JPS6361275B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for extending and retracting a supplementary jib in a wheel crane such as a truck crane or a rough terrain crane.

(Prior art) The refill jib that is added to the telescopic boom of a wheeled crane consists of a truss-type cantilever jib with a truss structure and a number of connecting rods between the side rods made of a pair of square pipes, etc. There are two types of suspension rod supported compression column type jibs (hereinafter simply referred to as truss type jibs and compression column type jibs), which are formed into a flat frame shape (ladder shape) with a tapered end. Among these, the latter compression column type jib is said to be advantageous in terms of manufacturing cost and weight.
On the other hand, there are generally two methods for storing the supplementary jib: a bottom-holding type in which the jib is folded onto the lower surface of the boom, and a side-holding type in which the jib is folded on the side surface of the boom.
In both of these storage methods, in the case of the undercarriage type, the thickness of the boom and jib in the vertical direction becomes large, so the visibility during traveling, especially the side visibility, becomes narrow.
In addition, if you try to lengthen the field of view, the overall height of the crane vehicle will increase, which also poses a problem when traveling. On the other hand, in the case of the side-carrying type, although the side view is widened, the thickness in the left-right direction is also large, which poses a problem in that it interferes with refraction on narrow running roads.

For this reason, conventionally, when using a compression column type jib, in order to ensure both side visibility and maneuverability in narrow spaces, a lower-hugging storage method was adopted in consideration of maneuverability in narrow spaces, and a truss type jib was used. When used, a side-carrying system is adopted in consideration of side visibility, but the reality is that it is not a fundamental solution because problems with either one remain.

Furthermore, regarding the work of extending and retracting the jib, in the horizontal holding method, the jib is rotated approximately 180 degrees from the side to the front on a horizontal plane, so a large space must be secured on the side. In addition, with the lower holding method, it was extremely troublesome to pass the main hook between the jib feet when rotating the jib approximately 180 degrees from the bottom to the top and extending it.

Therefore, as a completely new method, the jib is stored in a horizontal position on either the left or right side of the boom in a vertical position with its thickness direction facing left and right, and after hanging vertically from this stored position, it is twisted. One possible method is to rotate it and extend it. According to this method (hereinafter referred to as "jib twist type extension" or "storage method"), it is possible to reduce the vertical and horizontal thickness to a minimum in the retracted state, ensuring both side visibility and maneuverability in narrow spaces when driving. Moreover, the jib can be easily extended and retracted even in narrow spaces.

(Object of the Invention) The present invention provides a supplementary jib extension and storage device that can easily implement the above-described jib twist type extension and storage method with a simple configuration.

(Structure of the Invention) The present invention includes a telescoping boom and a suspension rod support compression column type replenishment jib that is added to the tip of the telescoping boom. Boom point pins are provided horizontally in the left and right directions on both the left and right sides of the tip, and the jib is attached to the tip of the telescopic boom with the jib foots on both sides supported by the boom point pins on both sides so as to be rotatable around the pin axis. In a wheel-type crane that is extended out and stored on the lateral side of the boom in a vertical position with the thickness direction facing left and right, the left and right jib feet are engaged with and disengaged from the boom point pins on both sides in the radial direction of the same pin. The jib foot is formed in a bifurcated shape, one of the jib feet is configured to be rotatable around the jib foot axis, and a pin hole provided in at least both of the jib feet and both boom point pins, and this pin hole an engaging means for holding the jib foots on both sides in a state where they are rotatably engaged with the corresponding boom point pins, and a jib is inserted into the lateral side of the boom. means for holding the jib in a vertical storage position with the thickness direction surface facing left and right, and a means for holding the jib in a vertically stored position with the jib's thickness direction surface facing left and right; a boom point sheave provided at the distal end of the telescopic boom to protrude further forward of the boom than the boom point pins on both sides; The jib point sheave installed at the tip of the jib, the auxiliary wire rope pulled out from the winch of the crane body and passed through the boom point sheave and the jib point sheave, and the jib by winding the auxiliary wire rope. It consists of a jib hook attached to the end of the wire rope so as to be locked to the tip.

