JPH0328070Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is a wheel crane such as a truck crane or a rough terrain crane, in which a compression column type jib (hereinafter simply referred to as a jib) is extended and retracted using the so-called jib twist method. This relates to a jib extension and storage device.

[Conventional technology]

An example of the basic configuration and jib storage procedure of a conventional device for extending and storing a jib using the above-mentioned jib twist method will be briefly explained with reference to FIGS. 23 to 26.

(A) First and second on both sides of the tip of boom 1.
Both jib mounting shafts 11 and 12 are provided protrudingly.

(B) Both sides of the base end of the jib 2 (left and right as seen from the operator's cab when the jib is extended; the same is true for the left and right directions below), that is, the base ends of both the first and second main girders 2a and 2b of the jib. , both bifurcated first and second jib feet 21 and 22 which can be engaged with and disengaged from the jib mounting shafts 11 and 12 are provided.

(C) Of the two jib feet 21 and 22, the first jib foot 21 is constructed as a movable jib foot that can rotate around its axis, and the second jib foot is constructed as a fixed jib foot that cannot rotate.

(D) When the jib 2 is in use, the first jib foot 21 is attached to the first jib mounting shaft 11 as shown in FIGS. 23 and 24.
, the second jib foot 22 is attached to the second jib mounting shaft 12.
Extend it from the tip of the boom with each of them engaged. In Fig. 23, S is the jib 2 in this extended state.
It is a suspension rod that supports.

Jib storage procedure (a) With the suspension rod S removed and only the first jib foot 21 engaged and connected to the first jib mounting shaft 11, move the jib 2 below the tip of the boom as shown by the imaginary line in Figure 23. hang. W is an auxiliary wire rope that supports the jib 2 at this time, and its end is fixed near the tip of the jib 2.

(b) After removing the end of the auxiliary wire rope W from the jib tip, attach the jib 2 as shown in Figure 25.
270° around the axis of the movable jib foot 21.

(c) Pass the auxiliary winding wire rope W through the guide sheave 23 provided at the tip of the jib, and with the end fixed to the boom base, slowly wind up the auxiliary winding wire rope W, as shown in Fig. 26. As shown in , the jib 2 is pulled toward the left side of the boom 1 around the first jib attachment shaft 11.

(iv) After this pulling, the jib 2 is fixed at the base and tip using known jib fixing means (not shown).

In this way, the jib 2 is stored vertically on the left side of the boom 1 in a so-called sideways position.

[The problem that the idea aims to solve]

However, according to the conventional device, as described above, the jib 2 is pulled and stored on the left side of the boom using the first jib foot 21 provided at the base end of the first main girder 2a of the jib 2 as a fulcrum. In the retracted state, most of the first main girder 2a of the jib 2 (shown with diagonal lines in FIG. 26) protrudes below the boom.

For this reason, this jib protrusion reduces the forward visibility from the driver's cab while the crane is moving, especially in the case of rough terrain cranes where the boom overhangs in front of the operator's cab is large and the forward visibility is poor. The protruding part of the jib was an obstacle to running.

On the other hand, as shown in Japanese Patent Application Laid-open No. 61-86386, after the jib is pulled to the side of the boom, the jib and boom are connected via a pulley, and the jib is moved downwards by the boom extension. There is a known device that is pulled up to an upper position that does not protrude as much as possible.

However, according to this configuration, the jib raising process (the opposite lowering process when the jib is extended) is required, which makes the jib storage and extension work troublesome, and this has the disadvantage of deteriorating work efficiency.

In addition, in the above-mentioned known technology, a connecting tool separate from the original jib foot is rotatably and slidably provided at the base end of the jib, and the jib is suspended and twisted using the connecting point between this connecting tool and one of the jib feet as a fulcrum. The structure is in place.

However, when extending the jib from its storage position,
If the boom is set to be tilted downward from the horizontal, when the jib is released from storage with the above coupling device connected to the jib mounting shaft, the relative sliding action between the jib and the coupling device will cause There is a risk that the jib may slip toward the tip of the boom.

Therefore, the present invention eliminates the need to raise and lower the jib in the retracted position, and allows the jib to be set in the upper position only by pulling the jib. To provide a crane jib extension and storage device that can prevent accidental movement of the crane.

