tower crane

Abstract

The present disclosure relates to a tower crane comprising: a tower; an arm assembly; a tower top connector configured to connect the arm assembly to the tower and comprising one or both of a front side hinge configured to releasably pivotally connect the arm assembly to a front end of the tower top connector in a regular working condition and to lock the arm assembly and the front end of the tower top connector in a non-regular working condition, and a rear side hinge configured to releasably pivotally connect the arm assembly to a rear end of the tower top connector in a regular working condition and to lock the arm assembly and the rear end of the tower top connector in a non-regular working condition. The tower crane can avoid dangerous situations caused by excessive bending moments.

Description

Technical Field

[0001] This disclosure generally relates to the field of cranes. More specifically, this disclosure relates to a tower crane that prevents it from collapsing in the event of an emergency. Background Technology

[0002] Existing tower cranes include an intermediate jib 132, and a lifting boom 131 and a counterweight 133 fixed to both ends of the intermediate jib 132, with a counterweight 105 installed at the tail end of the counterweight 133. For example... Figure 1 As shown, by inserting the pin 174 into the closed hole of the fixing ear plates 171 and 172, the intermediate arm 132 is fixedly connected to the tower body 102 in a non-releasable manner.

[0003] When a tower crane experiences a sudden unloading event, the jib 131 will be subjected to a massive impact load from the unloading. Under the combined force of the impact load on the jib 131 and the gravity of the counterweight on the counterweight boom 133, the tower crane is at risk of collapse and overturning. Furthermore, when a tower crane experiences an anchoring event, the lifting force on the jib 131 continuously increases, and the load on components such as the tower body 102 also continuously increases. When the bending moment on the jib 131 or the tower body 102 exceeds the structural limits, the tower crane faces the risk of structural fracture and collapse. Summary of the Invention

[0004] This disclosure provides a tower crane that overcomes at least one of the aforementioned defects of existing products.

[0005] One aspect of the present invention relates to a tower crane, wherein the tower crane comprises:

[0006] Tower body;

[0007] arm assembly;

[0008] A tower top connector, configured to connect a boom assembly to a tower body, and including one or both of a front hinge and a rear hinge, wherein the front hinge is configured to releasably pivot the boom assembly to the front end of the tower top connector under normal operating conditions and to lock the boom assembly and the front end of the tower top connector in non-normal operating conditions; and the rear hinge is configured to releasably pivot the boom assembly to the rear end of the tower top connector under normal operating conditions and to lock the boom assembly and the rear end of the tower top connector in non-normal operating conditions.

[0009] In some embodiments, each of the front hinge and the rear hinge includes an upper lug plate fixed to the arm assembly and a lower lug plate fixed to the top connector of the tower body, wherein the upper lug plate and the lower lug plate are releasably pivotally connected to each other by a hinge pin.

[0010] In some embodiments, the upper ear plate includes one or more hinge holes, the lower ear plate includes one or more upwardly open hinge slots, and the number and position of the hinge holes on the upper ear plate correspond to the number and position of the hinge slots on the lower ear plate, so that the hinge pin can pass through the hinge hole and rest in the hinge slot.

[0011] In some embodiments, with the hinge pin passing through the hinge hole and resting in the hinge slot, the upper ear plate is configured to pivot about the hinge pin relative to the lower ear plate, and to move the hinge pin away from the lower ear plate in the event of an emergency under normal operating conditions.

[0012] In some embodiments, both the upper and lower ear plates include two or more locking holes, and the number and position of the locking holes on the upper ear plate correspond to the number and position of the locking holes on the lower ear plate, so that the locking pin passes through them, thereby enabling the upper and lower ear plates to be connected and locked by the locking pin.

[0013] In some embodiments, the tower top connector further includes one or more damping connectors disposed between its front end and rear end, with one end of each damping connector connected to the tower top connector and the other end connected to the arm assembly.

[0014] In some embodiments, the damping connector is configured to return the arm assembly to its initial position when the arm assembly deviates from its initial position in a direction away from or toward the top connector of the tower.

