JP7660841B2 - Hook device - Google Patents

Description

The present invention relates to a hook device that allows the sling wire to be removed from a remote location, such as the driver's seat of a crane, and is equipped with a double locking mechanism that reliably prevents the hook from coming loose during lifting operations.

As a hook device suitable for use in conventional harbor and river construction, the two applicants have jointly developed a hook as described in Patent Document 1. This hook device uses a crane to lift a workpiece such as a sling-type root-stabilizing block (also called a wave-dissipating root-stabilizing block) via a hook that is kept closed by a lock arm that stops in a locked position under its own weight, and after it is hoisted to a designated location in a harbor or river, the operating wire can be pulled from a remote location such as the crane's driver's seat, causing the hook to automatically unlock under its own weight and the sling wire to be removed, eliminating the need for an operator to climb onto the block and perform the work manually, allowing work to be carried out safely and smoothly.

Patent Publication No. 2019-023122

However, with this hook device, the hook is merely held in the closed state by the locking arm, which stops at the hook engagement position under its own weight. If the operating wire gets caught on an external structure during a lifting operation and a force is applied in the direction of pulling the operating wire, the locking arm will move from the hook engagement position to the hook release position, causing the hook to come off, and the workpiece will fall together with the sling wire, posing the risk of a serious accident.

The problem that this invention aims to solve is therefore to provide a hook device that solves the above problems and allows the hook to be safely removed from a workpiece after it has been lowered by remote control, in which the hook not only stays in the hook locking position under its own weight, but also has an additional locking mechanism that forcibly holds the hook in the hook locking position, thereby preventing the risk of the hook accidentally coming loose during the lifting operation and causing the workpiece to fall.

In order to solve this problem, the present invention according to claim 1 is a hook device comprising: a main body having a hanging ring at an upper end; a hook rotatably connected to a lower end of the main body; a lock arm rotatably connected to the other side of the main body by a lock arm pin so as to be movable between a hook engagement position where the tip of the hook is engaged with one side of the main body by its own weight to maintain the hook in a closed state, and a hook release position where the hook is in an open state; a lock arm operating means connected to the tip of the lock arm for moving the lock arm from the hook engagement position to the hook release position; a stopper that is attached between the base end of the lock arm and the other end of the main body when the lock arm is in the hook engagement position, thereby acting to forcibly hold the lock arm in the hook engagement position; and a stopper operating means for removing the stopper from the lock arm.

The present invention according to claim 2 is characterized in that in the hook device according to claim 1, the lock arm operating means is a lock arm operating wire that is hooked to one end of the lock arm, and the stopper operating means is a stopper operating wire that is hooked to a stopper means that can be inserted into a space formed in the other end of the lock arm.

The present invention according to claim 3 is characterized in that in the hook device according to claim 2, both the lock arm operating wire and the stopper operating wire can be remotely controlled.

The present invention according to claim 4 is characterized in that in the hook device according to claim 2 or 3, the lock arm operating wire and the stopper operating wire are painted in different colors.

According to the present invention as set forth in claim 1, a stopper is provided that acts to forcibly hold the lock arm in the hook engagement position when attached to the lock arm in the hook engagement position. Therefore, even if the lock arm operating means gets caught on an external structure or the like and a pulling force is applied while performing lifting operations using this hook device, the lock arm is forcibly held in the hook engagement position and the hook is maintained in a closed state. This makes it possible to prevent the risk of the hook accidentally coming loose during lifting operations and the workpiece falling.

The hook device of the present invention has a double locking mechanism that maintains the hook in a closed state, consisting of a lock arm that moves to the hook engagement position under its own weight, and a stopper that is attached to the lock arm and forcibly holds the hook in this position. To release a hook that is in a closed state, it is necessary to pull the stopper operating means (wire) to remove the stopper from the lock arm, and then pull the lock arm operating means (wire) to move the lock arm from the hook engagement position to the hook release position. The hook will not come off unless the separately provided operating means are operated separately in a specified order. As a practical matter, it is almost unthinkable that such operations would be performed accidentally other than through manual operation by an operator, making this a very useful hook device with a high level of safety.

