JPH10338470A - Rope hoisting and lowering device of crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability by decreasing the degree of fatigue of a rope without restricted the degree of freedom of the arrangement of a winch drum in a structure for hoisting and lowering a rope through a process of laying the rope between a plurality of sheaves pivotally attached to two shafts in a rope hoisting and lowering device of a crane. SOLUTION: In a rope hoisting and lowering device, largediameter bridle sheaves 25a, 25b, 25f and small-diameter bridle sheaves 25c, 25d, 25e are pivotally attached to a bridle shaft 24, and large-diameter bail sheaves 29a, 29b, 29f, 29g and smalldiameter bail sheaves 29c, 29d, 29e are pivotally attached to a bail shaft 28. The large-diameter sheaves and the small-diameter sheaves are approximately alternately provided on two shafts 24, 28, and a boom derricking rope 31 delivered from a winch drum 30 is introduced to the large-diameter bail sheaves 29a provided on the central part of the bail shaft 28. The rope passing the upper side of the bail sheave 29a is wound from the upper side to the lower side of the large-diameter bridle sheave 25a and then alternately wound every sheave in the same rotational direction in the U-bent shape, and therefore, fatigue of the rope is decreased, and the life of the boom derricking rope 31 can be lengthened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for hoisting and lowering a rope of a crane, and more particularly to an apparatus for hoisting and lowering a rope hung between sheaves pivotally connected to two shafts.

[0002]

9 and 10 show a conventional crawler crane, in which a boom pendant 2 is locked at the rear end of a boom 1 and a bridle 3 is attached to an end of the boom pendant 2. FIG. Are linked. The bridle 3 is provided with a bridle shaft 4 in the left-right direction,
A plurality of bridle sheaves 5 are coaxially pivotally mounted on the bridle shaft 4.

On the other hand, a high mast 6 is erected behind the boom 1 and a bail shaft 8 is provided at the upper end of the high mast 6 in parallel with the bridle shaft 4. A plurality of bail sheaves 9 are coaxially mounted on the bail shaft 8. Being pivoted. The boom hoisting rope 11 drawn out from the boom winch drum 10 is alternately wound around the bail sheave 9 and the bridle sheave 5 to fix the rope end.

By driving the winch drum 10 and hoisting and lowering the boom hoisting rope 11, the bridle sheave 5 and the bail sheave 9 rotate and the distance between the bridle shaft 4 and the bail shaft 8 approaches and separates, as described later. The boom 1 is raised and lowered via the pendant 2.

A description will be given of an example of a state in which the boom hoisting rope 11 is wound around the conventional bridle sheave 5 and bail sheave 9. The boom hoisting rope 11 extended from the winch drum 10 is first provided at the center of the bail shaft 8. Into the bail sheave 9a. The rope passing above the bail sheave 9a is wound from the upper side to the lower side of the bridle sheave 5a provided substantially at the center of the bridle shaft 4, and thereafter, the bail sheave 9b, the bridle sheave 5b, the bail sheave 9c, and the bridle sheave 5c. ,
The bail sheave 9d, the bridle sheave 5d, the bail sheave 9e, the bridle sheave 5e, the bail sheave 9f, and the bridle sheave 5f are alternately wrapped around every other sheave.
The end of the rope is locked.

[0006] Here, the rope pulled out from the upper side of one sheave is wound above the other sheave, and the rope pulled out from the lower side of the other sheave is further wound down below the other sheave. Then, since the rope is hung between the bridle sheave 5 and the bail sheave 9 in the same rotation direction in a U-shaped bending state, the fatigue of the rope is reduced and the life of the boom hoist rope 11 can be extended.

However, a line extending from the upper side of the bail sheave 9b to the upper side of the bridle sheave 5b exists in a line connecting the upper side of the bail sheave 9c and the upper side of the bridle sheave 5c. Then, the rope pulled out from the upper side of the bail sheave 9c is wound upward through the lower side of the bridle sheave 5c. Accordingly, the boom hoisting rope 11 is wound around the bridle sheave 5c and the bail sheave 9c in an S-shaped state. Also, bridle sheave 5
Similarly, between e and the bail sheave 9f,
The boom hoisting rope 11 is wound around in an S-shaped state, and the rope is in an S-shaped state between two sets of sheaves.