[0015] In some embodiments, the tower top connector includes one or more pairs of damping connectors, and each pair of damping connectors is symmetrically arranged relative to the lateral center plane of the tower.

[0016] In some embodiments, the tower crane also includes a detachable counterweight that is removably attached near the free end of the boom assembly and can be detached from the boom assembly in the event of an emergency under normal operating conditions.

[0017] In some embodiments, in the event of a sudden loss of load on the tower crane, the boom assembly pivots about the rear hinge and the front portion of the boom assembly tilts upward by separating from the front end of the top connector of the tower body via the front hinge, thereby triggering the detachment of the counterweight.

[0018] In some embodiments, in the event of an emergency such as a tower crane anchoring, the boom assembly pivots about the front hinge and the rear portion of the boom assembly tilts upwards by separating from the rear end of the tower top connector via the rear hinge, thereby triggering a stop to the tower crane's operation.

[0019] In some embodiments, when the tower crane is in an unconventional installation, dismantling, or testing condition, both the front and rear hinges are locked, preventing the front and rear portions of the boom assembly from tilting upwards.

[0020] Other features and advantages of the subject matter of this disclosure will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the subject matter of this disclosure. The advantages of the subject matter of this disclosure will be realized and obtained through the structures particularly pointed out in the written description and the accompanying drawings.

[0021] It should be understood that the foregoing general description and the following detailed description are exemplary and illustrative, and are intended to provide further explanation of the subject matter of this disclosure. Attached Figure Description

[0022] Many aspects of this disclosure will be better understood after reading the following detailed description in conjunction with the accompanying drawings, in which:

[0023] Figure 1 A schematic diagram of an existing tower crane is shown;

[0024] Figure 2 A schematic diagram of a tower crane according to an embodiment of the present disclosure is shown;

[0025] Figure 3A and 3B Show each Figure 2 An 3D view and a separate 3D view of the installation status of the front or rear hinge of a tower crane.

[0026] Figure 4A and 4B A perspective view and a schematic diagram of the upper ear plate of the front hinge or the rear hinge are shown respectively.

[0027] Figure 5A and 5B A perspective view and a schematic diagram of the lower lug plate of the front hinge or the rear hinge are shown respectively.

[0028] Figure 6-8C Show respectively Figure 2 The operation process of a tower crane. Detailed Implementation

[0029] The present disclosure will now be described with reference to the accompanying drawings, which illustrate several embodiments of the present disclosure. However, it should be understood that the present disclosure can be presented in many different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the disclosure more complete and to fully illustrate the scope of protection of the present disclosure to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide further additional embodiments.

[0030] It should be understood that the same reference numerals denote the same elements in all the accompanying drawings. For clarity, the dimensions of certain features may be modified in the drawings.

[0031] It should be understood that the terminology used in this specification is for describing specific embodiments only and is not intended to limit this disclosure. All terms used in this specification (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. For the sake of brevity and / or clarity, well-known functions or structures may not be described in detail.

[0032] Unless otherwise specified, the singular forms “a,” “the,” and “the” used in this specification include the plural forms. The terms “comprising,” “including,” and “containing” used in this specification indicate the presence of the claimed feature but do not exclude the presence of one or more other features. The term “and / or” used in this specification includes any and all combinations of one or more of the related listed items. The terms “between X and Y” and “between approximately X and Y” used in this specification should be interpreted as including both X and Y. The term “between approximately X and Y” used in this specification means “between approximately X and approximately Y,” and the term “from approximately X to Y” used in this specification means “from approximately X to approximately Y.”

[0033] In the specification, when an element is described as being "on," "attached," "connected," "coupled," or "in contact" with another element, the element can be directly located on, attached to, connected to, coupled to, or in contact with the other element, or there may be intermediate elements present. Conversely, when an element is described as being "directly" located on, directly attached to, directly connected to, directly coupled to, or directly in contact with another element, no intermediate elements are present. In the specification, a feature arranged "adjacent" to another feature can mean that a feature has a portion overlapping with the adjacent feature or a portion located above or below the adjacent feature.

