Protection device for hydraulic cylinder, hydraulic cylinder assembly, grab bucket and operation machine

Abstract

The utility model relates to a protection device for a hydraulic cylinder, a hydraulic cylinder assembly, a grab bucket and an operation machine. The protection device comprises a flange, a protection pipe and a locking plate detachably installed on the flange. And the flange is sleeved on a cylinder rod of the hydraulic cylinder. The protection pipe is installed around the flange and a cylinder barrel of the hydraulic cylinder, and a circumferential groove and an axial groove are formed in the inner wall of the protection pipe. The lock plate has a protruding portion that protrudes radially outward from the outer peripheral surface of the flange. The protection pipe can rotate between an unlocking position and a locking position relative to the flange, and the protruding part of the locking plate is constructed to be aligned with the axial groove in the axial direction at the unlocking position and can enter and exit from the circumferential groove through the axial groove, and is embedded in the circumferential groove at the locking position. According to the protection device, the axial impact force possibly borne by the protection pipe is transmitted to the flange and the cylinder rod through the lock plate with the large stress area and strength, and the risk that in the prior art, the axial impact force of the protection pipe is directly borne through a bolt, and consequently the protection pipe and the bolt are damaged can be avoided.

Description

Technical Field

[0001] This utility model relates to the field of work machinery parts technology, and in particular to a protection device for a hydraulic cylinder, a hydraulic cylinder assembly including the protection device, a grab bucket including the hydraulic cylinder assembly, and work machinery including the grab bucket. Background Technology

[0002] Cranes and other machinery equipped with grabs use hydraulic cylinders to power the grabs, which in turn drive the grabs, which are composed of multiple grippers or jaws, to open and close, in order to grab and unload the corresponding materials.

[0003] In existing technologies, a protective tube or sleeve is typically fitted around the outer periphery of the hydraulic cylinder to protect it. The protective tube is fixed to the free end of the cylinder rod extending from the cylinder barrel by two bolts facing each other in the diametrical direction. This allows it to extend and retract relative to the cylinder barrel along with the cylinder rod, while protecting the cylinder rod from external damage. The bolt heads are often exposed outside the outer wall of the protective tube, making them susceptible to deformation from material impacts. Furthermore, the harsh operating environment of the grab bucket means that the protective tube may be subjected to significant external impact forces, especially axially, during operation. These impact forces are transmitted to the cylinder rod via the bolts, generating significant shear forces at the contact point between the bolts and the protective tube. This can cause plastic deformation of both the protective tube and the bolts, and may even lead to complete bolt breakage. Utility Model Content

[0004] The purpose of this invention is to solve at least one of the above-mentioned problems and / or other defects in the prior art.

[0005] To achieve the above objectives, according to one aspect of the present invention, a protective device for a hydraulic cylinder is provided, the hydraulic cylinder including a cylinder barrel and a cylinder rod retractable relative to the cylinder barrel, the protective device including a flange, a protective tube, and a locking plate detachably mounted on the flange. The flange is fitted onto the free end of the cylinder rod extending from the cylinder barrel. The protective tube is mounted around the flange and the cylinder barrel and includes a fixed end that can be fixed to the flange, the inner wall of the fixed end being provided with a circumferentially extending circumferential groove and an axial groove extending axially from the axial end face of the fixed end to the circumferential groove. The locking plate has a protrusion extending radially outward from the outer circumferential surface of the flange. The protective tube is rotatable relative to the flange between an unlocked position and a locked position, the protrusion of the locking plate being configured to axially align with the axial groove and be able to enter and exit the circumferential groove via the axial groove when the protective tube is in the unlocked position, and to be engaged within the circumferential groove when the protective tube is in the locked position.

[0006] According to one embodiment of the present invention, the flange is provided with a mounting groove recessed radially inward from its outer peripheral surface, and the locking plate includes a mounting portion fitted into the mounting groove and is detachably mounted to the flange by a first fastener passing axially through the flange and the mounting portion.

[0007] According to one embodiment of the present invention, the locking plate is detachably fixed to the flange by two parallel first fasteners.

[0008] According to one embodiment of the present invention, two locking plates arranged opposite each other in the diametrical direction are installed on the flange, and two axial grooves corresponding to the protrusions of the two locking plates are provided at the fixed end of the protective tube. The circumferential groove is a closed annular groove extending circumferentially to receive the protrusions of the two locking plates.