With this configuration, the jib can be stored vertically on the side of the boom, and the jib can be hung vertically using one boom point pin as a fulcrum, then twisted around the axis of one jib foot to extend it, and vice versa. The jib twist type overhang and storage method can be implemented using the following steps.

Furthermore, the jib hook can be used to easily and quickly move the jib from a vertically hanging position to a horizontal direction or vice versa during the process of extending and retracting the jib.

(Example) Embodiments of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show the jib in an extended state, and FIGS. 3 and 4 show the jib in a retracted state. 1 is a telescopic boom, 2 is a suspension rod support compression column type supplementary jib (hereinafter simply abbreviated as jib),
3, 3 is the suspension rod. Note that here, in order to make the explanation easier to understand, we will use the telescopic boom 1.
Although the present invention is configured as a one-stage telescoping type consisting of a base end boom 1A, which is a fixed boom, and a distal end boom 1B, which is a movable boom, the present invention is applicable to a two-stage telescoping type or a three-stage telescoping type boom. Of course, it is also applicable. Furthermore, the left and right direction hereinafter refers to the direction seen from the driver's seat. As is well known, the jib 2 includes a pair of side rods 2a, 2 made of flat square pipes, etc.
A large number of connecting rods 2c are fixed between b and the entire frame is formed into a flat frame shape with a tapered end.

Boom point pins 4 and 5 are attached to both left and right sides of the tip of the boom 1, that is, the tip (boom point) of the tip boom 1B, so as to be rotatable around the pin axis x. The left and right feet 6, 7 are engaged with the boom point pins 4, 5. The left and right jib feet 6, 7 are both formed into a bifurcated shape. However, the left side jib foot 6 is formed into a fork shape in which the lengths of the two pieces forming the bifurcation are equal, and the right side jib foot 7 is formed into a stepped fork shape in which one piece is shorter in length than the other piece. . Both of these jib feet 6, 7 are formed separately from the jib body, that is, the side bars 2a, 2b, respectively, and the right jib foot 7 is fixed to the base end of the right bar 2b. On the other hand, the left side jib foot 6 has an integral male threaded portion 6a as shown in FIG. 5, and this male threaded portion 6a is screwed into a socket 6b fixed inside the base end of the left side rod 2a of the jib. There is. In this way, the left side jib foot 6 is attached to the base end of the jib left side rod 2a so as to be threadably rotatable about the side rod axis (jib foot axis). The right side jib foot 7 has a pin hole 9 at one location, and the left side jib foot 6 has two pin holes 8 at the tip and middle.
a and 8b, of which the pin hole 8b in the middle is formed into a long hole shape. Further, pin holes 4a and 5a are provided in the boom point pins 4 and 5 on both the left and right sides in the radial direction.

As shown in FIGS. 3 and 4, when the jib 2 is stored, it is folded in a vertical position with its thickness direction facing left and right along the left side of the base end boom 1A. In this jib stored state, the jib 2 is Tip and base 2
It is fixed (stored and held) to the base end boom 1A at a certain point. That is, first, to explain the jib tip side, Figs. 1 to 4, and Figs.
As shown in FIG. 7, etc., an engagement pin 11 is provided in a shape of a horn to protrude from the tip of the jib 2 along the axial direction of the jib.
A box-shaped bracket 12 with openings on both sides in the axial direction of the boom is provided on the left side surface of the base end of the base end boom 1A, and the engaging pin 11 is configured to be engaged with this bracket 12 from the front. There is. The bracket 12 and the engagement pin 11 are provided with pin holes 12a, 11a that match in the vertical direction when the jib is stored, and the tip fixing pin 1 is inserted into the pin holes 12a, 11a.
3 so that the engaging pin 11 can be fixed to the bracket 12. On the other hand, the fixation of the base end of the jib is as shown in FIG.
And brackets 14 and 15 with pin holes protruding from the side surface of the left side rod 2a of the jib are connected to the base end fixing pin 1.
This is done by joining with 6.

