Adjustable luffing upper and lower limit device of jib tower crane

Abstract

The adjustable movable jib tower crane amplitude upper and lower limiting device comprises a limiter mounting plate, an adjustable limiting trigger assembly is connected to the limiter mounting plate through a limiting device connecting plate, and the limiting trigger assembly is connected with a travel switch; the limiter mounting plate is fixed on a hoisting arm through mounting bolts, the limiter mounting plate is provided with a track for the movement of the mounting bolts, and the relative angle between the limiter mounting plate and the hoisting arm is changed by moving the limiter mounting plate in the track. The adjustable movable jib tower crane amplitude upper and lower limiting device is provided with the adjustable limiting trigger assembly and the limiter mounting plate with the rotary track, the limiting device trigger is ensured to be accurate by using the adjustable screw rod, the trigger device precision is improved, meanwhile, the position of the limiting device can be adjusted according to the use condition of the hoisting arm, the limiter mounting plate is rotated, the position of the limiting device is adjusted, the limiting device is parallel to the direction of the hoisting arm, the scratching caused by the overwidth is prevented, and the safety in use is improved.

Description

Technical Field

[0001] This utility model relates to the field of engineering machinery technology, specifically an adjustable luffing tower crane upper and lower limit device. Background Technology

[0002] During the luffing process of a tower crane jib, a limit trigger device is installed at the jib root, and a limit switch is installed on the upper support. When the jib approaches the upper or lower luffing limits, the limit trigger device on the jib will trigger the limit switch to ensure that the jib is always within the safe elevation angle range and to avoid over-limit accidents.

[0003] When the limit trigger device is installed at the base of the crane boom, it may be damaged during transportation because the trigger device will extend beyond the boom. Traditional installation methods make it inconvenient to disassemble the limit trigger device. Therefore, an adjustable limit device installation method is needed to avoid damage to the limit trigger device due to transportation or other reasons. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide an adjustable luffing tower crane upper and lower limit device with simple structure and good effect.

[0005] This utility model is achieved through the following technical solution: an adjustable luffing tower crane upper and lower limit device, including a limiter mounting plate, wherein the limiter mounting plate is connected to an adjustable limit trigger component via a limiter device connecting plate, one end of the limit trigger component is fixed to the limiter device connecting plate, and the other end of the limit trigger component is in contact with a limit switch; the limiter mounting plate is fixed to the jib by mounting bolts, and the limiter mounting plate is provided with a track for the mounting bolts to move, wherein the limiter mounting plate moves within the track by the mounting bolts to change the relative angle with the jib.

[0006] Furthermore, the limit triggering component is a length-adjustable device, which includes a screw and a nut.

[0007] The nut is connected to the limiting device connecting plate, one end of the screw passes through the nut, and the other end of the screw is connected to the contact of the limit switch.

[0008] The limiter mounting plate is fixed to the lifting arm by two mounting bolts. One fixing bolt is the rotation point of the limiter mounting plate, and the limiter mounting plate is provided with a circular track at the rotation point. The other fixing bolt moves in a circular motion relative to the limiter mounting plate, and the limiter mounting plate is provided with an arc track that cooperates with the circular motion.

[0009] The circular track and the arc track are provided with limiting points, which are located outside the track and the two limiting points are in the same direction.

[0010] The length of the arc-shaped track is a quarter circle, and the limiting point of the arc-shaped track is at the end of the arc-shaped track. The limiting point of the dot track and the dot track form a 90° connected track.

[0011] This utility model has the following advantages: The adjustable luffing tower crane upper and lower limit device of this utility model is equipped with an adjustable limit triggering component and a limiter mounting plate with a rotation trajectory. The adjustable screw ensures accurate triggering of the limit device and improves the accuracy of the triggering device. At the same time, the position of the limit device can be adjusted by rotating the limiter mounting plate according to the use of the crane boom, so that the limit device is parallel to the direction of the crane boom, preventing scratches caused by excessive width and improving the safety of use. Attached Figure Description

[0012] The accompanying drawings, as part of this utility model, are used to provide a further understanding of the present utility model. The illustrative embodiments and descriptions of the present utility model are used to explain the present utility model, but do not constitute an undue limitation of the present utility model. Obviously, the drawings described below are merely some embodiments; those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0013] In the attached diagram: Figure 1 This is the front view of this utility model; Figure 2 This is the left view of this utility model; Figure 3 This is a schematic diagram of the state of the limiter mounting plate after rotation. Figure 4 This is a schematic diagram showing the change in the position of the mounting bolts after the limiter mounting plate of this utility model is rotated.

