JPH0952692A - Device for preventing over-winding of hook - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for preventing over-winding of a hook due to the artificial miss operation. SOLUTION: In a crane having a hook 3 suspended by a rope 16, which is wound around a top sheave 10 provided in a jib 2, a normal limit switch 26 is arranged in one side of the top sheave 10, and an emergency limit switch 27 is arranged in the other side thereof, and a weight 22 is suspended in the lower end of cable bodies 28, 29 connected to these limit switches 26, 27, and a weight 30 is fitted to the cable 29, which is connected to the emergency limit switch 27, at a position at the predetermined height. A reset button for canceling the operation of the only normal limit switch 26 is provided in an electrical circuit, of which wiring is arranged so that each operation of the hook 3 hoisting operation and the jib 2 falling operation can be stopped when each limit switch 26, 27 is operated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hook overwinding preventing device for preventing a crane hook from being overwound.

[0002]

2. Description of the Related Art FIGS. 5 to 9 show an example of a crane capable of performing a cargo handling operation using an undulating jib and a cargo handling operation performed by undulating a joint jib at the tip of the jib. As shown in FIG. 5, a jib 2 having a required length is provided on the upper part of the traveling device 1 so as to be capable of undulating and turning, and the tip of the jib 2 is used for cargo handling work by the jib 2. The hook 3 is equipped so that it can be hung up and down so that it can be carried out.

A jib foot 4 projecting forward from the front surface of the jib 2 is provided at the tip of the jib 2, and the jib foot 4 is capable of undulating a base end portion of a joint jib (not shown) via a fulcrum pin 5. Moreover, it can be detachably attached.

Further, at the central portion of the top steel structure 6 of the jib 2 in the width direction of the jib 2, the jib 2 is positioned on the front surface (side surface on the A side in FIG. 6) side and swings in the axial center direction of the jib 2. An equalizer 7 is provided which is rotatably mounted and rotatable in a plane orthogonal to the axis.

Further, a bracket 8 is provided at the tip of the jib 2 so as to project outward from the front surface of the jib 2 and stand parallel to each other at a predetermined interval in the width direction of the jib 2. Two top sheaves 10 are rotatably fitted to two end portions of the top sheave shaft 9 that are supported and extend in a direction parallel to the front surface of the jib 2 near both inner sides of the bracket 8. There is.

The top sheave 10 is arranged so that when the jib 2 is erected upright as shown in FIG. 6, the hook 3 is suspended at a predetermined distance from the front surface of the jib 2 which is undulating. There is.

Further, the jib 2 is supported by a bracket 11 provided on the rear surface side (the B side in FIG. 6) of the top member of the jib 2.
A rope anchor 13 is provided at one end of a guide sheave shaft 12 extending in the width direction of the guide sheave, and a guide sheave 14 is provided at the other end.

In order to suspend the hook 3 on the tip of the jib 2, the rope 16 wound around the hoisting drum 15 shown in FIG. 5 is paid out and wound around the guide sheave 14, and further, the top sheave 10 and the hook 3 are hooked. Each hook sheave 17, the equalizer 7, etc. are wound around as shown in FIG. 8, and one end thereof is connected to the rope anchor 13.

A limit switch 18 is provided to prevent the hook 3 from being overwound.

That is, on the upper part of each bracket 8,
To the front side of the jib 2 (A side in FIG. 6), the top sheave 10
Brackets 19, 19 extending to a position substantially equal to the outer circumference of the
Is provided, the limit switch 18 is attached to one of the brackets 19, 19, a cord 20 of a required length is attached to a rod 18a that is an operating portion of the limit switch 18, and the cord 19 is attached to the bracket 19 on the other side. A cord-shaped body 21 having a length such that the body 20 and the lower end reach substantially the same height position is attached, and a ring-shaped weight is attached to the lower ends of both the cords 20 and 21 so as to surround the rope 16. 22 is suspended.

Then, when the hook 3 is wound up or the jib 2 is laid down and the hook 3 reaches a predetermined position (uppermost winding position) with respect to the top sheave 10, the weight 22 of the hook sheave 17 of the hook 3 moves. It is formed so as to be hooked on the upper portion of the side cover 23 and pushed up.

FIG. 9 is an electric circuit diagram of the limit switch 18. When the hook 3 reaches the predetermined position (winding upper limit position) and the limit switch 18 operates, the connection part by the limit switch 18 is opened. When opened, relay RY1 is de-energized, contact X1 is opened and relay RY3 is excited, each contact X3 is opened and hook hoist unload solenoid S1 and jib fall unload solenoid S2 are de-energized respectively. Then, the winding operation of the hook 3 and the fall operation of the jib 2 can be stopped.

