Gripping and lifting device for gripping an object with at least two gripping jaws

Abstract

A gripping and lifting device for gripping a workpiece (32) with at least two gripping jaws (12, 14), comprising a support frame (25) which has a central section (28) that interacts with a lifting means (24) at its upper end and accommodates two oppositely directed supports (17) at its lower end, which are aligned at an obtuse angle to each other and at whose free end each a gripping jaw (12, 14) is arranged, characterized in that the support frame (25) has a gripping range adjustment device (36) which has a guide arm (41, 42) fixedly arranged on the central section (28) for each support (17) and each support (17) is slidably guided along a longitudinal axis of the respective guide arm (41, 42) and is adjustable to a gripping range and at least one of the supports (17) accommodates a pivot axis (16) at a free end opposite the guide arm (41, 42), on which the gripping jaws (12, 14) are pivotably mounted.

Description

[0001] The invention relates to a gripping and lifting device for gripping a gripping object with at least two gripping tongs.

[0002] IT VI 20100184 A discloses a gripping and lifting device comprising a Y-shaped support frame. A pivot axis is provided on each of the two spreading legs of the Y-shaped support frame, through which a gripping tong is pivotably mounted. This gripping tong grips a gripped object with gripping jaws. Opposite the gripping jaws, the gripping arms are guided via additional guide elements on a central section of the support frame, to which a lifting device engages.

[0003] When gripping cylindrical components, such as pipes, it is necessary to grip them not only with force or friction, but also with a positive fit. This requires the gripping jaws of the gripping pliers to engage below the centerline of the pipes to enable positive gripping.

[0004] Such positive and non-positive gripping is possible with the gripping and lifting device described above for a very narrow range of different diameters, ensuring not only non-positive or frictional gripping, but also positive gripping. However, such a gripping and lifting device is severely limited in its usability for handling different pipe sizes, so that several sizes of the gripping and lifting device must be provided to grip pipes with widely varying diameters.

[0005] DE 10 2004 044 615 A1 discloses a gripping and lifting device for cylindrical bodies, which has a gripping width adjustment for the gripping tongs to suit different sizes of the cylindrical components. For this purpose, a support frame in the form of a tube is provided, which is horizontally aligned with respect to a lifting device. A first gripping tong is fastened in the tube, which has two support arms angled at 90° to each other. Opposite, a similar design of the gripping tongs is provided, with this gripping tong being horizontally movable by a gear section within the support frame. The gripping tongs grip below a centerline of the tube and are adjustable to different gripping widths, but not to different diameters.Despite the adjustable gripping width, this gripping and lifting device is limited in its application because the gripping tongs are formed by two support arms arranged at right angles to each other, and the vertically aligned support arm is fixed in length. This gripping width adjustment, in turn, only allows adjustment for a very limited range of different diameters of cylindrical parts. Rather, this gripping width adjustment is intended for use with grippers that engage both internally and externally on the gripped object.

[0006] DE 10 2013 103 276 A1 discloses a hydraulic gripper for gripping pipe elements. This hydraulic gripper comprises a central section which accommodates a lifting device at its upper end. At the lower end of the central section, two pivot arms are arranged, which are pivotally mounted about a common axis in the central section. Adjacent to the pivot axis, a hydraulic cylinder is provided which opens and closes the pivot arms in a rotating manner about the common axis in the central section. This moves the gripping jaws of the gripping arms by a pivoting movement about the fixed and common central axis on the central section. When gripping a cylindrical component, the hydraulic gripper rests with a support surface on the upper area of ​​the pipe. The gripping jaws are then pivoted towards the pipe, engaging the pipe in the center line.In order to adapt to different diameters of the cylindrical components, the gripping jaws are arranged on clamping jaws which are telescopic relative to the pivoting arms which are pivotally mounted around a common axis in the central section.

[0007] The invention is based on the object of creating a gripping and lifting device for gripping a gripping object, in which an adjustment of the gripping width and the immersion depth of the gripping tongs to different sizes of the gripping object is made possible in a simple manner in order to increase the area of ​​application, as well as to maintain the safety of the gripping and lifting device for a force- and form-fitting gripping with differently adjusted gripping widths.

