bungee cord

Abstract

To provide a bungee cord which is easy to manufacture, has excellent durability, and significantly improves safety. [Solution] The bungee cord 10 comprises a bungee cord body 20 made up of multiple cord units 21 and a cylindrical, non-stretchable cover cord 30, with the cord units 21 equipped with at least a stretchable elastic cord 22 and a non-stretchable extension cord 23. The cord units 21 and the elastic cord 22 are tied together and connected, and the folded-back parts where the multiple extension cords 23 and cover cord 30 are layered are sewn to form sewn fixing parts 11, thereby forming loop-shaped connecting parts 12 at both ends of the bungee cord 10.

Description

[Technical Field]

[0001] The present invention relates to a bungee cord that can be used in various amusement facilities. [Background technology]

[0002] Patent Documents 1 and 2 disclose flying amusement facilities. This flying amusement facility is equipped with a guide member such as a wire rope stretched obliquely in the air along the flight path, and a bungee cord suspended from the guide member, and is configured so that a player can ride on the lower end of the bungee cord.

[0003] Patent Document 3 discloses a bungee cord configured by covering a multi-type bungee cord body, in which a plurality of rubber cords are aligned in the same direction, with a protective cover. At each end of the bungee cord, a metal ring is wrapped around the body of the bungee cord. The protective cover is a cylindrical resin sheet or fabric that covers the entire bungee cord body except for both ends to protect the bungee cord body from damage. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-33238 [Patent Document 2] Japanese Patent Application Laid-Open No. 2018-505749 [Patent Document 3] Japanese Patent Application Publication No. 10-57631 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional bungee cords have the following problems. <1> Because the bungee cord body is made up of an assembly of multiple rubber cords, it is technically difficult to secure the folded-over point of the bungee cord body when forming a loop-shaped connecting portion at the end of the bungee cord. <2> When a metal ring is wound around a group of rubber strings, variations in the attachment of each rubber string tend to occur, making it difficult to fix the group of rubber strings under uniform conditions. <3> In conventional bungee cords, the cross-sectional dimensions of the bungee cord body increase as the number of rubber cords increases, making it difficult to secure the bungee cord body by folding it back. <4> If the folded portion of the rubber cord assembly were to be sewn, the rubber cord would be damaged by the sewing needle, reducing the durability of the connecting portion of the bungee cord and adversely affecting the safety of the bungee cord.

[0006] The present invention has been made in view of the above points, and an object of the present invention is to provide a bungee cord that is easy to manufacture, has excellent durability, and significantly improves safety. [Means for solving the problem]

[0007] The present invention provides a bungee cord comprising a bungee cord body that is stretchable in the longitudinal direction and has a plurality of cord units aligned in the same direction, and a non-stretchable tubular cover cord that can cover the bungee cord body over its entire length, with the ends of the bungee cord body and cover cord folded back to form loop-shaped connecting portions at both ends, wherein the bungee cord body is an assembly of a plurality of cord units aligned in the same direction, the cord units comprise a stretchable elastic cord, and non-stretchable extension cords tied and connected to both ends of the elastic cord, the cover cord has a length that allows elastic deformation of the elastic cord, and a sewn and fixed portion is formed at the folded back portion where the plurality of extension cords and the cover cord are layered to form the loop-shaped connecting portion. In another embodiment of the present invention, the sewing direction of the sewn fixing portions is aligned in the transverse direction of the extension cords so that the sewing of all the extension cords is uniform. In another embodiment of the present invention, the tensile strength of the cover cord is greater than the tensile strength of the bungee cord body, and the covering length of the cover cord that covers the plurality of elastic cord groups is set shorter than the limit length of elastic deformation of the bungee cord body. In another embodiment of the present invention, the ends of the elastic cord of the single cord and the elastic cord are tied together in a figure-eight knot. In another embodiment of the present invention, the tensile strength of the extension cord made of the cord alone is equal to or greater than the tensile strength of the elastic cord. In another embodiment of the present invention, an identification piece for identifying the elongation of the bungee cord body may be provided in an exposed state on a part of the cover cord. In another form of the present invention, the cord may comprise an elastic cord that is stretchable by itself, non-stretchable extension cords that are tied and connected to both ends of the elastic cord, and a reinforcing cloth that is attached across multiple extension cords, and a sewn and fixed portion may be formed at the folded portion where the multiple extension cords attached to the reinforcing cloth and the cover cord are layered to form a loop-shaped connecting portion. [Effects of the Invention]