[0009] According to one embodiment of the present invention, a first fixing hole extending radially is provided on the outer peripheral surface of the flange, and a second fixing hole is provided at the fixed end of the protective tube. When the protective tube is in the locked position, the first fixing hole and the second fixing hole are aligned with each other and receive a second fastener so that the protective tube is locked relative to the flange.

[0010] According to one embodiment of the present invention, the second fastener is an internal hexagon bolt, and its head is at least partially embedded in the second fixing hole of the protective tube.

[0011] According to one embodiment of the present invention, the flange is further provided with a through groove on its outer circumferential surface, which extends axially through the thickness of the flange and is offset from the locking plate in the circumferential direction. The through groove and the inner wall of the protective tube together define a flow hole that communicates with the space between the protective tube and the cylinder.

[0012] According to another aspect of the present invention, a hydraulic cylinder assembly is provided, the hydraulic cylinder assembly including a hydraulic cylinder and a protection device according to any of the preceding claims.

[0013] According to another aspect of the present invention, a grab bucket is provided, the grab bucket comprising a plurality of grippers and a hydraulic cylinder assembly as described above for driving each gripper to pivot.

[0014] According to another aspect of the present invention, a working machine is provided, which includes the grab bucket as described above.

[0015] The protective device of this invention features a circumferential groove on the inner wall of the fixed end of the protective tube, and a locking plate fixed to the flange of the cylinder rod. By embedding the protrusion of the locking plate into the circumferential groove, the protective tube and the flange can be axially fixed relative to each other. Thus, the axial impact force that the protective tube may experience during grab bucket operations can be transmitted to the flange and cylinder rod via the locking plate. Since the locking plate has a larger bearing area and strength than bolts, it avoids the risk of damage to the protective tube and bolts caused by directly bearing the axial impact force of the protective tube through bolts in existing technologies. Attached Figure Description

[0016] The features and advantages of this utility model will become clear from the following detailed description provided with reference to the accompanying drawings. It should be understood that the following drawings are merely schematic and not necessarily drawn to scale, and therefore should not be considered as limitations on this utility model, wherein:

[0017] Figure 1 A perspective view of a protective device installed on a hydraulic cylinder according to an embodiment of the present invention is shown.

[0018] Figure 2 Show Figure 1 The diagram shows an exploded view of the protective device and hydraulic cylinder.

[0019] Figure 3 Show Figure 1 A perspective view of the flange in the protective device shown.

[0020] Figure 4 Show Figure 1 The end view shown shows the protective device and the cylinder rod of the hydraulic cylinder assembled together.

[0021] Figure 5 Show Figure 4 The protective tube in the protective device shown is in the unlocked position, viewed along line AA.

[0022] Figure 6 Show Figure 4 The protective tube in the protective device shown is in the locked position, along line AA.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1. Hydraulic cylinder; 11. Cylinder barrel; 111. Protrusion; 12. Cylinder rod; 2. Flange; 21. Mounting groove; 22. First side wall; 221. First orifice; 23. Second side wall; 231. Second orifice; 24. First fixing hole; 25. Through groove; 3. Protective tube; 31. Fixed end; 311. Circumferential groove; 312. Axial groove; 313. Second fixing hole; 32. Main body; 4. Locking plate; 41. Protrusion; 42. Mounting part; 5. First fastener; 6. Second fastener; 7. Flow hole; 8. Support ring. Detailed Implementation

[0025] Embodiments of the present invention are described below with reference to the accompanying drawings. In the following description, numerous specific details are set forth to enable those skilled in the art to more fully understand and implement the present invention. However, it will be apparent to those skilled in the art that implementations of the present invention may not include some of these specific details. Furthermore, it should be understood that the present invention is not limited to the specific embodiments described. Rather, the present invention can be conceived to be implemented with any combination of the features and elements described below, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments, and advantages are for illustrative purposes only and should not be construed as elements or limitations of the claims unless expressly set forth in the claims.

[0026] The terms "first" and "second" are used below to describe the elements of this application. These terms are used only to distinguish the individual elements and not to limit the nature, order, or number of these elements. The terms "comprising" and "having" are used to indicate an open-ended inclusion and mean that there may be additional elements / components besides those listed.