[0034] In the specification, spatial relation terms such as "up," "down," "left," "right," "front," "back," "high," and "low" describe the relationship between one feature and another in the accompanying drawings. It should be understood that spatial relation terms include not only the orientation shown in the drawings but also the different orientations of the device during use or operation. For example, when the device in the drawings is inverted, a feature previously described as "below" other features can now be described as "above" other features. The device can also be oriented in other ways (rotated 90 degrees or in other orientations), in which case the relative spatial relationships will be explained accordingly.

[0035] In this specification, the direction along the length of the boom assembly 3 of the tower crane 1 is referred to as the longitudinal direction, wherein the side facing the boom 31 is referred to as the longitudinal front side, and the side facing the counterweight boom 33 is referred to as the longitudinal rear side. The direction perpendicular to the length of the boom assembly 3 of the tower crane 1 is referred to as the transverse direction.

[0036] Figure 2 A schematic diagram of a tower crane 1 according to an embodiment of the present disclosure is shown. This tower crane 1 can prevent collapse in the event of an emergency (such as a sudden loss of load or an anchoring event). As shown, the tower crane 1 may include a tower body 2 and a boom assembly 3 disposed above the tower body 2. The boom assembly 3 includes an intermediate boom 32, a lifting boom 31 (also referred to as the front portion of the boom assembly 3) connected to the longitudinal front end of the intermediate boom 32, and a counterweight boom 33 (also referred to as the rear portion of the boom assembly 3) connected to the longitudinal rear end of the intermediate wall 3. The lower end of the intermediate boom 32 is connected to the top of the tower body 2 via a tower body top connector 6. In this embodiment, the tower body top connector 6 is shown as a special section; however, it will be understood that the tower body top connector 6 can be any other suitable component, such as an upper support.

[0037] The tower crane 1 may also include a detachable counterweight 4 and a movable counterweight 5. The counterweight 4 is removably attached (e.g., via a detachment device) to the vicinity of the free end of the counterweight boom 33 and can be detached from the counterweight boom 33 in the event of an emergency (e.g., a sudden loss of load). The counterweight 5 is mounted on the boom assembly 3 and can reciprocate between the jib 31, the intermediate boom 32, and the counterweight boom 33. Depending on the load on the jib 31 and the distance from the vertical center axis of the tower body 2, the counterweight 5 can be moved in real time to the appropriate position on the boom assembly 3, thereby balancing the bending moments on the front and rear sides of the tower body 2 together with the counterweight 4.

[0038] The tower top connector 6 may include one or more front hinges 7 and one or more rear hinges 7'. The front hinges 7 are used to releasably pivot the intermediate arm 32 to the top front end of the tower top connector 6, so that the intermediate arm 32 and the entire arm assembly 3 can both pivot about the top front end of the tower top connector 6 and be disengaged from the top front end of the tower top connector 6. The rear hinges 7' are used to releasably pivot the intermediate arm 32 to the top rear end of the tower top connector 6, so that the intermediate arm 32 and the entire arm assembly 3 can both pivot about the top rear end of the tower top connector 6 and be disengaged from the top rear end of the tower top connector 6.

[0039] Figure 3A and 3B A perspective view of the front hinge 7 in its installed state and a separate perspective view are shown. As shown, the front hinge 7 includes an upper ear plate 71 fixed to the intermediate arm 32 and a lower ear plate 72 fixed to the top connector 6 of the tower body. The upper ear plate 71 and the lower ear plate 72 are connected to each other by a locking pin 73 and / or a hinge pin 74. When the tower crane 1 is in normal operating condition, the upper ear plate 71 and the lower ear plate 72 are releasably pivotally connected to each other by the hinge pin 74, that is, the upper ear plate 71 can both pivot relative to the lower ear plate 72 about the hinge pin 74 and can also be separated from the lower ear plate 72. However, when the tower crane 1 is in non-normal operating condition (e.g., installation and dismantling condition or test condition), the upper ear plate 71 and the lower ear plate 72 are locked together by the locking pin 73, that is, the upper ear plate 71 and the lower ear plate 72 are fixed together together in a way that is neither pivotable nor separable, as will be described in detail below. In the illustrated embodiment, the front hinge 7 includes an upper ear plate 71 and two lower ear plates 72, with the upper ear plate 71 inserted between the two lower ear plates 72. However, it is understood that in other embodiments, the front hinge 7 may include two upper ear plates 71 and one lower ear plate 72, with the lower ear plate 72 inserted between the two upper ear plates 71; or, the front hinge 7 may include two or more upper ear plates 71 and two or more lower ear plates 72, with the upper ear plates 71 and lower ear plates 72 arranged alternately in the lateral direction.