[0008] The present invention has at least one of the following advantages. <1> When forming a loop-shaped connecting part at the end of the bungee cord, the sewn fixing part is formed by sewing the laminate of a plurality of extension cords and cover cords without including an elastic cord. Therefore, damage to the elastic cord due to piercing with a sewing needle and concentration of stress due to sewing on the elastic cord are avoided, thereby improving durability and safety. Therefore, the number of times the bungee cord can be used repeatedly increases compared to conventional methods. <2> To sew all extension cords under uniform conditions by a simple sewing operation in which the sewing direction of the sewn fixing parts is aligned in the transverse direction of a plurality of extension cords. This eliminates uneven stitching, allowing the tensile load to be distributed evenly to all extension cords, effectively preventing breakage of the sewing thread due to uneven load. <3> Each cord unit constituting the bungee cord body is configured by combining an elastic cord and an extension cord. Therefore, the stretch of the bungee cord can be easily and accurately adjusted simply by selecting the number of individual cords. <4> Even if players have different weights, the stretch (fall height) of the bungee cord can be set to be approximately the same by selecting the number and length of the individual cords that make up the bungee cord body. One of the attractions of amusement facilities that use bungee cords is that the bungee cords stretch the same regardless of the player's weight, so a wide range of players, from children to adults, can enjoy the amusement facilities. <5> The cover cord functions as a safety belt in an emergency, making the bungee cord significantly safer than conventional ones. <6> The cover cord not only functions as a protective cover to prevent damage to the bungee cord body, but also protects the bungee cord body from ultraviolet rays, improving the durability and weather resistance of the bungee cord. <7> By providing a reinforcing patch across a plurality of extension cords, it is possible to sew the extension cords while preventing unnecessary slippage when folding the extension cords to form a connecting portion. Therefore, the sewing accuracy of the sewn fixing portion is improved. <8> By providing a part of the cover cord with an identification piece that identifies the degree of elongation of the bungee cord body, it becomes possible to select and use a bungee cord that suits the player's weight. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a bungee cord according to the present invention with some parts omitted; [Figure 2] Diagram of the components of a bungee cord [Figure 3] A plan view of a bungee cord with part of the cover cord broken [Figure 4] Conceptual diagram of a cross section of the connection formed at the end of a bungee cord [Figure 5]An explanatory diagram of another embodiment of a bungee cord with an additional identification piece. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below with reference to the drawings.

[0011] 1. Bungee cord Referring to Figures 1 and 2, the bungee cord 10 of the present invention comprises an expandable bungee cord body 20 having a plurality of cord units 21 aligned in the same direction, and a tubular cover cord 30 that covers the bungee cord body 20 over its entire length. The overall length of the bungee cord 10 can be selected as appropriate, but when the bungee cord 10 is applied to an amusement park, a length of approximately 1.5 to 2.0 m is suitable.

[0012] In the present invention, the end of the bungee cord 10 is folded in a U-shape and the base of the folded portion is sewn to form a sewn fixing portion 11, thereby forming a loop-shaped connecting portion 12 at the folded portion of the bungee cord 10, and a connecting fitting 40 such as a carabiner can be attached via the connecting portion 12. Each part will be described in detail below.

[0013] 2. Bungee cord body This will be explained with reference to Figure 2. The bungee cord body 20 is made up of an assembly of a plurality of cord units 21 aligned in the same direction. By selecting the number of cord units 21 that make up the bungee cord body 20, the elongation (elastic force) of the bungee cord 10 can be adjusted. By producing a plurality of types of bungee cords 10 with different degrees of elongation, the bungee cords 10 can be appropriately selected depending on the weight (load) of the player.

[0014] <1> Code alone The cord unit 21 comprises an elastic cord 22 that can be stretched, non-stretchable extension cords 23, 23 that are tied to both ends of each elastic cord 22, and a reinforcing cloth 24 made of a non-stretchable material and attached across the extension cords 23. In the present invention, "non-stretchable" refers to a property of having a small elongation rate and being difficult to stretch.