[0027] Construction machinery such as cranes or loaders can be equipped with grippers such as claw-type or multi-claw-type grabs. These grabs include multiple claws arranged at equal intervals in the circumferential direction. Each claw can pivot under the drive of a corresponding hydraulic cylinder, causing the entire grab to open and close to grab or unload materials. Due to the harsh operating environment of grabs, the hydraulic cylinders can be equipped with protective devices, especially to protect the cylinder rods that need to extend and retract relative to the cylinder barrel.

[0028] Figure 1 and Figure 2 A protective device and a corresponding hydraulic cylinder according to an embodiment of the present invention are shown. Figure 1 and Figure 2As shown, the hydraulic cylinder 1 may include a cylinder barrel 11 and a cylinder rod 12. The cylinder barrel 11 is a cylindrical shape with one end open and the other end closed, defining a hydraulic chamber (not shown). The fixed end of the cylinder rod 12 is disposed in the hydraulic chamber and connected to a piston (not shown), which divides the hydraulic chamber into a rod chamber and a rodless chamber. Two oil pipes (not shown) are provided on the outside of the cylinder barrel 11, one oil pipe connecting to the rod chamber and the other oil pipe connecting to the rodless chamber. The free end of the cylinder rod 12 extends out of the cylinder barrel 11 from the open end of the cylinder barrel 11. The closed end of the cylinder barrel 11 is provided with a connecting part with a through hole, and the free end of the cylinder rod 12 is also provided with a connecting part with a through hole. These two connecting parts are hinged to the grab mounting structure and a gripper of the working machinery, respectively, so that hydraulic oil enters the rod chamber or the rodless chamber to push the cylinder rod 12 to extend and retract, thereby driving the gripper to pivot. The protective device for the hydraulic cylinder 1 according to this embodiment may include a flange 2, a protective pipe 3, and a locking plate 4.

[0029] Figure 3 A perspective view of flange 2 according to this embodiment is shown. Figure 3 As shown, flange 2 has a through hole in the middle for cylinder rod 12 to pass through, and is thus fixedly fitted onto the free end of cylinder rod 12. For mounting locking plate 4, flange 2 may, for example, be provided with a mounting groove 21 recessed radially inward from the axial middle portion of its outer circumferential surface, thereby forming a first sidewall 22 and a second sidewall 23 on both axial sides of the mounting groove 21. A first orifice 221 is provided on the first sidewall 22, and a second orifice 231 corresponding to the first orifice 221 is provided on the second sidewall 23.

[0030] like Figures 4 to 6As shown, the locking plate 4 may include a protrusion 41 and a mounting portion 42. The mounting portion 42 fits into the mounting groove 21 of the flange 2, so that the first sidewall 22 and the second sidewall 23 located on both axial sides of the mounting groove 21 can limit the axial position of the mounting portion 42 and thus the locking plate 4, so that the locking plate 4 is securely fixed relative to the flange 2 in both axial directions, and can transmit the impact force experienced by the protective tube in both axial directions. The mounting portion 42 is provided with mounting holes, and a first fastener 5, such as a bolt, passes sequentially along the axial direction of the flange 2 and the protective tube 3 through the first orifice 221 on the flange 2, the mounting hole on the mounting portion 42, and the second orifice 231 on the flange 2, so that the locking plate 4 can be detachably mounted to the flange 2. In other embodiments, the mounting groove 21 may also be a groove that is recessed radially inward from the outer peripheral surface of the flange 2, but only defines the first sidewall 22 or the second sidewall 23 on one axial side, while being open on the other axial side. In this case, the first fastener 5 is required to fix the locking plate 4 relative to the flange 2 in the axial direction. In the illustrated embodiment, the locking plate 4 is detachably mounted on the flange 2 by two parallel first fasteners 5, which fix the locking plate 4 in place within the plane of the locking plate 4 (in both circumferential and radial directions). Alternatively, only one fastener 5 can be used, with the mounting portion 42 of the locking plate 4 forming a form fit with the corresponding mounting groove 21, thereby fixing the locking plate 4 in place within its plane. The protrusion 41 of the locking plate 4 extends radially outward from the outer peripheral surface of the flange 2 and is used to fix the protective tube 3 relative to the flange 2 when it is installed onto the flange 2 (described in detail below).

