JPH0329719B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention pivots the proximal end of a jib to the distal end of a telescopic boom so that the jib can pivot in a vertical plane between an extended position and a retracted position along the underside of the boom. The present invention relates to a projecting and retracting device provided with a means for rotating the jib between a substantially vertical position and a horizontal position via a hook rope having a hook support tube secured to the tip of the jib.

As shown in FIG. 6, at the tip of a conventional jib, there is an overwind detector 6 whose upper end is connected to one side of the overwind detector 6 and which is constantly activated to contract. Suspension ropes 7 and 8 whose upper ends are connected to the other side, respectively;
An annular weight 9 is suspended and supported substantially horizontally from the lower ends of both suspension ropes, and when the annular weight is lifted by the hook support tube at the lower end of the hook cable 4 inserted through the annular weight,
Since an overwinding prevention device is installed that closes the alarm activation switch inside the overwinding detector 6 when it contracts, the annular weight 9 moves around the semicircular portions 9a and 9b as shown in the figure. The structure is such that the annular weight 9 is connected and fixed in a ring shape with bolts and nuts 10, and when the jib is extended or retracted, the annular weight 9 is disengaged from the hook cable 4 and the annular weight 9 is attached to a handle on one side of the jib tip. was.

This is because when the annular weight 9, which is supported in contact with the rising hook support cylinder, skids sideways and contacts the hook cable 4, the annular weight is moved between both pulley support plates at the tip of the jib and the upper end of the hook support cylinder. This is because there is a risk that the annular weight 9 and its hanging rope may be damaged if they are squeezed between the edges of the opening.

For this reason, the attachment and detachment of the annular weight to and from the hook rope not only hinders the speed of the jib extension or retraction operation, but also the attachment and detachment of the annular weight is often forgotten or neglected, resulting in an unexpected accident. It was hot.

The present invention deals with this problem, and includes a flange 2a for engaging the jib tip and a flange 2a for engaging the upper end of the hook support cylinder 3 above and below the annular weight 2 of the overwind prevention device attached to the tip of the jib 1. The lower flange 2b of the annular weight is provided integrally with the upper end of the hook support cylinder 3 which is lifted via the hook cable 4, and a means is provided between the two for positioning and engaging the lower flange 2b of the annular weight substantially concentrically. It is characterized by

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5. In FIG. 1, 11 is a car body of a self-propelled crane or a truck crane equipped with front and rear outriggers 12, 13, and 14 is a swivel table rotatably mounted on the car body 11 via a turntable.
Reference numeral 15 denotes a telescopic boom whose base end is pivotally mounted on the swivel base 14 by a foot pin 16 and lifted up and down by a derrick cylinder 17. At the bottom of the tip of the telescopic boom 15 is a pulley for suspending the main hook. Using the support shaft 19 of 18, the base end of the planar ladder-shaped jib 1 is removably pivoted so that it can rotate between the extended position (a) and the retracted position (b) along the bottom surface of the boom. be done.

The hook cable 4 let out from the winding drum (not shown) on the swivel base 14 is connected to the upper pulley 20 at the tip of the telescopic boom.
and a pulley 21 for jib tensioning and storage attached to an arm protruding from the lower end of the telescopic boom 15.
and the short shaft 25 connected to the lower end of the hook cable 4 via the horizontal pin 24 (FIG. 3), sequentially passing through the pulley 22 and cable guide 23 attached between the pulley support plates 5 and 5 on both sides at the tip of the jib. A cylindrical hook support tube 3 is attached so as to be freely pivotable. That is, the thick bottom portion 3a of the cylindrical hook support tube 3 is rotatably supported by the flange portion 25a at the lower end of the short shaft 25 via the thrust bearing 26, and the thick bottom portion 3a below the flange portion is supported. Attach the upper end of the hook 27 to the horizontal pin 28
By means of stopper plates 29, 29 on both sides fitted to the horizontal pin 28, the center positioning of the hook 27 with respect to the hook support cylinder 3 and the prevention of the short shaft 25 from falling downward are performed at the same time.

