JP3241308B2 - Electric chain block - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an electric chain block.

[0002]

2. Description of the Related Art In an electric chain block in which a hook is attached to a tip of a chain extending downward from a housing body, it is preferable that the hook can be raised to a position as high as possible when the chain is wound. For this purpose, it is preferable to stop the hoisting action of the chain when the top of the hook comes into contact with the lower surface of the housing.

In order to stop the hoisting action of the chain, it is necessary to stop the hoisting electric motor. For this purpose, it is necessary to detect that the top of the hook has contacted the lower surface of the housing. In order to perform such detection, a limit switch operation plate is conventionally mounted on the rotation shaft of the limit switch, and the operation plate is usually attached to the outside of the housing after the top of the hook reaches the vicinity of the outer surface of the housing during the winding operation of the chain. Until contact with the side surface, it is arranged so as to be moved toward the housing outer surface together with the hook top portion while being in contact with the hook top portion.

[0004]

When the operating plate is arranged in this manner, the top of the hook comes into contact with the lower surface of the housing via the operating plate, and at this time the limit switch is operated. The hoisting electric motor is stopped. However, if the top of the hook abuts on the lower surface of the housing via the operating plate in this way, that is, if the operating plate is strongly sandwiched between the top of the hook and the lower surface of the housing, the rotating shaft of the operating plate and the limit switch will be excessively moved. There is a problem that high stress is applied and thus their durability is impaired.

[0005]

According to the present invention in order to solve the above problems SUMMARY OF THE INVENTION, attach the hook to the tip of the chain extending below sideways from the housing body, winding the chain
During operation, the top of the hook reaches near the bottom surface of the housing.
When touching the top of the hook when
Limits that can be moved toward the lower side of the housing
Equipped with a switch plate, which is limited by movement of the switch plate
In an electric chain block where the hoisting action of the chain is stopped when the switch is actuated ,
The lower surface of the housing is formed flat and the top of the hook
When the abutment comes in contact with the operating plate,
Formed on the lower surface of the flat housing, the limit switch is
When activated, the hoisting action of the chain stops.
The top of the hook against the lower surface of the flat housing when
So that a gap is formed in the bottom surface and the working plates of this time groove while contact. That is, the pinching action is not generated on the operation plate.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS.
Is an electric chain block, 2 is a housing, 3 is a hook for suspending the electric chain block, 4 is a chain extending downward from the housing 2, 5 is a hook attached to the lower end of the chain 4, 6 is a limit switch , 7
Indicates rotation shafts connected to the limit switch 6, respectively.
A U-shaped recess 8 is formed on the lower side of the housing 2, and a block 9 constituting a part of the housing 2 is attached to the center of the recess 8. The rotating shaft 7 extends through the block 9 and is rotatably supported by the block 9.

Arms 10 fixed to the rotating shaft 7 and extending obliquely upward from the rotating shaft 7 are arranged on both sides of the block 9, and the distal ends of the arms 10 are bridged by an operating plate 11. The operation plate 11 is disposed above the top 12 of the hook 5 so as to be able to contact the top 12 of the hook 5.
In addition, a concave groove 13 into which the operation plate 11 can enter is formed on the flat lower side surface of the block 9 located above the operation plate 11. The groove 13 has a depth greater than the thickness of the operation plate 11.

[0008] The operating plate 11 is usually located at a position where it comes out of the groove 13 downward as shown in FIG. Chain 4
When the top 12 of the hook 5 reaches the vicinity of the lower surface of the block 9, the top 12 of the hook 5 comes into contact with the operating plate 11. Next, the operating plate 11 is moved upward while being in contact with the top 12 of the hook 5, and then the operating plate 11 enters into the concave groove 13. Then the top 1 of the hook 5
Immediately before the block 2 comes into contact with the lower surface of the block 9, the limit switch 6 is actuated, whereby a drive stop signal is given to the electric motor for winding. Then, the top 12 of the hook 5 abuts against the lower surface of the block 9, and this time, FIG.
Is shown in

[0009] As shown in FIG.
When the plate comes into contact with the lower surface of the block 9, the entire operation plate 11 enters the groove 13. At this time, a gap is formed between the bottom surface of the concave groove 13 and the operation plate 11. Therefore, the operating plate 11 is not pinched between the top 12 of the hook 5 and the bottom of the concave groove 13, and thus the arm 10 and the rotating shaft 7 are not sandwiched.
No excessive stress is generated. Therefore, the durability of the rotating shaft 7 and the like can be improved.

[0010]

According to the present invention, the durability of the rotary shaft of the limit switch can be improved while the hook can be raised to the highest possible position.

[Brief description of the drawings]

FIG. 1 is a side view of an electric chain block.

FIG. 2 is a front view of the electric chain block.

FIG. 3 is a partially enlarged view of FIG. 1;

[Explanation of symbols]

 2 ... housing 3, 5 ... hook 4 ... chain 11 ... operating plate 13 ... groove

Claims (1)

(57) [Claims] 1. A mounting hook at the distal end of the chain extending below sideways from the housing body, when the action winding of the chain
When the top of the hook reaches near the bottom surface of the housing
Abuts the top of the hook on the housing with the top of the hook
Limit switch that can be moved toward the lower side
Of the limit switch by moving the operation plate.
In the electric chain block hoist action of the chain is made to stop when the pitch has been actuated, Howe
The lower surface of the jing is formed flat and the top of the hook is
A flat groove into which the operating plate can enter when it comes into contact with the operating plate
Formed on the lower surface of the flat housing, the limit switch is
When activated, the hoisting action of the chain stops.
The top of the hook against the flat bottom of the housing when
Electric chain block as a gap on the bottom surface and the actuation plates of this time the concave grooves are formed as well as against.