KR102213444B1 - Link for excavator with fall prevention means of attachment - Google Patents

Abstract

The present invention relates to a link for an excavator having a fall prevention means of an attachment. More particularly, the present invention relates to a link for an excavator having an attachment fall prevention means of a new type, which safely maintains the bonding state of attachments such as buckets, breakers, and shears that are detachably connected to the link, and minimizes the deformation of the link and prevents safety accidents due to the fall of the attachment, in particular, by forming a safety pin that can physically block the natural separation of the attachment on a fixed hook.

Description

Link for excavator with fall prevention means of attachment

The present invention relates to a link for an excavator having a fall prevention means of the attachment, and more particularly, to safely maintain the coupling state of attachments such as buckets, breakers, and shears that are detachably connected to the link, and in particular, fixed This is a link for excavator that has a new type of attachment fall prevention means that minimizes the deformation of the link by forming a safety pin on the hook that can physically block the natural separation of the attachment, while preventing safety accidents caused by the fall of the attachment. About.

An excavator, generally called a poclain, is an equipment used to remove rocks or soil from the ground in the initial stage of foundation work for construction.

In an excavator, an arm composed of a plurality of joints and a boom cylinder provided on the inner side of the arm are connected by a link, and a bucket capable of pumping out rocks or soil is installed on the link. The excavator supplies hydraulic power to the boom cylinder through a hydraulic line, pumps up soil, etc. using a bucket, and then turns it and loads it onto a carrier or red soil.

In addition, a variety of attachments, such as a breaker that breaks rock or large concrete, or a shear that cuts steel plates, reinforcing bars, or H-beams, are selectively selected on the arm end link of the excavator instead of a bucket. Install it and proceed according to the conditions of the work site.

However, a link for coupling a conventional excavator attachment mechanism generally used is formed of a link body 1 as shown in FIG. 11, and a hydraulic cylinder 2 is formed at the bottom of the link body 1, and a hydraulic cylinder At the end of the cylinder shaft (3) of (2), an annular rotation hook (4) that engages and fixes the attachment mechanism connection shaft by hydraulic operation is formed as a link coupling type, but the annular shape of the rotation hook (4) In the direction, it corresponds to the rotation hook (4), and the fastening piece (5) integrated with the link body (1) that supports and fixes the attachment mechanism connection shaft and the other side of the rotation hook (4) wraps the connection shaft. Hook (6) is formed.

Therefore, the link for coupling attachment mechanisms of a conventional excavator having the above-described configuration is to allow the attachment mechanism to be installed and fixed simply by the support force of the rotating hook and the fastening piece by hydraulic action in attaching various attachment mechanisms as necessary, Not only the fixing force is quite weak, but when the hydraulic device of the hydraulic cylinder is damaged during excavator work, the attachment is detached from the link body as it is, and falls, causing a fatal problem in a safety accident.

Patent registration No. 10-2073345 (registration date: January 29, 2020) as a known conventional technology for solving the above problems, the attachment coupling device for heavy equipment is provided on the coupler body and the attachment coupled to the working link of the heavy equipment A fixing hook fixedly installed on the coupler body for constraining the first pin, spaced apart from the first pin, and spaced apart from the fixing hook for confinement of the second pin provided on the attachment. A moving hook rotatably coupled to the coupler body, and one side is connected to the moving hook via an actuator connection pin so that the moving hook is rotatable around the hook rotation axis, and the other side is spaced apart from the hook rotation shaft. An actuator rotatably coupled to the coupler body via a driving support shaft; And the first pin and the second pin coupled to the fixed hook are rotated around the drive support shaft in response to the operation of the actuator in a state coupled to the drive support shaft to restrain the moving hook coupled to the fixed hook. A pin restraint means; wherein the pin restraint means comprises: a pivot body portion rotatably coupled to the drive support shaft while being connected to the actuator; A hook support part integrally protruding along a normal direction of the driving support shaft from one side of the pivot body part to constrain the moving hook to which the second pin is coupled; A pin support portion integrally protruding from the hook support portion so as to intersect the normal direction of the driving support shaft for restraining the first pin coupled to the fixing hook; And a locking elastic part protruding from the other side of the pivot body in a direction opposite to the protruding direction of the pin support part and elastically supported by the working link.