Next, the jib guide mechanism will be explained. On the jib 2 side, the side surface of the right rod 2b (top surface when the jib is stored)
A rotatable roller 18 as an engaging member is provided through a bracket 17 and protrudes toward the left side of the boom when the jib is in the retracted state. On the other hand, on the boom 1 side,
A groove-rail jib guide 19 to which the roller 18 can be engaged and disengaged is provided on the left side surface near the tip of the base end boom 1A (the side surface where the jib is stored). This jib guide 19 is constructed by fixing a pair of upper and lower guide frames 20 and 21, which are bent in a U-shape, in parallel to the left side surface of the boom at the base end. In this state, the slanted groove portion 23 is formed in communication with the inclined groove portion 23 which becomes downward toward the tip end of the boom, and has an open groove rail shape with side portions and both ends open. In addition, the lower guide frame 21
The upper guide frame 20 has a flat plate shape, and the upper guide frame 20 has an L-shaped cross section and is integrally provided with a stopper 20a at its tip end to prevent the roller 18 from coming off laterally. In addition, the base end opening 23a of the inclined groove portion 23
opens diagonally downward from the lower end of the left side of the proximal boom when the boom 1 is viewed horizontally, and the roller 18 connects to the jib guide 19 through this tip opening 23a.
to engage and disengage from.

24, 24 are suspension rod mounting seats,
The rods 2a, 2b on both the left and right sides at the tip of the jib 2 are provided to protrude upward, and one end of the suspension rods 3, 3 is fixed to the mounting seats 24, 24 with pins 25, 25 when the jib is used or stored. I try to put it on. In addition, in order to store the suspension rods 3, 3 in the jib 2 when the jib 2 is stored, there are L-shaped rod receivers 26, 26 on the left and right sides of the base end of the jib 2.
Attach the rod holders 2 to the left and right sides of the middle part of the jib 2.
7 and 27, respectively. The rod holders 27, 27 each have a U-shaped holder body 28 as shown in FIGS. 10 and 11.
, an opening/closing link 29 that opens and closes the upper opening of the main body 28, and a torsion coil spring 30 that always biases this link 29 in the direction of closing the main body.When the rod is stored, the opening/closing link 29 closes the main body 28 and the rod 3 is closed. When the rod is in use, the link 29 is opened so that the rod 3 can be removed from the main body 28. 28a is an opening/closing link 29
This is a pin that holds the open state.

31 is a boom point sheave block, 32 is an auxiliary sheave bracket attached to the tip of the sheave block 31, 33 is an auxiliary sheave that is one of the boom point sheaves attached to the bracket 32, 34 is a jib point sheave block, 35 is a jib point sheave provided on the sheave block 34. Also, 36 is a jib hook, and 37 is a winch (not shown) on the crane body.
The rope 37 is an auxiliary winding wire rope for a jib hook (hereinafter referred to as auxiliary winding rope) pulled out from the
The tip is fixed to the jib hook 36, and when the jib is extended, as shown in FIG. Auxiliary winding sheave 3 when not in use
8 and the auxiliary sheave 33 for use in lifting work.

Here, to explain the structure of the jib hook 36,
As shown in FIGS. 12 and 13, the jib hook 36 includes a weight part 39, a hook part 40 attached to the lower part of the weight part 39, and a swivel joint part (a thrust bearing) in the upper part of the weight part 39. , not shown), and a box-shaped support part 42 which is removably attached to the upper part of the socket 41 with a bolt or the like, and the terminal part of the auxiliary winding rope 37 is , is passed from the support part 42 to the socket 41, and is inserted into the clip 43 within the support part 42.
It can be stopped at. 42a is a clip inspection window provided in the support portion 42. Also, 44,
Reference numeral 44 denotes jib twist handles provided on both sides of the jib point sheave block 34.