FIGS. 11 and 12 show bridle sheaves 5.
Shows an example in which all the ropes are wound in a U-shaped bent state between the bail sheave 9 and the bail sheave 9. The boom hoisting rope 11 drawn out from the winch drum 10 is introduced into a bail sheave 9 a provided at one end of the bail shaft 8. . The rope passing above the bail sheave 9a is wound from the upper side to the lower side of the bridle sheave 5a provided at one end of the bridle shaft 4, and thereafter the bale sheave 9b and the rope are alternately arranged on the sheave adjacent to the bridle sheave 5b. If the rope is wrapped, the rope is wrapped in the same rotational direction between the bridle sheave 5 and the bail sheave 9 in a U-shaped bent state, and fatigue of the rope can be reduced.

[0009] Regarding the bail sheave 9g at the rope end, the rope pulled out from the lower side of the bridle sheave 5f is wound above the bail sheave 9g, and the rope is wound in an S-shaped bent state. , Bale sheave 9g
And the distance between the socket 12 and the bale sheave 9g
Does not rotate, so it is not necessary to consider the fatigue of the rope here.

However, in the looped state shown in FIG. 12, when the number of sheaves increases, the fleet angle of the boom hoisting rope 11 increases, and the boom hoisting rope 11 may come off the bail sheave 5. In order to reduce the fleet angle in this hanging state, the winch drum 10 must be installed at the end of the fuselage, which limits the degree of freedom in designing the fuselage. For this reason, if the number of sheaves increases, the boom hoisting rope 11 drawn out from the winch drum 10 is inevitably introduced into the bail sheave 9a provided at the center of the bail shaft 8, as shown in FIG. Inevitably, the boom hoisting rope 11 is bent in an S-shape between a plurality of sheaves, causing a problem that the fatigue of the rope increases and the life of the boom hoisting rope 11 is shortened.

[0011] This has the same problem not only with the boom hoisting rope 11 but also with the hook rope 13. As shown in FIGS. 9 and 11, a head shaft 14 is provided at the front end of the boom 1.
4 and a plurality of head sheaves 15 pivotally connected to
A hook rope 13 is hung between a plurality of hook sheaves 17 pivotally connected to the hook rope 6.
Is wound in an S-shaped bent state, so that the fatigue of the rope increases and the life of the hook rope 13 is shortened.

Therefore, in a crane rope hoisting and lowering device, a rope is wound around a plurality of sheaves pivotally attached to two shafts to lower and raise the degree of freedom in arranging the winch drum. There is a technical problem to be solved without any restriction, in order to reduce the fatigue of the rope and improve the durability, and an object of the present invention is to solve this problem.

