JP4227494B2 - Shock absorber and safety belt rope using the same - Google Patents

Description

  The present invention relates to an impact absorbing device useful for a safety belt worn by an operator at high places such as a construction site, and a safety belt rope using the same.

  Generally, when working at a high place such as a construction site, an operator is required to wear a safety belt to prevent falling. This safety belt has a predetermined length of rope, and hooks attached to the tip of the rope are hung on the master rope etc. at the work site so that the operator is supported by the rope in the event of a fall. .

  However, if the human body is supported by a rope during the fall, an excessive load due to the weight of the user is applied to the rope, and it is necessary to absorb the impact. Therefore, an impact-absorbing belt is provided between the body belt of the safety belt and the rope, and a part of the belt-shaped member is folded and sewn, and when tension is applied to the rope, the sewn portion of the impact-absorbing belt is attached. A device that absorbs an impact while being separated is known (for example, see Patent Document 1).

  Also, when you are not using a safety belt, such as when you are not working at a high place, hook the rope on the safety belt side of the worker, or hold it in a predetermined bag, The rope hangs from the safety belt side in a loop of two folds.

For this reason, the rope hanging down in a loop shape is caught on the surrounding projections, etc., which hinders work and movement, or the rope wears out due to contact with the floor etc., and the strength of the rope decreases. was there. Therefore, it is known that the rope of the safety belt is formed in a coil shape that can be expanded and contracted, and when the tension is not generated, the rope is contracted to shorten the length of the rope when not in use. (For example, refer to Patent Document 2). This safety band rope is formed of a core material made of a chemical fiber such as nylon and a covering material made of vinyl resin or the like, and is restored to a coil shape by the elasticity of the covering material.
Japanese Patent Laid-Open No. 4-49978 Japanese Utility Model Publication No. 3-30131

  However, since the impact absorbing belt is made of a wide belt-like member, it must be configured as a separate part from the round string rope. For this reason, the connection structure with a rope is required and there existed a problem that a structure became complicated.

  In addition, the chemical fiber used for the core material of the rope is stretched according to its elastic modulus when subjected to a load in the tensile direction, but after the load is removed and the elongation is eliminated, before the elongation occurs. On the other hand, a shape change may occur. For this reason, if the coiled rope is stretched by excessive tension or is repeatedly expanded and contracted, the length of the coiled rope when not loaded will not be restored to the predetermined length, resulting in a decrease in the resilience of the rope. There was a problem that it was easy.

  The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an impact absorbing device that can be integrated with a rope with a simple configuration and a safety belt rope using the same. There is. Another object of the present invention is to provide a safety belt rope capable of improving the restoring property of the coiled rope in addition to the above object.

  In order to achieve the above object, the present invention provides an impact absorbing device that is provided on a rope connected to a safety belt and absorbs an impact applied to the rope. The rope is composed of a winding member, a part of which is spirally wound between the ridges, and a fixing member that fixes the rope to the winding member by covering the outer peripheral surface of the winding member around which the rope is wound. The rope is pulled out from between the winding member and the fixing member while breaking the protrusion of the winding member by the tension applied to the winding member.

  As a result, the rope is pulled out from between the winding member and the fixing member while breaking the ridge portion of the winding member by the tension applied to the rope, so that the shock applied to the rope due to the buffering action due to the rupture of the ridge portion is exerted. Since it is absorbed, it can be integrated with the rope with a simple configuration.

  In order to achieve the above object, the present invention comprises a rope body composed of a core material having a predetermined strength and a covering material covering the core material, and at least a part of the rope body is formed into a coil shape capable of expanding and contracting. In the formed safety belt rope, the shock absorber according to claim 1 is provided, and the core material is formed of a high elastic modulus fiber having a tensile elastic modulus of 300 cN / dtex or more.

  Thereby, in addition to the said effect | action, when the rope is not used, the coil part of a rope main body shrink | contracts and the length of a rope becomes short. In this case, since the core material of the rope body is made of a high elastic modulus fiber, even when the rope body is stretched by excessive tension or repeatedly expanded and contracted, the core material itself is very little stretched.