Further, after stopping the hoisting operation of the hook 3 and the falling operation of the jib 2, the reset button 2 is used as necessary when assembling the crane or avoiding a special danger.
Pressing 4 opens the connection and relays RY1, R
Y3 is de-excited and each contact X3 is closed so that the hoisting device and the jib hoisting device can be restarted in a region exceeding the hoisting upper limit position.

When carrying out cargo handling work using the jib 2 in the above-mentioned crane, the base end of the jib 2 which has been laid down on the ground is pivotally attached to the traveling device 1, and the jib 2 is lifted by the jib hoisting rope 25. After assembling the crane by raising it as shown in FIG. 5, the hook 3 suspended from the tip of the jib 2 by the rope 16 or the bucket (not shown) or the like is generally used while turning and undulating the jib 2. Various cargo handling work.

At this time, when the hook 3 reaches the winding upper limit position and the weight 22 is hooked on the side cover 23 of the hook sheave 17 of the hook 3 and pushes up the weight 22, the limit is passed through the cord 20. Switch 18
As a result of the weight of the weight 22 hanging on the upper part being released, the limit switch 18 is activated to stop the hoisting operation of the hook 3 and the falling operation of the jib 2.

[0016]

However, in the above-described hook overwinding prevention device, the hook 3 reaches the predetermined position (winding upper limit position) and the limit switch 18 is actuated, so that the hook 3 winds up and the jib 2 moves. The operation of the reset button 24 allows the hoisting device and the jib undulating device to be restarted when the crane is assembled or when hoisting is required for special danger avoidance after stopping the laying motion of the crane. However, at this time, there is a problem that the hook 3 may be overwound due to an artificial operation error.

In view of the above-mentioned circumstances, the present invention can be caused by restarting by disposing another limit switch at a winding limit position exceeding the winding upper limit position in addition to the limit switch operating at the winding upper limit position. It is an object of the present invention to provide a hook over-winding prevention device that can prevent a hook from being overwound.

[0018]

According to a first aspect of the present invention, a first limit switch and a second limit switch are arranged on both sides of a top sheave provided at the tip of a jib of a crane. , A cord of a required length is connected to the operating portion of each limit switch, and a rope for suspending a hook is suspended from the top sheave at the lower end of each cord and the upper part of the hook is connected. A first weight formed in a ring shape is suspended so that the first weight is hooked to the upper portion of the hook or the first weight at a predetermined height position of the cord-like body connected to the second limit switch. And a second weight is attached so that when the first and second limit switches are activated, an electric circuit is configured so that the hook hoisting operation and the jib fall operation can be stopped. Serial first hook Kamaki prevention apparatus characterized in that a reset button to be deactuated only of the limit switch, it relates to.

The invention according to claim 2 of the present invention provides:
A first limit switch and a second limit switch are arranged on both sides of a top sheave provided at the tip of the jib of the crane, and a cord of a required length is connected to an operating portion of the first limit switch. At the same time, a cord having a length shorter than that of the cord is connected to the actuating portion of the second limit switch, and the lower end of each cord can be hooked on the upper portion of the hook. The weight and the second weight are respectively hung, and an electric circuit is configured to stop each operation of hook hoisting and jib fall when the first and second limit switches are actuated. The present invention relates to the hook excessive winding prevention device, wherein a reset button is provided in the circuit so as to release only the operation of the first limit switch.

Therefore, according to the present invention, when the hook is wound around the top sheave by each operation of hoisting the hook or falling down of the jib, the hook is suspended via the cord-like body.
Weight is hooked on the upper part of the hook that has been wound up and pushed up, and the weight of the first weight applied to the first limit switch via the cord is released, and the first limit is released. The switch is activated, and the hook hoisting and jib fall operations are stopped.

At this time, when the reset button is pushed, the operation of the first limit switch is released, and the state before the operation of the first limit switch, that is, the hook hoisting operation or the jib fall operation can be continued. Return to the state.

Then, when the reset button is pressed and each operation of hoisting or jib laying is continued, the upper part of the hook that has been hoisted and raised or the first hook that is hooked on the upper part of the hook. When the weight pushes up the second weight, the weight of the second weight applied to the second limit switch via the cord is released, the second limit switch operates, and the reset button is pressed, for example. Even in the state where the hook is wound up, the hook hoisting operation or the jib fall operation is stopped.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show an example in which the hook overwinding preventing device according to claim 1 of the present invention is applied to the conventional crane shown in FIGS. 5 to 9. In the drawings, Figure 5
The same parts as those in FIG. 9 are designated by the same reference numerals and the description thereof will be omitted.