Next, the jib twist type extension and storage method implemented by this device will be explained.

As shown in FIGS. 3 and 4, the jib 2 is placed along the left side of the proximal boom 1A in a vertical position with the right side rod 2b up and the left side rod 2a down in the extended state, as shown in Figures 3 and 4. In this state, the engaging pin 11 at the tip of the jib is engaged with the bracket 12 at the proximal end of the proximal boom 1A and fixed with the tip fixing pin 13, and the brackets 14 and 15 are fixed at the proximal end. By fixing with the pin 16, the jib 2 is fixed in the vertical storage position. In addition, in this jib storage state, the rollers 18 of the jib 2 are
As shown in the figure, it engages with a horizontal groove 22 in the jib guide 19. The jib 2 is extended from this state by the following procedure.

(b) With the crane outrigger (not shown) extended to stabilize the aircraft, fully retract the boom 1 and point it toward the aircraft side or rear in an almost horizontal position.

(b) As shown in FIG. 14b, remove the jib tip fixing pin 13 and insert the pin 13 across the pin hole 4a of the left boom point pin 4 and the intermediate pin hole 8b of the left jib foot 6. Thereby, the left jib foot 6 and the boom point pin 4 are engaged and connected, and the jib tip fixing pin 13 is used as a jib foot engagement and holding pin.

(c) Remove the jib base end fixing pin 16. This pin 1
6 will be used later as an engagement and holding pin for the right side jib foot 7.

(d) As shown in Figures 13 and 14, move boom 1.
Raise the boom 1 to about 80 degrees, and
Extend the roller 18 until it comes off the jib guide 19 (about 60 cm). In this way, jib 2
is raised together with the tip boom 1B, and the roller 18 of the jib 2 is moved up by the jib guide 19 of the proximal boom 1A.
At this point, it enters the inclined groove part 23 from the horizontal groove part 22 and moves through the inclined groove part 23. Due to the guiding action of the jib guide 19 and rollers 18, the jib 2 first moves linearly upward and the engagement pin 11 disengages from the bracket 12, and then, as the jib 2 rises, the axis x of the boom point pin 4 It rotates forward and comes off the base end boom 1A, and assumes a vertical position. In this way, the jib 2 is rotationally guided from the storage position to a vertically hanging position by the jib guide means. By the way, in the jib guide function described above, since the stopper 20a is provided on the upper guide frame 20 of the jib guide 19,
It is possible to prevent the roller 18 from unexpectedly coming off to the side of the jib guide 19 while moving along the jib guide 19. Therefore, the above-described jib guiding action is reliably achieved.

(e) Next, lower the boom 1 to a height where the handles 44, 44 of the jib point sheave block 34 can be operated from the ground.

(F) Hold the handles 44, 44, and rotate the jib 2 at approximately 255° (16th
From the state shown in the figure to the state shown in Fig. 17 and then to the state shown in Fig. 18), twist and rotate the right jib foot 7.
is engaged with the right boom point pin 5.

In this way, since the jib 2 is twisted and set at the tip of the boom, the main hook (not shown) suspended below the boom point sheave block 31 can be easily moved around the tip of the jib 2. . Alternatively, if you lower the main hook to the ground beforehand, you only need to change the suspension wire of the hook, so you can pass the main hook through the base end of the jib when extending the jib, as in the case of the conventional under-carrying type. You will no longer have to struggle with your work. Moreover, since the distance between the jib feet 6, 7 and the proximal connecting rod 2C can be smaller than that of the conventional method, it is advantageous in terms of jib strength.

In addition, the auxiliary winding rope 37 and the jib foot 36
is already set in the auxiliary sheave 33 before the start of jib extension, but is not shown in the illustrations as it is not needed in the steps up to this point (FIGS. 14 to 17).