[0015] <2> Elastic cord The elastic cord 22 is a string-like or rope-like cord made of an elastic material (rubber or the like) that has stretchability (the property of allowing stretching within a certain range). The elongation of the elastic cord 22 is selected appropriately. The cross-sectional shape of the cord unit 21 is not particularly limited, but may be rectangular, circular, elliptical, or the like. When a plurality of cord units 21 are used, all of the elastic cords 22 have the same overall length, cross-sectional dimensions and elongation.

[0016] <2.1> Folded part of elastic cord The elastic cord 22 has both ends folded back and the folded base portions bound together to form loop-shaped folded portions 22a. The folded portion 22 a of the elastic cord 22 is the connecting portion to the extension cord 23 .

[0017] <3> extension cord The extension cord 23, which functions as an alternative member to the elastic cord 22, is a string-like or rope-like cord made of a non-stretchable material.

[0018] <3.1> Purpose of use of extension cord The extension cords 23 are connected to both ends of the elastic cord 22 in order to form the connecting portion 12 of the bungee cord 10 without including the elastic cord 22 .

[0019] <3.2> Relationship between the tensile strength of extension cords and elastic cords The tensile strength of the extension cord 23 is greater than or equal to the tensile strength of the elastic cord 22 . This is to prevent the extension cord 23 from breaking before the elastic cord 22 when the bungee cord 10 is stretched.

[0020] <3.3> Examples of extension cord materials The extension cord 23 can be a known flat belt material made of chemical materials such as nylon, polyester, or polypropylene, which have excellent tensile strength.

[0021] <3.4> Extension cord dimensions The total length of the extension cord 23 is appropriately selected depending on the loop length of the connecting portion 12 . In this example, the elastic cord 22 is folded in two for use, but the elastic cord 22 may be used in a single layer without being folded in two.

[0022] When used folded in half, the total length of extension cord 23 is about 800 to 1200 mm. The width and thickness of the extension cord 23 are appropriately selected taking into consideration the material, tensile strength, and the like.

[0023] <3.5>Means for connecting elastic cord and extension cord The elastic cord 22 and the extension cord 23 are directly connected by bundling so that load can be transmitted between them. The method of binding the elastic cord 22 and the extension cord 23 will be described in detail later.

[0024] <4> Reinforcement fabric The reinforcing cloth 24 is a single sheet that serves both to neatly align the extension cords 23 and to reinforce the connecting portion 12.

[0025] The reinforcing patch 24 has an area (dimension) that allows a plurality of extension cords 23 to be attached together. For the reinforcing cloth 24, a high strength sheet material having strength equal to or greater than that of the extension cord 23 can be used. The reinforcing fabric 24 is not essential and may be omitted.

[0026] 3. Cover Code The cover cord 30 is a tubular covering member made of a non-stretchable, high-strength material. The cover cord 30 functions as a protective cover for the bungee cord body 20 and also functions as a safety belt in an emergency.

[0027] <1> Cover cord total length The overall length of the cover cord 30 is sized to be able to cover the entire length of the bungee cord body 20 and has an overall length that allows the elastic cord 22 to stretch. When the elastic cord 22 expands and contracts, the overall length of the cover cord 30 that covers the section of the extension cord 23 does not change. The cover cord 30 that covers a section of the elastic cord 22 is bellows-shaped, and its overall length changes in accordance with the expansion and contraction deformation of the elastic cord 22.

[0028] The maximum extension of the bungee cord 10 is determined by the covering length of the cover cord 30 that covers the entire length of the group of elastic cords 22 that make up the bungee cord body 20. Therefore, the overall length of the cover cord 30 is selected appropriately taking into consideration the environment in which the bungee cord 10 is used, etc.

[0029] <2> Relationship between tensile strength of cover cord and elastic cord group The tensile strength of the cover cord 30 is greater than or equal to the elastic limit (tensile strength) of the group of elastic cords 22 that make up the bungee cord body 20 . In practice, the tensile strength of the cover cord 30 is set to be greater than the tensile strength of the elastic cord 22 .

[0030] <3> Cover cord material The cover cord 30 may be made of synthetic fibers such as nylon or polyester. These high-strength synthetic fibers may be kneaded with titanium oxide or special ceramic particles to provide UV protection and overheating protection.