[0008] This object is achieved by a gripping and lifting device which has a support frame with a central part which cooperates with a lifting means at the upper end of the central part and receives two supports pointing in opposite directions at the lower end, which are aligned at an obtuse angle to one another and at whose free ends a gripping tong is arranged, wherein the support frame has a gripping width adjustment device which has a guide arm fixedly arranged on the central part for each support and each support is guided displaceably along a longitudinal axis of the respective guide arm and can be adjusted to a gripping width and at least one of the two supports receives a rotation axis at a free end opposite the guide arm, on which axis the gripping tong is pivotally mounted.This gripping and lifting device offers the advantage that when adapting the gripping and lifting device to a new size of the object to be handled, not only can the gripping tongs be adjusted to the gripping width range, but the insertion depth of the gripping jaws can also be adjusted simultaneously. This not only saves time when adapting the gripping and lifting device to different sizes of the object to be handled, but also increases operating safety.

[0009] To ensure the compact design of the gripping and lifting device, the guide arms are designed to intersect at a fictitious intersection point, preferably located along the longitudinal center axis of the center section. This allows the gripping and lifting device to be designed for both very small and very large items to be handled and to have a compact design.

[0010] Furthermore, it is advantageously provided that the guide arms lie directly adjacent to one another, particularly at the intersection point. This has the advantage of enabling a rigid and almost symmetrical design of the gripping and lifting device.

[0011] A further preferred embodiment of the invention provides that the guide arm is U-shaped or tubular, in which the carrier is movably guided. Preferably, a polygonal, particularly square or rectangular, tubular profile is provided for a tubular guide arm, in order to simultaneously prevent the carrier from rotating relative to the guide arm. Alternatively, the carrier can be U-shaped or tubular and can be movably guided inside or outside the guide arm.

[0012] The carrier, which is arranged so that it can be moved relative to the guide arm, has a guide section along which the carrier is guided to the guide arm, as well as a bent support arm at its free end. This allows the gripper's receiving or pivot point to be positioned lower relative to the object being gripped.

[0013] A preferred embodiment of the invention provides that the carrier's position relative to the guide arm can be adjusted using an adjustment device. This allows for easy adjustment to the various gripping width ranges, which is maintained by the adjustment device while the object is being gripped.

[0014] According to a first embodiment of the adjustment device, it is provided that it is formed by a locking pin that can be inserted into a hole pattern provided in the support and guide arm. This represents a simple design suitable for construction sites.

[0015] An alternative embodiment of the adjustment device provides that a detachable locking pawl is provided between the carrier and the guide arm, which engages in one of several openings on the carrier or guide arm after adjustment of the gripping width and immersion depth.

[0016] An alternative design of the adjustment device provides for an adjustment drive, which drives the supports to be extended and retracted synchronously relative to the respective guide arm on the support frame. This allows the operation of only one adjustment element or adjustment means to jointly extend and retract the supports arranged on the support frame. This also enables them to extend and retract synchronously, further increasing the safety of the gripping and lifting device when setting different gripping widths and insertion depths.

[0017] Alternatively, the adjustment device can further be provided with a threaded spindle acting between the carrier and the guide arm, so that the carrier can be driven in and out of the guide arm. This allows for continuous adjustment and adaptation of the gripping width and insertion depth of the grippers to the object to be gripped.

[0018] The design of the support with a guide section and a support arm bent at its free end provides good accessibility for the adjustment device, which features a threaded spindle. This threaded spindle is located within the support and extends outward in the area of ​​the bent support arm with an adjustment mechanism. Opposite the adjustment mechanism, the threaded spindle is connected to an adjusting nut located on the guide section.

[0019] Furthermore, it can be provided that a fixed gripping tong is provided at the free end of the first support, in particular at the bent support arm, and a pivoting gripping tong is provided at the free end of the further support, in particular at the bent support arm.

[0020] Preferably, a rotational axis is provided at the free end of each support, in particular the bent support arm, on each of which a gripping tong is pivotably mounted. This makes it possible, for example, when gripping cylindrical components, for the rotational axis of the gripping tongs to engage the cylindrical component slightly above a center line and for the gripping jaws of the gripping tongs to engage below the center line. This gripping width adjustment device thus moves the rotational axes not only outwards or inwards, but also upwards or downwards at the same time, so that the gripping width and immersion depth of the gripping tongs are adjusted simultaneously.

