipe and supplies compressed air to the gripping tongs 10 as needed to actuate the piston 12 and close the gripping arm 13.

[0086] The gripping tongs 10 and the guide operating device 101 are combined to form a gripping system 100, which is shown, for example, in Figure 4.

[0087] Furthermore, unlike the gripping tongs 10 shown in Figures 1 to 3, the gripping arm 13 is divided. In particular, the second leg portion 17 of the gripping arm is divided into two parts. The second leg portion 17 has a quick joint 41, which holds the gripping arm portion 42 of the second leg portion 17 in a replaceable manner. The quick joint 41 is integrated with the second leg portion 17. As shown in Figure 5, the quick joint 17 includes a spring and a pin, which, when fitted together, secure the replaceable gripping arm portion 42. The pin is inserted through the spring into the fitting opening. To replace the gripping arm portion 42, it is necessary to move the pin by hand against the spring force of the spring to release the fitting connection.

[0088] It should be noted that the individual or multiple features of the two embodiments of the gripping tongs 10 shown in Figures 1 to 3 and Figures 4 and 5 can be freely combined. For example, the gripping tongs 10 in Figures 1 to 3 may also have at least one interchangeable gripping arm portion 42. [Explanation of Symbols]

[0089] 10 Gripping Tongs 11 Housing 12 pistons 13 Gripping Arm 14 Lifting Elements 15 First leg of the gripping arm 16. Claw-shaped ends of the legs 17 Second leg of the gripping arm 18 First piston rod section 19. Outer perimeter of the lifting element 21 Notches 22 Information section 23 First spring element 24 Guidance and support elements 24a Circumferential portion of the guide support element 24b Circumferential ring 25 Piston operating chamber 26 Through-holes in guide support elements 27 Spring seat of guide support element 28a First housing section 28b Second housing section 29 Bottom 31. Through-hole at the bottom 32 Second piston rod section 33 Perforation 34 Second operating area 35 Second spring element 36 Sewer pipe 37 Connectors 38 First operating area 39 Hexagonal Outline 41 Quick Fittings 42 Replaceable gripping arm section 43 Housing interior wall 44 Piston spring seat 45 Connector / Passage of another connector 46 Inner stopping surface 47 Cylindrical section 48 Another connector 100 Gripping System 101 Guidance Actuator 102 Hose M center axis G hinge axis AU external environment L Housing Length D max Maximum diameter of the housing

Claims

1. A housing (11) having a central axis (M), The housing (11) includes at least one piston (12) slidably arranged along a central axis (M), A plurality of gripping arms (13), each of which is mounted in and / or on the housing (11) so as to be rotatable about a hinge axis (G), In a gripping tong (10) for gripping an object, particularly in a sewage system, A gripping tong (10) comprising at least one lifting element (14) connected to the piston (12), wherein the lifting element (14) is connected to the gripping arm (13) such that when the piston (12) strokes away from the gripping arm (13), the gripping arm (13) moves from an open position to a closed position.

2. The gripping arm (13) has at least one particularly short first leg (15), at least a portion of which is located within the housing (11), and the first leg is guided in a state fitted onto the lifting element (14) so ​​that the gripping arm (13) rotates about the hinge axis (G), and the first leg (15) preferably has at least one claw-shaped end (16), the claw-shaped end (16) to which the lifting element (14) engages. The gripping tongs (10) according to claim 1, characterized in that...

3. The gripping arm (13) is designed in an L-shape, and at least the second, particularly long, leg (17) of the gripping arm (13) extends at least partially, particularly mostly, outside the housing (11) for gripping an object. The gripping tongs (10) according to claim 1 or 2, characterized in that...