[0014] In the diagram: 1. Mounting bolt, 2. Limit switch mounting plate, 3. Limit device connecting plate, 4. Limit trigger assembly, 5. Limit switch.

[0015] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0017] In the description of this utility model, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0018] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0019] like Figures 1 to 4 The adjustable luffing tower crane luffing upper and lower limit device shown includes a limiter mounting plate 2. The limiter mounting plate 2 is connected to an adjustable limit trigger component 4 via a limiter device connecting plate 3. One end of the limit trigger component 4 is fixed to the limiter device connecting plate 3, and the other end of the limit trigger component 4 is in contact with a limit switch 5. The limiter mounting plate 2 is fixed to the crane boom by mounting bolts 1. The limiter mounting plate 2 is provided with a track for the mounting bolts 1 to move. The limiter mounting plate 2 moves within the track by the mounting bolts 1 to change the relative angle with the crane boom. This utility model discloses an adjustable luffing tower crane upper and lower limit device, including a limit switch mounting plate, a connecting plate, a limit trigger assembly, and a limit switch. The limit trigger assembly is a length-adjustable device and works in conjunction with the limit switch to complete the limit action. The limit trigger assembly is mounted to the limit switch mounting plate via the connecting plate. The limit switch mounting plate is fixed to the jib by mounting bolts. The angle between the limit switch mounting plate and the jib is adjustable. The limit switch mounting plate is provided with a track for the mounting bolts to move. The track ensures the smoothness of the limit switch mounting plate's rotation and the accuracy of the rotation angle, thereby improving safety and efficiency.

[0020] like Figures 1 to 3The diagram illustrates an adjustable luffing tower crane luffing upper and lower limit device. The limit triggering component 4 is a length-adjustable device, comprising a screw and a nut. The nut is connected to the limit device connecting plate 3. One end of the screw passes through the nut, and the other end is connected to the contact of the limit switch 5. In this adjustable luffing tower crane luffing upper and lower limit device, the length of the limit triggering component is adjusted through the cooperation of the screw and nut. Adjusting the extension length of the screw of the limit triggering component ensures that the limit triggering device can trigger the limit switch. Furthermore, after hoisting is completed, the screw of the limit triggering component can be retracted to prevent interference with the crane boom.

[0021] like Figure 1 , Figure 3 and Figure 4 The diagram illustrates an adjustable luffing tower crane upper and lower limit device. The limiter mounting plate 2 is fixed to the jib by two mounting bolts 1. One bolt serves as the rotation point of the limiter mounting plate 2, and a circular track is provided at this rotation point. The other bolt moves in a circular motion relative to the limiter mounting plate 2, and an arc-shaped track is provided on the limiter mounting plate 2 to coordinate with this circular motion. Limiting points are located outside the tracks, and the two limiting points are oriented in the same direction. In this utility model of an adjustable luffing tower crane upper and lower limit device, the limiter mounting plate is connected to the jib by two fixing bolts. The limiter mounting plate is provided with tracks that cooperate with the two fixing bolts. Since one fixing bolt serves as the center of rotation when the limiter mounting plate rotates, the track cooperating with this fixing bolt is a circular through-hole track, facilitating the rotation of the limiter mounting plate around this fixing bolt. Simultaneously, the other fixing bolt undergoes relative displacement with the limiter mounting plate during rotation, with the displacement trajectory being an arc around the center of rotation. Therefore, the limiter mounting plate is provided with an arc-shaped track that cooperates with this fixing bolt. Furthermore, to ensure the limiter mounting plate remains in its fixed position after rotation, a limit stop is provided on the track. The limit stop is located outside the track and does not coincide with the original track. When the fixing bolt moves to the vicinity of the limit stop, the limiter mounting plate is moved, causing the fixing bolt to engage within the limit stop, preventing the limiter mounting plate from rotating back to its original position, thus completing the limit adjustment.

