JP3248427B2 - Slab tong - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slab tong used when a slab is lifted and transported by a crane,
In particular, the present invention relates to a slab tong that can prevent a slab from falling.

[0002]

2. Description of the Related Art A slab tongue conventionally used for lifting a slab has a structure as shown in FIG. 4 , for example. In FIG. 4, (a) is a front view of Surabutongu, (b) is a side view of Surabutongu. This slab tong is used by suspending suspension portions 32 provided at both ends of a suspension beam 31 with crane hooks. On the hanging beam 31, two hanging arm holding devices 34 for hanging the facing hanging arms 33a and 33b are arranged. The interval between the two hanging arm holding devices 34 is set in the hanging beam 31. By rotating the screw thus set, it is possible to adjust the interval according to the length (L) of the slab 35.

In each of the hanging arm holding devices 34, the distance between the opposed hanging arms 33a and 33b can be adjusted according to the width (W) of the slab 35. The slab 35 can be hung by sandwiching both side surfaces in the width direction by the claws 36 attached to the claw holders provided at the respective ends of the slabs 33b.

The claw holder for holding the claw 36 is a hanging arm 3
Since the slab is guided downwardly and inwardly along the guide surfaces provided on 3a and 33b, the entire weight of the slab is applied to both the claws sandwiching the slab, and the respective claws have large friction. Force acts. The horizontal component of the frictional force acting on each claw is a force acting toward the center of the slab in the width direction, so that the gripping force for gripping the slab is strong.

[0005] In order to guide the above-mentioned claw holder downward and inward, the hanging arm is provided with a tapered sliding surface. This sliding surface is a surface that guides the downward movement of the claw holder and acts on a reaction force when the claw grips the slab. That is, the surface has a high load, and durability is a problem.

[0006] As a countermeasure, conventionally, a device in which the surface shape of the sliding surface is variously devised has been used.

In the technique disclosed in Japanese Patent Application Laid-Open No. 59-36091, the downward movement guide of the claw holder and the support of the reaction force are for locking the rotational moment acting on the claw holder by the holding reaction force. In addition, two rotatable rollers provided to engage the claw holder at the upper and lower reaction force fulcrum positions are used.

[0008] As described above, in slab tongs,
The slab is lifted by exerting a sufficient gripping force.

Further, since falling of the slab leads to breakage of the equipment, various measures for preventing the slab from falling have been conventionally studied.

A slab tong based on the technology disclosed in Japanese Patent Application Laid-Open No. 4-303382 has a hacker arm which pivots down to a hanging position by its own weight and pivots down at the lower end of a hanging arm for gripping the slab, and this hacker arm. Means for lifting the slab with the lifting arm, a means for locking the raised hacker arm, and a means for unlocking the slab when lifting the slab with the lifting arm. It holds the slab and prevents the slab from falling.

[0011]

However, the above-mentioned prior art has the following problems. (1) Technology disclosed in JP-A-59-36091 The down movement guide device of the claw holder becomes complicated, equipment costs increase, and when a component force in the direction of the rotation axis of the roller acts, the device is damaged. Or the nail holder may not move down smoothly.

If the frictional resistance of the slab surface between the claws is small, the slab may fall.

(2) Technology disclosed in Japanese Patent Application Laid-Open No. 4-303382 Since the hacker arm is provided separately from the suspension arm, the tongue's own weight is increased, and the allowable suspension load is reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems of the prior art, and a slab in which a sliding surface of a claw holder is not damaged and a claw holder moves down smoothly. It is an object of the present invention to provide a slab tong which can securely hold the slab and a slab tong which can prevent the slab from falling without significantly increasing the weight of the tong.

[0015]

Means for Solving the Problems Claim 1 according to the present invention.
The slab tongs described in the paragraph, attached to each of the opposing inner portions of the pair of hanging arms provided so that the opposing spacing on the beam can be adjusted, a claw holder including a claw for gripping the slab, these claw holders In a slab tongue configured to move downward from the initial rest position at the time of lifting of the hanging arm to the diagonally inward downward by the weight of the slab held by the claw and approach each other to increase the gripping force, A configuration in which the downwardly guided portion of each of the claw holders is configured to be guided downwardly along a guide surface that is in close contact with the peripheral surface thereof, and a power cylinder is provided as a downwardly moving drive unit of the claw holder. It is.