The annular weight 2 has circular flanges 2a and 2b arranged concentrically on the upper and lower sides of a throat part 2c, and is integrated with a plurality of brackets 2d and 2e distributed evenly around the outer circumference between the throat part and the upper and lower flanges. The pair of left and right brackets 2d, 2d are connected to the lower ends of the hanging cables 7, 8 of the overwind prevention device, as shown in FIG. 4.

The means for engaging the upper end of the hook support cylinder 3 substantially concentrically with the lower flange 2b of the annular weight 2 is to form the upper part of the hook support cylinder into an upwardly tapered truncated conical portion 3b, and to connect the upper end of the hook support cylinder 3 to the lower flange 2b of the annular weight 2. The truncated conical part 3
The upper end of b is configured in a cap shape into which it fits loosely. The maximum inner diameter of the lower end of the cap-shaped lower flange 2b is the maximum inner diameter of the hook cable 4.
It has a size that allows the upper end of the truncated conical portion 3b to be guided into the cap-shaped lower flange no matter how freely the truncated conical portion 3b moves within the throat portion 2c.

Each side pulley support plate 5 at the tip of the jib has a tip engagement surface 5a disposed perpendicular to the jib axis, a bottom engagement surface 5c parallel to the jib axis, and an inclined engagement surface connecting the two engagement surfaces. 5b, and a stopper 5d for the annular weight 2 is appropriately provided at the upper end of the engagement surface 5a. The hook cable 4 connects a pulley 22 and a cable guide 23 to a pulley support plate 5.
It can only oscillate between

When extending the jib from the retracted position (B), which is secured to the lower side of the telescopic boom 15, to the extended position (A), first raise the telescopic boom 15 near the upright position and secure the jib. By untying it, the engaging surface 5a at the lower end is positioned above the hook support tube 3 supported by the hook receiver 14a on the swivel base 14, and then the hook cable 4 is secured to the hook support cylinder 3 on the swivel base 14. After lifting the hook support tube 3 by winding it up and supporting the annular weight 2 substantially concentrically on the hook support tube by engaging the truncated conical portion 3b at the upper end and the cap-shaped lower flange 2b, The upper flange 2a of the annular weight is brought into approximate contact with the engagement surface 5a at the tip of the jib.

Next, when the telescopic boom 15 is brought down to the position shown by the solid line in FIG.
The lower end of the hook cable 4 is disposed perpendicularly to the engagement surface 5a. Therefore, the winding drum of the hook rope is locked, and the telescopic boom 15 is gradually extended, and at the same time, the telescopic boom is held approximately horizontally so that the hook support tube 3 maintains the height above the ground as shown in FIG. When the jib 1 is laid down, the tension of the hook cable 4 caused by the extension of the telescopic boom causes the jib 1 to rotate relatively around the support shaft 19 to the extended position (A). In this case, since the lower end of the hook cable is perpendicular to the engagement surface 5a and has the shortest length, there is no fear that the annular weight 2 or the hook support cylinder 3 will fall along the engagement surface 5a.
Therefore, the top of the tip of the telescopic boom 15 and the tip of the jib 1 are connected to tension rods or retaining ropes 30 on both sides.
(See Figure 2) to support the jib in the extended position, then raise the telescopic boom 15 slightly and let out the hook line 4 from the hoisting drum. The annular weight 2 and the hook support tube 3 suspended and supported are automatically separated. Therefore, the connector or switch of the electric circuit of the overwinding prevention device is connected to carry out cargo handling work.