[Means to solve the problem]

In this invention, there is a first
A jib mounting shaft and a second jib mounting shaft are provided on the other side, while first and second jib feet are provided at the base end of the jib to be detachably connected to both of the jib mounting shafts. The jib is stored on the side of the boom in a vertical position with the first jib foot on the lower side and the second jib foot on the upper side.The jib is then lowered, twisted, and swung up.The first jib foot is placed on the first jib mounting axis. In this crane, the second jib foot extends from the tip of the boom while being connected to the second jib mounting shaft, and is retracted in the reverse order, and has the following configuration.

() A connector is provided on the lower side of the jib base end when the jib is stored in the jib storage state, and is connected to the first jib mounting shaft in a detachable manner and rotatable about the first jib mounting shaft.

() This connector is rotatable around an axis in the length direction of the jib that is shifted downward relative to the lower side of the jib in the jib storage state, and an advanced position in which it advances toward the base end of the jib along this axis. and a retracted position in which the jib is retracted toward the tip of the jib and separated from the first jib mounting shaft, and can be engaged with the first jib mounting shaft at the advanced position in the jib retracted state. shall be configured.

() When the jib is extended, the jib is moved from the storage position to the hanging position using this connection point as a fulcrum with the connecting tool connected to the first jib mounting shaft, and when the jib is retracted, the jib is moved in the opposite direction. Have the means.

() Equipped with a jib lifting means for raising and lowering the jib in a hanging state between a position where both jib feet engage with both jib mounting shafts and a position where these are separated.

() Equipped with advancing fixing means for fixing the above-mentioned connector at the above-mentioned advanced position when the jib is in the retracted position.

[Effect]

With this configuration, the jib is twisted and extended around the parallel axis below the jib lower side in the retracted state, and is retracted, and when the jib is retracted, the jib lower side is located above the jib mounting axis and is attracted to. That is, the jib is automatically set to the upper position only by the jib pulling operation without requiring any operation to raise or lower the jib in the storage position.

Furthermore, in the jib retracted position, the connector is fixed at the advanced position, and relative sliding movement between the connector and the jib is prevented, so that unexpected movement of the jib can be prevented.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 to 20.

Basic Embodiment (See FIGS. 1 to 11) The boom 3 is usually composed of a basic boom and a plurality of movable booms. However, in order to make the explanation easier to understand, here, a case is shown in which the boom 3 is constructed as a one-stage telescoping type consisting of only a basic boom 3A and a single-stage movable boom 3B.

The jib 4 has a tapered ladder shape with a plurality of connecting bars 4c attached between the first and second main girders 4a and 4b.

The boom 3 has first and second jib attachment shafts 31 and 32 horizontally protruding from both left and right sides of the distal end of the movable boom 3B.

Of these, the first jib mounting shaft 31 has an auxiliary mounting portion 3 attached to a main mounting portion 31a having the same length as the second mounting shaft 32.
1b are integrally extended (see FIGS. 5, 6 and 11).

Reference numeral 5 denotes a known jib guide as a jib moving means provided on the left side of the tip of the basic boom 3A.A pair of parallel guide rails 51 and 52 are attached to the left side of the boom in a U-shape, so that the groove rail is It is formed in a shape and consists of an inclined groove part 5a which is inclined downwardly when the boom is in a horizontal state, and a horizontal groove part 5b connected to the rear of this inclined groove part 5a. 33 is an idler sheave provided at the tip of the movable boom 3B, 34 is the main sheave, and 35 is the auxiliary sheave.

On the other hand, the jib 4 has bifurcated first and second jib feet 41 and 42 fixed to both left and right sides of its base end, that is, at the base ends of both the first and second main girders 4a and 4b. In FIGS. 8 and 9, reference numerals 41a and 42a are fixing pin holes provided through these jib feet 41 and 42.

When in use, the jib 4 is
As shown in Fig. 1, both jib feet 41 and 42 are extended from the tip of the boom while being engaged and connected to both jib mounting shafts 31 and 32, respectively, and when not in use, the first
As shown in the figure and Figures 8 and 9, the first main girder 4a
and the first jib foot 41 is on the lower side, the second main girder 4
b and the second jib foot 42 are located on the upper side in a vertical position, the boom is pulled to the left side surface, stored, and fixed by a known jib fixing means (not shown).

