JP7015042B2 - Safety belt strap winder - Google Patents

Description

The present invention relates to a strap winding device for a safety belt worn by an operator to prevent a fall when working at a high place, and having a centrifugal cam type lock structure.

A strap winder that winds the lanyard strap may be attached to the safety belt worn by workers working at high places such as construction sites. As this strap take-up device, when the hook at the tip of the strap is locked to the structure at the work place and the worker accidentally falls and the strap begins to be unwound rapidly, the unwinding of the strap is immediately locked. , The one with a lock mechanism that can minimize the fall distance is known.

In this lock mechanism, the take-up drum is rotatably supported by a fixing member such as a bracket, and the lock claw provided on the take-up drum side swings outward due to the centrifugal force generated by the rotation of the take-up drum. There is a centrifugal cam type that moves and engages the tip of the lock claw with the engaging portion formed on the stop plate on the fixing member side to lock the extension of the strap (see Patent Document 1 below). ..

In addition, a lock claw is provided swingably like a seesaw on the fixing member side such as a drum support frame, and one end of the lock claw protrudes like a claw wheel on the take-up drum side as the take-up drum rotates. There is also a striking type in which the engaging portion is hit and the other end of the lock claw is engaged with the engaging portion before being restored by the urging force of the spring to lock the extension of the strap (the following patent document). 2).

Registered Utility Model No. 308656 Japanese Unexamined Patent Publication No. 2011-149247

However, in any of the above locking mechanisms, a step of crimping a plurality of fixing pins is required in order to fix the stopper plate or the claw wheel that engages with the lock claw to another structural member, and as a result, the strap winding device. The manufacturing cost of the product tended to increase.

Therefore, the present invention is intended to provide a strap winding device provided with a lock mechanism capable of reducing the fastening process of parts and suppressing the manufacturing cost.

In order to solve the above problems, in the present invention, the take-up drum for winding the lanyard strap is rotatably supported by the bracket, and the centrifugal force generated by the rotation of the take-up drum locks the take-up drum side. A safety belt strap having a centrifugal cam type locking mechanism in which the claw swings outward and the tip of the lock claw engages with the engaging portion on the bracket side to lock the extension of the strap. In the take-up device
The bracket has a stepped portion that is an engaging portion with the tip of the lock claw so as to be located in a range on the inner diameter side of the rotation locus of the tip of the lock claw in a state of being swung outward by centrifugal force. Was provided.

Further, the bracket is made of a metal plate material, and the stepped portion is formed by bending the bracket.

Further, the stepped portion is formed between a portion of the bracket that forms a space in which the lock claw is accommodated and a portion along the side surface of the take-up drum.

In the strap winding device provided with the centrifugal cam type locking mechanism according to the present invention, the stepped portion formed on the bracket that rotatably supports the winding drum is moved outward by centrifugal force as the winding drum rotates. Since it is used as an engaging portion in which the tip of the rocking lock claw is engaged, the process of separately fastening parts can be reduced and the manufacturing cost can be suppressed.

Front view showing the entire lanyard equipped with the strap winding device according to the present invention. Front view showing the inside of (2A) case of the strap winding device as above, (2B) vertical sectional side view. (3A) Schematic front view before locking, (3B) Schematic front view when locked when centrifugal force is applied to the lock claw of the same locking mechanism. An exploded perspective view of the lock mechanism as above.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 1, the strap winding device 1 provided with the locking mechanism according to the present invention is a winding drum for winding a strap 2 using a high-strength fiber such as an aramid fiber around a drum shaft 10. 11 is rotatably supported by the bracket 21, and the take-up drum 11 and the bracket 21 are built in the case 31.

A connecting metal fitting 3 for connecting to a safety belt is attached to the strap winding device 1 on the side opposite to the feeding direction of the strap 2, and a hook 5 is attached to the tip end side of the strap 2 via a shock absorber 4. It constitutes a lanyard.

As shown in FIGS. 2 to 4, the take-up drum 11 winds the strap 2 between the flanges 12b and 13 on both sides of the winding core, and is formed on the outer surface of the flange 13 on one side of the take-up drum 11. A lock claw 15 is provided swingably inward and outward around a claw shaft 14 located in the vicinity of the drum shaft 10, and the lock claw 15 is urged inward by a claw spring 16.

The bracket 21 is formed by bending a metal plate material such as carbon steel for machine structure by pressing, and has a bifurcated shape in which a pair of side plate portions 21a and 21b are connected via a connecting portion 21c.

One side plate portion 21a has a portion that forms a space in which the lock claw 15 is accommodated apart from the flange 13 of the take-up drum 11, and a portion that approaches along the flange 13 and is fixed to the inner protruding portion of the case 31. A step portion 21d is provided between the two.