(G) Now, when raising the jib 2, which has been set in a vertically hanging position as described above, to a horizontal or nearly horizontal position, the guide roller 50 of the jib point sheave block 34 is once removed, and the auxiliary hoisting rope 37 is moved to the jib point. After passing it through the sheave 35 and setting the guide roller 50 on the sheave block 34 again, the auxiliary winding rope 37 is wound up and attached to the jib hook 3, as shown in FIGS.
6 is wound up, and the upper surface of the support portion 42 of the hook 36 is brought into contact with the end surface (lower surface) of the jib point sheave sheave block 34. In this state, while further hoisting the jib hook 36 or extending the tip boom 1B (this method is usually used), the boom 1 is lowered so that the jib 2 is approximately 1 m above the ground.

In the state shown in FIG. 18, the auxiliary winding rope 37 is apparently passed through both of the auxiliary sheave 38, but as the jib 2 is raised, the auxiliary winding rope 37 comes off from the auxiliary sheave 33. The auxiliary sheave bracket 32 on which the auxiliary sheave 33 is installed is provided with a wire stopper pin to prevent the auxiliary rope 37 from coming off the auxiliary sheave 33, especially during lifting work without using the jib 2. If this pin is left as is, there is a risk that the pin or the auxiliary sheave bracket 32 will be damaged by the auxiliary winding rope 37 when the jib 2 is raised. For this reason, the wire retaining pin is removed before starting the jib extension work (the stage shown in FIG. 14).

(H) After lowering the boom 1 horizontally or slightly below it, attach the jib base end fixing pin 16 that was previously removed to the right side jib foot 7 as shown in Figure 20.
By inserting the jib foot 7 between the pin hole 9 of the right boom point pin 5 and the pin hole 5a of the right boom point pin 5, the jib foot 7 is prevented from coming off from the boom point pin 5. In addition, in (b) above, the pin holes 8b and 4a of the left jib foot 6 and the left boom point pin 4 are
The jib tip fixing pin 13 inserted into the jib foot 6 is removed once, and the pin 13 is replaced into the tip pin hole 8a of the jib foot 6 as shown in FIG. Note that when replacing the pin 13, the pin 13 can be easily removed since the intermediate pin hole 8b of the left jib foot 6 is made into a long hole. In this manner, in the jib extended state, the left jib foot 6 and the left boom point pin 4 are brought into close contact with each other while maintaining their engaged state.

(li) Remove the base ends and middle parts of the suspension rods 3, 3 from the rod receivers 26, 26 and rod holders 27, 27, and attach the base ends of the rods to the boom point sheave block 31 as shown in FIG. Thereby, the suspension rods 3, 3 are suspended between the jib 2 and the tip boom 1B to support the jib 2.

The extension of the jib 2 is completed in the above manner, and the boom 1 is raised from the state shown in FIG. 22 to perform the lifting operation. At this time, it goes without saying that the jib hook 36 and the auxiliary rope 37 used to extend the jib 2 as described above are used for the original lifting work together with the main hook and the main wire rope (not shown).

Furthermore, the jib 2 is stored in the reverse order to the above-mentioned extension procedure. To summarize the main points, the boom 1 is tilted horizontally or slightly lower, and the length is slightly extended (for example, 60 to 70 cm) rather than fully retracted. Next, the jib hook 36 is wound up, and its support portion 4 is
2 to the end face of the jib point sheave sheave block 34, and
With the jib 2 supported, the suspension rods 3, 3 are removed and stored in the jib 2. Then, the jib tip fixing pin 13 used as the engagement holding pin for the left jib foot is re-inserted in the opposite direction to that in (h) at the time of extension, and the jib base fixing pin 16 is removed from the right jib foot 7. After that, by loosening the auxiliary hoisting rope 37 while raising the boom 1 (or by reducing the tip boom 1B in advance), the jib 2 is rotated downward to hang in a vertical position, and the auxiliary hoisting rope 7 is loosened. After removing the guide roller 50 of the jib point sheave block 34 and removing the auxiliary hoisting rope 37 from the jib point sheave 35, move the jib 2 around the jib foot axis y approximately.
Rotate 255°.