[0040] Figure 4A and 4BA perspective view and a schematic diagram of the upper ear plate 71 are shown respectively. The upper ear plate 71 is flat and is fixed (e.g., by welding) at its top to the intermediate arm 32 (e.g., the bottom of the lower chord of the intermediate arm 32). The upper ear plate 71 includes two or more locking holes 71A and one or more hinge holes 71B for the locking pin 73 and the hinge pin 74 to pass through, respectively. In the illustrated embodiment, the upper ear plate 71 is generally quadrilateral, and the locking holes 71A and the hinge holes 71B are generally circular. However, it is understood that the upper ear plate 71, the locking holes 71A, and the hinge holes 71B can all be any other suitable shape. In the illustrated embodiment, the upper ear plate 71 includes two locking holes 71A and one hinge hole 71B. However, it is understood that the upper ear plate 71 may include more than two locking holes 71A and / or more than one hinge hole 71B. In the illustrated embodiment, the hinge hole 71B is disposed above the locking holes 71A. However, it is understandable that the hinge hole 71B may be located below or flush with the locking hole 71A.

[0041] Figure 5A and 5B A perspective view and a schematic diagram of the lower ear plate 72 are shown respectively. The lower ear plate 72 is flat and is fixed (e.g., by welding) at its bottom to the tower top connector 6 (e.g., the upper part of the chord of the tower top connector 6). The lower ear plate 72 includes two or more locking holes 72A through which locking pins 73 pass, and includes one or more upwardly open hinge slots 72B for resting on the hinge pins 74. In the illustrated embodiment, the lower ear plate 72 is generally quadrilateral, the locking holes 72A are generally circular, and the hinge slots 72B are generally U-shaped. However, it is understood that the lower ear plate 72, the locking holes 72A, and the hinge slots 72B can all be any other suitable shape. In the illustrated embodiment, the lower ear plate 72 includes two locking holes 72A and one hinge slot 72B. However, it is understood that the lower ear plate 72 can include more than two locking holes 72A and more than one hinge slot 72B. In the illustrated embodiment, the hinge slot 72B is disposed above the locking hole 72A. However, it is understood that the hinge slot 72B may be disposed flush with the locking hole 72A.

[0042] The positions and number of locking holes 71A and hinge holes 71B on the upper ear plate 71 correspond to the positions and number of locking holes 72A and hinge slots 72B on the lower ear plate 72. When the tower crane 1 is in normal operating condition, the hinge pin 74 is inserted through the hinge hole 71B of the upper ear plate 71 and rests in the upwardly open hinge slot 72B of the lower ear plate 72, and the locking pin 73 is not used. At this time, the upper ear plate 71 can remain stationary relative to the lower ear plate 72 or pivot about the hinge pin 74 relative to the lower ear plate 72, or, in the event of an emergency, the hinge pin 74 can be moved away from the lower ear plate 72, i.e., the upper ear plate 71 and the lower ear plate 72 form a releasable pivot connection. When the tower crane 1 is in an unconventional operating condition, the locking pin 73 is inserted through the locking hole 71A of the upper ear plate 71 and the locking hole 72A of the lower ear plate 72, and the hinge pin 74 is not used. At this time, the upper ear plate 71 cannot move away from the lower ear plate 72, nor can it pivot relative to the lower ear plate 72, thus the upper ear plate 71 and the lower ear plate 72 are locked together.