The step portion 21d is located at a portion where the tip portion of the lock claw 15 does not interfere when the strap 2 is slowly extended from the take-up drum 11 (see FIG. 2 (2A)).

On the other hand, when the strap 2 is rapidly unwound from the take-up drum 11, the take-up drum 11 rotates at high speed, and the lock claw 15 swings outward by centrifugal force, the tip of the lock claw 15 has a stepped portion. The step portion 21d is located in a range on the inner diameter side of the rotation locus R at the tip of the lock claw 15 so as to engage with the 21d (see FIG. 3 (3A)).

On the outside of the flange 12b on the other side of the take-up drum 11, a spring case 18 having a built-in spring for applying a rotational force in the direction in which the strap 2 is taken up is provided on the take-up drum 11.

The drum shaft 10 that pivotally supports the take-up drum 11 is locked to the bracket 21 by inserting the drum shaft 10 into the shaft holes 21e and 21f formed in the pair of side plate portions 21a and 21b of the bracket 21, respectively. See Figure 4).

Further, the case 31 is divided into a front cover and a back cover, and the front cover and the back cover are coupled and integrated by tightening screws (not shown) (see FIG. 2 (2B)).

When working at a high place using a lanyard as shown in FIG. 1 equipped with the strap winding device 1 as described above, the connecting metal fitting 3 is connected to the safety belt worn by the worker, and the hook 5 is attached. Lock to the structure in the work area.

If the operator accidentally drops from a high place in such a state, the strap 2 starts to be rapidly unwound from the take-up drum 11, and the take-up drum 11 rotates at high speed.

Then, as shown in FIG. 3 (3A), the lock claw 15 swings outward against the tensile force of the claw spring 16 due to the centrifugal force generated by the rotation of the take-up drum 11, and the lock claw 15 The tip of the lock claw 15 rotates on the rotation locus R in a state where the end side of the lock claw 15 is in contact with the drum shaft 10.

After that, as shown in FIG. 3B, when the tip of the lock claw 15 and the stepped portion 21d of the bracket 21 engage with each other, the rotation of the take-up drum 11 is stopped and the extension of the strap 2 is locked. , The fall distance of the worker is minimized.

In the strap winding device 1 having the centrifugal cam type locking mechanism as described above, the stepped portion 21d formed on the bracket 21 that rotatably supports the winding drum 11 is subjected to centrifugal force as the winding drum 11 rotates. Since it is used as an engaging part where the tip of the lock claw 15 that swings outward is engaged, the process of separately fastening parts to the bracket 21 as in the conventional strap winding device becomes unnecessary, and the manufacturing cost is reduced. Can be suppressed.

In this strap winding device 1, in addition to the lanyard for connecting to the harness type safety belt wound from both shoulders to both thighs of the worker (see FIG. 1), the connecting metal fitting 3 and the like are appropriately changed. It can also be applied to lanyards for torso belts that are wrapped only around the worker's torso.

1 Strap take-up device 2 Strap 3 Connecting bracket 4 Shock absorber 5 Hook 10 Drum shaft 11 Take-up drum 12b, 13 Flange 14 Claw shaft 15 Lock claw 16 Claw spring 18 Spring case 21 Bracket 21a, 21b Side plate 21e, 21f Shaft hole 21c Connection part 21d Step part 31 Case R Rotational trajectory

Claims (1)

The take-up drum (11) that winds up the lanyard strap (2) is rotatably supported by the bracket (21), and the centrifugal force generated by the rotation of the take-up drum (11) causes the take-up drum (11). ) Side lock claw (15) swings outward, the tip of the lock claw (15) engages with the engaging portion on the bracket (21) side, and the strap (2) is extended. In a safety belt strap winder with a centrifugal cam-type locking mechanism that locks
The bracket (21) is made of a metal plate material, and is bent into a bifurcated shape in which a pair of side plate portions (21a, 21b) are connected via a connecting portion (21c).
In one side plate portion (21a) of the bracket (21), a space located on the connecting portion (21c) side and away from the flange (13) of the take-up drum (11) to accommodate the lock claw (15). Centrifugal by bending at two points across both flanks in the width direction between the portion forming the With the engaging portion with the tip of the lock claw (15) so that it is located within the range on the inner diameter side of the rotation locus (R) of the tip of the lock claw (15) in a state of being swung outward by force. A stepped portion (21d) is provided,
With the high-speed rotation of the take-up drum (11), the lock claw (15) swings around the claw shaft (14), and the claw shaft (14) with respect to the tip end side of the lock claw (15). The tip of the lock claw (15) rotates on the rotation locus (R) with the end side located opposite to the winding drum (11) in contact with the drum shaft (10) that pivotally supports the take-up drum (11). death,
After that, the strap winding device of the safety belt is characterized in that the tip end portion of the lock claw (15) and the stepped portion (21d) are engaged with each other to stop the rotation of the winding drum (11).

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