As another conventional technology, patent registration No. 10-1533841 (Registration date: June 29, 2015) The automatic safety device of the quick coupler includes a quick coupler body 100 connected to an arm of an excavator, and one side of the quick coupler body A fixing hook provided in the first attachment pin and coupled to the first attachment pin, a hitch provided on the other side of the quick coupler body and connected to the rod of the hydraulic cylinder to be coupled to the second attachment pin when the rod moves forward, and the first and second A cylinder having safety means for preventing arbitrary disengagement of an attachment pin, wherein the safety means is connected to the rod of the hydraulic cylinder and slides backward by a reaction force generated when the hitch and the second attachment pin are coupled. The tube and a spring member that is compressed when the cylinder tube moves backward and provides an elastic bias force in one direction to the cylinder tube, and the cylinder tube is connected through a first interlocking means so as to be interlocked and rotated interlockingly, and the end thereof is connected to one side of the hitch. Safety bar that is in contact with limiting the rotation of the hitch, and is connected to the safety bar so as to be interlocked via a second interlocking means, and is rotated interlocked when the safety bar is rotated to lock or release the coupling state of the first attachment pin and the fixing hook It is characterized by having a hook.

However, in the case of a link having the above configuration, the configuration for driving the rotating hook of the link is very complex, and a large cost is incurred in manufacturing the product, making it impossible to make a practical product. Moreover, a link that is easily exposed to foreign substances such as soil or sand Due to its characteristics, foreign substances easily cause failure of the hydraulic cylinder, resulting in a high link failure rate and a lot of time and cost for maintenance related to repair.

In addition, when the inflow cylinder is damaged by the foreign material as described above, there is a problem in that the pressure of the cylinder is removed and the attachment connected to the link is easily separated, so that a fall accident due to separation of the attachment occurs frequently.

Registered Patent Publication No. 10-2073345 (Registration date: January 29, 2020) "Attachment coupling device for heavy equipment" Registered Patent Publication No. 10-1533841 (Registration date: June 29, 2015) "Automatic safety device of quick coupler" Registered Utility Model Publication No. 20-0343651 (Registration date: February 23, 2004) "Link device of forkrain arm"

The present invention was made in consideration of the above circumstances, and an object of the present invention is to provide a stable coupling and separation form of the rotating hook by the operation of the inlet cylinder in coupling and installing various attachments as necessary to the link of the excavator. By providing a configuration that can physically fix the attachment state in addition to the hydraulic cylinder while maintaining it, safety accidents caused by detachment of the attachment during use are prevented by providing a configuration that can physically fix the attachment state in addition to the hydraulic cylinder, and stable excavator work is guaranteed with a solid fixing force. It is to provide a link for an excavator having a fall prevention means of a new type of attachment that can be done.

Another object of the present invention is to simplify the configuration of the link for an excavator to reduce the occurrence of failure due to the introduction of foreign substances, and to enable rapid repair. In particular, even if the hydraulic force of the hydraulic cylinder is removed due to a failure, it is physically attached. It is to provide a link for an excavator having a fall prevention means of an attachment that can prevent a safety accident due to a fall of the attachment by maintaining the fastened state of the attachment.

A link for an excavator having a fall prevention means of an attachment according to an embodiment of the present invention for achieving the above task includes a link body coupled to an arm of the excavator, and a fixed hook fixedly installed on a lower side of the main link And, in a link for an excavator consisting of a rotary hook rotatably fixed to the other side of the fixed hook and a hydraulic cylinder that rotates the rotary hook, wherein the rotary hook is formed in a shape of a hook to surround the connection shaft And a first through hole to which the rotation shaft connected to the link body 10 is coupled at the center portion and a second through hole at the upper portion to which the piston of the hydraulic cylinder is connected. The ring part rotates and the attachment is combined or unfolded in a form that wraps the connection shaft inside, and the hydraulic cylinder is connected to a rotating hook on one side and rotatable to the link body on the other side, and the connection part is extended to the lower part of the connection part. A connection part is formed integrally, and a first connection part rotatably connected to the expansion connection part and a second connection part connected to the second link on the other side are integrally formed, and the first connection part is formed by rotation of the hydraulic cylinder. The first link is assembled in the form of an up-and-down motion with the second connection part on the other side and the second connection part is assembled to the second connection part, and is inserted into the safety pin joint hole formed in the fixing hook, and is in close contact with the outer surface of the fixing hook at the top. And the cover is formed integrally with a guide hole in the center, a connection hole through which the upper part is connected to the second link through the guide hole of the cover, a pin having a stepped in the center part, and the cover is accommodated in the inside of the cover It can be achieved by a link for an excavator having a fall prevention means of the attachment, characterized in that it comprises a safety pin composed of a packing fixed inside of the.