[0022] like Figure 1 , Figure 3 and Figure 4The invention discloses an adjustable luffing tower crane upper and lower limit device. The arc-shaped track is a quarter circle in length, and its limit point is located at the end of the arc-shaped track. The limit point of the dotted track forms a 90° connecting track with the dotted track. The quarter-circle length of the arc-shaped track allows the limiter mounting plate to rotate 90°, from a direction perpendicular to the jib to a direction parallel to the jib. In use, the limiter connecting plate is rotated 90° around the mounting bolt to make the limiter parallel to the jib direction. Then, the limiter mounting plate is moved downwards along the length of the jib, engaging the mounting bolt into the lower limit point. This prevents scratches caused by excessive width and ensures the effectiveness of the limit position, greatly improving safety.

[0023] Currently, when the boom of a luffing tower crane (hereinafter referred to as "luffing tower crane") is extended, mechanical limit switches are required at the upper and lower limits of the extension. When the boom is extended to the specified angle, the limit switches are triggered to prevent the boom from tilting excessively backward or forward. After the limit switches are installed, they may extend beyond the boom, which could lead to damage to the limit switches during transportation.

[0024] This utility model discloses an adjustable luffing tower crane luffing upper and lower limit device, suitable for the jib root of a luffing tower crane. When the jib reaches its maximum luffing angle, the upper limit contact engages the limit switch, preventing the jib from tilting backward further. When the jib reaches its minimum luffing angle, the lower limit contact engages the limit switch, preventing the jib from tilting forward further. During debugging, the screw length of the limit trigger component is adjusted to adjust the trigger position, making the limiter trigger more precise when the jib reaches the limit. The limiter mounting plate has a movable track for the mounting bolts, allowing the limit device to rotate around the mounting bolts, improving the safety of the limit device. The lower end of the arc-shaped groove is open, allowing the limit device to be rotated and locked into the groove, preventing the limit connecting plate from rotating back to its original position. After hoisting, the bolts are loosened, and the limit device is rotated and retracted to avoid damage from scratches, increasing installation convenience and reducing the risk of damage.

[0025] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0026] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features found in other embodiments but not others, combinations of features from different embodiments are also within the scope of protection of this invention and form different embodiments. For example, in the embodiments described above, those skilled in the art can use them in combination based on known technical solutions and the technical problems to be solved by this application.

[0027] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. An adjustable luffing tower crane upper and lower limit device, characterized in that: The device includes a limiter mounting plate (2), which is connected to an adjustable limit trigger assembly (4) via a limit device connecting plate (3). One end of the limit trigger assembly (4) is fixed on the limit device connecting plate (3), and the other end of the limit trigger assembly (4) is in contact with a limit switch (5). The limiter mounting plate (2) is fixed to the crane arm by mounting bolts (1). The limiter mounting plate (2) is provided with a track for the mounting bolts (1) to move. The limiter mounting plate (2) moves within the track by the mounting bolts (1) to change the relative angle with the crane arm.

2. The adjustable luffing tower crane upper and lower limit device as described in claim 1, characterized in that: The limit trigger component (4) is a length adjustable device, which includes a screw and a nut.

3. The adjustable luffing tower crane upper and lower limit device as described in claim 2, characterized in that: The nut is connected to the limiting device connecting plate (3), one end of the screw passes through the nut, and the other end of the screw is connected to the contact of the limit switch (5).

4. The adjustable luffing tower crane upper and lower limit device as described in claim 1, characterized in that: The limiter mounting plate (2) is fixed to the lifting arm by two mounting bolts (1). One fixing bolt is the rotation point of the limiter mounting plate (2). The limiter mounting plate (2) is provided with a circular track at the rotation point. The other fixing bolt makes a circular motion relative to the limiter mounting plate (2). The limiter mounting plate (2) is provided with an arc track that cooperates with the circular motion.

5. The adjustable luffing tower crane upper and lower limit device as described in claim 4, characterized in that: The circular track and the arc track are provided with limiting points, which are located outside the track and the two limiting points are in the same direction.

6. The adjustable luffing tower crane upper and lower limit device as described in claim 5, characterized in that: The length of the arc track is a quarter circle, the limiting point of the arc track is at the end of the arc track, and the limiting point of the dot track and the dot track form a 90° connected track.

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