[0043] See Figure 3A-5B The rear hinge 7' includes an upper ear plate 71' fixed to the intermediate arm 32 and a lower ear plate 72' fixed to the top connector 6 of the tower body. The upper ear plate 71' includes a locking hole 71A' and a hinge hole 71B', and the lower ear plate 72' includes a locking hole 72A' and a hinge groove 72B'. The upper ear plate 71' and the lower ear plate 72' can be locked together by a locking pin 73' or pivotally connected by a releasable hinge pin 74'. The structure and working principle of the rear hinge 7' are similar to those of the front hinge 7, and will not be described again.

[0044] return Figure 2 The tower top connector 6 may further include one or more damping connectors 9 disposed between its front and rear ends. One end of each damping connector 9 is connected to the tower top connector 6, and the opposite end is connected to the intermediate arm 32. In the initial position, the intermediate arm 32 rests against the tower top connector 6 near both its front and rear ends. When the intermediate arm 32 deviates from its initial position in a direction away from the tower top connector 6, the damping connector 9 can gently pull the intermediate arm 32 back to its initial position; when the intermediate arm 32 deviates from its initial position in a direction toward the tower top connector 6, the damping connector 9 can gently push the intermediate arm 32 back to its initial position. That is, regardless of which direction the intermediate arm 32 deviates from its initial position, the damping connector 9 can gently reset the intermediate arm 32 to its initial position. In some embodiments, the tower top connector 6 may include one or more pairs of damping connectors 9, and each pair of damping connectors 9 is symmetrically arranged relative to the lateral center plane of the tower 2.

[0045] The following reference Figure 6-8CThe operation process of the tower crane 1 according to an embodiment of the present disclosure is described. The tower crane 1 can be in a working state or a non-working state under normal operating conditions. At this time, by inserting the hinge pin 74 through the hinge hole 71B of the upper ear plate 71 and placing it in the upwardly open hinge groove 72B of the lower ear plate 72, the front hinge member 7 is in a releasable pivot connection state; by inserting the hinge pin 74' through the hinge hole 71B' of the upper ear plate 71' and placing it in the upwardly open hinge groove 72B' of the lower ear plate 72', the rear hinge member 7' is in a releasable pivot connection state.

[0046] like Figure 6 As shown, when the tower crane 1 is operating normally, the boom 31 bears a front bending moment due to the weight of the load 10, and the counterweight 33 bears a rear bending moment due to the weight of the counterweights 4 and 5. The front and rear bending moments are approximately the same, thus balancing the front and rear sides of the boom assembly 3. The hinge pins 74 of the front hinge 7 and 74' of the rear hinge 7' are both under pressure within the hinge slots 72B and 72B'. The boom assembly 3, including the boom 31 and the counterweight 33, can operate normally.

[0047] When the tower crane 1 is not in operation, the boom 31 is not subjected to the gravity of the load 10, while the counterweight 33 is still subjected to the gravity of the counterweights 4 and 8. The rear bending moment on the counterweight 33 is greater than the front bending moment on the boom 31. At this time, the damping connector 9 intervenes and provides tension to the boom assembly 3 to prevent the boom 31 from tilting upwards, and the movable counterweight 5 is transferred to the boom 31 to balance the front and rear sides of the boom assembly 3. The hinge pins 74 of the front hinge 7 and 74' of the rear hinge 7' are both under pressure in the hinge slots 72B and 72B', ensuring the structural safety and reliability of the tower crane 1.

[0048] like Figure 7A As shown, when a sudden loss of load occurs during the operation of the tower crane 1, i.e., the load 10 on the boom 31 suddenly and accidentally falls off, the rear bending moment borne by the counterweight boom 33 will be significantly greater than the front bending moment borne by the boom 31 and the bending moment provided by the damping connector 9. The intermediate boom 32 will pivot around the rear hinge 7', and the upper ear plate 71 of the front hinge 7 will move away from the lower ear plate 72 along with the hinge pin 74, causing the boom 31 to tilt upwards as a whole. Figure 7B As shown. Through the action of the control system, the upward tilting of the boom 31 triggers the detachment device of the counterweight 4, causing the counterweight 4 to detach from near the free end of the boom 33, reducing the rear bending moment of the boom assembly 3. After the counterweight 4 detaches, the front bending moment of the boom assembly 3 is greater than the rear bending moment, and the boom 31 will slowly fall under the tension of the damping connector 9, ensuring that the tower crane 1 does not collapse in the event of sudden unload. Figure 7CAs shown.