Since the outer peripheral surface of the portion guided downwardly by the claw holder is completely in close contact with the sliding surface, even if a reaction force of the gripping force acts on the sliding surface via the claw holder, the reaction force is reduced. Is large, the reaction force is dispersed and the sliding surface is not damaged.

If the frictional resistance on the sliding surface increases for some reason when the claw holder moves down, the load of the suspended load on the claw is reduced by the frictional force, and the claw is sufficiently gripped. Although no force is generated, in the present invention, the power cylinder can assist the downward movement of the claw holder, so that the claw holder moves down smoothly, and the entire load of the suspended load is applied to the claw. Can be demonstrated.

Further, the direction of scan <br/> Rabutongu of claim 2 according to the invention extends from the pawl holder is provided an auxiliary pawl holder, approach each other by rotating means in the secondary pawl holder Is mounted on the slab, and after the slab is gripped by the claw, the auxiliary claw is rotated to hold the lower surface of the slab with the auxiliary claw.

An auxiliary claw for preventing the slab from falling is provided with the claw.
Since the tongue is provided on the auxiliary claw holder extending from the holder , the weight of the tongue does not significantly increase, and the slab can be prevented from falling without reducing the allowable hanging load of the tongue.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described.
The love tong will be described with reference to FIG. In addition, the present invention
There is a feature in the nail holder part, the other parts are conventional
There is no difference from the slab tong, so the nail holder
Only the parts will be described.

FIG . 1 (a) sandwiches a slab of a nail holder.
FIG. 1B is a front view seen from the direction, and FIG.
It is an arrow view.

The claw holder 1 of this slab tong is
The claw holder supporting casing 2 provided in the arm 33 is
It is mounted via the inner 3. And nail holder
At the tip of 1, a claw 4 sandwiching the side surface of the slab 35 is provided with a bolt.
5 attached.

The claw holder 1 is held by a power cylinder 6.
Power cylinder 6
Makes the nail holder 1 smoothly along the liner 3
Provided on the hanging arm 33 so that it can descend and ascend
By the rotating shaft 8 horizontally supported by the shaft supporting member 7
And can be rotated.

Also, the nail holder 1 is in contact with the liner 3.
The cross section of the part that goes up and down while touching and sliding is square
When the slab 35 is hung, the liner 3
Along the guide surface configured in a box shape, the inside of the hanging arm 33
It descends obliquely downward.

As described above, the nail holder 1 is
The entire circumference of the rudder 1 slides in close contact with the box-shaped guide.
As it moves up and down, it acts on the sliding surface
The reaction force of the gripping force of the moving slab concentrates on a specific part
No, the sliding surface is damaged due to locally large stress.
Never.

The claw holder 1 is connected to the power cylinder 6
As it moves up and down, the friction on the sliding surface
Even if the rub resistance increases for some reason,
The nail holder 1 is lowered to overcome such frictional resistance.
I can do it.

Therefore, the nail 4 is attached to the slab 35 by its own weight.
Thus, a sufficient gripping force can be given.

Next, a slab tong according to a second embodiment of the present invention will be described with reference to FIG. FIG. 2A is a front view of the claw holder viewed from the direction in which the slab is sandwiched, and FIG.
FIG. 2 is a view taken in the direction of arrows BB in FIG. The claw holder 1 of this slab tong is provided in the hanging arm 33, and its supporting form is not particularly limited, so that the detailed structure is omitted.

At the tip of the claw holder 1, a claw 4 sandwiching the side surface of the slab 35 is attached by a bolt 5.

[0030] FIG. 2 (a), the as shown in FIG. 2 (b), from the plane perpendicular to the mounting surface 1 a of the claw 4 of the nail holder 1,
The auxiliary claw holder 9 extends in the horizontal direction. An auxiliary claw 11 is provided on the auxiliary claw holder 9 via a bracket 10.
The auxiliary claw rotation motor 12 that rotates the motor toward the width direction end of the slab 35 is provided.

Next, a rotation mechanism of the above-described auxiliary claw 11 will be described with reference to FIG. FIG. 3A is a plan view of the auxiliary claw rotation mechanism, and FIG. 3B is a view taken along the line CC in FIG. 3A. A rotation shaft 13 of the auxiliary claw rotation motor 12 and a rotation shaft 15 of the worm 14 are connected by a coupling 16 in the bracket 10. The worm 14 meshes with a worm wheel 18 that is rotated by a rotation shaft 17. A pinion 19 is attached to the rotating shaft 17, and an arc-shaped rack 20 is provided on the side surface of the auxiliary claw 11 formed in a partially annular shape.
And are engaged.