The first main girder 4a in the stored state in this jib 4
A box-shaped bracket 43 is fixed to the lower surface of the proximal end, and the connector 6 is attached to the bracket 43 via a rod 61.

Like the jib feet 41 and 42, this connector 6 is
It is formed into a bifurcated shape and is fixed to one end of the rod 61.

The rod 61 is inserted into the first main girder 4 at a position shifted downward by a predetermined distance d ₁ (shown in FIG. 8) from the first main girder 4a.
The rod is supported by a bracket 43 in a state parallel to a, so as to be rotatable around the rod axis x and slidable on the same axis x.

Thereby, the connector 6 is configured to be rotatable around the rod axis x and slidable on the same axis x. Note that the rod 61 may be slightly inclined with respect to the axis of the first main girder 4a.

Further, a thrust plate 62 is screwed and fixed to the other end of the rod 61.
2 is in contact with the end surface of the bracket 43,
The rod 61, that is, the connector 6 is in a state in which it protrudes to the maximum extent toward the base end of the jib (hereinafter, this state is referred to as an advanced state, and the state in which it slides toward the distal end of the jib from this state is referred to as a retracted state).

In this advanced state, the connecting tool 6 is connected to the first jib foot 41.
The connector 6 protrudes further toward the base end of the jib (d ₂ indicates this protrusion dimension in Fig. 8), and at this extended position, the connector 6
can be engaged with the auxiliary attachment portion 31b of the first jib attachment shaft 31.

Further, as shown in FIGS. 8 to 10, a protruding piece 63 is provided on the outer periphery of the thrust plate 62,
When the jib is retracted, the protruding piece 63 comes into contact with the stopper 44 provided on the distal end surface of the bracket 43, thereby preventing the rod 61, that is, the connector 6, from moving backward (this action will be explained in detail later). ).

Note that the projecting pieces 63 are provided at two symmetrical locations, and any one of them can be selectively used. In FIGS. 8 and 9, numerals 45 and 45 are shaft bearings that rotatably and slidably support the rod 61, and 6a is a pin hole formed through the tip of the connector 6.

On the other hand, as shown in FIGS. 1 and 2, a guide roller 46 is provided protruding from the upper surface of the base of the second main girder 4b in the stored state in the jib 4, and this guide roller 46 and
The jib guide 5 of the boom 3 allows the jib 4 to move from the storage position shown in FIG. 1 to the hanging position shown in FIG. 2 when the jib is extended, and vice versa when the jib is retracted.

Next, the procedure for extending and retracting the jib using this device will be explained.

Jib Extension The jib 4 is fixed to the left side surface of the basic boom 3A at its tip and middle portion in the retracted state shown in FIG.
Also, at this time, the guide roller 46 is
The horizontal groove portion 5b is engaged with the horizontal groove portion 5b in the horizontal groove portion 5b.

(a) With the boom 3 fully retracted and laid down almost horizontally, engage the connector 6 with the auxiliary attachment part 31b of the first jib attachment shaft 31, and insert the fixing pin P into the pin hole 6a. Connector 6 to auxiliary mounting part 31b
It is connected to the mounting portion 31b so that it cannot be separated from the mounting portion 31b and is rotatable about the mounting portion 31b.

(b) Unfasten the jib 4, raise the boom 3 to about 80 degrees, and simultaneously extend it.

This boom extension operation causes the guide roller 4 to
6 is removed from the jib guide 5 from the horizontal groove 5b of the jib guide 5 through the inclined groove 5a. Due to this movement of the guide roller 46, the jib 4 assumes a hanging position with the first jib mounting shaft 31 (auxiliary mounting portion 31b) as a fulcrum, as shown in FIG. In addition,
In FIG. 2, 0 indicates the jib center of gravity.

(c) Twist the jib 4 about 270 degrees around the rod axis x to the state shown in Fig. 3 and then in Figs. 4 and 5.

In the state shown in Figures 4 and 5, both jib feet 41 and 4
2 are in a state of facing both jib mounting shafts 31 and 32 from below, respectively. Furthermore, due to the approximately 270° twist of the jib 4, the stopper 44 of the coupling mounting bracket 43 comes off the protrusion 63 of the thrust plate 62 (as shown by the imaginary line in FIG. 10), so that the coupling 6 moves backward. It becomes possible to do so.