[0031] 4.Connection part Both ends of the bungee cord 10 are folded back in a U-shape to form loop-shaped connecting portions 12. The connecting portion 12 is composed of a laminate of a plurality of extension cords 23, a reinforcing cloth 24 and a cover cord 30.

[0032] 5.Sewing fixing part The sewn and fixed portion 11 is a portion where the end of the bungee cord 10 is folded back in a U-shape and the base of the folded back portion is sewn and fixed. The sewing direction of the sewing thread in the sewn fixing portion 11 will be described later.

[0033] 6. Relationship between the tensile strength of the cover cord and the bungee cord itself and the covering length of the cover cord The tensile strength of the cover cord 30 is greater than that of the bungee cord body 20, and the covering length of the cover cord 30 covering the group of elastic cords 22 is set shorter than the limit length of elastic deformation of the bungee cord body 20. This is to allow the cover cord 30 to function as a safety belt in an emergency.

[0034] [How to make a bungee cord] Next, a method for manufacturing the bungee cord 10 will be described.

[0035] 1. Making the bungee cord itself A method for manufacturing the bungee cord body 20 will now be described.

[0036] <1> Assembly of the cord alone As shown in FIG. 2, a plurality of cord units 21 are produced by bundling extension cords 23, 23 to both ends of an elastic cord 22.

[0037] Both ends of the elastic cord 22 and one end of each extension cord 23 are tied together. The extension cord 23 may be connected to the elastic cord 22 in a folded state, or the extension cord 23 may be connected to the elastic cord 22 in a single state. The elastic cord 22 and the extension cord 23 can be bound together by various known binding means such as a "figure eight knot."

[0038] <2> Temporarily attaching the extension cord to the reinforcing fabric A plurality of the cord units 21 are aligned in the same direction and arranged in parallel. A group of a plurality of extension cords 23 arranged side by side is temporarily fastened to a reinforcing cloth 24 to produce a bungee cord body 20.

[0039] <2.1> Arrangement of extension cords The extension cords 23 are arranged adjacent to and parallel to the reinforcing cloth 24 without overlapping. The bundling portion of the elastic cord 22 and the extension cord 23 is wider than the width of each cord 22, 23, so that the bundling portions are arranged so that they overlap each other.

[0040] <2.2>Temporary fastening method To temporarily secure (position) the extension cords 23 to the reinforcing cloth 24, each extension cord 23 is temporarily secured to the reinforcing cloth 24 by adhesive means such as double-sided tape or temporary stitching means. The purpose of temporarily fixing the extension cords 23 to the reinforcing patch 24 is to prevent unnecessary movement of the extension cords 23 when the extension cords 23 are folded back and the connecting portions 12 are firmly sewn.

[0041] 2. Cover cord exterior The cover cord 30 is fitted onto the bungee cord body 20. The plurality of cord units 21 and the reinforcing fabrics 24 attached to both ends of the cord units 21 are covered with a cover cord 30 so as to be hidden.

[0042] 3. Method of forming the bungee cord connection A plurality of extension cords 23 corresponding to the ends of the bungee cord 10 are folded back together with the cover cord 30 in a U-shape, and the base of the folded back portion is sewn to form a sewn fixing portion 11, thereby forming a loop-shaped connecting portion 12 at the folded back portion. When both ends of the bungee cord 10 are sewn together, the elastic cord 22 is sewn in a stretched state. After sewing, as the elastic cord 22 shrinks and deforms, the cover cord 30 covering the elastic cord 22 is folded in an accordion-like shape. A method for forming the connecting portion 12 will be described in detail below.

[0043] <1> Sewing target The objects to be sewn are the plurality of extension cords 23, the reinforcing patch 24 and the cover cord 30, but the elastic cord 22 is not the object to be sewn. The elastic cord 22 is not subject to sewing in order to avoid damage to the elastic cord 22 due to piercing with the sewing needle.