Furthermore, according to the present invention as set forth in claim 2, the lock arm operating means (wire) is engaged with one end of the lock arm, and the stopper operating means (wire) is engaged with the stopper means inserted near the other end of the lock arm, so that one end of each of these operating means (wires) is engaged at a position spaced apart by a distance approximately equal to the axial length of the lock arm. Therefore, it is highly unlikely that both of these operating means (wires) will get caught on an external structure, etc., resulting in a hook device with higher safety.

Furthermore, according to the present invention as set forth in claim 3, both the lock arm operating means (wire) and the stopper operating means (wire) can be remotely operated, so that the operator can operate these operating means from a remote location such as the crane operator's seat, eliminating the need for the operator to stand on a block above the water surface and perform the work manually, allowing the work to be performed safely and smoothly.

Furthermore, according to the present invention as set forth in claim 4, the lock arm operating means (wire) and the stopper operating means (wire) are painted in different colors, thereby preventing erroneous operation.

1 is a side view showing the overall state of use of the crane hook and the sling wire when the hook according to one embodiment of the present invention is used to hoist a workpiece (not shown). In this state of use, the lock arm is securely held in the hook-locked state by the stopper, and therefore the hook is locked in the closed state by the tip of the hook being locked by the lock arm. FIG. 2 is an enlarged side view showing the hook and its associated members in FIG. 1 . FIG. 3 is an enlarged side view showing a main part of FIG. 2 in a further enlarged manner. 13 is an enlarged side view showing a state in which the lock arm is pulled by an operating wire (lock arm operating means) to move the lock arm from a hook engaging position to a hook releasing position, thereby opening the hook under its own weight. FIG. FIG. 5 is an enlarged side view showing a main part of FIG. 4 in a further enlarged manner.

The configuration and operation of a hook according to one embodiment of the present invention will be described in detail below with reference to Figures 1 to 3.

This hook device 10 has a main body 11, a hook 12, and a locking arm 13, similar to the hook device of the conventional technology described above.

A suspension ring 16 is formed at the upper end of the main body 11, which is connected to a crane hook 15 via a suspension material 14 such as a chain sling. The main body 11 is a generally elongated plate-like member in the vertical direction, with its middle portion protruding in one direction to form a protrusion 27 (Fig. 3). When a stopper plate 23 (described later) is attached to the lock arm 13, the protrusion 27 works together with a base end spacer 21b (described later) to forcibly hold the lock arm 13 in a hook-engaged state.

The hook 12 is rotatably connected to the lower end of the body 11 by a hook pin 17, and can be in an open state (Figures 4 and 5) in which it hangs down due to its own weight, or in a closed state (Figures 1 to 3) in which its tip is locked by a lock arm 13, as described below.

The lock arm 13 has its base end rotatably connected to approximately the center of the main body 11 by a lock arm pin 18, and tends to rotate downward (clockwise in the figure) due to its own weight, so that the tip of the hook 12 can be engaged and the hook 12 can be maintained in a closed state. However, by pulling the lock arm operating wire 20 engaged in the engaging hole 19 at the tip, the lock arm 13 rotates upward (counterclockwise in the figure), and the engagement with the tip of the hook 12 is released, so that the closed state of the hook 12 can be released and it can be moved to an open state.

In this embodiment, the lock arm 13 is formed by connecting a pair of elongated plate-like members in parallel on both sides of the main body 11 with spacers 21a, 21b, and is configured to engage the tip of the hook 12 by sandwiching it between the pair of elongated plate-like members and between the main body 11 and the tip spacer 21a. The lock arm tip 22 having the engagement hole 19 is fixed to the outer surface of the tip spacer 21a.

The hook device 10 further includes a stopper plate 23 that can be attached to the space between the pair of elongated plate members constituting the lock arm 13 and between the main body protrusion 27 and the base end spacer 21b when the lock arm 13 is in the hook engagement position, and a stopper operation wire 24 connected to the stopper plate 23 in order to remove the stopper plate 23 attached to the lock arm 13. When the stopper plate 23 is attached to the lock arm 13, even if the lock arm operation wire 20 is pulled on the lock arm 13 in the hook engagement position, the main body protrusion 27 of the lock arm 13 interferes with the stopper plate 23, preventing the lock arm 13 from rotating. The lock arm 13 is locked in the hook engagement position and is forcibly prevented from moving to the hook release position, thereby preventing an accident in which the hook 12 opens and the workpiece falls.