(d) Pass the auxiliary winding wire rope W, which has been passed through the idler sheave 33 and the auxiliary sheave 35 in advance, through the guide sheave 47 at the tip of the jib, and lock the auxiliary hook F attached to the end of the guide sheave to the tip of the jib.

(E) In this state, when the auxiliary wire rope W is hoisted (normally, the boom 3 is extended with the rope fixed), the jib 4 is pulled up while the connector 6 is moved backward due to the tensile force. , the first jib foot 41 is the main attachment part 31 of the first jib attachment shaft 31.
a, the second jib foot 42 is attached to the second jib mounting shaft 3.
2 (state shown in FIG. 6). In this state, the jib feet 41, 42 and the coupling tool 6 are aligned coaxially.

(f) When the auxiliary winding wire rope W is further wound up, the jib 4 is pulled forward about the jib attachment shafts 31 and 32, and at the same time, the boom 3 is lowered almost horizontally, resulting in the state shown in FIG. 7. In this state, the pin holes 41 of both jib feet 41 and 42
Both jib feet 41 and 42 are fixed to the jib mounting shafts 31 and 32 by inserting fixing pins (not shown) into a and 42a, respectively.

(G) Install the suspension rod S between the jib 4 and the tip of the boom, as shown by the imaginary line in Figure 7.

With the above steps, the extension of the jib 4 is completed.

Jib storage Jib storage is performed by following the above-mentioned extension procedure in reverse.

To summarize the main points, lower the boom 3 almost horizontally, lock the auxiliary hook F to the tip of the jib, and lower the jib 4.
7, remove the suspension rod S and remove the jib foot fixing pins on both sides to raise the boom 3. Next, loosen the auxiliary wire rope W to let the jib 4 hang down as shown in Figure 6, then lower the jib 4 as shown in Figures 4 and 5, and then twist it approximately 270 degrees in the opposite direction to when it was stretched out. The state shown in FIG. 2 is obtained.

At this time, the guide roller 46 faces the entrance of the jib guide 5, and by contracting the boom 3, the guide roller 46 enters the jib guide 5 and moves from the inclined groove part 5a to the horizontal groove part 5b. As a result, the jib 4 is connected to the connecting tool 6 and the first jib mounting shaft 31.
The boom is automatically pulled to the left side of the boom using the connecting point as a fulcrum, and becomes the retracted state shown in Figure 1.

When using this device, in the jib retracted state shown in FIG. 1, the jib first main girder 4a is located above the rod 61, which is the torsion center axis, by a distance d ₁ .
This distance d ₁ compared to a conventional device in which the twisting center is the first jib foot axis coaxial with the first main girder.
The entire jib 4 is retracted upward. That is,
By pulling the jib 4 from the hanging state shown in Fig. 2 to the left side of the boom, the jib 4 can be automatically stored in an upper position where it hardly protrudes below the boom, and after pulling the jib 4, it can be returned to the upper position. Good forward visibility can be ensured without the need to pull up.

Further, the connecting tool 6 is attached to the jib 4 so as to be able to slide forward and backward, and the connecting tool 6 is attached to the jib foot 41, 42.
A state in which the jib feet 41 and 42 protrude a distance d ₂ toward the base end of the jib, or in other words, the jib feet 41 and 42
1 and 32, the jib 4 is pulled and stored in a state closer to the base end of the boom than the jib foot. It is stored (shifted back) to the rear position. Therefore, during crane work with the jib retracted, as the jib 4 is shifted back as described above, the center of gravity of the boom shifts toward the base end of the boom, reducing the overturning moment.
The crane capacity can be increased, and the front and rear axle loads due to the boom weight are well balanced during travel.

By the way, when extending the jib 4 from the retracted state shown in Fig. 1, if the boom 3 is set in a state where the boom 3 is tilted downward from the horizontal, when the jib 4 is released, the jib 4 will be at the tip of the boom. There is a risk that it may move in the direction.

In addition, during the jib retraction work, in the process of pulling the jib 4 from the state shown in FIG. 5 (particularly the inclined groove portion 5a), the jib 4 tends to move toward the tip of the boom (the connector 6 moves relatively backward) due to the reaction force, and the jib pulling action is performed smoothly. There is a risk that it will disappear.