Next, when the boom 1 is raised to nearly 80 degrees, the roller 18 of the jib 2 will be in a position facing the tip opening 23a of the inclined groove 23 in the jib guide 19 of the base end boom 1A, so when the boom 1 is retracted,
The roller 18 enters the inclined groove part 23 of the jib guide 19, and as the boom retracts, the roller 18 rolls in the inclined groove part 23 toward the horizontal groove part 22.
This roller 18 and the inclined groove part 23 of the jib guide 19
Due to the jib guiding action, the jib 2 is automatically drawn to the left side of the boom 1A. and,
Subsequently, the roller 18 moves rearward in the horizontal groove 22, causing the jib 2 to retreat along the base boom 1A, and the engagement pin 11 at the tip of the jib automatically fits into the bracket 12 of the base boom 1A. In this way, it is finally folded into the posture shown in FIGS. 3 and 4.

It should be noted that the situation of such jib guide action, that is, the roller 18 is
It enters the groove part 23 from a, and then enters the inclined groove part 2.
Since the jib guide 19 has an open groove rail, the operator in the driver's seat can confirm the situation when the jib guide 19 moves through the horizontal groove section 22 and reaches the horizontal groove section 22. Therefore, there is no possibility of erroneous operation of the jib guide, and the operator is given a sense of security.

In the above state, the jib 2 is fixed in the retracted state by setting the fixing pins 13 and 16 at both the tip and base ends.

When this jib twist type extension and storage method is used, the jib 2 is stored along with the boom 1 in a vertical position with its thickness direction facing left and right. The total thickness can be kept to a minimum. Also, of course, the thickness in the vertical direction can be reduced to a minimum of approximately the thickness of one boom.
Therefore, it is possible to simultaneously ensure side visibility while driving and maneuverability in narrow spaces.

Moreover, when extending and retracting the jib 2, the jib 2 is placed in a vertical position and twisted around the jib foot axis y, thereby changing the position from the vertical position (position when stowed) to the horizontal position (position when extended) or vice versa. Because of this, although it is a side-hugging storage method, there is no need to secure a wide sideward turning space for the jib as in the conventional case, and the jib 2 can be easily extended and stored even in a narrow space.

Furthermore, since the jib 2 can be moved from a vertically hanging position to a horizontal position (during extension work) or vice versa (during stowage work) using the jib hook 36, for example, the auxiliary hoisting rope 37 can be
This eliminates the need to interrupt the work before and after moving the jib, as would be the case when performing similar work by removing the terminal from the jib and attaching it to the tip of the jib. It can be done even more easily and quickly.

In the above embodiment, the left foot 6 of the jib 2 is configured to be rotated around the axis y by screw rotation, but a bearing structure may be adopted instead of the screw rotation structure. In addition, Jibfutsuk 36 is
In short, it is sufficient to have a shape and structure sufficient to support the jib 2 by contacting the jib point sheave block 34 when the jib is extended and retracted, and the specific shape and structure thereof are those mentioned in the above embodiments. Other changes may be made as appropriate. Also, as a means for engaging and holding the jib feet 6, 7 on both sides with the boom point pins 4, 5 on both sides, the method shown in FIGS.
As shown, the boom point pin can be inserted into the jib foot in a manner that confines the pin within the jib foot. In this case, the pin hole on the boom point pin side becomes unnecessary.

(Effect of the invention) As described above, when using the jib extension and storage device of the present invention, the jib twist type extension and storage method,
That is, the jib can be stored vertically on the lateral side of the boom, and when extended, the jib is allowed to hang vertically from this stored state, then twisted and rotated, and the jib can be stored in the reverse order. By implementing this method, it is possible to minimize the horizontal thickness of the boom and jib in the retracted state, even though the jib is side-hugging. It also makes it easier to enter narrow spaces while ensuring security.
Furthermore, the jib can be easily extended and stowed even in a narrow space, and in particular, the jib hook can be used to easily and quickly move the jib from a vertical position to a horizontal position or vice versa during the jib extension and stowing process. I can do it. Therefore, the jib extension and storage operations can be made more efficient.

