JP2019076372A - Safety belt strap winding device - Google Patents

Abstract

To provide a strap winding device which is compact even including a buffer function, a strap protecting function, and a lock mechanism, and can suppress a cost of manufacture.SOLUTION: A safety belt strap winding device is such that: a winding drum 11 for winding a strap 2 comprises a drum body 12 including a flange at one side of a winding core 12a, and a flange at the other side which are joined and fixed with buffer pins 17; the drum body 12 has surrounding walls 12c, 12d and has a centrifugation cam type lock mechanism; the strap 2 whose ring-like part in a terminal part is hooked to the winding core 12a is wound onto a part reinforced with a claw shaft 14 of the surrounding wall 12c followed by being wound around the surrounding walls 12c, 12d, and is wound onto a part where the buffer pins 17 of the surrounding wall 12d are positioned; the total quantity of the strap 2 is delivered in a state that the lock mechanism is not operated; and when a tension load of a specified value or more is applied to the strap 2, the buffer pins 17 are deformed or broken by shear force so as to soften an impact load.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a strap take-up device for a safety belt which a worker wears to prevent a fall when working at a high place.

  The straps of the lanyard are taken up on the take-up drum, and the strap take-up device to which the straps are fed out is attached as the take-up drum rotates. Sometimes.

  The strap winding device is usually used by interposing a belt type shock absorber between the strap winding device and the safety belt at the joint of the strap winding device and the safety belt or the base of the hook at the tip of the strap in order to reduce the impact when the operator falls. Be done. This belt type shock absorber is to absorb an impact by tearing the belt folded and wound in multiple layers.

  However, such a belt-type shock absorber tends to be large in size in order to ensure the necessary shock absorbing properties, which may cause bother of the operator wearing the belt and may increase the manufacturing cost. is there.

  As measures therefor, in Patent Documents 1 and 2 below, a buffer member that is tightened when a tensile load is applied to the strap, a buffer pin that breaks, a reinforcing pin that protects a winding core, etc. It has been proposed that a belt type shock absorber can be omitted by adding it separately.

  As another problem, in the conventional strap winding device, when the entire amount of the strap is pulled out from the case for storing the winding drum, the sewn portion of the end portion of the strap hooked on the winding core of the winding drum is Some are exposed, and when used outdoors for a long period of time, the sewn parts may be worn out and degraded by ultraviolet light.

  For this reason, as described in Patent Document 3 below, even when the surrounding wall is provided inside the winding drum and the entire amount of the strap is pulled out, the sewn portion of the end portion of the strap is contained in the surrounding wall. Structure is generally adopted.

Registered Utility Model No. 3011404 Registered Utility Model No. 3009430 Japanese Utility Model Publication 7-31061

  However, in order to obtain a buffer function and to protect the sewn portion of the end portion of the strap, a lock mechanism is employed that suppresses the falling distance at the time of fall prevention while adopting the structure as described in the above patent documents. If such provision is made, the size and weight become considerably large relative to the amount of straps that can be wound on the winding drum, and the problem arises that the manufacturing cost also increases.

  In addition, even if it is equipped with a lock mechanism, in the standard of safety belt, it is necessary to conduct a test to confirm the safety assuming that the entire length of the strap is pulled out without the lock mechanism operating. The structures described in Patent Documents 1 and 2 are complicated because buffer pins and the like are separately provided in consideration of this point.

  Therefore, the present invention is intended to provide a strap winding device which is compact even if it has a buffer function, a strap protection function, a lock mechanism and the like, and which can suppress the manufacturing cost.

In order to solve the above-mentioned problems, according to the present invention, a strap for a high-level work safety belt on which a take-up drum for taking up a strap of a lanyard is rotatably supported and the strap is drawn out as the take-up drum rotates. In the winding device
In the winding drum, a drum main body provided with a flange on one side of the winding core and a flange on the other side are fixedly coupled by a buffer pin.
The drum body has a multi-layered surrounding wall and has a centrifugal cam type lock mechanism in which a lock claw swings about a claw axis,
The strap is wound on the surrounding wall after the ring of the end portion is hooked on the core and wound on the portion reinforced by the claw shaft of the surrounding wall, and then wound around the surrounding wall to cushion the surrounding wall. Wrap around the part where the pin is located,
In the case where the entire strap is unwound in a state in which the locking mechanism does not operate, and a tensile load equal to or more than a predetermined value is applied to the strap, the buffer pin is deformed or broken by shear force and the impact load is relaxed It is

  In the strap winding device according to the present invention, the buffer pin, which deforms or breaks when a tensile load equal to or more than a predetermined value acts on the strap, is used as the pin for coupling and fixing the drum main body of the winding drum and the flange. The strap pulled out from the surrounding wall is wound around a portion reinforced by the claw shaft of the lock claw to protect the winding core of the winding drum from a tensile load.