[0013]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above-mentioned object, and a plurality of sheaves are pivotally coaxially mounted on two parallel shafts, respectively, and are fed out of a winch drum. In a crane in which a rope is alternately wrapped around a sheave on one shaft and a sheave on the other shaft, and the two shafts can be separated from each other by hoisting and lowering the rope, a large-diameter sheave is provided on each of the two shafts. And a small-diameter sheave are juxtaposed and pivotally connected, and a rope fed out of a winch drum is introduced into a sheave substantially at the center of one shaft, and the rope is wrapped in the same rotation direction between movable sheaves. A rope hoisting and lowering device of a crane, and a plurality of sheaves coaxially connected to two shafts provided in parallel, respectively, and a rope pulled out from a winch drum is alternately provided with a sheave on one shaft and a sheave on the other shaft. In a crane which is formed so that two shafts can be connected to and separated from each other by winding and lowering the rope, a large-diameter sheave and a small-diameter sheave are pivotally attached to the two shafts approximately every other, and a winch drum The rope drawn out of the shaft is introduced into a large-diameter or small-diameter sheave provided substantially at the center of one shaft, and the rope passing above the sheave is supplied to a large-diameter or small-diameter provided substantially at the center of the other shaft. Each of the large-diameter only or small-diameter only sheaves which are wound on the two shafts alternately from the sheave at the center of the shaft to the sheave at one shaft end from the upper side to the lower side of the sheave. In the meantime, the rope is wrapped around in the same rotation direction, and after the rope is wrapped around the sheave at one shaft end, every other one is moved from the sheave at the shaft end toward the sheave at the center of the shaft. Attach the rope between each pivoted sheave. A rope hoisting and lowering device for a crane hung in the rotating direction, and a plurality of sheaves coaxially pivotally connected to two shafts provided in parallel, respectively, and a rope drawn out from a winch drum is connected to a sheave of one shaft and the other shaft. A crane in which two shafts are formed so that the two shafts can be separated from each other by hoisting and lowering the ropes, and a large-diameter sheave is arranged almost every other shaft on either one of the two shafts. A small-diameter sheave is pivotally mounted, and a rope fed out of a winch drum is introduced into a large-diameter or small-diameter sheave provided substantially at the center of one shaft, and the rope passing above the sheave is substantially moved to the other shaft. Winding from the upper side to the lower side of the large or small diameter sheave provided in the center,
Further, the rope is wrapped in the same rotation direction between every other sheave pivotally connected to the two shafts from the sheave at the center of the shaft to the sheave at the one end of the shaft. After the rope is wrapped around the sheave of the shaft, the rope is wrapped in the same rotation direction between every other sheave pivotally attached from the sheave at the shaft end to the sheave at the center of the shaft. An object of the present invention is to provide a rope hoisting and lowering device for a turned crane.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a crawler crane in which one end of a boom pendant 22 is locked at the rear end of the boom 21, and a bridle 23 is connected to the other end of the boom pendant 22. The bridle 23 is provided with a bridle shaft 24 in the left-right direction, and a plurality of bridle sheaves 25 are coaxially pivotally mounted on the bridle shaft 24.

On the other hand, a high mast 26 is provided behind the boom 21.
And a bail shaft 28 is provided at the upper end of the high mast 26 in parallel with the bridle shaft 24.
In FIG. 8, a plurality of bail sheaves 29 are pivotally mounted coaxially.
The boom hoisting rope 31 drawn out from the boom winch drum 30 is alternately wound around the bail sheave 29 and the bridle sheave 25 to fix the end of the rope.

A head shaft 3 is provided at the front end of the boom 21.
4 is provided between a multiple head sheave 35 pivotally attached to the head shaft 34 and a multiple hook sheave 37 pivotally attached to the hook shaft 36, and is fed from a winch drum 38 for hooks. Hook rope 39 is hung around.

By driving the winch drum 30 for the boom and hoisting and lowering the boom hoisting rope 31, the bridle sheave 25 and the bail sheave 29 rotate to move the distance between the bridle shaft 24 and the bail shaft 28, and the boom pendant 22. The boom 21 is raised / lowered through. Also,
By driving the winch drum 38 for the hook and hoisting and lowering the hook rope 39, the head sheave 35 and the hook sheave 37 rotate to rotate the head shaft 34 and the hook shaft 3.
6, the hook 40 moves up and down.

FIG. 2 shows an embodiment of the second aspect of the present invention, in which a bridle shaft 24 has a large diameter bridle sheave 2.
5a, 25b, 25f and small diameter bridle sheave 25
c, 25d, and 25e are alternately pivotally mounted side by side, and the bail shaft 28 has a large-diameter bail sheave 29a, 2b.
9b, 29f, 29g, and small diameter bail sheave 29c,
29d and 29e are pivotally mounted side by side approximately every other one.

In order to reduce the fleet angle of the boom hoisting rope 31, the winch drum 30 is installed at the center of the fuselage, and the boom hoisting rope 31 extended from the winch drum 30 is provided at substantially the center of the bail shaft 28. It is introduced into the bail sheave 29a. The rope passing above the bail sheave 29a is wound from the upper side to the lower side of the bridle sheave 25a provided substantially at the center of the bridle shaft 24, and thereafter, every other bale sheave 29b and the bridle sheave 25b are placed. The rope is looped in the same rotation direction from the sheave at the center of the shaft to the sheave at the end of the shaft, between the large-diameter sheaves pivotally mounted on the shaft.