In this case, in this device, when the jib 4 is set in the retracted attitude (the attitude shown in Figs. 1 and 2), the stopper 44 of the bracket 43 is moved to the third position that coincides with the protrusion 63 of the thrust plate 62 in the circumferential direction. The state shown in Figures 8 to 10 is reached, and the backward movement of the connector 6 is prevented by these, so there is no risk of the jib 4 moving toward the boom tip during the jib pulling-in and jib extension preparation stages. . Therefore,
Jib storage and extension operations can be performed smoothly and safely according to the procedure.

Note that after the jib is retracted, the connector 6 may be left in the extended state shown in Fig. 1, etc., but normally, the jib attachment shaft 31 (auxiliary attachment part 31b) is removed from the connector 6 by extending the boom. , by rotating the rod 61 and releasing the retraction lock, the connector 6 is removed.
Let's move back.

Other Embodiments (a) In the above embodiments, the connector 6 is formed into a bifurcated shape, but the connector 6 may be formed into a ring shape as shown in FIG. 12. In this case, as a means for removably connecting the ring-shaped connector 6 to the jib attachment shaft 31, in the embodiment shown in FIG. This auxiliary attachment part 31
b through the ring-shaped connector 6 and attach it to the main attachment part 31a.
A means is taken to fit it externally and connect it with a pin 31c.

According to this configuration, by removing the auxiliary attachment part 31b when the jib is not in use, the protrusion of the attachment shaft 31 from the side surface of the boom tip can be reduced, making it easier to operate the crane by entering the boom 3 into narrow spaces. be advantageous to

(b) In the embodiment shown in FIGS. 13 and 14, the length of the auxiliary attachment portion 31b of the first jib attachment shaft 31 is This allows the dimensions to be reduced. Note that this configuration applies to the 12th
Using the ring-shaped connector 6 shown in the figure, and the main attachment part 31a and the auxiliary attachment part 31b of the jib attachment shaft 31.
It is also possible to adopt an embodiment in which the and is configured separately.

(c) In the embodiment shown in FIGS. 15 to 17, the connecting tool of the rod 61 is arranged so that the connecting tool 6 is located on the axis of the jib foot 41 in the twisted state of the jib shown in FIG. The 6 side end portion is bent into a crank shape, and this bent portion including the connector 6 is formed by two parallel plates.

In this configuration, when the jib 4 is pulled up after twisting the jib, the upper end surface of the jib foot 41 comes into contact with the lower surface of the bent portion, and this is pushed up, causing the jib foot 41 to engage with the jib mounting shaft 31. .

According to this configuration, since it is not necessary to provide the auxiliary attachment portion 31b on the jib attachment shaft 31, the protruding dimension of the attachment shaft 31 can be minimized.

(d) In the basic embodiment, the protrusion 63 was provided on the thrust plate 62 and the stopper 44 was provided on the bracket 43 as means for fixing the connector 6 in the advanced position (preventing backward movement) in the jib retracted position, but other The configuration shown in FIGS. 18 to 22 can be adopted.

(d)-1 In the embodiment shown in FIG.
A circumferential groove 64 is provided on the outer circumferential surface of the intermediate portion of 1. On the other hand, the bracket 43 is provided with a fixing pin mechanism 7 at a position corresponding to the circumferential groove 64 when the connector is in the advanced state.

This fixing pin mechanism 7 includes a cylindrical pin holder 71 and a pin 72 provided on the pin holder 71 so as to be able to move in and out toward the outer peripheral surface of the rod.
It consists of a spring 73 that presses the pin 72 toward the outer peripheral surface of the rod, and a spring receiver 74.

Further, a lever 75 having a knob 75a is provided at the base end of the pin 72, and this lever 75 is brought into contact with the outer end surface of the spring receiver 74.

The outer end surface of this spring receiver 74 has a high surface portion 74a.
and a low surface portion 74b are formed into a cam surface that is connected in the circumferential direction via an inclined surface, so that when the jib is retracted, the tip of the pin 72 is placed outside the pin holder 71 when the lever 75 is in contact with the low surface portion 74b. The rod 61 protrudes and comes into pressure contact with the outer peripheral surface of the rod 61.