In this embodiment, both the lock arm operating wire 20 and the stopper operating wire 24 pass through a shackle 25 suspended from the crane hook 15 and extend to a position where they can be operated by a worker on the ground. In order to eliminate operating errors by the worker, these operating wires are colored to be clearly distinguishable; for example, the lock arm operating wire 20 is painted white and the stopper operating wire 24 is painted red. Furthermore, it is preferable to attach a plate with the word "lock arm" or the like to the lock arm operating wire 20 and the word "stopper" to the stopper operating wire 24 near the part where the worker holds them in his/her hand to prevent erroneous operation.

When using this hook device 10 to lift a workpiece (not shown) such as a wave-dissipating block or a base protection block, the hook 12, which has the sling wire 26 looped around the workpiece engaged, is closed, and the hanging material 14 connected to the hanging ring 16 is hooked onto the crane hook 15 and the crane is operated (Figure 1). At this time, the tip of the hook 12 is engaged with the lock arm 13, which rotates downward (clockwise in the figure) under its own weight and stops at the hook engagement position, and the stopper plate 23 attached to the base end of the lock arm 13 prevents the lock arm 13 from rotating from the hook engagement position to the hook release position, so the hook 12 is locked in the closed state. While lifting a workpiece in the state shown in Figures 1 to 3, even if the lock arm operating wire 20 gets caught on an external structure or the like and an external force acts to pull the lock arm 13, the stopper blade 13 forcibly prevents the lock arm 13 from rotating, so the lock arm 13 is securely locked in the hook engagement position, preventing an accident in which the hook 12 accidentally opens and the workpiece falls.

After the workpiece lifted by the hook device 10 is placed at a designated location in a harbor or river, the sling wire 26 can be removed by a worker from the crane driver's seat or the like, by remote control. That is, the worker first pulls the stopper operating wire 24 to remove the stopper 23 from the lock arm 13, and then pulls the lock arm operating wire 20 to rotate the lock arm 13 from the hook locking position (Figs. 1 to 3) to the hook release position (phantom line in Fig. 2). When the lock arm 13 that has been locking the hook 12 moves to the hook release position and the lock on the hook 12 is released, the hook 12 rotates clockwise under its own weight in the figure and moves to the open state (Figs. 4 and 5), and the sling wire 26 is automatically released. This eliminates the need for a worker to stand on a block on the water surface to remove the sling wire as in the past, and the sling wire 26 can be safely and reliably removed by remote control.

The hook device according to the present invention has been described in detail above based on the illustrated embodiment, but the present invention is not limited to this and can be implemented with a wide variety of modifications and changes within the scope of the invention described in the claims.

REFERENCE SIGNS LIST 10 Hook device 11 Main body 12 Hook 13 Lock arm 14 Suspension member 15 Crane hook 16 Suspension ring 17 Hook pin 18 Lock arm pin 19 Locking hole 20 Lock arm operation wire 21a, 21b Spacer 22 Lock arm tip 23 Stopper plate 24 Stopper operation wire 25 Shackle 26 Sling wire 27 Main body protrusion

Claims (4)

a hook device comprising: a main body having a hanging ring at an upper end; a hook rotatably connected to a lower end of the main body; a lock arm rotatably connected to the other side of the main body by a lock arm pin so as to be movable between a hook engagement position where the tip of the hook is engaged with one side of the main body by its own weight to maintain the hook in a closed state, and a hook release position where the hook is in an open state; a lock arm operating means connected to the tip of the lock arm for moving the lock arm from the hook engagement position to the hook release position; a stopper that is attached between the base end of the lock arm and the other end of the main body when the lock arm is in the hook engagement position, thereby acting to forcibly hold the lock arm in the hook engagement position; and a stopper operating means for removing the stopper from the lock arm. The hook device according to claim 1, characterized in that the lock arm operating means is a lock arm operating wire that is attached to one end of the lock arm, and the stopper operating means is a stopper operating wire that is attached to a stopper means that can be inserted into a space formed at the other end of the lock arm. The hook device according to claim 2, characterized in that both the lock arm operating wire and the stopper operating wire can be remotely controlled. The hook device according to claim 2 or 3, characterized in that the lock arm operating wire and the stopper operating wire are painted in different colors.