  Therefore, even if the cushioning function, the strap protection function, the locking mechanism, etc. are provided, the weight and size can be reduced, and it is not necessary to distinguish between the cushioning structure and the locking mechanism in the manufacturing process. it can.

  In addition, since the sewn part at the end of the strap can fit between the surrounding walls and can not be exposed to the outside, the function to prevent fraying of the sewn part due to long-term use outdoors and deterioration due to ultraviolet rays is also possible. Secured.

Front view showing the whole lanyard provided with the strap winding device according to the present invention The disassembled perspective view of the winding drum of the same strap winding device (3A) Longitudinal side view of strap take-up device same as above, (3B) Front view with front cover removed The vertical front view which shows the winding state of the terminal part of the strap same as the above Longitudinal front view which shows the deformation fracture state of the buffer pin same as the above

  Hereinafter, embodiments of the present invention will be described based on the attached drawings.

  As shown in FIG. 1, a strap winding device 1 having a lock mechanism according to the present invention is a winding drum for winding a strap 2 using high strength fibers such as aramid fibers centering on a drum shaft 10. 11 is rotatably supported by a bracket 21, and the winding drum 11 and the bracket 21 are built in a 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 delivery direction of the strap 2, and a hook 5 is attached to the tip end side of the strap 2 to constitute a lanyard. doing.

  As shown in FIGS. 2 to 4, the winding drum 11 includes a drum body 12 having a flange 12 b on one side of a cylindrical core 12 a through which the drum shaft 10 is inserted, and the other side of the core 12 a. It is comprised from the disk shaped flange 13 attached. The drum body 12 is made of plastic such as polyacetal, and the flange 13 is made of metal such as stainless steel.

  The drum body 12 is provided with double-structured surrounding walls 12c and 12d on the outer periphery of the winding core 12a at a small radial distance, and the inner surrounding wall 12c has a hollow structure to enhance its buffer property. It is assumed. Strap outlets 12e and 12f are formed on the surrounding walls 12c and 12d, respectively, at portions interrupted in the circumferential direction.

  On the outer surface of the flange 13, a lock claw 15 is provided so as to be pivotable 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. It is done.

  The claw shaft 14 is made of metal such as carbon steel for machine structure, and is inserted into the claw shaft spacer 14a sandwiched between the flanges 12b and 13 and fitted in the shaft hole of the lock claw 15 via the claw shaft bush 14b. ing.

  The drum main body 12 and the flange 13 are fixed by two buffer pins 17 arranged in the circumferential direction at a portion of the surrounding wall 12 d separated from the winding core 12 a toward the outer diameter side. The buffer pin 17 is made of metal such as a carbon steel wire for cold forming, and is sequentially inserted into the pin holes 13a and 12g formed in the flange 13 and the drum main body 12 and caulked.

  The bracket 21 is formed by bending a plate material made of metal such as carbon steel for machine structure into a bifurcated shape and forming a step 21 d on one side surface. The stepped portion 21d does not interfere with the tip of the lock claw 15 when the winding drum 11 is rotating at a normal speed, but when the winding drum 11 rotates at high speed, the lock is pivoted outward by centrifugal force The tip end of the claw 15 is engaged, and a lock mechanism is configured by this.

  Further, on the outer side of the drum main body 12 flange 12b, a spring case 18 is provided in which a spiral spring is provided for applying a rotational force in a direction in which the strap 2 is wound on the winding drum 11.

  Further, the case 31 is divided into a front cover and a back cover, and the front cover and the back cover are integrally connected by tightening a screw (see FIG. 3 (3A)).

  Then, as shown in FIG. 4, in the strap 2, the ring-like portion of the end portion is hooked on the winding core 12a, and the double-stitched portion of the strap 2 is the outer peripheral side of the surrounding wall 12c via the strap outlet 12e. After being drawn out and wound around a portion reinforced by the claw shaft 14 of the surrounding wall 12c, the surrounding wall 12c is wound around the surrounding wall 12c between the surrounding walls 12c and 12d.