One side of the first link further includes a second link formed with a hole connected to the second connection portion of the first link and a hole in the form of a long hole connected to the pin of the safety pin in order to smoothly move the safety pin up and down. It is characterized.

The hole of the second link is characterized in that it also includes a plurality of deformable packings for preventing the attachment from falling by changing the elevation angle of the safety pin.

The link for an excavator having a fall prevention means of an attachment according to the present invention prevents the disconnection of the connection shaft coupled to the fixed hook on one side of the hydraulic cylinder configured to rotate the rotating hook connected to the connection shaft of the attachment in a detachable form. A retractable pin is formed, and the safety pin is configured so that it can be operated only by the operation of the cylinder, so that even if the hydraulic cylinder is damaged by foreign substances, separation of the attached attachment can be prevented by the configuration of the safety pin. There is an effect that can physically prevent a fall.

Moreover, the link for an excavator having a fall prevention means of the attachment according to the present invention is easy to manufacture and handle because the overall configuration is simple, and it can significantly reduce the occurrence of failure, so it operates smoothly even if foreign substances such as soil or sand are introduced. The overall link configuration maintains the configuration of the link that has been used in the past, and only the minimum configuration is modified or added to prevent the fall of the attachment. Because it is easy, there is an effect that can improve the safety of the site according to the improvement of supply power.

In addition, since the safety pin installed on the fixed hump is connected through the first link and the second link, there is an effect that the movement of the safety pin by the hydraulic cylinder can always be smoothly maintained.

1 is a schematic view of a link for an excavator having a fall prevention means of an attachment according to a first embodiment of the present invention
2 is a perspective view of a fall prevention means among links for an excavator having a fall prevention means of an attachment according to a first embodiment of the present invention
3 is a partial exploded view of a fall prevention means among links for an excavator having a fall prevention means of an attachment according to a first embodiment of the present invention
FIG. 4 is an exploded view of a cylinder and a first link of a link for an excavator having a fall prevention means of an attachment according to a first embodiment of the present invention;
5 is a view showing the shape of the fall prevention means in a state in which the attachment is fastened among links for an excavator having the fall prevention means of the attachment according to the first embodiment of the present invention.
6 is an enlarged cross-sectional view of part A of FIG. 5
7 is a view showing the shape of the fall prevention means in a state in which the attachment is separated among links for an excavator having the fall prevention means of the attachment according to the first embodiment of the present invention.
8 is an enlarged cross-sectional view of part B of FIG. 7
9 is a perspective view showing another embodiment of a second link among links for an excavator having a fall prevention means of an attachment according to a first embodiment of the present invention
FIG. 10 is a cross-sectional view of another embodiment of a second link among links for an excavator having a fall prevention means of an attachment according to the first embodiment of the present invention;
11 is a schematic view of a link for a conventional excavator

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. However, since the description of the present invention is merely an embodiment for structural or functional description, the scope of the present invention should not be construed as being limited by the embodiments described in the text. That is, since the embodiments can be modified in various ways and have various forms, the scope of the present invention should be understood to include equivalents capable of realizing the technical idea. In addition, since the object or effect presented in the present invention does not mean that a specific embodiment should include all of them or only those effects, the scope of the present invention should not be understood as being limited thereto.

Meanwhile, the meanings of terms described in the present invention should be understood as follows.

Terms such as "first" and "second" are used to distinguish one component from other components, and the scope of rights is not limited by these terms. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component.

When a component is referred to as being "connected" to another component, it should be understood that although it may be directly connected to the other component, another component may exist in the middle. On the other hand, when it is mentioned that a component is "directly connected" to another component, it should be understood that there is no other component in the middle. On the other hand, other expressions describing the relationship between the constituent elements, that is, "between" and "just between" or "neighboring to" and "directly neighboring to" should be interpreted as well.