Subsequently, the rope is moved in the same rotational direction toward the center of the shaft between the small diameter sheaves pivotally attached to the other ones, such as the bail sheave 29c, the bridle sheave 25c, the bail sheave 29d, and the bridle sheave 25d. After being alternately wrapped around bail sheave 29e, bridle sheave 25e, bail sheave 29f, and bridle sheave 25f, and approximately every other sheave, the rope end passes through bail sheave 29g to socket 32. Locked.

As shown in the drawing, the rope drawn from the upper side of the sheave is wound above the other sheave, and the rope drawn from the lower side of the sheave is wound below the other sheave. Since the diameters of the sheaves are different, for example, large-diameter sheaves 29a and 25a, 29b and 2
In the state where the ropes are wound from the upper side to the upper side of each of 5b, 29f and 25f, small-diameter sheaves 29c, 25c and 29d
And 25d, 29e and 25e, even if the ropes are wound from the upper side to the upper side, the ropes do not come into contact with each other and interfere with each other.

Similarly, with the rope wound from the lower side to the lower side of the large-diameter sheaves 25a and 29b, the small-diameter sheave 2
Even if the rope is wound from the lower side to the lower side of 5c and 29d, contact between the ropes does not occur. In addition, the rope wrapped around the bridle sheave 25 and the bail sheave 29, including the combination of the sheaves 25b and 29c and 25e and 29f having different diameters, does not interfere with each other at any point. .

Thus, the bail sheave 2 on the rope end side
Boom hoisting rope 3 between movable sheaves other than 9g
1 can be wrapped around in the same rotation direction in a U-shaped bending state, so that the fatigue of the rope is reduced and the life of the boom hoisting rope 31 is extended. Regarding the bale sheave 29g at the rope end, the rope pulled out from the lower side of the bridle sheave 25f is wound on the upper side of the bail sheave 29g, and the rope is wound in an S-shaped bent state. Since the distance to the bale sheave 29g is always constant and the bail sheave 29g does not rotate, it is not necessary to consider the fatigue of the rope here.

Here, even when the positions of the large-diameter sheave and the small-diameter sheave in FIG. As shown in FIG. 3, the bridle shaft 24 has small-diameter bridle sheaves 25a and 25a.
5b, 25f and large diameter bridle sheaves 25c, 25
d and 25e are alternately arranged side by side, and pivotally connected.
8 small bale sheaves 29a, 29b, 29f, 29
g and the large-diameter bail sheaves 29c, 29d, 29e are pivotally attached to each other approximately every other side.

Then, the boom hoisting rope 31 extended from the winch drum 30 is introduced into the bail sheave 29a, and the rope passing above the bail sheave 29a is wound from the upper side to the lower side of the bridle sheave 25a, and thereafter, the bail sheave 29b, Bridle sheave 25b, bail sheave 29c, bridle sheave 25c, bail sheave 29d, bridle sheave 25d, bail sheave 2
9e, bridle sheave 25e, bail sheave 29f,
By alternately wrapping around the bridle sheave 25f and approximately every other sheave, the rope can be wrapped around in the same rotation direction without interfering with each other at any point.

FIG. 4 shows an embodiment of the third aspect of the present invention, in which all bridle shafts 24 are pivotally mounted with large-diameter bridle sheaves 25a to 25f.
Have large diameter bail sheaves 29a, 29b, 29f, 29
g and small diameter bail sheaves 29c, 29d, 29e are pivotally mounted approximately every other.

The winch drum 30 is installed at the center of the fuselage, and the boom hoisting rope 31 drawn out from the winch drum 30 is introduced into a bail sheave 29a provided substantially at the center of the bail shaft 28. The rope passing above the bail sheave 29a is wound from above to below the bridle sheave 25a provided substantially at the center of the bridle shaft 24, and thereafter, the bail sheave 29b and the bridle sheave 25b
In this way, the rope is wound around the sheave at the center of the shaft from the sheave at the center of the shaft to the sheave at the end of the shaft in the same rotational direction between the sheaves of the large diameter pivotally attached to every other.