[0021] To facilitate handling of the grippers, traction devices are attached to the holding arms opposite the gripping jaws, which are connected to the lifting device. This allows the grippers to be easily closed when the gripping and lifting device is raised. The grippers are preferably mounted on the support frame in a scissor-like manner.

[0022] The invention, as well as further advantageous embodiments and developments thereof, are described and explained in more detail below with reference to the examples shown in the drawings. The features shown in the description and the drawings can be used individually or in any combination according to the invention. They show: Fig. 1 a schematic view of the gripping and lifting device from the front, Fig. 2 a schematic side view of the gripping and lifting device according to Fig. 1, Fig. 3 a schematic side view of the gripping and lifting device with a minimum gripping width setting for a small object, Fig. 4 a schematic side view of the gripping and lifting device with a maximum gripping width setting for a large item, Fig. 5 a schematic side view of a support frame of the gripping and lifting device according to Fig. 1 with supports arranged thereon, Fig. 6 a schematic side view of Fig. 5 and Fig. 7 a schematic side view of the support frame according to Fig. 5 with a large gripping width adjustment.

[0023] In Fig. 1 is a schematic view from the front and in Fig. 2 shows a schematic side view of a gripping and lifting device 11 according to the invention. The gripping and lifting device 11 comprises gripping tongs 12, 14, which interact in particular in a scissor-like manner. According to this embodiment, two opposing gripping tongs 12, 14 are provided, each of which is pivotably mounted on a respective support 17 about a rotation axis 16. The gripping tongs 12, 14 have gripping jaws 19 at a first free end, which are advantageously replaceable and, if necessary, angularly adjustable. These are aligned parallel to the rotation axis 16. Opposite the gripping jaws 19, the gripping tongs 12, 14 comprise holding arms 21, which engage a head 23 of a support frame 25 with a traction means 22. A lifting means 24, in particular a holding eyelet, which is provided for connection to a support device (not shown in detail), is attached to the head 23 of the support frame 25.The gripping and lifting device 11 is handled by such a carrier device.

[0024] The support frame 25 has a central part 28, which is formed, for example, by an outer tube 26 and an inner tube 27 slidably guided within the outer tube 26. The head 23, which is also engaged by the lifting means 24, is provided at the upper end of the inner tube 27. Furthermore, a height-adjustable support element 29 can be provided on the central part 28. This support element 29, together with the gripping jaws 19, enables a three-point contact with a gripping object 32 to be gripped, such as a cylindrical component, in particular a pipe.

[0025] As soon as a load acts on the lifting device 24, for example, by lifting it by means of the carrier device, the inner tube 27 is pulled out relative to the outer tube 26, causing the gripping jaws 19 to move toward each other to grip the object 32. When the load on the lifting device 24 is relieved, the inner tube 27 can be inserted into the outer tube 26, and the gripping tongs 12, 14 are moved away from each other relative to the gripping jaws 19.

[0026] The gripping and lifting device 11 is in Fig. 1, for example, in an opening position 31, so that the gripping and lifting device 11 can be placed on a gripping item 32, that is to say that the gripping jaws 19 on the gripping item 32, such as a pipe, according to Fig. 3, until the support element 29 comes to rest on the gripping item 32. Subsequently, the gripping and lifting device 11 is moved into a gripping position 34, which in Fig. 3. When the gripping and lifting device 11 is lifted via the lifting means 24, the gripping tongs 12, 14 are moved into the gripping position 34, so that according to the Fig. 3, both a force-fitting or frictional and a form-fitting gripping of the gripping item 32 is provided. The gripping jaws 19 preferably engage below the center line of the gripping item 32. Due to the presence of the support element 29, the gripping jaws 19 can enable a force-fitting or frictional and form-fitting reception of the gripping item 32 through the three-point system.

[0027] The gripping and lifting device 11 has a gripping width adjustment device 36. The gripping width adjustment device 36 is according to Fig. 3 is set to a minimum gripping width of the gripping tongs 12, 14. In Fig. 4, the gripping and lifting device 11 is adjusted to a maximum gripping range by means of the gripping range adjustment device 36.