Singular expressions are to be understood as including plural expressions unless the context clearly indicates otherwise, and terms such as "comprises" or "have" refer to specified features, numbers, steps, actions, components, parts, or It is to be understood that it is intended to designate that a combination exists and does not preclude the presence or addition of one or more other features or numbers, steps, actions, components, parts, or combinations thereof.

All terms used herein have the same meaning as commonly understood by one of ordinary skill in the field to which the present invention belongs, unless otherwise defined. Terms defined in a commonly used dictionary should be interpreted as having the meaning of the related technology in context, and cannot be interpreted as having an ideal or excessively formal meaning unless explicitly defined in the present invention.

Now, a link for an excavator having a fall prevention means of an attachment according to a first embodiment of the present invention will be described in detail with reference to the drawings.

In the accompanying drawings, FIG. 1 is a schematic view of a link for an excavator having a fall prevention means of an attachment according to a first embodiment of the present invention, and FIG. 2 is a schematic view of a link for an excavator having a fall prevention means of an attachment according to a first embodiment of the present invention. A perspective view of a fall prevention means among links for an excavator, and FIG. 3 is a partial exploded view of a fall prevention means among links for an excavator having a fall prevention means of an attachment according to a first embodiment of the present invention, and FIG. 4 is a first embodiment of the present invention. An exploded view of a cylinder and a first link part of an excavator link having a fall prevention means of an attachment according to an embodiment, and FIG. 5 is an attachment among an excavator link having a fall prevention means of the attachment according to the first embodiment of the present invention. It is a view showing the form of the fall prevention means in a fastened state, FIG. 6 is an enlarged cross-sectional view of part A of FIG. 5, and FIG. 7 is a link for an excavator having a fall prevention means of the attachment according to the first embodiment of the present invention. It is a view showing the form of the fall prevention means in a state in which the attachment is separated, and FIG. 8 is an enlarged cross-sectional view of part B of FIG. 7.

The present invention securely maintains the coupling state of attachments such as buckets, breakers, and shares that are detachably connected to the link, and in particular, by forming a safety pin that can physically block the natural separation of the attachment on the fixing hook Note that it is related to a link for an excavator having a fall prevention means of a new type of attachment that can minimize the deformation of the link and prevent a safety accident due to the fall of the attachment.

As shown, the link for an excavator having a fall prevention means of the attachment according to the first embodiment of the present invention (hereinafter referred to as "link") 100 includes a connecting shaft 11 fixed to the end of the excavator. One link body 10, a fixing hook 12 provided on one side of the lower end of the link body 10 to which the connection shaft 200 of the attachment is fitted, and formed on the front side of the fixing hook 12 and inside Rotating hook 30 having a shape that rotates by the operation of the hydraulic cylinder 20 installed in, and a first link 40 and a second link connected in a rotatable shape to the other side of the hydraulic cylinder 20 (50) And the second link 50 is connected to the upper part and the lower part is composed of a safety pin 60 that is connected to the fixing hook 12 in a vertically movable form.

The configuration of the link body 10 on which the connection shaft 11 is formed is the same as that of a conventionally known link, so a detailed configuration description is omitted. Hereinafter, a hydraulic cylinder formed under the link body 10, which is a characteristic of the present invention, 20), and the configuration of the rotating hook 30 and the fixing hook 12 assembled on both sides of the inflow cylinder 20, and an operation relationship due to their coupling will be described in detail.

The link body 10 is formed on one side in the longitudinal direction, one side is opened, and a fixing hook 12 is formed in which a safety pin coupling hole 121 is formed in a central portion.

The hydraulic cylinder 20 is installed inside the link body 10, and a rotation hook 30 rotatably connected to the link body 10 is connected to the piston 21 on one side, and the other side is the link body 10 ) Is formed rotatably connected to the connection part 22, and an extension connection part 23 to which one side of the first link 40 is rotatably connected is formed under the connection part 22.

That is, the expansion connection part 23 is formed on the lower side of the connection part 22 so that when the hydraulic cylinder 20 rotates, the expansion connection part 232 rotates in a fan shape around the connection part 22.