Subsequently, a bail sheave 29c, a bridle sheave 25c, a bail sheave 29d, and a bridle sheave 25d are provided between the small diameter sheave and the large diameter sheave which are pivotally attached to every other one, toward the center of the shaft. The rope is wrapped around in the same rotation direction, and the bale sheave 29e, the bridle sheave 25e, and the bail sheave 29
f, the bridle sheave 25f and the alternate sheave are alternately wrapped, and then the rope end is locked to the socket 32 through the bail sheave 29g.

As shown in the figure, the rope pulled out from the upper side of the sheave is wound above the other sheave, and the rope pulled out from the lower side of the sheave is wound below the other sheave. Since the diameters of the adjacent sheaves are different on the shaft 28 side, for example, the sheaves 29c are wound in a state in which the ropes are wound from the upper side to the upper side of the large-diameter sheaves 29a and 25a, 29b and 25b, and 29f and 25f. And 2
Even if the ropes are wound from above the small-diameter sheave to above the large-diameter sheave like 5c, sheaves 29d and 25d, and sheaves 29e and 25e, the ropes do not contact and interfere with each other.

Similarly, the rope is wound from the lower side of the large-diameter sheave 25c to the lower side of the small-diameter sheave 29d with the rope wound from the lower side to the lower side of each of the large-diameter sheaves 25a and 29b. Even when turned, no contact between the ropes occurs. In addition, sheaves 25b and 29c, 25e and 29e of different diameters
The rope hung around the bridle sheave 25 and the bail sheave 29 does not interfere with each other at any point.

As shown in FIG. 5, the bridle shaft 2
Pivot a large diameter sheave and a small diameter sheave every other to 4,
When all the bail sheaves having a large diameter are arranged on the bail shaft 28, the same operation and effect as the configuration shown in FIG. The bridle shaft 24 has a large diameter bridle sheave 2
5a, 25b, 25f and small diameter bridle sheave 25
c, 25d, and 25e are alternately arranged side by side and pivoted, and all the bail shafts 28 have large diameter bail sheaves 29a to 29a.
Pivot 9g.

Then, the boom hoisting rope 31 drawn out from the winch drum 30 is introduced into the bail sheave 29a, and the rope passing above the bail sheave 29a is wound from the upper side to the lower side of the bridle sheave 25a, and thereafter, the bail sheave 29b, Bridle sheave 25b, bail sheave 29c, bridle sheave 25c, bail sheave 29d, bridle sheave 25d, bail sheave 2
9e, bridle sheave 25e, bail sheave 29f,
By alternately wrapping around the bridle sheave 25f and approximately every other sheave, the rope can be wrapped around in the same rotation direction without interfering with each other at any point.

Further, as shown in FIG.
4, small-diameter bridle sheaves 25a to 25f are pivotally connected to the bail shaft 28, and the small-diameter bail sheaves 29a, 29
9b, 29f, 29g and large diameter bail sheave 29c,
29d and 29e are arranged approximately every other, and FIG.
As shown in FIG. 7, small-sized bridle sheaves 25a, 25b, 25f and large-diameter bridle sheaves 25c, 25d, 25e are pivotally mounted on the bridle shaft 24, and all the small-diameter bail sheaves 29a to 29b are attached to the bail shaft 28. 29g
Also has exactly the same operation and effect as the configurations shown in FIGS. 4 and 5.

Then, the boom hoisting rope 31 drawn out from the winch drum 30 is introduced into the bail sheave 29a, and the rope passing above the bail sheave 29a is wound from the upper side to the lower side of the bridle sheave 25a, and thereafter, the bail sheave 29b, Bridle sheave 25b, bail sheave 29c, bridle sheave 25c, bail sheave 29d, bridle sheave 25d, bail sheave 2
9e, bridle sheave 25e, bail sheave 29f,
By alternately wrapping around the bridle sheave 25f and approximately every other sheave, the rope can be wrapped around in the same rotation direction without interfering with each other at any point.