  According to the impact absorbing device of the present invention, since it can be configured integrally with the rope with a simple configuration, the structure can be simplified and the cost can be reduced.

  Moreover, according to the rope for safety band of the present invention, in addition to the above effect, when the rope is not used, the coil portion of the rope body can be contracted to shorten the length of the rope body. It is possible to improve the performance. In this case, since the shape change due to the elongation of the core material of the rope body can be surely prevented, the length of the coiled portion at the time of contraction can always be restored to a predetermined length, and the durability of the coiled portion Can be improved.

  1 to 6 show an embodiment of the present invention. FIG. 1 is an overall view of a safety belt, FIG. 2 is a cross-sectional view of a rope body, FIG. 3 is a side cross-sectional view of an impact absorbing device, and FIG. FIG. 5 is a partially sectional side view showing the operation of the shock absorbing device, and FIG. 6 is a view showing the characteristics of the core material.

  A safety belt 1 shown in the figure is used in a high place work such as a construction site, and includes the safety belt rope 10 of the present invention.

  That is, the safety belt 1 has a torso belt 1a to be worn by the user, and a D-shaped ring 1b for connecting the rope 10 is attached to the torso belt 1a.

  The rope 10 includes a rope body 11 partially formed in a coil shape, and a hook 12 attached to one end of the rope body 11, and the other end of the rope body 11 is connected to the ring 1 b of the safety belt 1. Yes.

  The rope body 11 includes a core material 11a having a predetermined strength and a covering material 11b covering the core material 11a, and the entire length of the rope body 11 in a tension state is formed to a predetermined length (eg, 1.7 m). Yes.

  The core material 11a is made of high-strength and high-modulus yarn having a tensile modulus of 300 cN / dtex or more. Polyarylate fiber, aramid fiber, high-strength polyethylene fiber, PBO fiber (polyparaphenylene benzobisoxazole) made of molten liquid crystal polymer. And the like are preferred. For example, as shown in FIG. 6, polyarylate fibers exhibit advantageous properties in terms of tensile strength and elongation as compared with vinylon (elastic modulus 200 cN / dtex) and polyester (elastic modulus 150 cN / dtex).

  For the covering material 11b, an elastic synthetic resin or the like is used. For example, urethane resin is preferable from the viewpoint of elastic recovery. That is, a part of the covering material 11b is previously formed into a coil shape, and the coil portion of the rope body 11 is expanded and contracted by the elasticity of the covering material 11b.

  The hook 12 has a known mechanism and is configured to be detachable from a master rope or the like at the work site. In this case, the hook 12 can be stored in a storage bag 1 c provided on the body belt 1 a of the safety belt 1.

  In addition, the rope 10 of the safety belt 1 is provided with an impact absorbing device 20 that absorbs an impact applied to the rope 10.

  The shock absorbing device 20 includes a winding member 21 in which a part of the rope 10 is spirally wound, and a fixing member 22 that fixes the rope 10 wound around the winding member 21, and the other end of the rope 10. On the side. The winding member 21 is formed of nylon resin, and a spiral protrusion 21a is provided on the outer peripheral surface thereof. That is, the winding member 21 is configured to wind the rope 10 around the groove portion 21b between the ridge portions 21a. The fixing member 22 is made of a metal such as aluminum and is formed in a cylindrical shape so as to cover the outer peripheral surface of the winding member 21. Further, the fixing member 22 is fixed to the winding member 21 by reducing the diameter by caulking or the like and pressing it on the outer peripheral surface of the winding member 21 to fix the rope 10 wound around the winding member 21. Yes.

  The safety belt rope 10 configured as described above is used by hanging the hook 12 on a master rope or the like at the work site, and the coiled rope main body 11 is appropriately expanded and contracted during the work.