[0031] refer to Figure 2 As shown, the protective tube 3 is arranged around the cylinder 11 and the flange 2 and may include a fixed end 31 and a main body 32. The fixed end 31 of the protective tube 3 can fix the protective tube 3 to the flange 2, while the main body 32 of the protective tube 3 covers the rod body of the cylinder rod 12 and at least a portion of the outer periphery of the cylinder 11, so that the protective tube 3 can slide axially outside the cylinder 11 as the cylinder rod 12 extends and retracts. To facilitate the axial sliding of the protective tube 3, the cylinder 11 has two protrusions 111 spaced apart on its outer peripheral wall near its open end to form a limiting portion between the two protrusions 111. A support ring 8 can be fitted into this limiting portion. When the protective tube 3 is installed in place, the outer peripheral wall of the support ring 8 abuts against the inner wall of the protective tube 3, thereby providing support for the main body 32 of the protective tube 3 when the protective tube 3 slides axially and reducing the friction between the inner wall of the protective tube 3 and the entire outer wall of the cylinder.

[0032] The inner wall of the fixed end 31 of the protective tube 3 is provided with a circumferential groove 311 and an axial groove 312. In the illustrated embodiment, the circumferential groove 311 can extend around the entire circumference of the protective tube 3 to form an integral closed annular groove; in other embodiments, the circumferential groove 311 can also extend only along a portion of the circumference of the protective tube 3 to form an arc-shaped groove. The axial groove 312 extends from the axial end face of the fixed end 31 along the axial direction of the protective tube 3 to the circumferential groove 311. The circumferential widths of the axial groove 312 and the protrusion 41 of the locking plate 4 are each set such that the axial groove 312 can receive the protrusion 41, thereby allowing the protrusion 41 to enter and exit the circumferential groove 311 via the axial groove 312. The protrusion of the locking plate 4 can extend into the axial groove 312 and the circumferential groove 311 during the process of installing the mounting tube 3 onto the flange 2 and locking it.

[0033] The protective tube 3 can rotate relative to the flange 2 between the unlocked position and the locked position. Figure 5 It shows Figure 4 The protective tube 3 is in the unlocked position relative to flange 2. Figure 6 It shows Figure 4 The protective tube 3 is in the locked position relative to the flange 2. When the protective tube 3 is in the unlocked position, the protrusion 41 of the locking plate 4 is aligned axially with the axial groove 312, allowing the protrusion 41 to move in and out of the circumferential groove 311 along the axial groove 312. When the protective tube 3 rotates from the unlocked position to the locked position relative to the flange 2, the protrusion 41 is no longer aligned axially with the axial groove 312, but is instead fitted into the circumferential groove 311. At this time, the locking plate 4 and the flange 2 are axially fixed relative to the protective tube 3.

[0034] In the illustrated embodiment, flange 2 has two mounting grooves 21 arranged opposite each other in its diametrical direction, each groove 21 receiving a locking plate 4. Correspondingly, the fixed end 31 of the protective tube 3 is provided with two axial grooves 312 arranged opposite each other in its diametrical direction, allowing the corresponding two locking plates 4 to respectively enter and exit the circumferential grooves 311 and fix the protective tube 3 axially relative to flange 2. Such two opposing locking plates 4 can achieve balanced and stable fixation of the protective tube 3 relative to flange 2, and can also transmit greater impact force using the two locking plates 4. It should be noted that the number and arrangement of locking plates 4 (and corresponding axial grooves 312) are not particularly limited. In addition to the two arranged opposite each other in the diametrical direction as illustrated, there can also be one, or three or more arranged at equal or unequal intervals in the circumferential direction, as long as the impact force borne by the protective tube 3 can be sufficiently transmitted.

[0035] like Figure 2 and 3As shown, the flange 2 may also have a first fixing hole 24 at a position offset circumferentially from the mounting groove 21, and the fixed end 31 of the protective tube 3 may have a second fixing hole 313 corresponding to the first fixing hole 24 on the flange 2. When the protective tube 3 is in the locked position, the first fixing hole 24 and the second fixing hole 313 are aligned with each other and can accommodate the second fastener 6 passing through them, thereby locking the protective tube 3 circumferentially relative to the flange 2.