As described above, in the rope hoisting / lowering device of the present invention, in order to reduce the fleet angle of the boom hoisting rope 31, the winch drum 30 is installed at the center of the fuselage and is fed from the winch drum 30. The boom hoisting rope 31 is introduced into a bail sheave 29 a provided substantially at the center of the bail shaft 28. When the boom hoisting rope 31 is wrapped around in the same rotational direction in a U-shaped bending state, in order to avoid interference between the ropes, the center of the shaft between two shafts combining a large sheave and a small sheave is used. It is necessary to wrap the rope around every other sheave between the sheave at the shaft end and the sheave at one end of the shaft, but not every other sheave between the sheave at the center of the shaft and the sheave at the other end of the shaft. Instead of the sheave, the rope may be sequentially wound around the adjacent sheave in the same rotation direction, and the end of the rope may be arranged at the other shaft end.

For example, as shown in FIG. 8, a bail sheave 29a, a bridle sheave 25a, and a bail sheave 29a are provided between the sheave at the center of the shaft and the sheave at one end of the shaft.
b, wrap around the rope like bridle sheave 25b, and then bail sheave 29c, bridle sheave 2
5c, bale sheave 29d, bridle sheave 25d, etc.
Between the sheave at the center of the shaft and the sheave at the other end of the shaft,
In a configuration in which a rope is sequentially wound around adjacent sheaves such as the bridle sheave 25d, the bail sheave 29g, the bridle sheave 25f, the bail sheave 29e, and the bridle sheave 25e, and the rope end is arranged at the other shaft end, the boom undulation is also possible. The rope 31 can be hung in the same rotation direction in a U-shaped bending state.

Alternatively, although not shown, between the sheave at the center of the shaft and the sheave at the other end of the shaft, even if only sheaves of the same diameter are arranged instead of sheaves of large and small diameters, the sheaves adjacent to the other sheaves may be arranged. If the ropes are sequentially wound, the ropes can be wound in the same rotation direction without interference between the ropes. Further, as the processing of the rope end, the socket 32 may be locked to the main body side, or directly to the bail shaft 28 or the bridle shaft 24.

It should be noted that the rope hoisting and lowering device of the present invention is not limited to the boom hoisting rope 31.
With a configuration in which a rope is wound around a plurality of sheaves pivotally attached to two shafts, the same effect can be obtained, for example, for the hook rope 39 shown in FIG. With the diameter of the head sheave 35 pivotally connected to the head shaft 34 being different, a large diameter sheave and a small diameter sheave are alternately pivoted, and a hook sheave 37 pivotally connected to the hook shaft 36.
Also, a large-diameter sheave and a small-diameter sheave are alternately juxtaposed and pivoted. The hook rope 39 is wound around the other sheaves in a U-shaped state between the head sheave 35 and the hook sheave 37, so that the hook rope 39 is wound around in the same rotation direction, and the fatigue of the rope is reduced. Can be reduced.

Thus, the present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

[0040]

As described above, the large-diameter sheave and the small-diameter sheave are pivotally connected to the two shafts, respectively, and the rope drawn out from the winch drum is wound around each sheave in the same rotation direction. If a large-diameter sheave and a small-diameter sheave are alternately provided on each shaft, and the ropes are wound around every other sheave in a U-shaped bend, the ropes do not interfere with each other in the same rotational direction. The rope can be wrapped around, reducing the fatigue of the rope. Further, since the rope drawn out from the winch drum is introduced into the sheave provided at the center of one shaft, the fleet angle of the rope can be reduced.

In this way, it is possible to reduce the fatigue of the rope and improve the durability without restricting the degree of freedom in the arrangement of the winch drum.

[Brief description of the drawings]

FIG. 1 is a side view of a crawler crane, showing an embodiment of the present invention.

FIG. 2 is an explanatory view showing the embodiment of the invention according to claim 2 and showing a state in which a boom hoisting rope is wound around bridle sheaves and bail sheaves.

FIG. 3 shows another embodiment of the invention described in claim 2,
Explanatory drawing which shows the state of looping of a boom hoisting rope with respect to a bridle sheave and a bail sheave.

FIG. 4 is an explanatory view showing the embodiment of the invention according to claim 3 and showing a state in which a boom hoisting rope is wound around bridle sheaves and bail sheaves.