  Further, when the rope 10 is not in use, such as when not working at a high place, the rope 10 is folded into two loops by holding the hook 12 of the rope 10 in the storage bag 1c of the safety belt 1. And hangs down from the safety belt 1 side. At that time, the rope main body 11 is contracted by the elastic force of the covering material 11b so that the length of the rope main body 11 is shortened. Therefore, the rope 10 hanging down in a loop shape is not caught by surrounding projections or the like.

  Furthermore, since the core material 11a of the rope 10 is made of a high elastic modulus fiber, the core material 11a itself is very little stretched even when the rope main body 11 is stretched by excessive tension or repeatedly expanded and contracted.

  In the unlikely event of a fall, if a load due to the fall of the user is applied to the rope 10, the coiled portion of the rope body 11 extends as shown in FIG. 5 (a), and the load exceeds a predetermined magnitude. 5 (b), the ridges 21a of the winding member 21 are sequentially broken from both ends of the winding member 21 as shown in FIG. The main body 11 is pulled out, and the shock applied to the rope 10 is absorbed by the buffering action caused by the rupture of the protrusion 21a.

  Thus, according to the impact absorbing device 20 of the present embodiment, a portion of the rope 10 is spirally wound between the ridges 21a of the winding member 21 and the rope 10 wound around the winding member 21 is The rope body 11 is fixed between the winding member 21 and the fixing member 22 while being fixed by the fixing member 22 covering the outer peripheral surface of the winding member 21 and breaking the protrusion 21a of the winding member 21 by the tension applied to the rope 10. Therefore, the shock absorbing device 20 can be integrated with the rope 10 with a simple configuration, and the structure can be simplified and the cost can be reduced.

  Further, since the core material 11a of the rope 10 provided with the impact absorbing device 20 is made of a high elastic modulus fiber, the elongation of the core material 11a is extremely reduced. This can be surely prevented, and the length of the coiled portion at the time of contraction can always be restored to a predetermined length.

  Further, since the covering material 11b is formed of an elastic resin, the elastic recovery rate can be arbitrarily set depending on the material of the covering material 11b. In this case, a stable coil shape is always maintained by forming the covering material 11b so that the coil shape recovery rate after applying a load that is 1/20 of the tensile breaking stress of the core material 11a is 95% or more. It is extremely advantageous in handling and durability.

  In the above embodiment, the shock absorbing device 20 is provided on the coiled rope 10. However, the shock absorbing device of the present invention is for a safety belt in which portions other than the winding member are not formed in a coil shape. It can also be applied to ropes.

Overall view of safety belt showing one embodiment of the present invention Cross section of rope body Side cross-sectional view of shock absorber Side view of winding member Partial cross-sectional side view showing the operation of the shock absorber Diagram showing core properties

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Safety belt, 10 ... Rope, 11 ... Rope main body, 11a ... Core material, 20 ... Shock absorber, 21 ... Winding member, 21a ... Projection part, 22 ... Fixing member.

Claims (3)

In the shock absorber that is provided on the rope connected to the safety belt and absorbs the shock applied to the rope,
A winding member having a spiral ridge on the outer peripheral surface, and a part of the rope is spirally wound between the ridges;
It consists of a fixing member that fixes the rope to the winding member by covering the outer peripheral surface of the winding member around which the rope is wound,
An impact absorbing device, wherein the rope is pulled out from between the winding member and the fixing member while breaking the protrusion of the winding member by the tension applied to the rope. In a rope for safety belt comprising a rope body composed of a core material having a predetermined strength and a covering material covering the core material, and forming at least a part of the rope body in a coil shape that can be expanded and contracted,
While comprising the impact absorbing device according to claim 1,
A rope for safety band, wherein the core material is formed of high elastic modulus fibers having a tensile elastic modulus of 300 cN / dtex or more. The rope for safety band according to claim 2, wherein the core material is formed of any one of high modulus fiber of polyarylate fiber, aramid fiber, high strength polyethylene fiber and PBO fiber.

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