[0044] <2> Sewing direction of the fixed sewing part When forming the sewn fixing portion 11, the sewn fixing portion 11 is sewn along the transverse direction (crossing direction) of the plurality of extension cords 23. In other words, the sewing direction of the sewn fixing portion 11 is aligned in the transverse direction of the plurality of extension cords 23 when sewing. The stitching in the transverse direction of the extension cord 23 is repeated along the longitudinal direction of the extension cord 23 to form the sewn fixing portion 11. The number of repetitions of sewing along the longitudinal direction of the extension cord 23 is selected as appropriate. The stitching in the transverse direction of the extension cord 23 may be performed so that the threads are parallel to each other, or may be performed in a zigzag pattern. At the sewn and fixed portion 11, the extension cords 23 are sewn in the transverse direction thereof, so that the overlapping extension cords 23, the reinforcing cloth 24 and the cover cord 30 are integrated.

[0045] <3> The reason why the folded part is sewn in the direction transverse to the extension cord The reason why the folded portions at both ends of the bungee cord 10 are sewn in the transverse direction of the extension cord 23 is as follows.

[0046] If the extension cords 23 were sewn along their longitudinal direction, it would be technically difficult to sew the extension cords 23 at equal positions and at equal intervals, which would tend to result in uneven sewing force at the sewn fixing portions 11. In particular, since the cover cord 30 covers the fabric, and the state inside the cover cord 30 cannot be seen, it is difficult to sew the fabric evenly. If there is variation in the sewing strength of the sewn fixing portion 11, the load may be concentrated on some extension cords 23 with weak sewing strength, causing the sewing thread to break.

[0047] In order to solve this problem, the present invention sews the extension cord 23 in the transverse direction. By sewing along the transverse direction of the extension cords 23, unlike the sewing method used for ring belts, etc., all the extension cords 23 are sewn to have a uniform length, which not only makes the sewing work easier but also eliminates variations in the sewing lengths of the multiple extension cords 23. Since the load can be distributed in the sewn and fixed part 11, breakage of the sewing thread 11a can be effectively prevented, and the durability of the sewn and fixed part 11 is improved.

[0048] 4. Installing the connecting fittings After forming loop-shaped connecting portions 12 at both ends of the bungee cord 10 via the sewn fixing portions 11, a connecting metal fitting 40 such as a carabiner is attached to each connecting portion 12. The member attached to the connecting portion 12 of the bungee cord 10 is not limited to the connector 40, but can be selected appropriately depending on the flying amusement facility in which the bungee cord 10 is used.

[0049] 5. Bungee cord extension and contraction The expansion and contraction action of the bungee cord 10 will now be described.

[0050] <1> Bungee cord stretch deformation When a tensile force acts on the bungee cord 10 in the longitudinal direction, the group of elastic cords 22 that make up the bungee cord body 20 is uniformly stretched and deformed, and the overall length of the bungee cord 10 increases. At this time, the cover cord 30 in the area where it covers the group of elastic cords 22 of the bungee cord body 20 in an accordion-like manner expands in accordance with the expansion and deformation of the group of elastic cords 22 . When the bungee cord 10 is stretched, no load is applied to the cover cord 30 that covers the group of elastic cords 22.

[0051] <2> Contraction and deformation of bungee cords When the tensile force acting on the bungee cord 10 is smaller than the elastic limit of the bungee cord body 20, when the bungee cord 10 is stretched to a certain extent, the bungee cord body 20 contracts and deforms due to the elastic restoring force of the group of elastic cords 22 that make up the bungee cord body 20. As the elastic cords 22 contract and deform, the entire length of the bungee cord body 20 returns to the length before it was stretched. At this time, the cover cord 30 follows the contraction and deformation of the bungee cord body 20 and returns to its bellows shape. Even when the bungee cord body 20 contracts, no load is applied to the cover cord 30.

[0052] <3> Cover cord restricts bungee cord extension When the tensile force acting on the bungee cord 10 approaches the elastic limit of the group of elastic cords 22 constituting the bungee cord body 20, the accordion-shaped cover cord 30 stretches to its full extent, and a tensile force acts on the cover cord 30. Since the cover cord 30 is made of a non-stretchable material, once the cover cord 30 is fully stretched, it will not stretch any further and will resist the tensile force with its own strength. In this way, by fully stretching the cover cord 30, the extension of the bungee cord body 20 is restricted, and the cover cord 30 functions as a safety belt in an emergency.

[0053] [Other Examples] Other embodiments will be described below, and in the description, the same parts as those in the above-described embodiment will be given the same reference numerals and detailed description thereof will be omitted.