FIG. 5 shows another embodiment of the invention described in claim 3,
Explanatory drawing which shows the state of looping of a boom hoisting rope with respect to a bridle sheave and a bail sheave.

FIG. 6 shows another embodiment of the invention described in claim 3,
Explanatory drawing which shows the state of looping of a boom hoisting rope with respect to a bridle sheave and a bail sheave.

FIG. 7 shows another embodiment of the invention described in claim 3,
Explanatory drawing which shows the state of looping of a boom hoisting rope with respect to a bridle sheave and a bail sheave.

FIG. 8 is an explanatory view showing another embodiment of the present invention and showing a state in which a boom hoisting rope is wound around bridle sheaves and bail sheaves.

FIG. 9 is a side view showing an example of a conventional crawler crane.

FIG. 10 is an explanatory view showing an example of a state in which a boom hoisting rope is wound around a conventional bridle sheave and bail sheave.

FIG. 11 is a side view showing another example of the conventional crawler crane.

FIG. 12 is an explanatory view showing another example of a state in which a boom hoisting rope is wound around bridle sheaves and bail sheaves.

[Explanation of symbols]

 21 Boom 24 Bridle Shaft 25 Bridle Sheave 28 Bail Shaft 29 Bail Sheave 30 Winch Drum 31 Boom Raising Rope 34 Head Shaft 35 Head Sheave 36 Hook Shaft 37 Hook Sheave 38 Winch Drum 39 Hook Rope 40 Hook

Claims (3)

[Claims] 1. A plurality of sheaves are coaxially mounted on two shafts provided in parallel with each other, and a rope drawn out from a winch drum is alternately wound around a sheave on one shaft and a sheave on the other shaft. In a crane in which two shafts are formed so as to be able to be separated from each other by hoisting and lowering, a large-diameter sheave and a small-diameter sheave are respectively attached to the two shafts to be pivotally connected, and a rope fed out of a winch drum is used. A rope hoisting / lowering device for a crane, wherein the rope is introduced into a sheave at a substantially central portion of one shaft and the rope is wound around the movable sheave in the same rotation direction. 2. A plurality of sheaves are coaxially pivotally mounted on two shafts provided in parallel, and a rope drawn out from a winch drum is alternately wound around a sheave on one shaft and a sheave on the other shaft. In a crane formed so that two shafts can be separated from each other by hoisting and lowering, a large-diameter sheave and a small-diameter sheave are pivotally attached to each of the two shafts approximately every other one, and a rope fed out of a winch drum is used. While introducing into the large or small diameter sheave provided at the approximate center of one shaft,
The rope passing above the sheave is wound from the upper side to the lower side of the large-diameter or small-diameter sheave provided substantially at the center of the other shaft, and further from the sheave at the center of the shaft to the sheave at one shaft end. The rope is wrapped in the same rotation direction between the sheaves of only the large diameter or only the small diameter pivotally attached to every other of the two shafts, and the rope is wrapped around the sheave at one shaft end. After that, between the sheaves at the other end of the shaft from the sheave at the shaft end toward the sheave at the center of the shaft, the rope is wrapped around in the same rotation direction. Rope hoisting and lowering device. 3. A plurality of sheaves are coaxially mounted on two shafts provided in parallel with each other, and a rope drawn out from a winch drum is alternately wound around a sheave on one shaft and a sheave on the other shaft. In a crane in which two shafts are formed so as to be able to be separated from each other by hoisting and lowering, a large-diameter sheave and a small-diameter sheave are pivotally mounted on approximately one of the two shafts, and a winch drum The rope drawn out of the shaft is introduced into a large-diameter or small-diameter sheave provided substantially at the center of one shaft, and the rope passing above the sheave is supplied to a large-diameter or small-diameter provided substantially at the center of the other shaft. The rope is wound from the upper side to the lower side of the sheave, and further, the rope is the same between every other sheave pivotally connected to the two shafts from the sheave at the center of the shaft to the sheave at one shaft end. Wrap in the direction of rotation, After the rope is wrapped around the sheave, the rope is wrapped in the same rotation direction between every other sheave pivotally attached from the sheave at the shaft end to the sheave at the center of the shaft. A crane rope hoisting and lowering device.