The common limit switch 2 is attached to one of the brackets 19 and 19 above the bracket 8 provided at the tip of the jib 2.
6 is attached, and the emergency limit switch 27 is attached to the other side, and rods (operating parts) 26a and 27 of the normal limit switch 26 and the emergency limit switch 27 are attached.
Attaching the cords 28, 29 of a required length to a, so that the four ropes 16 wound between the top sheave 10 and the hook sheave 17 can be enclosed at the lower ends of the cords 28, 29. Ring-shaped weight (first weight)
22 is suspended so as to be substantially horizontal.

Further, a weight (second weight) 30 is attached to a predetermined position in the lengthwise direction of the cord 29 on the side of the emergency limit switch 27.

The weight 30 has a hole 31 through which one of the four ropes 16 wound around the top sheave 10 and the hook sheave 17 can be inserted.
The rope 16 is formed so as not to deviate from the moving line of the rope 16 by passing through the rope 16.

Then, when the hook 3 is wound up or the jib 2 is laid down and the hook 3 reaches a predetermined position (usual winding limit position), the weight 22 is attached to the side cover 23 of the hook sheave 17 of the hook 3. It is formed so that it can be hooked up and pushed up.

When the hook 3 is further wound up or the jib 2 is further laid down and the hook 3 reaches a predetermined position (emergency hoisting limit position), the weight 30 is set.
Is formed so as to be hooked and pushed up by the weight 22 hooked on the upper portion of the side cover 23 of the hook sheave 17 of the hook 3.

FIG. 3 is an electric circuit diagram related to the service limit switch 26 and the emergency limit switch 27. When the hook 3 reaches the service winding limit position and the service limit switch 26 operates, the limit switch 2 is activated.
The relay RY1 is de-energized by opening the connection part by 6, the relay RY3 is excited by opening the contact X1 and each contact X3 is opened and the hook hoisting unload solenoid S1 and the jib fall unload solenoid S2 are opened. Are turned off so that the winding operation of the hook 3 and the fall operation of the jib 2 can be stopped.

After that, when it is necessary to assemble the crane or avoid special danger, the relay RY is opened by pressing the reset button 24 to open the connection portion.
1, RY3 is de-energized, and each contact X3 is closed so that the hoisting device and the jib hoisting device can be restarted in a region exceeding the hoisting upper limit position.

Furthermore, in this electric circuit, when the hoisting device and the jib hoisting device are restarted by the reset button 24, when the hook 3 reaches the emergency hoisting limit position and the emergency limit switch 27 operates, The limit switch 27 opens the connection, and the relay R
Y2 is de-energized, each contact X2 is opened, hook hoisting unload solenoid S1 and jib fall unload solenoid S2 are respectively de-energized, and even if reset button 24 is pressed, hook It is possible to stop the hoisting operation of 3 and the fall operation of the jib 2.

The operation of this embodiment will be described below.

When the hook 3 is wound around the top sheave 10 by each of the operations of winding the hook or falling down the jib,
When the hook 3 reaches the usual winding limit position, the side cover 23 of the hook sheave 17 of the hook 3 causes the weight 2 to move.
2, the weight 22 is pushed up to push up the weight 22, and the weight of the weight 22 hanging on the service limit switch 26 through the cord 28 is released. As a result, the service limit switch 26 operates and the circuit for hoisting 3 hooks is released. It is cut off to stop the hoisting operation, or the circuit of jib 2 laying down is cut off to stop the jib 2 laying down operation.

After that, when the crane is assembled or special danger is avoided, the hoisting device and the jib hoisting device are restarted by operating the reset button 24.

When the hoisting device and jib hoisting device are restarted, the hook 3 reaches the emergency hoisting limit position,
When the weight 22 hooked on the upper portion of the hook 3 pushes up the weight 30, the weight of the weight 30 applied to the emergency limit switch 27 via the cord 29 is eliminated, and as a result, the emergency limit switch 27 is released. The switch 27 is actuated, and the hoisting operation of the hook 3 and the fall operation of the jib 2 are stopped.

According to the above, in response to the hoisting operation after the hoisting device and the jib hoisting device are restarted by operating the reset button 24, or the fall operation of the jib 2, the hook 3 is placed immediately before the top sheave 10. Since the second overwinding prevention mechanism is provided by the emergency limit switch 27 so that the hook 3 can be stopped, it is possible to prevent the hook 3 from being overwound due to an artificial erroneous operation after the restart.