The rotation hook 30 has a shape having a lower portion in a shape of a hook to surround the connection shaft 200, and a first through hole 31 to which the rotation shaft 13 connected to the link body 10 is coupled at a central portion. ) And a second through hole 32 to which the piston 21 of the hydraulic cylinder 20 is connected is formed integrally, and the lower ring portion rotates by the extension and contraction of the piston 21, and the connecting shaft ( 200) is wrapped inside, and the attachment is separated by combining or unfolding.

The first link 40 has an approximately "a" shape surrounding the connection part 22 of the hydraulic cylinder 20 on one side, and a first connection part 41 having an end rotatably connected to the expansion connection part 23 And, the second connection part 42 coupled to the second link 50 on the other side is integrally formed, and the first connection part 41 rotates in a fan shape by rotation of the hydraulic cylinder 20 and at the same time The second connection portion 42 on the other side has a vertical motion.

When the first link 40 is operated, the second link 50 induces the vertical movement of the second connector 42 to be performed more accurately, and substantially the safety pin 60 connected to the second link 50 It is a configuration that allows the vertical movement to be made smoothly, and a pair of holes 51 are formed inside to be connected to the second connector 42 and the safety pin 60 in a rotatable form.

The safety pin 60 is fitted into the safety pin coupling hole 121 and is in close contact with the outer surface of the fixing hook 12 at the top, and a cover 61 having a guide hole 611 integrally formed at the center portion, and the cover 61 ) Through the guide hole 611, the upper part is connected to the second link 50, a pin 62 having a stepped 622 formed at the center portion, and the cover 61 It is configured with a packing 63 that is caught by the stepped 622 and fixed to the inside of the cover 61.

The operation process of the link 100 having the above configuration will be described in detail with reference to the drawings.

5 to 6 show a state in which the attachment is coupled to the link 100.

As shown, the piston 21 of the hydraulic cylinder 20 is elongated and the rotation hook 30 at the front is rotated to accommodate the connection shaft 200 inside the ring, and at the same time, the connection shaft inside the fixed hook 12 (200) is fitted and the safety pin (60) is lowered and protruded to the inside of the fixing hook (12) to maintain a state to physically prevent the natural detachment of the connection shaft (200).

As described above, when the attachment is separated while the attachment shaft 200 is coupled to the link 100, the piston 21 of the inlet cylinder 20 contracts and moves to the lower side as shown in FIGS. 7 to 8. When rotated, the connection part 22 of the hydraulic cylinder 20 rotates at the same time, and the expansion connection part 23 at the lower part rotates in the form of a fan bone.

In addition, during the rotation of the expansion connection part 23, the first link 40 connected to the expansion connection part 23 in a rotatable form rotates, and the end is moved upward and the first link 40 is connected to the first link 40. The second link 50 moves upward, and the safety pin 60 connected to the second link 20 is compressed by the upward pressure in the space between the cover 61 and the stepped step 622 in the inner packing 63 Is deformed and the safety pin 60 is inserted into the fixing hook 12 so that the connection shaft 200 is smoothly separated without being caught by the safety pin 60.

On the other hand, when the hydraulic cylinder 20 is damaged by a foreign substance in the process of coupling and separating the link 100 and the attachment shaft 200 as described above, and the hydraulic force is removed, the rotation hook is caused by the load of the attachment. Even if 30) is rotated and the front connection shaft 200 is separated, the connection shaft 200 inserted in the rear fixing hook 12 is substantially a safety pin by maintaining the original state while the packing 63 overcomes the load of the attachment. It is possible to substantially prevent the fall of the attachment by maintaining a state in which 60 is protruded into the inside of the fixing hook 12 so that the connection shaft 200 is not separated and remains connected.

On the other hand, Figures 9 to 10 is a modified embodiment of the second link 50 of the link for an excavator having a fall prevention means of the attachment according to the present invention.

As shown, the hole 51 formed in the second link 50 is formed in a circular shape on one side, and the hole 51 on the other side is formed in a long hole shape, and the deformation packing 52 is inserted inside the first When the cylinder is damaged by connecting the link 40 and the safety pin 60, the angle at which the safety pin 60 rises when the connection shaft 200 of the attachment is about to be separated from the fixing hook 12 by the load is changed. 52) is deformed and the angle is changed to prevent the safety pin 60 from rising easily, thereby delaying the rising time of the safety pin 60 to prevent separation of the attachment.