Therefore, when the connector 6 is in the advanced state (the state shown in Figs. 4 and 5) during the jib storage operation, the pin 7
2 engages with the circumferential groove 64 to prevent the connector 6 from moving backward. Also, when extending the jib, lever 7
5 in contact with the high surface part 74a of the spring receiver 74,
It is sufficient to keep the pin 72 out of the circumferential groove 64.

In addition, in this embodiment, a circumferential groove 65 is also provided at the end of the rod 61 on the coupling tool 6 side, and after the jib is retracted,
The connector 6 is configured to be held in a retracted state.

(d)-2 In the embodiment shown in FIGS. 19 to 22, the rod 61 has a hollow shaft, and the peripheral wall of the hollow rod 61 has a first pin hole 66 for retracting and a second pin hole for extending. The pin holes 67 are provided on the same circumference at the same angle as the jib twist angle (approximately 270 degrees).

On the other hand, the fixing pin mechanism 7 used in the embodiment shown in FIG. 18 is provided on the bracket 43, and the pin 72
However, when the jib is retracted, it engages with the first pin hole 66, and when the jib is extended, it engages with the second pin hole 67, respectively.

In addition, one hole edge 66a, 67a
is formed on an inclined surface. Also, the first pin hole 6
6, in order to fix the connector 6 in the extended position in the jib retracted posture, the pin 72 is made into a straight hole shape that cannot be removed in the rod axis direction, as shown in FIG. 21, and the second pin hole 67 is As shown in FIG. 22, a hole edge 67b in the backward direction of the connector 6 is formed to allow the connector 6 to move backward.
is formed into an inclined surface from which the pin 72 can be removed.

According to the configuration of this embodiment, in addition to the effect that the connector 6 can be fixed in the extended position when the jib is retracted, when the jib 4 is twisted in the retracting direction, the pin 72 is inserted into the first pin hole 66, and the pin 72 is twisted in the extending direction. When the jib 4 is rotated, the pins 72 engage with the second pin holes 67 to restrict the twisting angle of the jib 4, so that the twisting operation is performed accurately. That is,
When storing the guide roller 46 at the stage shown in FIG.
When the jib foot 41 faces the entrance of the jib guide 5 and is extended, both jib feet 41,
42 is accurately twisted so that it is located directly below the jib mounting shafts 31 and 32 on both sides.

(e) In each of the above embodiments, in order to shift and store the jib 4 as far as possible toward the base end of the boom as described above, the coupling device 6 is configured to slide with a relatively large stroke relative to the jib 4. , when the shift back function is not required, the slide stroke of the coupling device 6 is such that the jib feet 41, 42 are close to below the jib mounting shafts 31, 32 at the jib twisting stage during extension as shown in FIG. Only the stroke required to move from the facing position to the position where it engages with the mounting shafts 31 and 32 is sufficient.

(f) As a jib moving means for moving the jib 4 between the hanging position and the storage position, in addition to the jib guide 5 and guide roller 46 exemplified in the above embodiment, the method disclosed in Japanese Patent Application Laid-open No. 61-86386 can be used. Alternatively, a structure in which the jib is moved by a rope as shown in Japanese Patent Application Laid-Open No. 58-130883 may be used.

[Effect of idea]

As described above, according to the present invention, a coupling device is attached to the lower side of the jib when the jib is in the retracted state, which is rotatable around an axis that is shifted downward with respect to the lower side of the jib and can freely slide forward and backward in the direction of the base end of the jib. established,
With this connector connected to the jib mounting shaft, the jib is allowed to hang down using this connection point as a fulcrum, and is twisted around the axis to extend and store the jib. The boom can be set in an upper position where there is almost no downward protrusion, thereby ensuring good forward visibility when traveling.

Moreover, since the jib retracting operation to the upper position is automatically performed only by the jib pulling operation, there is no need to pull the jib back to the upper position after storing the jib.

In addition, since we have provided a means to fix the coupling in the advanced position when storing the jib, it is possible to release the jib from the stowed position when the boom is tilted downward from horizontal during the jib pulling stage in the jib stowing process or when extending the jib. This can prevent unexpected movement of the jib, such as movement of the jib toward the tip of the boom.