4. The lifting element (14) is positioned on the first piston rod portion (18), the first piston rod portion (18) is connected to the piston (12), and extends from the piston (12) along the central axis (M) in a first direction, particularly in the direction opposite to the gripping arm (13), A gripping tong (10) according to any one of the prior claims, characterized in that

5. The lifting element (14) has a plurality of notches (21) on its outer circumference (19), the gripping arm (13) engages with the notches (21) particularly by the claw-shaped end (16) of the first leg, and the lifting element (14) preferably has at least one guide portion (22), particularly a pin, for each notch (21), the guide portion (22) extends transversely with respect to the central axis (M) of the housing (11) and guides the gripping arm (13) engaged with the notches (21). A gripping tong (10) according to any one of the prior claims, particularly claims 2 to 4, characterized in that

6. At least one first spring element (23), particularly a first conical compression spring, is provided, and the first spring element (23) interacts with the lifting element (14) such that the lifting element (14) holds the gripping arm (13) in an open position when the piston is in a non-operating state, and the first spring element (23) is preferably located on the first piston rod portion (18) and biases the lifting element (14) with a spring force in the direction of the central axis (M). A gripping tong (10) according to any one of the prior claims, characterized in that

7. At least one guide support element (24) is positioned between the piston (12) and the lifting element (14), and the guide support element (24) seals the piston operating chamber (25) of the housing (11). A gripping tong (10) according to any one of the prior claims, characterized in that

8. The guide support element (24) has at least one through hole (26) through which the first piston rod portion (18) is slidably guided, and / or the guide support element (24) has at least one spring seat (27), particularly a recess, through which the first spring element (23) is supported. The gripping tongs (10) according to claim 7, characterized in that...

9. The guide support element (24) is connected to the housing (11) by pressure fitting and / or interlocking, and in particular the guide support element (24) is at least partially positioned between two housing portions (28a, 28b) of the housing (11). The gripping tongs (10) according to claim 7 or 8, characterized in that...

10. The housing (11) has a bottom (29) having at least one through-hole (31), within which a second piston rod portion (32), particularly on the side opposite to the gripping arm (13), is slidably guided, and / or the housing (11) has at least one perforation (33), the perforation (33) connecting the second operating area (34) of the piston operating chamber (25) to the external environment (AU), and in particular, at least one filter covering the perforation, A gripping tong (10) according to any one of the prior claims, particularly claims 7 to 9, characterized in that

11. At least one second spring element (35), particularly a second conical compression spring, is provided, the second spring element (35) interacts with the piston (12) such that the lifting element (14) holds the gripping arm (13) in the open position when the piston is in a non-operating state, the second spring element (35) is preferably located within the piston operating chamber (25) and contacts the piston (12) to apply a spring force in the axial direction. A gripping tong (10) according to any one of the prior claims, particularly claims 7 to 10, characterized in that

12. A gripping tong (10) according to any one of the preceding claims, particularly claim 10 or 11, characterized in that a connector (37) for supplying a working fluid, particularly compressed air, is fluidly connected to a first working area (38) of a piston working chamber (25) formed between a guide support element (24) and a piston (12), with at least one passage (36) formed in the second piston rod portion (32) and / or the piston (12).

13. A gripping tong (10) according to any one of the preceding claims, characterized in that at least one connector (37) for supplying a working fluid, in particular compressed air, is connected to the housing (11), and the connector (37) has a mating contour formed on its outer circumference, in particular a hexagonal contour (39).

14. The gripping tongs (10) according to any one of the preceding claims, characterized in that the gripping arm (13) has at least one quick joint (41) for replacing the gripping arm portion (42), and the gripping arm portion (42) is located outside the housing (11).

15. A gripping system (100) comprising at least a gripping tong (10) as described in any one of the preceding claims, and comprising at least one guide actuator (101), in particular a hose and / or an air push rod, wherein the guide actuator (101) is connected or connectable in a manner capable of withstanding torque to the connector (37) of the gripping tong (10), in particular a connector for compressed air, for transmitting torque.

16. Use of the gripping tongs (10) according to any one of claims 1 to 14 and / or the gripping tong system (100) according to claim 15 for cleaning pipelines, in particular wastewater systems and / or sewage facilities.

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