  Thereafter, the strap 2 is pulled out to the outer peripheral side of the surrounding wall 12d via the strap outlet 12f, wound around the surrounding wall 12d, and wound around the portion of the surrounding wall 12d where the buffer pin 17 is located. Thus, the case 31 is pulled out.

  When performing work at a high place using a lanyard as shown in FIG. 1 provided with the strap winding device 1 as described above, the connection fitting 3 is connected to the safety belt worn by the worker, and the hook 5 is Lock the structure of the work place.

  In such a state, if the operator erroneously falls from a high place, the strap 2 starts to be drawn out rapidly from the winding drum 11, and the winding drum 11 rotates at a high speed, but this occurs as the winding drum 11 rotates. The distal end portion of the lock claw 15 pivoted outward by the centrifugal force engages the step portion 21d of the bracket 21 and the rotation of the winding drum 11 is stopped, so that the delivery of the strap 2 is locked. Fall distance is minimized.

  Further, even if a tensile load equal to or greater than a predetermined value acts on the strap 2 due to the inertia of a worker who is about to fall when the entire amount of the strap 2 is fed out in a state where the lock mechanism does not operate, as shown in FIG. The buffer pin 17 is crushed in the outer diameter direction, and is deformed or broken by shear force, and the impact load is relaxed.

  In the strap winding device as described above, the buffer pin 17 which is broken when a tensile load equal to or more than a predetermined value acts on the strap 2 is combined with the pin for coupling and fixing the drum body 12 and the flange 13 in the winding drum 11. To protect the core 12a of the take-up drum 11 from tensile load by winding the strap 2 pulled out from the strap outlet 12e of the surrounding wall 12c around the portion reinforced with the claw shaft 14 of the lock claw 15 And

  Therefore, even if the cushioning function, the strap protection function, the locking mechanism, etc. are provided, the weight and size can be reduced, and it is not necessary to distinguish between the cushioning structure and the locking mechanism in the manufacturing process. it can.

  In addition, since the sewn portion of the end portion of the strap 2 fits between the surrounding walls 12c and 12d and can not be exposed to the outside, the sewn portion is worn out due to long-term use outdoors and deterioration due to ultraviolet rays is caused. The function to prevent is also secured.

  In addition, the strap winding device 1 appropriately changes the connection metal fittings 3 etc. in addition to the lanyard (refer to FIG. 1) for connection to the harness type safety belt which is wound from the shoulders of the operator to the thighs. The present invention can also be applied to a lanyard for a body belt which is wound only on the body of a worker.

DESCRIPTION OF SYMBOLS 1 strap take-up device 2 strap 3 connection fitting 5 hook 10 drum shaft 11 take-up drum 12 drum main body 12a core 12b flange 12c, 12d surrounding wall 12e, 12f strap outlet 12g pin hole 13 flange 13a pin hole 14 claw shaft 14a Claw shaft spacer 14b Claw shaft bush 15 Lock claw 16 Claw spring 17 Buffer pin 18 Spring case 21 Bracket 21 d Stepped portion 31 Case

Claims (1)

A safety belt for work at a high place where a take-up drum (11) for taking up a strap (2) of a lanyard is rotatably supported and the strap (2) is unwound as the take-up drum (11) rotates. In the strap winding device of
In the winding drum (11), a drum body (12) provided with a flange (12b) on one side of a winding core (12a) and a flange (13) on the other side are coupled and fixed by a buffer pin (17). It is assumed that
The drum body (12) has a multi-layered surrounding wall (12c, 12d) and has a centrifugal cam type lock mechanism in which the lock claw (15) swings about the claw shaft (14),
The strap (2) is wrapped around the ring-like portion of the end portion by being hooked on the core (12a) and wound around the portion reinforced with the claw shaft (14) of the surrounding wall (12c), It is wound around a wall (12c, 12d) and wound around the portion of the surrounding wall (12d) where the buffer pin (17) is located,
The entire amount of the strap (2) is unwound in a state where the lock mechanism does not operate, and when a tensile load equal to or more than a predetermined value acts on the strap (2), the buffer pin (17) is deformed or broken by shear force And a strap take-up device for a safety belt characterized in that impact load is relieved.

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