[0049] like Figure 8A As shown, when an anchoring event occurs during the operation of the tower crane 1, i.e., the load 10 to be lifted by the boom 31 far exceeds the rated load, the lifting force on the boom 31 will continuously increase, thereby continuously increasing the front bending moment on the boom 31. When the front bending moment on the boom 31 is greater than the rear bending moment on the counterweight boom 33 and the bending moment provided by the damping connector 9, the intermediate boom 32 will pivot around the front hinge 7, and the upper ear plate 71' of the rear hinge 7' will move away from the lower ear plate 72' along with the hinge pin 74', causing the counterweight boom 33 to tilt upwards as a whole. Figure 8B As shown. Through the control system, the upward tilting of the counterweight boom 33 triggers the operation of the tower crane 1 to stop, or through manual observation, the upward tilting of the counterweight boom 33 prompts the operator to stop the operation of the tower crane 1. After the load 10 is unloaded from the boom 31, the counterweight boom 33 slowly lowers under the tension of the damping connector 9, ensuring that the tower crane 1 does not collapse during anchoring, as... Figure 8C As shown.

[0050] In addition to conventional operating conditions, the tower crane 1 can also operate under unconventional conditions. When the tower crane 1 is in the installation / disassembly phase, the boom assembly 3 needs to be installed or disassembled. The front bending moment borne by the boom 31 and the rear bending moment borne by the counterweight 5 are significantly different, causing the front and rear sides of the boom assembly 3 to become unbalanced. Therefore, by inserting the locking pin 73 through the locking hole 71A of the upper ear plate 71 and the locking hole 72A of the lower ear plate 72, the front hinge 7 is locked in a connected state; by inserting the locking pin 73' through the locking hole 71A' of the upper ear plate 71' and the locking hole 72A' of the lower ear plate 72', the rear hinge 7' is locked in a connected state; at this time, the boom assembly is completely locked. Regardless of the difference in the front bending moment borne by the boom 31 and the rear bending moment borne by the counterweight 33, neither the boom 31 nor the counterweight 33 can tilt upwards, ensuring the safety of the installation or disassembly operation. After the tower crane 1 is installed or dismantled, the front and rear sides of the boom assembly 3 are leveled. At this time, the locking pins 73 and 73' can be pulled out to release the connection lock.

[0051] When the tower crane 1 is under test, the load 10 to be lifted by the boom 31 is greater than the rated load. The front bending moment on the boom 31 is greater than the rear bending moment on the counterweight 5, thus the front and rear sides of the boom assembly 3 are unbalanced. Therefore, by inserting the locking pin 73 through the locking hole 71A of the upper ear plate 71 and the locking hole 72A of the lower ear plate 72, the front hinge 7 is locked; by inserting the locking pin 73' through the locking hole 71A' of the upper ear plate 71' and the locking hole 72A' of the lower ear plate 72', the rear hinge 7' is locked; at this time, the boom assembly is completely locked. This prevents the load 10 on the boom 31 from being too heavy and causing the counterweight boom 33 to lift, ensuring the safety of the test environment. After the tower crane 1 completes the test, the front and rear sides of the boom assembly 3 are balanced, at which point the locking pins 73 and 73' can be pulled out to release the locked state.

[0052] The tower crane according to an embodiment of this disclosure has a lug plate with a hinge slot, so that the upper part of the lug plate is open. When the tower crane is working normally, the hinge pin resting in the hinge slot can bear pressure; when the tower crane suddenly loses load or anchors, the hinge pin will change from a pressure state to a tension state. By releasing the tensioned hinge pin from the hinge slot, the tower crane can avoid being subjected to excessive bending moment and causing danger.

[0053] Specifically, when a tower crane faces a sudden unloading event, the boom is subjected to an impact load and can tilt upwards as a whole, thereby triggering the detachment device to detach the counterweight at the tail of the counterweight boom, instantly reducing the rear torque and achieving the anti-overturning effect of the tower crane under sudden unloading conditions, effectively improving safety.