FIG. 4 shows an example of the form of the hook excessive winding prevention device according to claim 2 of the present invention. In this form example, the rod 26a of the common limit switch 26 is shown.
To the rod 27a of the emergency limit switch 27, and the lower end of each cord 28, 29 is connected to the rod 27a of the emergency limit switch 27. The cylindrical weights 22 ′ and 30 ′ are individually hung on the upper part of the hook 3 so that they can be hooked individually, and these weights 22 ′ and 30 ′ are wound between the top sheave 10 and the hook sheave 17. By passing at least one of the four ropes 16 provided inside, it is configured so as not to deviate from the moving line of the rope 16.

Thus, in the case of this embodiment, when the hook 3 is wound around the top sheave 10 by each of the operations of winding the hook or falling down the jib, the hook 3 reaches the usual winding limit position, and the hook 3 reaches the normal winding limit position. The side cover 23 of the hook sheave 17 of No. 3 abuts against the weight 22 'and pushes up the weight 22', and the weight of the weight 22 'hung on the regular limit switch 26 via the cord 28 is eliminated, resulting in the regular use. When the limit switch 26 is actuated to stop the hoisting operation of the hook 3 and the falling operation of the jib 2, and then restart the hoisting device and the jib hoisting device, the hook 3 reaches the emergency hoisting limit position. , The side cover 23 of the hook sheave 17 of the hook 3 comes into contact with the weight 30 ′ to push up the weight 30 ′, and through the cord 29, the emergency Since the weight of the weight 30 ′ applied to the mitt switch 27 is released, and as a result, the emergency limit switch 27 operates and the hoisting operation of the hook 3 and the fall operation of the jib 2 are stopped. As in the case of the embodiment shown in FIG. 3, it is possible to prevent the hook 3 from being overwound due to an artificial erroneous operation after the restart.

The hook overwinding preventing device of the present invention is not limited to the above-mentioned embodiment, and the cord may be a wire rope or the like other than the chain as shown in the drawing. Needless to say, various changes can be made without departing from the scope of the invention.

[0041]

As described above, according to the hook overwinding prevention device of the present invention, the hoisting device or the jib hoisting device is re-operated by operating the reset button in order to avoid the crane assembling and a special danger. It is possible to obtain an excellent effect that it is possible to prevent the hook from being overwound due to an artificial erroneous operation that may occur when the hook is activated.

[Brief description of drawings]

FIG. 1 is a side view showing an example of an embodiment of the present invention.

FIG. 2 is a view taken along the line II-II of FIG.

FIG. 3 is an electric circuit diagram of a limit switch according to an example of an embodiment of the present invention.

FIG. 4 is a side view showing another example of the embodiment of the present invention.

FIG. 5 is a side view showing an example of a crane.

FIG. 6 is a side view showing a conventional hook excess winding prevention device applied to the crane of FIG.

FIG. 7 is a view on arrow VII-VII in FIG.

FIG. 8 is a perspective view showing how to hang a rope that suspends the hook of the crane of FIG.

FIG. 9 is an electric circuit diagram relating to a limit switch in a conventional example.

[Explanation of symbols]

2 jib 3 hook 10 top sheave 16 rope 17 hook sheave 22 weight (first weight) 22 'weight (first weight) 24 reset button 26 regular limit switch (first limit switch) 26a rod (operating part) 27 emergency Limit switch (second limit switch) 27a Rod (actuator) 28 Cord-like body 29 Cord-like body 30 Weight (second weight) 30 'Weight (second weight)

Claims (2)

[Claims] 1. A first limit switch and a second limit switch are arranged on both sides of a top sheave provided at the tip of a jib of a crane, and a cord of a required length is provided at an operating portion of each limit switch. A first weight formed in a ring shape so as to surround a rope for suspending a hook hanging from the top sheave at a lower end portion of each cord and hooked on an upper portion of the hook. And a second weight is attached to the upper portion of the hook or the first weight so that the second weight can be hooked at a predetermined height position of the cord-like body connected to the second limit switch. The electric circuit can be configured to stop the hook hoisting operation and the jib fall operation when each limit switch is operated, and only the operation of the first limit switch can be released in the electric circuit. A device for preventing excessive winding of hooks, which is provided with a reset button. 2. A first limit switch and a second limit switch are arranged on both sides of a top sheave provided at a tip of a jib of a crane, and a rope having a required length is provided at an operating portion of the first limit switch. While connecting the cords, a cord having a length shorter than that of the cord is connected to the operating portion of the second limit switch, and the lower end of each cord is hooked to the upper portion of the hook. The first weight and the second weight are respectively hung so as to enable the electric circuit to be configured to stop the hook hoisting operation and the jib fall operation when the first and second limit switches are operated. In addition, the hook overwinding prevention device is characterized in that a reset button is provided in the electric circuit so as to release only the operation of the first limit switch.