[0028] The gripping width adjustment device 36 enables the rotational axes 16 for the gripping tongs 12, 14 to be positioned above the center line and the gripping jaws 19 to be positioned below the center line of the gripping object 32, both for a cylindrical gripping object 32 with a small diameter and for one with a large diameter. The gripping width adjustment device 36 not only moves the rotational axes 16 outwards in a horizontal direction relative to a longitudinal center axis 30 of the support frame 25, but simultaneously moves them downwards when setting the gripping tongs 12, 14 to a large gripping width or upwards when setting the gripping tongs 12, 14 to a small gripping width. This gripping width adjustment device 36 thus enables the gripping range and the insertion depth of the gripping jaws 19 to the gripping object 32 to be adjusted simultaneously.

[0029] The gripping tongs 12, 14 have, according to the embodiments in the Fig. 1 to 4, an embodiment in which a long lever arm is formed between the rotational axis 16 and the point of application of the traction means 22 on the holding arm 21, and a short lever arm is formed between the rotational axis 16 and the gripping jaw 19. The ratio of the long to the short lever arm is 2:1 or greater, meaning that the longer effective lever arm is at least twice the length of the short effective lever arm. This allows at least twice the security for applying the clamping force when gripping the gripped item 32.

[0030] In Fig. 5 is a view from the front and in Fig. 6 shows a side view of the support frame 25 with the gripping width adjustment device 36 arranged thereon. The support frame 25 comprises the central part 28, which, according to the previously described embodiment, is formed by an inner tube 27 guided in the outer tube 26. Alternatively, the central part 28 can also be formed by an outer tube 26 being movable relative to the inner tube.

[0031] The gripping width adjustment device 36 comprises the supports 17 and the guide arms 41, 42, each of which slidably accommodates a support 17. According to this exemplary embodiment, the supports 17 have a guide section 45, which is slidably guided in the guide arm 41, 42. The supports 17 further have a support arm 46 that is bent relative to the guide section 45. The bent portion of the support arms 46 of the supports 17 is designed such that they are directed toward one another, i.e., that they are inclined toward the longitudinal center axis 30 of the central part 28.

[0032] The guide arm 41, 42 is preferably U-shaped. The guide section 45 is geometrically adapted to the guide arm 41, 42 so that it is slidably received therein. Furthermore, the carrier 17 is held in the guide arm 41, 42 by the guide section 45 in a rotationally secure manner.

[0033] The guide arms 41, 42 are aligned symmetrically with respect to the central part 28. The guide arms 41, 42 are arranged at an obtuse angle to one another, so that the guide arms 41, 42 are inclined downward relative to the longitudinal central axis 30 compared to a horizontal alignment. Preferably, the angle between the two guide arms 41, 42 is greater than the angle between one guide arm 41 and the central part 28 and the other guide arm 42 and the central part 28. This allows the supports 17 to be arranged at a distance from one another relative to the central part 28.

[0034] The longitudinal axes of the guide arms 41, 42 intersect at a fictitious intersection point 48, which preferably lies in the longitudinal central axis 30 of the central part 28.

[0035] The gripping width adjustment device 36 further comprises an adjustment device 51. This is according to the embodiment in Fig. 5 and Fig. 6 is designed as a continuously adjustable adjustment device 51, by means of which the carrier 17 can be moved in and out relative to the guide arm 41, 42. For example, a threaded spindle 52 is provided, which is fixedly but rotatably fastened to a holding plate 53 on the carrier 17. Preferably, an adjustment means 54 protrudes relative to the bent support arm 46, so that easy actuation of the threaded spindle is possible. The threaded spindle 52 extends within the carrier 17 in the direction of the guide arm 41, 42. An adjusting nut 56 is provided on the latter. By rotating the threaded spindle 52, the carrier 17 with its guide section 45 can be moved in and out relative to the guide arm 41, 42.

[0036] In Fig. 7, the support frame 25 with the supports 17 is shown in a maximum gripping width setting of the gripping width adjustment device 36. This shows that the guide section 45 is fully extended and still extends within the guide arm 41, 42, but does not extend beyond its opposite side. This is the case with the minimum gripping width setting, as shown in Fig. 5 is evident.