[0036] In this embodiment, the second fastener 6 can be an internal hex bolt, and its head can be at least partially embedded in the second fixing hole 313 of the protective tube 3, thereby reducing the probability of being impacted by external materials. Alternatively, the first fastener 5 can also be an internal hex bolt whose head is at least partially embedded in the first hole 221 of the flange 2. Therefore, the first fastener 5 and the second fastener 6 can be easily installed using an internal hex bolt tool.

[0037] like Figure 3 As shown, flange 2 may also have a through groove 25 provided at a position offset circumferentially from mounting groove 21 (or locking plate 4) and first fixing hole 24. The through groove 25 extends through the thickness of flange 2 along its axial direction (i.e., the axial direction of the hydraulic cylinder), so that when the protective tube 3 is installed to the outer periphery of flange 2, it can be confined together with the inner wall of the protective tube 3 to a certain extent. Figure 4 The flow hole 7 shown allows the space between the protective pipe 3 and the cylinder 12 to be connected to the outside, enabling venting and drainage of the space. The through groove 25 is located on the outer periphery of the flange 2, which is easy to process and relatively concealed. Therefore, it allows for venting and drainage while preventing foreign objects from entering the space through the through groove 25.

[0038] This utility model also provides a hydraulic cylinder assembly including the above-mentioned protective device, the hydraulic cylinder assembly including the above-mentioned hydraulic cylinder 1 and the protective device.

[0039] This utility model also provides a grab bucket and a working machine. The grab bucket includes multiple grippers and the aforementioned hydraulic cylinder assembly, the hydraulic cylinders of which can drive each gripper to pivot in order to grab or unload material.

[0040] Industrial applicability

[0041] As described above, the protective device according to this utility model is applicable to various working machines equipped with grab buckets as working implements, and is used to provide protection for the hydraulic cylinders that drive the opening and closing of the grab buckets. However, it should be understood that the protective device according to this utility model can also be applied to hydraulic cylinders in other scenarios where protection of the cylinder rod is required.

[0042] The following is based on Figures 1 to 6Taking the illustrated embodiment as an example, the installation and disassembly process of the protective device relative to the hydraulic cylinder 1 is specifically described. The flange 2 is pre-installed and fixed in place on the cylinder rod 12, thereby connecting it integrally with the cylinder rod 12.

[0043] During the installation of this protective device, the protective tube 3 is first inserted through the free end of the cylinder rod 12, and the flange 2 is exposed from the fixed end 31 of the protective tube 3. Then, the mounting portions 42 of the two locking plates 4 are respectively inserted into the two mounting slots 21 of the flange 2, and the two locking plates 4 are fixed to the flange 2 by multiple first fasteners 5. Next, the protective tube 3 is rotated so that the two axial grooves 312 of its fixed end 31 are aligned with the protrusions 41 of the two locking plates 4 respectively, at which point the protective tube 3 is in the unlocked position. Then, the protective tube 3 is pulled toward the flange 2 so that each protrusion 41 can slide past the corresponding axial groove 312 and reach the circumferential groove 311 on the inner wall of the fixed end 31. Next, rotate the protective tube 3 so that the protrusion 41 engages with the circumferential groove 311 and rotates along the circumferential groove 311 until it is no longer aligned with the axial groove 312, thus preventing it from moving out through the axial groove 312. At this point, the protective tube 3 enters the locked position, and the protrusion 41 is axially confined within the circumferential groove 311, thereby achieving axial fixation of the locking plate 4 and the flange 2 relative to the protective tube 3. Finally, continue rotating the protective tube 3 until the second fixing hole 313 on the protective tube 3 aligns with the first fixing hole 24 on the flange 2. Then, pass the second fastener 6 radially through the second fixing hole 313 and the first fixing hole 24 in sequence, thereby fixing the protective tube 3 circumferentially relative to the flange 2.

[0044] The disassembly process of this protective device is exactly the reverse of the installation process described above: First, remove the second fastener 6, then rotate the protective tube 3 so that the axial groove 312 at the fixed end of the protective tube 3 aligns with the protrusion 41 of the corresponding locking plate 4. Next, push and pull the protective tube 3 towards the closed end of the cylinder 11 so that the protrusion 41 can disengage from the protective tube 3 along the axial groove 312, thereby exposing the locking plate 4 from the protective tube 3. Then, remove each of the first fasteners 5, and then pull the mounting part 42 of the locking plate 4 out of the mounting groove 21, that is, remove the locking plate 4. Finally, push and pull the protective tube 3 so that it slides over the flange 2 and is completely removed from the free end of the cylinder rod 12.