As described above, the link for an excavator having a fall prevention means of an attachment according to the present invention is of a connection shaft coupled to a fixed hook on one side of a hydraulic cylinder configured to rotate a rotating hook connected to a connection shaft of the attachment in a detachable form. Since the infeed pin is formed to prevent it from falling off, and the safety pin is configured so that it can be operated only by the operation of the cylinder, even if the hydraulic cylinder is damaged by foreign substances, it is possible to prevent separation of the attached attachment by the configuration of the safety pin. There is a constitutive feature that can physically prevent the fall of the attachment.

Moreover, the link for an excavator having a fall prevention means of the attachment according to the present invention is easy to manufacture and handle because the overall configuration is simple, and it can significantly reduce the occurrence of failure, so it operates smoothly even if foreign substances such as soil or sand are introduced. The overall link configuration maintains the configuration of the link that has been used in the past, and only the minimum configuration is modified or added to prevent the fall of the attachment. It is easy to improve the safety of the site according to the improvement of supply power, and the safety pin installed on the fixed hump is connected through the first link and the second link, so that the movement of the safety pin by the hydraulic cylinder is always smooth. There are features that can be maintained.

As described above, an optimal embodiment has been disclosed in the drawings and specification. Although specific terms have been used herein, these are only used for the purpose of describing the present invention and are not used to limit the meaning or the scope of the present invention described in the claims. Therefore, those of ordinary skill in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

10: link body 11: connecting shaft
12: fixed hook 13: rotating shaft
20: hydraulic cylinder 21: piston
22: connection part 23: expansion connection part
30: rotary hook 31: first through hole
32: second through hole 40: first link
41: first connector 42: second connector
50: second link 51: hole
52: deformation packing 60: safety pin
61: cover 62: pin
63: packing

Claims (3)

The link body 10 coupled to the arm of the excavator, the fixing hook 12 fixedly installed on the lower one side of the link body 10, and the rotation fixed rotatably to the other side of the fixing hook 12 In the link for an excavator consisting of a hook 30 and a hydraulic cylinder 20 for rotating the rotary hook 30,
The rotation hook 30 has a shape having a lower portion of a hook shape to surround the connection shaft 200, and a first through hole 31 through which the rotation shaft 13 connected to the link body 10 is coupled at a central portion. The second through hole 32 to which the piston 21 of the hydraulic cylinder 20 is connected is integrally formed at the top and the lower ring portion rotates by the extension and contraction of the piston 21, and the connecting shaft 200 ) In the form of enclosing or spreading the attachments,
The hydraulic cylinder 20 includes a connection part 22 connected to the link body 10 in a rotatable manner on one side and connected to the rotation hook 30 on the other side, and an extension connection part 23 on the lower part of the connection part 22 Formed integrally,
A first connection part 41 that is rotatably connected to the expansion connection part 23 and a second connection part 42 that is connected to the second link 50 on the other side are integrally formed, so that the hydraulic cylinder 20 ) By the rotation of the first connection part 41 to rotate in the form of a fan bone, and at the same time, the second connection part 42 on the other side has a vertical movement form,
It is assembled to the second connection part 42 and is inserted into the safety pin coupling hole 121 formed on the fixing hook 12, and is in close contact with the outer surface of the fixing hook 12 at the top, and a guide hole 611 is integrally formed at the center. The cover 61, a connection hole 621 through which the upper portion is connected to the second link 50 through the guide hole 611 of the cover 61, and a pin 62 having a stepped 622 formed at the center portion And a safety pin (60) consisting of a packing (63) accommodated in the cover (61) and fixed to the inside of the cover (61) by being caught by the stepped jaw (622). Link for excavator with.
The method of claim 1,
One side of the first link 40 includes a hole 51 and a safety pin 60 connected to the second connection 42 of the first link 40 in order to smoothly move the safety pin 60 up and down. Link for an excavator having a fall prevention means of the attachment, characterized in that it further comprises a second link (50) formed with a long hole (51) connected to the pin (62).

The method of claim 2,
The hole 51 of the second link 50 includes a plurality of deformable packings 52 for preventing the attachment from falling by changing the elevation angle of the safety pin 60. Link for excavator with.

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