In addition, when storing the jib in the extended position, the telescopic boom 15, which has been extended beyond a certain length required for storing the jib, is lowered approximately horizontally as shown in Fig. 2, and at the same time, the hook support tube is lowered as shown in Fig. 4. The hook line 4 is wound up by the winding drum until the hook line 3 approaches the annular weight 2, and then the electric circuit of the overwind prevention device is cut off and the hook line is further wound up. As in the above case, after the upper end of the hook support tube 3 engages with the annular weight 2 substantially concentrically, the annular weight is brought into pressure contact with the engagement surface 5b as shown in FIG. 2 or 3. lifts the tip of the jib slightly to relieve tension on the tension rod or retaining line 30. Therefore, hook search 4
When the hoisting drum is locked and the tension rod etc. are removed, the telescopic boom 15 is raised while being gradually contracted.
It rotates downward using the fulcrum as a fulcrum and reaches a relatively hanging state as shown by the solid line in FIG. Next, the telescopic boom is raised until the hook support tube 3 reaches directly above the hook receiver 14a, the hook support tube is suspended above the hook receiver by the hoisting drum, and the jib 1 is pulled to the telescopic boom and secured. do.

In the present invention, since the lower flange 2b of the annular weight is positioned substantially concentrically and engaged with the upper end of the hook support cylinder 3 that is lifted via the hook cable 4, the upper flange 2b of the annular weight
After a contacts the engagement surface 5a or 5b at the tip of the jib, the annular weight 2 and the hook support cylinder 3 move to the hook rope locking position where the lower end of the hook rope 4 is approximately perpendicular to the engagement surface. They can slide together along the engagement surface, and if the hook support tube 3 is suspended via the hook cable, the annular weight 2 can be attached to the suspension cables 7 and 8 as shown in FIG.
After being supported at the tip of the jib via the hook supporting tube 3, it can be automatically separated and lowered from the annular weight by its own weight, so that when the jib is extended or retracted, the annular weight can be attached to the hook. The troublesome work of attaching and detaching the jib to and from the rope is no longer necessary, and the jib can be quickly extended or retracted, and there is an effect that it is possible to prevent unexpected accidents caused by forgetting to attach or detach the annular weight.

[Brief explanation of drawings]

1 and 2 are side views schematically showing an embodiment of the present invention when the jib is extended and retracted, respectively; FIG. 3 is a longitudinal side view showing an enlarged view of the main parts of FIG. 2;
FIG. 4 is a longitudinal sectional front view of the overwinding prevention device in a non-operating state, FIG. 5 is a sectional view taken along line XX in FIG. 3, and FIG. 6 is a perspective view schematically showing a conventional overwinding prevention device. . 6... Overwinding detector, 7, 8... Suspension rope, 11...
Vehicle body, 12, 13... outrigger, 14... swivel base, 15... telescopic boom, 17... derrick cylinder, 20, 21, 22... pulley, 23... cable guide, 30... tension rod or retaining cable.

Claims (1)

[Scope of Claims] 1. The base end of the jib is pivoted to the tip of the telescopic boom so that the jib can rotate in a vertical plane between an extended position and a retracted position along the lower surface of the boom, and In a jib extending and retracting device provided with a means for rotating the jib between a substantially vertical position and a horizontal position via a hook cable to which a hook support tube is fixed, a Annular weight 2 of anti-winding device
A flange 2a for engagement with the tip of the jib and a flange 2b for engagement with the upper end of the hook support cylinder 3 are integrally provided on the upper and lower sides of the A jib extension and storage device characterized in that a means is provided between the lower flange 2b of the lower flange 2b to be engaged with the lower flange 2b while positioning the lower flange 2b substantially concentrically. 2. As a means for engaging the upper end of the hook support cylinder 3 approximately concentrically with the lower flange of the annular weight, the upper part of the hook support cylinder 3 is formed into a tapered truncated cone shape, and the lower flange 2b of the annular weight is engaged with the lower flange 2b of the annular weight. 2. The jib extension and storage device according to claim 1, wherein the upper end of the hook support cylinder is formed into a cap shape into which the upper end portion of the hook support cylinder fits loosely.