[0045] The protective device of this invention has a circumferential groove on the inner wall of the fixed end of the protective tube, and a locking plate is fixed on the flange of the cylinder rod. By inserting the protrusion of the locking plate into the circumferential groove, the protective tube and the flange can be fixed relative to each other in the axial direction. Thus, the axial impact force that the protective tube may be subjected to during grab bucket operation can be transmitted to the flange and cylinder rod through the locking plate. Since the force-bearing area and strength of the locking plate are larger than those of bolts, the risk of damage to the protective tube and bolts caused by directly bearing the axial impact force of the protective tube through bolts in the prior art can be avoided.

[0046] Various modifications and variations can be made to the embodiments disclosed above without departing from the scope or spirit of this invention. Other embodiments of this invention will be apparent to those skilled in the art based on the practice of this invention disclosed in this specification. This specification and the examples disclosed herein should be considered illustrative only, and the true scope of this invention is defined by the appended claims and their equivalents.

Claims

1. A protective device for a hydraulic cylinder (1), the hydraulic cylinder (1) comprising a cylinder barrel (11) and a cylinder rod (12) retractable relative to the cylinder barrel, characterized in that, The protective device includes: Flange (2), which is fitted onto the free end of the cylinder rod (12) extending from the cylinder barrel (11); A protective tube (3) is mounted around the flange (2) and the cylinder and includes a fixed end (31) that can be fixed to the flange. The inner wall of the fixed end is provided with a circumferentially extending circumferential groove (311) and an axial groove (312) extending axially from the axial end face of the fixed end to the circumferential groove. A locking plate (4) is detachably mounted to the flange (2), the locking plate having a protrusion (41) extending radially outward from the outer peripheral surface of the flange. The protective tube (3) is rotatable between an unlocked position and a locked position relative to the flange (2). The protrusion (41) of the locking plate (4) is configured to be axially aligned with the axial groove (312) when the protective tube (3) is in the unlocked position and to be able to enter and exit the circumferential groove (311) through the axial groove, while being fitted into the circumferential groove when the protective tube (3) is in the locked position.

2. The protection device according to claim 1, characterized in that, The flange (2) is provided with a mounting groove (21) recessed radially inward from its outer peripheral surface, and the locking plate (4) includes a mounting portion (42) fitted into the mounting groove and is detachably mounted to the flange (2) by a first fastener (5) passing axially through the flange and the mounting portion.

3. The protection device according to claim 2, characterized in that, The locking plate (4) is detachably fixed to the flange (2) by two parallel first fasteners (5).

4. The protective device according to any one of claims 1 to 3, characterized in that, The flange (2) is equipped with two locking plates (4) arranged opposite each other in the diameter direction. The fixed end of the protective tube (3) is provided with two axial grooves (312) corresponding to the protrusions (41) of the two locking plates respectively. The circumferential groove (311) is a closed annular groove extending around the circumference to receive the protrusions of the two locking plates.

5. The protection device according to claim 4, characterized in that, The outer circumferential surface of the flange (2) is provided with a first fixing hole (24) extending radially, and the fixed end of the protective tube (3) is provided with a second fixing hole (313). When the protective tube is in the locked position, the first fixing hole (24) and the second fixing hole (313) are aligned with each other and receive a second fastener (6) so that the protective tube (3) is locked relative to the flange (2).

6. The protection device according to claim 5, characterized in that, The second fastener (6) is an internal hex bolt, and its head is at least partially embedded in the second fixing hole (313) of the protective tube (3).

7. The protective device according to any one of claims 1 to 3, characterized in that, The flange (2) is also provided with a through groove (25) on its outer peripheral surface, which extends axially through the thickness of the flange and is offset from the locking plate (4) in the circumferential direction. The through groove and the inner wall of the protective tube (3) together define a flow hole (7) that communicates with the space between the protective tube and the cylinder (11).

8. A hydraulic cylinder assembly, characterized in that... It includes a hydraulic cylinder (1) and a protection device according to any one of claims 1 to 7.

9. A grab bucket, characterized in that... It includes multiple grippers and a hydraulic cylinder assembly as described in claim 8 that drives each gripper to pivot.

10. A type of operating machinery, characterized in that, Includes the grab bucket according to claim 9.

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