[Brief explanation of drawings]

FIG. 1 shows a jib extension according to an embodiment of the present invention;
Side view with jib extended showing storage device, 2nd
3 is a side view of the jib in the retracted state, FIG. 4 is a plan view of the same, FIG. 5 is an enlarged perspective view of the jib foot portion of the device, and FIG. 6 is a side view of the jib in the retracted state. An enlarged view, Fig. 7 is a cross-sectional view taken along the line of Fig. 6, Fig. 8 is an enlarged view of section E in Fig.
10 is an enlarged view of the part O in Fig. 4, Fig. 11 is a sectional view taken along line XI-XI in Fig. 10, Fig. 12 is an enlarged view of the jib hook part, and Fig. Figure 12 - Enlarged sectional view along line, 1st
Figure 4a is a schematic side view showing the state of preparation for overhanging, the first
Figure 4b is an enlarged view of the left jib foot in the same state, Figure 15 is an enlarged side view of the jib guide mechanism in the middle of moving the jib to a vertical position, and Figure 16 is a state in which the jib is suspended in a vertical position. Fig. 17 is a schematic side view of the jib rotated approximately 165 degrees, Fig. 18 is a schematic side view of the jib rotated further approximately 90 degrees, and Fig. 19 is a preparation for moving the jib from a vertically hanging position to a horizontal position. An enlarged view of the jib point showing the state; FIGS. 20 and 21 are side views showing the jib foot set in the jib extended position;
FIG. 22 is a schematic side view showing the fully extended state. 1... Telescopic boom, 1A... Base end (fixed boom), 1B... Tip (movable) boom, 2... Jib,
3... Suspension rod, 4, 5... Boom point pin, 6... Bifurcated left jib foot,
7... Same right side jib foot, 34... Jib point sheave sheave block, 36... Jib foot, 3
7... Auxiliary wire rope, 33... Auxiliary sheave as a boom point sheave, 38... Auxiliary sheave, x... Boom point pin axis, y... Jib foot axis, 8a, 8b, 9... Pin holes 13, 16 . . . pins constituting the jib foot engagement and holding means.

Claims (1)

[Claims] 1.Equipped with a telescoping boom and a suspension rod support compression column type supplementary jib that is added to the tip of the telescoping boom, with jib feet on both left and right sides of the base end of the jib, and horizontal horizontal jib feet on both left and right sides of the tip of the telescoping boom. boom point pins are provided on each side, and the jib is extended from the tip of the telescopic boom with the jib foots on both sides supported by the boom point pins on both sides so as to be rotatable about the pin axis, and In a wheeled crane in which the jib foot is stored on the side surface of the boom in a vertical position facing left and right, the left and right jib feet are formed in a bifurcated shape that can be engaged with and detached from the boom point pin on both sides in the radial direction of the pin. , one jib foot is configured to be rotatable around the jib foot axis, and comprises a pin hole provided in at least both side jib feet of the both side jib feet and both side boom point pins, and a pin inserted into the pin hole, engaging means for holding the jib foots on both sides in a state where they are rotatably engaged with the corresponding boom point pins, and the jib is attached to the lateral side of the boom with the jib thickness direction facing left and right. and a jib rotation for rotating the jib about the boom point pins on both sides with the jib foots on both sides being engaged and held by the engagement and holding means on the boom point pins on both sides. The jib rotating means includes a boom point sheave provided at the distal end of the telescopic boom so as to protrude further forward of the boom than the boom point pins on both sides, and a boom point sheave provided at the distal end of the jib. A jib point sheave, an auxiliary wire rope pulled out from the winch of the crane body and passed through the boom point sheave and the jib point sheave, and a winding of this auxiliary wire rope to be secured to the tip of the jib. and a jib hook attached to the end of the wire rope.