[0054] When a tower crane faces an anchoring event, the lifting force on the jib will continuously increase. When the front bending moment on the jib exceeds the rear bending moment on the counterweight jib, the counterweight jib will tilt upwards, at which point the tower crane will stop operating, effectively improving safety.

[0055] While exemplary embodiments of this disclosure have been described, those skilled in the art will understand that various changes and modifications can be made to the exemplary embodiments of this disclosure without departing from the spirit and scope thereof. Therefore, all changes and modifications are included within the scope of protection of this disclosure as defined by the claims. This disclosure is defined by the appended claims, and equivalents of those claims are also included.

Claims

1. A tower crane, characterized in that, The tower crane includes: Tower body; arm assembly; A tower top connector, configured to connect an arm assembly to the tower body, includes a front hinge and a rear hinge. The front hinge is configured to releasably pivot the arm assembly to the front end of the tower top connector under normal operating conditions and to lock the arm assembly to the front end of the tower top connector under unconventional operating conditions. The rear hinge is configured to releasably pivot the arm assembly to the rear end of the tower top connector under normal operating conditions and to lock the arm assembly to the rear end of the tower top connector under unconventional operating conditions, including installation / disassembly conditions or testing conditions. Each of the front and rear hinges includes an upper ear plate fixed to the arm assembly and a lower ear plate fixed to the top connector of the tower body. The upper ear plate includes one or more hinge holes, and the lower ear plate includes one or more upwardly open hinge slots. The upper and lower ear plates are releasably pivotally connected to each other by mounting hinge pins through the hinge holes and hinge slots. Both the upper and lower ear plates include two or more locking holes, and the upper and lower ear plates are locked together by mounting locking pins through the locking holes.

2. The tower crane according to claim 1, characterized in that, The number and position of the hinge holes on the upper ear plate correspond to the number and position of the hinge slots on the lower ear plate.

3. The tower crane according to claim 1, characterized in that, With the hinge pin passing through the hinge hole and resting in the hinge slot, the upper ear plate is configured to pivot about the hinge pin relative to the lower ear plate, and in the event of an emergency under normal operating conditions, it can move the hinge pin away from the lower ear plate.

4. The tower crane according to claim 1, characterized in that, The number and position of the locking holes on the upper ear plate correspond to the number and position of the locking holes on the lower ear plate.

5. The tower crane according to any one of claims 1-4, characterized in that, The tower top connector also includes one or more damping connectors disposed between its front and rear ends, with one end of each damping connector connected to the tower top connector and the other end connected to the arm assembly.

6. The tower crane according to claim 5, characterized in that, The damping connector is configured to return the arm assembly to its initial position when it deviates from its initial position in a direction away from or toward the top connector of the tower.

7. The tower crane according to claim 5, characterized in that, The top connector of the tower body includes one or more pairs of damping connectors, and each pair of damping connectors is symmetrically arranged relative to the transverse center plane of the tower body.

8. The tower crane according to claim 5, characterized in that, The tower crane also includes a detachable counterweight that is removably attached near the free end of the boom assembly and can be detached from the boom assembly in the event of an emergency under normal operating conditions.

9. The tower crane according to claim 8, characterized in that, In the event of a sudden loss of load on a tower crane, the boom assembly pivots around the rear hinge and, by separating from the front end of the top connector of the tower body via the front hinge, causes the front portion of the boom assembly to tilt upward, thereby triggering the detachable counterweight to fall.

10. The tower crane according to claim 8, characterized in that, In the event of an emergency involving a tower crane anchoring, the boom assembly pivots around the front hinge and, by separating from the rear end of the top connection of the tower body via the rear hinge, causes the rear portion of the boom assembly to tilt upwards, thereby triggering a stop to the tower crane's operation.

11. The tower crane according to any one of claims 1-4, characterized in that, When the tower crane is in an unconventional installation, dismantling, or testing condition, both the front and rear hinges are locked, preventing the front and rear portions of the boom assembly from tilting upwards.

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