[0037] The gripping and lifting device 11 with the gripping width adjustment device 36 can be used in an embodiment in which the gripping tongs 12, 14 are both pivotably mounted on a respective rotation axis 16. Alternatively, this gripping width adjustment device 36 can also be provided in gripping and lifting devices 11 in which only one of the gripping tongs 12, 14 is pivotally mounted and at least one other of the gripping tongs is fixedly mounted on the carrier 17. Furthermore, such a gripping width adjustment device 36 can also be provided on a gripping and lifting device 11 in which, instead of the embodiments shown, the gripping tongs 12, 14 are clamped from the outside, and can also be provided for gripping tongs 12, 14 that generate a clamping force on the object 32 from the inside out.

Claims

[1] Gripping and lifting device for gripping a gripping item (32) with at least two gripping tongs (12, 14), with a support frame (25) which has a central part (28) which cooperates at the upper end with a lifting means (24) and at the lower end receives two supports (17) pointing in opposite directions, which are aligned at an obtuse angle to each other and at the free end of which a gripping tong (12, 14) is arranged, characterized by in that the support frame (25) has a gripping width adjustment device (36) which has a guide arm (41, 42) fixedly arranged on the central part (28) for each support (17), and each support (17) is guided displaceably along a longitudinal axis of the respective guide arm (41, 42) and can be adjusted to a gripping width, and at least one of the supports (17) receives a rotary axis (16) at a free end opposite the guide arm (41, 42), on which axis the gripping tongs (12, 14) are pivotally mounted. [2] Gripping and lifting device according to claim 1, characterized by that the guide arms (41, 42) intersect at a fictitious intersection point (48) and the intersection point (48) lies in a longitudinal central axis (30) of the central part (28). [3] Gripping and lifting device according to one of the preceding claims, characterized by that the guide arms (41, 42) are preferably arranged directly adjacent to one another at the intersection point (48). [4] Gripping and lifting device according to one of the preceding claims, characterized by that the guide arm (41, 42) is U-shaped or tubular profile-shaped, in which the carrier (17) is displaceably guided or the carrier (17) has a U-shaped or tubular profile-shaped cross-section and is guided on or in the guide arm (41, 42). [5] Gripping and lifting device according to one of the preceding claims, characterized bythat the carrier (17) is arranged with a guide section (45) displaceably relative to the guide arm (41, 42) and has at its free end a bent support arm (46) for receiving the gripping tongs (12, 14). [6] Gripping and lifting device according to claim 1, characterized by that the at least one carrier (17) is adjustable in its position relative to the guide arm (41, 42) by means of an adjusting device (51). [7] Gripping and lifting device according to claim 6, characterized by that the adjusting device (51) is formed by a plug pin which can be inserted into a hole pattern provided in the support (17) and guide arm (41, 42). [8] Gripping and lifting device according to claim 6, characterized by that the adjusting device (51) has a locking pawl arranged in particular on the guide arm (41, 42) which engages in one of several openings arranged in particular on the carrier (17). [9] Gripping and lifting device according to claim 6, characterized by that the adjusting device (51) has an adjusting drive by means of which the supports (17) can be moved in and out synchronously with the respective guide arm (41, 42) on the support frame (25). [10] Gripping and lifting device according to claim 6, characterized by that the adjusting device (51) comprises a threaded spindle (52) by means of which the carrier (17) can be moved in and out towards the guide arm (41, 42). [11] Gripping and lifting device according to claim 10, characterized by that the threaded spindle (52) is arranged within the support (17) and has an adjusting means (54) in a region of the bent support arm (46) and is connected opposite in the guide arm (41, 42) to an adjusting nut (56) fixedly arranged thereon. [12] Gripping and lifting device according to one of the preceding claims, characterized bythat a fixed gripping tong is provided at the free end of one support (17) and a pivoting gripping tong (12, 14) is provided at the free end of the further support (17). [13] Gripping and lifting device according to one of claims 1 to 11, characterized by that at the free end of the respective support (17), in particular of the support arm (46) on the support (17), a rotational axis (16) is provided, by means of which a gripping tong (12, 14) is pivotally mounted thereon. [14] Gripping and lifting device according to one of the preceding claims, characterized by that the gripping tongs (12, 14) are arranged opposite one another on the respective support (17) and each act on holding arms (21) of the gripping tongs (12, 14) by traction means (22) which are operatively connected to the lifting means (24).

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