[Brief explanation of the drawing]

Figures 1 to 11 show the basic embodiment of the present invention, with Figure 1 showing the jib in the retracted state, Figure 2 in the hanging state, Figure 3 in the middle of twisting the jib, and Figure 4 in the completed state of twisting the jib. Fig. 5 is a side view showing the 4th
Figure 6 is a front view with the jib pulled up vertically, Figure 7 is a side view of the jib extended state, Figure 8 is a partially enlarged view of the state shown in Figure 1, and Figure 9 is a front view of the state shown in Figure 1. 10 is an enlarged sectional view taken along the line A-A in FIG. 8, FIG. 11 is a partial enlarged view of the state shown in FIG. 6, and FIG. 9 is a diagram equivalent to FIG. 9, FIG. 13 is a diagram equivalent to FIG. 9 showing yet another embodiment, FIG. 14 is a diagram equivalent to FIG. 11 of the embodiment in FIG. 13, and FIG. 15 is a diagram corresponding to yet another embodiment. Figure 5 Partially enlarged front view of stage 1
Figure 6 is equivalent to Figure 11, Figure 17 is Figure 16B.
-B sectional view, FIG. 18 is a partially enlarged side sectional view showing another embodiment, FIG. 19 is a partially enlarged side sectional view showing still another embodiment, and FIG. 20 is FIG. 19C.
- C-line enlarged sectional view, Figure 21 is Figure 20 D-D
22 is a sectional view taken along line E-E, FIG. 23 is a side view of the conventional example with the jib extended, FIG. 24 is a plan view of the same, and FIG.
The figures are side views showing the same storage state. 3... Telescopic boom, 31... First jib mounting shaft,
31a... Main mounting part of the mounting shaft, 31b... Auxiliary mounting part, 4... Jib, 4a... First main girder of the jib (lower side of the jib), 4b... Second main girder, 41... ...First jib foot, 42...Second jib foot, 6...
Connecting tool, 61...Rod for installing the connecting tool, x...
The rod axis (axis shifted downward with respect to the lower side of the jib), 62... Thrust plate constituting means for fixing the coupling in the advanced position, 63... Projection of the thrust plate, 44... Stopper, 7...Fixing pin mechanism constituting another example of the same means, 72...
Pins of the mechanism, 64, 66, 67... pin holes of the connector, 5... jib guide constituting the jib moving means, 46... the guide roller, W... auxiliary winding wire rope constituting the jib lifting means , F... Same supplementary futsuk.

Claims (1)

[Scope of Claim for Utility Model Registration] A first jib mounting shaft is provided on one side of the left and right sides of the tip of the telescoping boom, and a second jib mounting shaft is provided on the other side, while a second jib mounting shaft is provided on the base end of the jib relative to both of the above jib mounting shafts. first and second jib feet are provided which are detachably connected to each other, and the first jib foot is on the lower side and the second jib foot is on the lower side and the second jib foot is on the lower side and
The jib is stored on the side of the boom in a vertical position with the jib foot on the upper side, and the jib is attached to the first jib mounting shaft and the second jib foot to the second jib after going through the steps of hanging, twisting, and swinging up. 1. A crane jib extension and storage device for a crane that extends from the tip of the boom while connected to a mounting shaft and stores it by reversing the procedure, the crane jib extension and storage device having the following configuration. () A connector is provided on the lower side of the jib base end when the jib is stored in the jib storage state, and is connected to the first jib mounting shaft in a detachable manner and rotatable about the first jib mounting shaft. () This connector is rotatable around an axis in the length direction of the jib that is shifted downward relative to the lower side of the jib in the jib storage state, and an advanced position in which it advances toward the base end of the jib along this axis. and a retracted position in which the jib is retracted toward the tip of the jib and separated from the first jib mounting shaft, and can be engaged with the first jib mounting shaft at the advanced position in the jib retracted state. shall be configured. () When the jib is extended, the jib is moved from the storage position to the hanging position using this connection point as a fulcrum with the connecting tool connected to the first jib mounting shaft, and when the jib is retracted, the jib is moved in the opposite direction. Have the means. () Equipped with a jib lifting means for raising and lowering the jib in a hanging state between a position where both jib feet engage with both jib mounting shafts and a position where these are separated. () Equipped with advancing fixing means for fixing the above-mentioned connector at the above-mentioned advanced position when the jib is in the retracted position.