[0054] <1> Identification piece Referring to FIG. 5, another embodiment in which an identification piece 13 is additionally provided on a part of the bungee cord 10 will be described.

[0055] The identification piece 13 is an identifier for identifying the stretchability (elongation) of the bungee cord 10 . The identification piece 13 may be used, for example, by expressing the stretchability of the bungee cord 10 in a number of different colors, or by marking on the identification piece 13 letters or symbols such as numbers or letters of the alphabet that indicate the stretchability.

[0056] The identification piece 13 is provided at one or both ends of the bungee cord 10. To attach the identification piece 13, for example, when forming the connecting part 12 at the end of the bungee cord 10, the identification piece 13 is sandwiched between the folded cover cord 30 and attached to the sewn fixing part 1. At this time, the identification piece 13 is attached in a state where a part of the identification piece 13 protrudes from the side of the sewn-on fixing part 1 so that the identification piece 13 is exposed.

[0057] <2> Effects of this example In this example, in addition to obtaining the same effects as the previous example, by visually inspecting the identification piece 13 protruding from the side of the sewn-on portion 1, the grade of the stretch performance of the bungee cord 10 indicated on the identification piece 13 can be accurately determined. For example, the usable weight range of 40 to 100 kg is divided into multiple ranges in increments of 20 to 30 kg, and multiple types of identification pieces 13 having preselected colors such as "red," "yellow," "white," and "blue" are used according to the divided weight ranges. In this way, in this example, the combination of the player's weight and the stretchability of the bungee cord 10 makes it possible to avoid using the wrong bungee cord 10 and select the most suitable bungee cord 10 according to the player's weight. Therefore, even if players have different weights, the bungee cord 10 exhibits stable elastic deformation performance, allowing players to enjoy optimal flying play without being affected by weight. [Explanation of symbols]

[0058] 10. Bungee cord 11... Sewing fixing part 11a... Sewing thread 12...Connection part 13. Identification piece 20 Bungee cord body 21.... Code alone 22 Elastic cord 22a...Folding section 23 Extension cord 24 Reinforcement fabric 30····Cover Code 40····Connecting fittings

Claims

1. A bungee cord comprising a bungee cord body that is stretchable in the longitudinal direction and has a plurality of single cords aligned in the same direction, and a cylindrical, non-stretchable cover cord that can cover the bungee cord body over its entire length, with loop-shaped connecting portions formed at both ends by folding back the ends of the bungee cord body and the cover cord, The bungee cord body is made up of a collection of multiple cord units aligned in the same direction, The cord is a stretchable elastic cord, and a non-stretchable extension cord is bound and connected to both ends of the elastic cord. the cover cord has a total length that allows elastic deformation of the elastic cord, a sewn and fixed portion is formed at the folded portion where the plurality of extension cords and the cover cord are laminated to form a loop-shaped connecting portion, Bungee cord.

2. 2. The bungee cord according to claim 1, wherein the sewing direction of the sewn fixing parts is aligned in a transverse direction of the plurality of extension cords so that the sewing of all the extension cords is uniform.

3. 2. The bungee cord according to claim 1, wherein the tensile strength of the cover cord is greater than the tensile strength of the bungee cord body, and the covering length of the cover cord that covers the plurality of elastic cord groups is set to be shorter than the limit length of elastic deformation of the bungee cord body.

4. 2. The bungee cord according to claim 1, wherein the ends of the single elastic cord and the elastic cord are connected by tying them together in a figure-eight knot.

5. 2. The bungee cord according to claim 1, wherein the tensile strength of the extension cord as a single cord is equal to or greater than the tensile strength of the elastic cord.

6. 2. The bungee cord according to claim 1, wherein an identification piece for identifying the elongation of the bungee cord body is provided in an exposed state on a part of the cover cord.

7. 2. The bungee cord according to claim 1, comprising an elastic cord that is stretchable by itself, non-stretchable extension cords that are tied and connected to both ends of the elastic cord, and a reinforcing cloth that is attached across multiple extension cords, wherein a sewn and fixed portion is formed at the folded portion where the multiple extension cords attached to the reinforcing cloth and the cover cord are layered, thereby forming a loop-shaped connecting portion.

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