Since the auxiliary claw rotation mechanism is configured as described above, the worm 14 is rotated by driving the auxiliary claw rotation motor 12, and the worm 14 causes the worm wheel 18 to rotate. The rotation of the worm wheel 18 causes the worm wheel 1 to rotate.
The pinion 19 provided on the rotation shaft 17 of 8 rotates, and the auxiliary claw 11 rotates by the rack 20 meshing with the pinion 19. Since the rack 20 is formed in an arc shape, the trajectory of the auxiliary claw 11 is an arc. A guide roller 21 is provided on the upper surface of the auxiliary claw holder 9 in accordance with the trajectory of the auxiliary claw 11.

When the auxiliary claw 11 is turned toward the widthwise end of the slab 35, its tip 11a
Is designed to come into contact with the lower surface 35a of the slab 35, and if the widthwise end of the slab 35 is sandwiched by the claws 4 in such a state, the slab 35 slides from the claws 4 to drop. Even in this case, since the slab 35 is held from below by the auxiliary claw 11, the slab 35 does not fall.

The auxiliary claw 11 becomes an obstacle when the suspended slab 35 is lowered, so that it may be rotated in a direction away from the slab 35 and retracted.

As long as the slab 35 does not slip off the nail 4, no load is applied to the auxiliary nail 11, so that the auxiliary nail 1
A load cell for detecting that a load has been applied to 1 may be provided on the auxiliary claw holder 9, and an alarm may be issued based on a signal from the load cell to notify the slab falling.

[0036]

【The invention's effect】 According to this invention, the sliding surface of the claw holder is
It is not damaged and the nail holder moves down smoothly,
Love can be grasped securely and the tongue's own weight is greatly increased
To prevent the slab from falling
Can be.

[0037]

[0038]

[Brief description of the drawings]

1A and 1B are explanatory views of a claw holder portion of a slab tong according to a first embodiment of the present invention, wherein FIG. 1A is a front view of the claw holder viewed from a direction in which the slab is sandwiched, and FIG. A-
FIG.

FIGS. 2A and 2B are explanatory views of a claw holder portion of a slab tong according to a second embodiment of the present invention, wherein FIG. 2A is a front view of the claw holder viewed from a direction in which the slab is sandwiched, and FIG. B-
FIG.

3A and 3B are explanatory views of an auxiliary claw rotation mechanism in an auxiliary claw holder portion extending from the claw holder, wherein FIG. 3A is a plan view of the auxiliary claw rotation mechanism, and FIG. It is an arrow view.

FIG. 4 is an explanatory view of a general slab tong, and FIG.
Is a front view, and (b) is a side view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Claw holder 2 Claw holder support casing 3 Liner 4 Claw 5 Bolt 6 Power cylinder 7 Shaft support member 8 Rotating shaft 9 Auxiliary claw holder 10 Bracket 11 Auxiliary claw 12 Auxiliary claw rotation motor 13 Auxiliary claw rotation motor rotation shaft 14 Worm 15 Rotation axis of worm 16 Coupling 17 Rotation axis of worm wheel 18 Worm wheel 19 Pinion 20 Arc-shaped rack 21 Guide roller

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B66C 1/00-1/68

Claims (2)

(57) [Claims] 1. A claw holder including a claw for grasping a slab is attached to each of opposing inner portions of a pair of hanging arms provided so as to be able to adjust a distance between each other on a beam, and the claw holders include: The pair of slab tongs, which are configured to be guided downward and obliquely downward from the initial rest position of the hanging arm by the weight of the slab held by the claws to approach each other and increase the gripping force, form the pair. The above-mentioned downwardly guided portion of each of the claw holders is configured to be downwardly guided along a guide surface which is in close contact with the peripheral surface thereof, and a power cylinder is provided as a downwardly moving drive means of the claw holder. Characterized slab tongs. Wherein an auxiliary pawl holder and extending from said pawl holder, fitted with a secondary pawl to pivot toward each other by rotating means in the secondary pawl holder, auxiliary after grabbing the slab with the pawl The slab tong according to claim 1, wherein the claw is rotated so that the lower surface of the slab can be held by the auxiliary claw.